JPH06273914A - Original substrate for exposure - Google Patents

Abstract

PURPOSE:To suppress the deterioration in the definition of patterns at the ends of periodic patterns, the decrease in the thickness of a resist and the decrease in line width and to make the depth of focus equal to or larger than the depth of focus of the other parts of the periodic patterns so as to obtain actually a higher resolution and larger depth of focus by designing only the patterns at the ends of the periodic patterns where the deterioration in the definition and the degradation in the depth of focus are generated larger by a prescribed quantity than the other parts of the periodic patterns at the time of executing projection exposure by diagonal incident illumination. CONSTITUTION:Light shielding parts 31, periodic light shielding line pattern 32 existing between these light shielding parts 31 and transmission space patterns 33 are alternately and repetitively formed on an original substrate 30. The width of the light shielding line patterns 32 and the transmission space patterns 33 is set at the fine width w approximate to the resolution threshold of the uniform periodic pattern of a projection exposure optical system exclusive of the transmission space patterns 33a at both ends. The width of the transmission space patterns 33a is set at the width (w+DELTAw) larger than the line width w of the other transmission space patterns 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention forms a latent image of a fine pattern such as a semiconductor integrated circuit on an original substrate by projection exposure and transfer onto a photosensitive material formed on a substrate to be exposed. The present invention relates to an exposure original drawing substrate used.

[0002]

2. Description of the Related Art In order to form a fine pattern such as a semiconductor integrated circuit on a substrate to be exposed such as a semiconductor wafer easily, at high speed and at low cost, a projection exposure method using short wavelength visible light or far ultraviolet rays is used. . In this method, a reticle or mask as an exposure original drawing substrate on which a fine pattern such as a semiconductor integrated circuit is formed is illuminated by an exposure light beam, and a photosensitive material formed on a substrate to be exposed such as a semiconductor wafer is projected onto a projection lens or the like. The fine pattern of the semiconductor integrated circuit or the like on the original substrate is projected and transferred through the projection exposure optical system of 1 above to form a latent image of the fine pattern, and then development is performed to form the pattern.

FIG. 33 shows "LS" issued by Densho Shoin Co., Ltd.
This is the projection exposure optical system of the conventional projection exposure apparatus described in “I Design and Manufacturing 4 Techniques” on page 248. This will be described in brief with reference to FIG. 1. Light emitted from the mercury lamp 1 is condensed by the elliptic concave mirror 2 and the collimator lens 3, passes through the filter 4 for monochromaticity, and enters the fly-eye lens 5. A first reflecting mirror 6 is provided between the mercury lamp 1 and the collimator lens 3 for converting the light from the lamp 1 in a direction substantially orthogonal to the optical axis of the light source and for transmitting heat rays to the back side.

The fly-eye lens 5 is composed of an assembly of many small-diameter lenses, and the light emitted from each lens is reflected by the second reflecting mirror 7 and condensed by the condenser lens 8 to be exposed. By illuminating the reticle 9, which is the original drawing substrate, it is possible to improve the uniformity of illumination. The mercury lamp 1 is the original light source (primary light source), whereas the exit side of the fly-eye lens 5 serves as a substantial emission source of the light that illuminates the reticle 9, and is called a secondary light source. The second reflecting mirror 7 is for changing the direction of the light ray again.

The reticle 9 is formed on a reticle holding table 10 on which a fine pattern such as a semiconductor integrated circuit is formed, and when illuminated by light emitted from the condenser lens system 8, the fine pattern is formed. It is transferred onto the resist-coated wafer 12 which is the substrate to be exposed through the projection lens 11. The projection lens 11 is made by combining a large number of lenses in order to eliminate various aberrations, but basically it is composed of lens groups 11a and 11b on the reticle 9 side and the wafer 12 side, and an aperture stop between them. 13 are installed. Light emitted from an arbitrary point on the reticle 9 exits the reticle-side lens group 11a from the aperture stop 13 of the projection lens 11 and then becomes substantially parallel to the aperture stop 13 to pass through the wafer 1.
It enters the second lens group 11b. Then, after that, they gather at one point at the resist position on the surface of the wafer 12 to form an image.

The wafer 12 has a position and a projection lens 1.
It is placed on the X moving stage 14, the Y moving stage 15, the Z moving stage 16, and the rotating stage 17 for adjusting and determining the height with respect to 1.

The resolution of the transferred pattern depends on the reticle 9
It depends on how much diffracted light from the pattern existing above can be taken into the aperture diaphragm 13, and whether the periodic pattern is resolved or not depends on whether the 0th-order diffracted light and the 1st-order diffracted light emitted from the periodic pattern on the reticle 9 are open. It is largely determined by whether it can be taken into the diaphragm 13. The direction in which the first-order and higher-order diffracted light travels is determined by the cycle of the pattern and the fineness of the pattern. Therefore, when the reticle 9 is illuminated vertically, the diffracted light of the first order or more advances toward the outside of the projection lens 11 when the pattern is fine. For this reason,
The larger the aperture of the aperture stop 13, the more the first-order diffracted light emitted from a fine pattern can be captured, and the higher the resolution becomes.

However, it is difficult to make the aperture of the aperture stop 13 extremely large because the size of the projection lens 11 is limited in manufacturing, and there is a drawback that the depth of focus is reduced. Therefore, as a measure for achieving high resolution under a constant size of the aperture diaphragm 13, a grazing incidence illumination projection exposure method has been proposed (Japanese Patent Application No. 3-99822, Japanese Patent Application No. 3-157401, etc.). There is. In this oblique incident illumination exposure method, the reticle 9 is obliquely illuminated so that the 0th-order diffracted light of the pattern existing on the reticle 9 passes near the outer periphery of the aperture stop 13 in the oblique illumination light traveling direction, and the first If the folded light passes near the outer periphery on the opposite side of the aperture stop 13, the first-order diffracted light on the other side cannot pass through the aperture stop 13, so that only one side can diffract the first-order diffracted light on the reticle. 9
As compared with the case where the first-order diffracted light on both sides from the pattern existing on the reticle 9 is allowed to pass through the aperture diaphragm 13 by illuminating the light vertically to the outside at an angle about twice the direction of the incident light. Since even the first-order diffracted light that spreads can be captured, the resolution is extremely high. Further, when the method of illuminating the reticle 9 at an oblique incidence is adopted as described above, a transfer image is formed only by the 0th-order diffracted light and the 1st-order diffracted light on one side.
From the case of a total of 3 light fluxes of the first-order diffracted light and the first-order diffracted light on both sides,
There is also an advantage that the depth of focus during fine pattern transfer is significantly improved.

To illuminate the reticle 9 at an oblique incidence, as disclosed in Japanese Patent Application No. 59-212169, light from the central portion on the exit side of the fly-eye lens 5 is reduced and light from the peripheral portion is used. Just illuminate. That is, it suffices to illuminate with an annular or pseudo annular secondary light source.

Further, as disclosed in Japanese Patent Application Laid-Open No. 4-267515, etc., four locations around the exit side of the fly-eye lens 5 are provided corresponding to the case where the pattern to be transferred is mainly composed of vertical and horizontal patterns. Illumination may be performed by a four-point light source having a light source of.

Further, in the case where the pattern to be transferred is mainly only in one of the vertical and horizontal directions, one or two off-axis positions in the direction perpendicular to the pattern to be transferred at the secondary light source emission port or two.
You may illuminate with the light source of a location.

When the reticle 9 is illuminated by oblique incidence,
The 1st-order diffracted light due to the pattern existing on the reticle 9 can be taken into the aperture stop only for one side, whereas all the 0th-order diffracted light traveling in a straight line passes through the aperture stop, so that the 1st-order diffracted light and the 0th-order diffracted light are balanced. And the 0th-order diffracted light becomes too much and the contrast of the fine pattern image formed at the resist position is lowered. Therefore, in order to adjust the amount of 0th-order diffracted light to an appropriate amount at the time of oblique incidence illumination, a method has been devised in which a filter for adjusting the transmittance around the aperture is placed at the position of the aperture diaphragm 13. This method is described, for example, in Applied Physics Vol. 61, No. 11 (1992), 113.
Pages 9 to 1142 disclose "high resolution lithography using a new illumination system".

The above-mentioned various types of oblique-incidence illumination projection exposure are not limited to the case where a reticle having a pattern having a magnification with respect to a pattern transferred onto the exposed substrate is used as the original substrate, and the original substrate is exposed on the exposed substrate. It is also effective to use a mask having a pattern of the same size as the pattern to be transferred to.

Even in the case of performing projection exposure by applying various types of oblique incidence illumination as described above, conventionally, as a reticle (or mask) which is an exposure original drawing substrate, a normal secondary light source illuminates the original drawing substrate. Then, the same one as in the case of projection exposure was used. The ordinary secondary light source referred to here is a light having a substantially uniform light intensity distribution or a peripheral light intensity smaller than the central light intensity in a shape that is substantially axisymmetric and not hollow, such as a substantially circular shape or a substantially regular polygonal shape. It is a secondary light source having an intensity distribution. That is, in the conventional reticle, when the periodic pattern exists in the reticle, all the patterns constituting the periodic pattern have the same line width.

34 and 35 are examples of basic periodic patterns on a reticle (or reticle) used in the case of conventional normal illumination. The figure shows an enlarged view of the periodic pattern portion. In FIG. 34, the same line width w
2 is a space-type line-and-space pattern in which a plurality of transparent space patterns 21 are uniformly arranged with a light-shielding line pattern 22 having the same line width w as the transparent space pattern 21. Further, in FIG. 35, a large number of light-shielding line patterns 24 having the same line width w are arranged in the transmissive portion 23, and the light-transmitting space patterns 25 having the same line width w as the light-shielding line pattern 23 are evenly arranged. A line-and-space pattern is shown.

[0016]

However, when a reticle (or a mask) having such a conventional uniform periodic pattern is projected and exposed by oblique incidence illumination, the periodic pattern varies depending on the illumination condition, but the periodic pattern is different. Most of the area of the image has a high resolution and the depth of focus is deep, but the resolution is lower and the depth of focus is shallower at both ends of the periodic pattern than at other areas. This is because in the case of oblique incidence illumination, the contrast of the light intensity between the light-shielding portion and the transmitting portion is smaller at the end portion of the periodic pattern than at the central portion other than the end portion. The contrast referred to here is {(maximum value of light intensity of transmission pattern portion)-(minimum value of light intensity of light shielding pattern)} / {(maximum value of light intensity of transmission pattern portion) + (light of light shielding pattern). Minimum value of strength)}. 36 and 37, a transparent space pattern having a line width of 0.35 μm on the substrate to be exposed is separated by a light blocking line pattern having the same line width as the transparent space pattern in the light blocking portion of the original drawing substrate. It is a comparison of the difference in the result of calculating the light intensity distribution between the conventional normal exposure and the annular illumination oblique incidence projection exposure for 12 space type line-and-space patterns arranged inside. The exposure light beam is an i-line having a wavelength of 365 nm, the numerical aperture of the projection lens is NA = 0.52, and exposure is performed using a 1/5 reduction projection exposure apparatus. The normal illumination condition is that when the aperture stop radius of the projection lens is 1, the size of the illumination light source image at the aperture stop position is a circle with a radius of 0.6, and the annular illumination condition is the projection lens. The size of the illumination light source image at the aperture stop position is a ring having an outer radius of 0.6 and an inner radius of 0.5 when the aperture stop radius is 1.

36 (a) and 37 (a), when an image of a pattern on the original drawing substrate is formed on the substrate to be exposed by just focus, FIGS. 36 (b) and 37 (b) show ,
This is a case where the image of the pattern on the original drawing substrate is formed on the exposed substrate at a position where the focus is shifted ± 1 μm from the just focus point. The rectangular light intensity distribution in the figure shows the transmitted light intensity distribution of the pattern of the original drawing substrate, and the curve is the light intensity distribution on the exposed substrate at the corresponding position. The “position” on the horizontal axis is shown in terms of the dimensions on the substrate to be exposed.

As is clear from the comparison between FIG. 36 (b) and FIG. 37 (b), in the case of oblique incidence illumination by annular illumination,
Even if the light is defocused, the contrast of the light intensity can be made larger than that in the case of normal illumination, but the light intensity of the transmission space pattern portions at both ends of the line and space pattern becomes lower than the light intensity of the other transmission space pattern portions. Therefore,
The amount of exposure is likely to be insufficient in the transmission space pattern portions at both ends.
For this reason, when a positive photosensitive material such as a positive resist, which removes the material in the exposed portion during development, is used, the material remains in the transmission space pattern portions at both ends, and non-resolution easily occurs. Also,
In the case of a negative photosensitive material such as a negative resist in which only the material of the exposed portion remains during development, the thickness of the material tends to decrease at the transmission space pattern portions at both ends, and the line width becomes thin.

On the other hand, in FIGS. 38 and 39, twelve light-shielding line patterns having a line width of 0.35 μm on the substrate to be exposed are provided in the transparent portion of the original drawing substrate at the same spacing as the light-shielding line pattern. 2 is a comparison of the difference in the light intensity distribution between the conventional normal illumination projection exposure and the circular illumination oblique incidence projection exposure for the line type line and space pattern arranged side by side. The conditions for normal illumination and circular illumination are shown in FIG.
37, and the rectangular light intensity distribution in the figure is the transmitted light intensity distribution of the pattern on the original drawing substrate.
The curve is the light intensity distribution on the exposed substrate at the corresponding position. The “position” on the horizontal axis is shown in terms of the dimensions on the substrate to be exposed.

38 (a) and 39 (a), when the image of the pattern on the original drawing substrate is formed on the substrate to be exposed with just focus, FIGS. 38 (b) and 39 (b).
Is a case where an image of the pattern on the original drawing substrate is formed on the exposed substrate at a position where the focus is shifted ± 1 μm from the just focus point. As is clear from FIGS. 38 (b) and 39 (b), in the case of oblique incidence illumination, the contrast of the light intensity can be made larger than in the case of normal illumination even if defocused, but at both ends of the line and space pattern. The light intensity of the light-shielding line pattern part of is higher than the light intensity of the other light-shielding line pattern parts, and the light is overexposed, and the light intensity of the light-transmitting space inside the light-shielding line patterns at both ends is the other light-transmitting space. Since the light intensity is lower than that of the pattern portion, the exposure amount becomes insufficient. Therefore, in a positive photosensitive material such as a positive resist, the material thickness is reduced or the line width is narrowed at the light shielding line patterns at both ends, and the transmission space pattern inside the light shielding line patterns at both ends is reduced. The material remains in the part, which causes non-resolution. In the case of a negative photosensitive material such as a negative resist, the material remains in the light-shielding line patterns at both ends to cause non-resolution, or the thickness of the material in the light-transmitting space pattern inside the light-shielding line patterns at both ends is increased. It decreases or the line width becomes narrower.

FIGS. 40 and 41 show that the resist remained when the experiment for transferring the actual pattern using the positive resist was conducted under the exposure conditions whose light intensity distributions are shown in FIGS. 36 and 37, respectively. The state in which the resolution occurs is shown by tracing the cross section of the formed pattern. As shown in the figure, the portion which traveled in a comb shape is the cross section of the resist pattern formed after development, and the lower flat portion is the surface portion of the silicon wafer used as the substrate to be exposed. FIG. 40 is a pattern cross-sectional shape in the case of conventional normal illumination projection exposure, and FIG.
Is the pattern cross-sectional shape in the case of circular illumination oblique incidence projection exposure. In FIG. 40, the + side is not already resolved with the 0.4 μm focus deviated, and the − side is the resolution limit just before the 0.4 μm defocused state. On the other hand, FIG.
Then, even if the focus is shifted by ± 1 μm, the central part of the line and space pattern is resolved very well. However, the space pattern at the edge is not resolved even under just focus conditions. As described above, in FIG. 41, the central portion of the pattern is resolved very well and a large depth of focus can be obtained as compared with FIG. 40, while the space pattern forming characteristics at both ends are deteriorated. In addition, in FIG. 40, between the center portion and the end portion, as shown in FIG.
There is no big difference like 1.

42 and 43 respectively show FIGS. 38 and
In the example of the light intensity distribution shown in FIG. 39, when a pattern is actually transferred using a positive resist, a state in which the resist remains and non-resolution occurs, or the thickness of the resist decreases, This is shown by tracing the cross section of the formed pattern. FIG. 42 shows the pattern cross-sectional shape of the conventional normal exposure, and FIG. 43 shows the pattern cross-sectional shape in the case of circular illumination oblique incidence projection exposure. In FIG. 42, the + side is 0.4 μm and the resolution is not already resolved with the focus shifted, and the − side is 0.4 μm.
The resolution is close to the limit when the focus is shifted. On the other hand, in FIG. 43, the center of the line-and-space pattern is resolved very well even if the focus is shifted ± 1 μm. However, under the condition of defocusing 1 μm to the negative side,
The resist thickness of the line patterns at both ends is reduced, and the line width is narrower than the line pattern in the central portion. on the other hand,
Under the condition of defocusing to the + side by 1 μm, it is difficult to resolve the space pattern portions inside the line patterns at both ends, and the resist residue remains. Although the line patterns on both ends are not on the near side, the thickness of the resist is decreasing and the line width is narrower than the line pattern in the central portion. As described above, in FIG. 43, the central portion of the pattern is very well resolved and a large depth of focus can be obtained as compared with FIG. It becomes narrower than the width. Further, it becomes difficult to resolve the space pattern portions inside the line patterns at both ends. In FIG. 42, a large difference as in FIG. 43 does not occur between the central portion and the end portion.

When a reticle is illuminated by a normal circular illumination secondary light source, there is no limit on the focus position where non-resolution or the resist thickness is reduced in both cases of FIG. 40 and FIG. The difference between the two end portions and the central portion is 0.2 μm at most. As a result, the depth of focus of the 0.35 μm line-and-space pattern in normal illumination is shown in FIGS.
In both cases, it was 0.4 μm excluding both ends and 0.2 μm including both ends. On the other hand, in the case of the circular illumination oblique incidence projection exposure described above, in the case of FIG. 41, the depth of focus is 2.4 μm except for both ends, but it is difficult to resolve both ends and the entire pattern is There wasn't a proper depth of focus. Also, in the case of FIG. 43 as well, the depth of focus was 2.4 μm excluding both ends, but the depth of focus including both ends was 1.4 μm. The above facts show a big problem that the large depth of focus, which is a feature of grazing incidence illumination exposure, is not necessarily realized when both ends are included. That is, even if the original pattern substrate is obliquely illuminated to achieve a high resolution and a large depth of focus of the periodic pattern, practical progress can be obtained only slightly considering the practical use including the edge pattern. If not, or conversely, the usable range decreases.

The degree of deterioration of the pattern at both ends of the line-and-space pattern, which occurs in the case of the oblique incident projection exposure, depends on the oblique incident illumination condition and the numerical aperture N of the projection lens.
A, it changes depending on the transmittance distribution of the transmittance adjusting filter placed at the projection lens aperture stop position. In any case, however, the oblique incidence illumination causes the pattern formation situation at both ends of the line-and-space pattern to be worse than in the case of illuminating with a normal circular illumination secondary light source. When projection exposure is performed with oblique incidence illumination as described above, the periodic pattern causes deterioration of resolution only at the end portions thereof, a decrease in resist thickness, and a decrease in line width, and the depth of focus changes only at the end portions. Cause a decline.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to reduce the deterioration of resolution and the depth of focus when projection exposure is performed by oblique incidence illumination. Only the pattern at the end of the periodic pattern
By designing a predetermined amount larger than the other parts of the periodic pattern, the resolution of the pattern at the end of the periodic pattern is reduced, the thickness of the resist is reduced, and the line width is reduced. It is an object of the present invention to provide an exposure original substrate which can be made equal to or larger than a portion and can achieve a practical high resolution and a large depth of focus.

[0026]

In order to achieve the above object, the first invention is a projection exposure of a fine pattern such as a semiconductor integrated circuit on an original substrate onto a photosensitive material formed on a substrate to be exposed, In the exposure original drawing substrate used when transferring and forming the latent image of the fine pattern, only at the both ends of the periodic fine pattern existing on the original drawing substrate or in the vicinity of both ends,
The pattern width is made larger than the pattern width of other portions in the periodic fine pattern. A second invention is the same as the first invention, wherein the exposure original drawing substrate is used when performing projection exposure by illuminating at an oblique incidence. In a third aspect based on the first or second aspect, the light shielding portion of the original drawing substrate has a periodic pattern formed of a transmission pattern,
The width of the transmission pattern at least at both ends of the periodic transmission pattern is formed larger than the widths of other transmission patterns in the periodic pattern. In a fourth aspect based on the first or second aspect, there is a periodic pattern formed of a light-shielding pattern in the transmissive portion of the original drawing substrate, and at least the inner portion of the light-shielding pattern at both ends of the periodic light-shielding pattern exists. The width of the portion is formed to be larger than the width of the other transmission portions between the light shielding patterns in the periodic pattern. In a fifth aspect based on the first or second aspect, there is a periodic pattern formed of a light shielding pattern in the transmissive portion of the original drawing substrate, and the light shielding pattern width at least at both ends of the periodic light shielding pattern is a periodic pattern. It is formed to be wider than the width of the other light-shielding patterns. In a sixth aspect based on the first or second aspect, there is a periodic pattern formed of a light shielding pattern in the transmissive portion of the original drawing substrate, and the light shielding pattern width at least at both ends of the periodic light shielding pattern is a periodic pattern. It is formed to be wider than the width of the other light-shielding patterns in the inside, and the width of the transmitting portions inside the light-shielding patterns at the both ends is formed to be larger than the width of the other transmitting portions between the light-shielding patterns in the periodic pattern. is there.

[0027]

If the pattern at the end of the periodic pattern is made larger than the other parts of the periodic pattern, as described above, the oblique incident illumination projection exposure causes the deterioration of the resolution and the reduction of the depth of focus at the end pattern. However, the reduction or non-resolution of the resist thickness at the end pattern portion is less likely to occur than the portion other than the end portion of the periodic pattern or the portion other than the end portion of the periodic pattern.
Therefore, the above-described periodic pattern having a large size only in the end portion pattern can obtain high resolution similar to the conventional uniform periodic pattern in portions other than the end portion, and at the same time, the depth of focus including the end portion can be obtained. It has a very deep depth of focus similar to the part other than the conventional edge part. On the other hand, by enlarging only the end pattern and using a fine pattern close to the resolution limit other than the end part, the entire periodic pattern occupies the entire pattern including the end part pattern. As described above, there is almost no difference from the case of using the fine pattern close to the resolution limit.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings. (Embodiment 1) FIG. 1 is a view showing an embodiment of pattern arrangement when an exposure original drawing substrate according to the present invention is applied to a reticle. The structure of the reticle 28 is the same as that of the conventional one, such as a quartz film, a fluorite, various glass materials, etc. A light-shielding pattern is formed by a light-shielding film capable of blocking exposure light, such as 31.
Reference numeral 33 is a transparent space pattern. Shading line pattern 3
2 and the transmission space pattern 33 each have a fine width w close to the resolution limit of the uniform periodic pattern of the projection exposure optical system of the grazing incidence illumination projection exposure apparatus used for projection exposure.
It is alternately and repeatedly formed with an arbitrary number of four or more. However, the transparent space patterns 33a at both ends
Is set to a width (w + Δw) larger than the line width w of the other transparent space pattern 33.

2A and 2B show the numerical aperture of the projection lens on the assumption that the line and space pattern of 0.35 μm shown in FIG. 34 is improved as a specific case of FIG. When the i-line 1/5 reduction projection exposure apparatus with NA = 0.52 is used and the aperture stop radius of the projection lens is 1, the size of the illumination light source image at the aperture stop position is an outer radius of 0.6 and an inner radius of 0.6. Circular illumination with a radius of 0.5 is performed, and 12 transmission space patterns 33 on the 5 × reticle of the present invention are
This is a calculation of the light intensity distribution on the wafer when ⅕ reduction projection exposure is performed on the wafer that is the substrate to be exposed. In the conventional reticle shown in FIG. 34, 0.35 μm
5 to project and expose the line and space pattern of
The widths of the transmission space pattern 21 and the light-shielding line pattern 22 on the double reticle were all uniformly 1.75 μm, but in the reticle of the present invention, only the widths of the transmission space patterns 33a at both ends are 2.00 μm. With this arrangement, as is clear from FIG. 2, the light intensity at a location corresponding to the end transmission space portion is higher than the light intensity at a location corresponding to the other space portion even in the defocused state of 1 μm. Distribution. Therefore, when the positive type resist is used, only the transmission space portions at both ends are not resolved, and rather the transmission space portions at the ends are more easily resolved than the other transmission space portions.
Further, even when a negative / positive type resist is used, the resist thickness does not decrease only in the transmission space portions at both ends. As a result, it is possible to form a line-and-space pattern group having a large line-and-space pattern of 0.35 .mu.m, which is close to the resolution limit of the oblique illumination oblique exposure, with a large focal depth.

As described above, in the present invention, only the transmission space patterns 33a at both ends are set to 2.00 μm (transfer size onto the wafer is 0.40 μm), and the widths of the other transmission space patterns 33 and the light shielding line patterns 32 are 1.75 μm.
(Transfer size to wafer is 0.35 μm), so compare with the case where the width of all transmission space patterns and light-shielding line patterns is 2.00 μm where end patterns can be used (transfer size to wafer is 0.40 μm). Then, when the number of patterns is large, the occupied width of the patterns is roughly (0.3
5 / 0.40) × 100≈88% downsizing can be achieved.

In the above example, w = 1.75 μ
Since m and Δw = 0.25 μm, Δw≈0.14w. Δw is the same as the portion other than the end portion of the periodic pattern or the non-resolution at the end of the periodic pattern, even when the light intensity distribution deteriorates at the both end portions of the transmission periodic pattern when the reticle is projected by oblique illumination illumination. Decide so that it is harder to get up than other parts. In the case of the above example, Δw = 0.05 μm≈
The effect is about to begin even at 0.03 w, and Δw = 0.1
When 5 μm≈0.08 w, the light intensity of the transmission space pattern portions at both ends is approximately the same as the portion other than the end portions of the periodic pattern. Then, as described above, Δw = 0.25μ
If m≈0.14 w, the light intensity becomes larger than that of the portion other than the end portion of the periodic pattern, and the effect becomes very remarkable.
That is, depending on Δw, when a positive resist is used, non-resolution of the transmissive space pattern portions on both ends hardly occurs, and when a negative resist is used, the resist thickness of the transmissive space pattern portions on both ends is reduced. Is less likely to occur. Then, the depth of focus in forming the entire pattern including both ends is improved. The optimum value of Δw varies depending on the conditions such as the grazing incidence illumination condition, the aperture stop condition of the projection exposure optical system, and the condition of the transmittance adjustment filter placed at the aperture stop position of the projection exposure optical system. However, when w is close to the resolution limit. In general, Δw = kw (k = 0.05 to 0.2) may be set regardless of the conditions. The upper limit of Δw is determined as follows. If Δw is made too large, a line-type line-and-space pattern as shown in FIG. 35 is placed inside the transmission space pattern, and the light-shielding line portion inside the transmission space pattern, that is, the light shielding at both ends The light intensity of the line pattern portion is increased, and the light intensity of the transmission space pattern inside thereof, that is, the light intensity of the second transmission space pattern portion from both ends is decreased. From the standpoint of reducing the occupied width of the entire periodic pattern, and from the viewpoint of use, it is easiest to use that both end parts behave almost the same as the parts other than the end parts. Therefore, Δw should be in the above range. Optimal.

(Embodiment 2) FIG. 3 is a view showing another embodiment of pattern arrangement in the reticle of the present invention. In this embodiment, an arbitrary number of four or more light-shielding line patterns 34 having a fine width w close to the resolution limit of the uniform periodic pattern of the projection exposure optical system of the grazing incidence illumination projection exposure apparatus used for projection exposure are provided. , The light-shielding line pattern 34
The transparent space pattern 36 having the same line width w is repeatedly formed. However, only the width of the transmission space pattern 33a inside the light-shielding line pattern at both ends is larger than the line width w of the other transmission space pattern 34 (w + Δ).
w).

FIGS. 4 (a) and 4 (b) show the numerical aperture of the projection lens assuming the case of improving the 0.35 μm line-and-space pattern shown in FIG. 35 as a specific case of FIG. When the i-line 1/5 reduction projection exposure apparatus with NA = 0.52 is used and the aperture stop radius of the projection lens is 1, the size of the illumination light source image at the aperture stop position is an outer radius of 0.6 and an inner radius of 0.6. On the wafer when the circular illumination with a radius of 0.5 is performed and the 12 light-shielding line patterns 34 on the 5 × reticle of the present invention are subjected to ⅕ reduction projection exposure on the wafer. The light intensity distribution is calculated.

In the conventional reticle, the line-and-space pattern of 0.35 μm is projected and exposed, so that the width of the light-shielding line pattern on the 5 × reticle is uniformly 1.75 μm.
However, in the reticle of the present invention, only the width of the transmission space pattern 36a inside the light shielding line patterns at both ends is set to 2.00 μm. That is, w = 1.75 μm, Δ
w = 0.25 μm. With this arrangement, the light intensity distribution is such that the light intensity at the locations (36a) corresponding to the transmission space portions inside the light-shielding line patterns at both ends is greater than the light intensity of the other transmission space portions even when defocused by 1 μm. growing. Therefore, when a positive resist is used, only the transmissive space portions inside the light-shielding lines at both ends are not resolved, and rather, the transmissive space patterns 36a inside the light-shielding line patterns at both ends are resolved more than other portions. Easier to do. Even when a negative resist is used, the resist thickness is not reduced and the line width is not thinned only in the transmission space portions inside the light shielding line patterns at both ends. As a result, it is possible to form a group of line-and-space patterns that occupy most of the line-and-space pattern of 0.35 μm, which is close to the resolution limit of the oblique illumination oblique incidence exposure, to a large depth of focus including both ends.

In this case, the increase amount Δw of the width of the transmission space pattern 36a inside the light-shielding line patterns at both ends is also shown in FIG.
Further, similar to the case of the first embodiment shown in FIG. 2, when the pattern size w is close to the resolution limit, approximately Δw =
It may be (0.05 to 0.2) w. If Δw is made too large, the light intensity of the light-shielding line pattern portions at both ends will increase. In addition, as shown in FIG.
The line-type line-and-space pattern shown in Fig. 6 is placed, and the light intensity of the light-shielding line pattern portion inside the transmission space pattern, that is, the second light-shielding line pattern portion from both ends is increased, and the transmission inside the light-shielding line pattern portion is increased. The light intensity of the space pattern part decreases. From the viewpoint of reducing the occupied width of the entire periodic pattern, it is the easiest to use that both end parts behave almost the same as the parts other than both ends from the viewpoint of use. Therefore, it is optimal to set Δw in the above range. Is. When the number of patterns is large, the width of all patterns is (w + Δ
The width of the pattern can be reduced compared to w).
This is similar to the case of the first embodiment described with reference to FIGS. 1 and 2.

(Embodiment 3) FIG. 5 is a view showing another embodiment of pattern arrangement in the reticle of the present invention. In this embodiment, four or more arbitrary light-shielding line patterns 34 having a fine width w close to the resolution limit of the uniform periodic pattern of the projection exposure optical system of the grazing incidence illumination projection exposure apparatus used for projection exposure are provided. , The light-shielding line pattern 34
The transparent space pattern 36 having the same line width w as the above is repeatedly formed with the transparent space pattern 36 a at both ends.
Instead of, the width of the light-shielding line pattern 34a is made larger than the line width w of the other light-shielding line patterns 34 (w + Δw).
3 is different from the above-described embodiment shown in FIGS. 3 and 4.

FIGS. 6A and 6B show the numerical aperture of the projection lens on the assumption that the line and space pattern of 0.35 μm shown in FIG. 35 is improved as a specific case of FIG. When the i-line 1/5 reduction projection exposure apparatus with NA = 0.52 is used and the aperture stop radius of the projection lens is 1, the size of the illumination light source image at the aperture stop position is an outer radius of 0.6 and an inner radius of 0.6. On the wafer when the circular illumination with a radius of 0.5 is performed and the 12 light-shielding line patterns 34 on the 5 × reticle of the present invention are subjected to ⅕ reduction projection exposure on the wafer. The light intensity distribution is calculated.

In the conventional reticle, the line-and-space pattern of 0.35 μm is projected and exposed, so that the width of the light-shielding line pattern on the 5 × reticle is uniformly 1.75 μm.
However, in the reticle of the present invention, only the width of the light shielding line patterns 34a at both ends is set to 2.00 μm. That is, w = 1.75 μm and Δw = 0.25 μm. By doing so, the light intensity distribution can be made to be smaller than the light intensities of the other light-shielding line pattern portions, even in the defocused state of 1 μm, at the positions corresponding to the light-shielding lines at both ends. Therefore, when the positive resist is used, the resist thickness does not decrease or the line width does not become thin only at the light-shielding line pattern portions at both ends, but rather the light-shielding line pattern portions 34a at both ends are different from each other. The resist thickness is less likely to decrease than the light-shielding line pattern portion 34, and the line width can be thickened. Further, when the negative resist is used, the resist does not remain only in the light-shielding line pattern portions 34a at both ends to prevent non-resolution. As a result, it is possible to form a group of line-and-space patterns, which occupy most of the line-and-space pattern of 0.35 μm close to the resolution limit of the oblique illumination oblique incidence exposure, to a large depth of focus including both ends.

In this case, the light-shielding line patterns 34a on both ends are provided.
Similarly to the case of the first embodiment described with reference to FIG. 1 and FIG. 2, the increase amount Δw of the width of Δ is approximately Δw = (0.05-0 ．
2) w can be used. If Δw is made too large, the space type line and space pattern as shown in FIG. 34 is placed inside the light shielding line pattern,
The light intensity of the transmission space pattern portion inside the light-shielding line patterns 34a at both ends is reduced. Also, from the viewpoint of reducing the occupied width of the entire periodic pattern, it is easiest to use that both end portions behave almost the same as the other portions from the viewpoint of use. Therefore, Δw should be in the above range. Is the best. When the number of patterns is large, the width of all patterns is (w + Δ
The width of the pattern can be reduced compared to w).
This is similar to the case of the first embodiment.

(Embodiment 4) FIG. 7 is a view showing still another embodiment of pattern arrangement in the reticle of the present invention.
In this embodiment, the invention described with reference to FIGS. 3 and 4 and the invention described with reference to FIGS. 5 and 6 are carried out at the same time. Transparent space pattern 36a
Is set to a width (w + Δw) larger than the line width w of the other light-shielding line pattern 34 and the transmission space pattern 36. According to this structure, when there is a line-type line-and-space pattern in the transmission part 35, the light intensity of the light-shielding line pattern parts 34a at both ends is increased and the transmission space pattern inside the light-shielding line patterns at both ends is increased. The reduction of the light intensity of 36a can be improved at the same time, and the effect can be further enhanced as compared with the case where the invention described with reference to FIGS. 3 and 4 or the invention described with reference to FIGS.

FIGS. 8A and 8B show the numerical aperture of the projection lens, assuming the case of improving the 0.35 μm line-and-space pattern shown in FIG. 35 as a specific case of FIG. 7. When the i-line 1/5 reduction projection exposure apparatus with NA = 0.52 is used and the aperture stop radius of the projection lens is 1, the size of the illumination light source image at the aperture stop position is an outer radius of 0.6 and an inner radius of 0.6. On the wafer when the circular illumination with a radius of 0.5 is performed and the 12 light-shielding line patterns 34 on the 5 × reticle of the present invention are subjected to ⅕ reduction projection exposure on the wafer. The light intensity distribution is calculated.

In the conventional reticle, the line-and-space pattern of 0.35 μm is projected and exposed, so that the width of the light-shielding line pattern on the 5 × reticle is uniformly 1.75 μm.
However, in the reticle of the present invention, only the width of the light-shielding line pattern 34a at both ends and the transmission space pattern 36a inside thereof is 2.00 μm. That is, w =
1.75 μm and Δw = 0.25 μm. By doing so, the light intensity distribution can be made to be smaller than the light intensities of the other light-shielding line pattern portions 34 at the positions corresponding to the light-shielding line patterns 34a at both ends even in the defocused state of 1 μm. The transparent space pattern part 36a inside the light-shielding line pattern at both ends
Can be made smaller than the light intensity of the other transmission space pattern portion 36. Therefore, when a positive resist is used, only the transmission space inside the light-shielding line pattern on both ends is not resolved,
The resist thickness does not decrease or the line width does not become thin only at the light-shielding line portions at both ends, but rather the transmission space pattern 36a inside the light-shielding line pattern 34a at both ends.
Is easier to resolve than other portions, and the resist thickness of the light-shielding line pattern portions 34a at both ends is less likely to decrease than that of the other light-shielding line pattern portions 34, and the line width becomes thicker. When a negative resist is used, the resist thickness is reduced only in the transmission space pattern portions inside the light-shielding line patterns 34a at both ends, the line width is reduced, and the resist is applied only to the light-shielding line portions at both ends. Will not be left unresolved. As a result, it is possible to form a line-and-space pattern group in which most of the line-and-space pattern of 0.35 .mu.m, which is close to the resolution limit of the oblique illumination oblique incidence exposure, with a large focal depth including both ends.

In this case, the light-shielding line patterns 34a on both ends are provided.
1 and the width increase amount Δw of the transmission space pattern 36a inside the light-shielding line patterns at both ends.
Similarly to the case of the first embodiment described with reference to FIG. 2, when the pattern size w is close to the resolution limit, Δw = approximately.
It may be (0.05 to 0.2) w. If Δw is made too large, a line-type line-and-space pattern as shown in FIG. 8B is placed inside the light-shielding line pattern, and the light intensity of the second light-shielding line pattern from both ends is increased. Will rise and the light intensity of the transmission space pattern portion inside will decrease. Also, from the viewpoint of reducing the occupied width of the entire periodic pattern, it is easiest to use that both end portions behave almost the same as the other portions from the viewpoint of use. Therefore, Δw should be in the above range. Is the best.
When the number of patterns is large, the occupied width of the pattern can be reduced as compared with the case where the width of all patterns is (w + Δw), as in the case of the first embodiment described with reference to FIGS. 1 and 2. In this example, the amount of increase in the width of the light-shielding line pattern and the amount of increase in the width of the transmission space pattern 36a inside the light-shielding line patterns 34a at both ends are equal to Δw, but they may be different from each other.

In each of the above embodiments, the case where the light-shielding line pattern width w and the transmission space pattern width w have the same size has been described. However, it is clear that the present invention is also effective when the ratio between the light-shielding line pattern width and the transmission space pattern width is not always 1: 1.

9 to 12 show an embodiment of the present invention in which the ratio of the light-shielding line pattern width to the transmission space pattern width is not 1: 1.

(Embodiment 5) FIG. 9 shows an oblique illumination illumination projection exposure optical used by a transmission space pattern width (w1) in a space type line and space pattern formed by a transmission space pattern 33 in a light shielding portion 31. It is an example in which the present invention is applied in the case of a size close to the limit resolution of the system. In this embodiment, the width of the light shielding line pattern 32 is w2,
The width of the transmission space pattern 33 is set to w1, and only the width of the transmission space pattern 33a at both ends where the light intensity is likely to decrease is set to be larger than the width w1 of the other transmission space pattern 33 by Δw1. It is possible to prevent the light intensity from decreasing in the space pattern portion. As in the case of the first embodiment described with reference to FIGS. 1 and 2, Δw1 = (0.05 to 0.2)
0) w1 is enough. By improving the light intensity of the transmission space pattern portions at both ends, it is possible to increase the depth of focus for the entire line-and-space pattern including both end portions. The occupied width can be suppressed to a very small increase as compared with the case where the entire transparent space pattern width is increased. In FIG. 9, the transmissive space pattern width w1 is drawn smaller than the width w2 of the light-shielding line pattern 9 between them, but also when the transmissive space pattern width w1 is larger than the light-shielding line pattern width w2. The present invention is effective.

(Embodiment 6) In FIG. 10, in the line type space-and-space pattern formed by the light-shielding line pattern 34 in the light transmitting portion 35, the width w3 of the light transmitting space pattern 36 between the light shielding line patterns 34 is It is an embodiment of the present invention applied to a case where the size is close to the limit resolution of the grazing incidence illumination projection exposure optical system used. Similar to the case of FIG. 3, only the width of the transmissive space pattern 36a inside the light-shielding line patterns at both ends where the light intensity is likely to decrease is set to be larger than the width w3 of the other transmissive space pattern 36 by Δw3. As a result, it is possible to prevent a decrease in light intensity in the transmission space pattern portions inside the light-shielding line patterns at both ends.

The dimension Δw3 for enlarging the transmission space pattern width w3 inside the light-shielding line patterns at both ends is Δw3 = (0.05-0.05) as in the case of the third embodiment described with reference to FIGS.
0.20) w3 is sufficient. By improving the light intensity of the transmission space pattern inside the shading line pattern at both ends,
It is possible to increase the depth of focus for the entire line and space pattern including both ends. The occupied width can be suppressed to a very small increase as compared with the case where the entire transparent space pattern width is increased. In FIG. 10, the width w4 of the light shielding line pattern 34 is drawn larger than the width w3 of the transmission space pattern 36 between them, but when the width w4 of the light shielding line pattern is smaller than the width w3 of the transmission space pattern. Also, the present invention is effective.

(Embodiment 7) FIG.
In the line type line and space pattern formed by the light shielding line pattern 34, the light shielding line pattern width w
5 is an embodiment of the present invention applied to the case where the size is close to the limiting resolution of the oblique incidence illumination projection exposure optical system used in FIG. As in the case of FIG. 5, the widths of the light-shielding line patterns at both ends where the light intensity is likely to increase are increased by Δw5 from the widths w5 of the other light-shielding line pattern portions. As a result, it is possible to prevent the light intensity of the light-shielding line pattern portions at both ends from increasing.

The dimension Δw5 for widening the light-shielding line pattern width w5 at both ends may be Δw5 = (0.05 to 0.20) w5 as in the case of the third embodiment described with reference to FIGS. By improving the light intensity of the light-shielding line pattern portions at both ends, it is possible to increase the depth of focus for the entire line-and-space pattern including both end portions. The occupied width can be suppressed to an extremely small increase as compared with the case where the entire light-shielding line pattern width is increased. In FIG. 11, the width w4 of the light shielding line pattern 34 is drawn smaller than the width w3 of the transmission space pattern 36 between them, but when the light shielding line pattern width w4 is larger than the transmission space pattern width w3. Also, the present invention is effective.

(Embodiment 8) FIG.
In the line type line and space pattern formed by the light shielding line pattern 34, the light shielding line pattern 34
Is a working example of the present invention applied when both the width w7 and the width w8 of the transmissive space pattern 36 separating the light shielding line pattern 34 are close to the limit resolution of the oblique incident illumination projection exposure optical system used. Although the light-shielding line pattern width w7 and the light-transmitting space pattern width w8 are different, there is a concern that both the light intensity of the light-transmitting space pattern portion inside the light-shielding line 34a at both ends may decrease and the light intensity of the light-shielding line pattern portions at both ends may increase. It is effective when

Similar to the case of FIG. 7, the width of the light shielding line pattern at both ends where the light intensity is easily increased is set to the other light shielding line pattern 34.
The width of the transmission space pattern inside the light-shielding line pattern at both ends, which is apt to be larger than the width w7 of the other transmission space pattern by Δw7, is smaller than the width w8 of the other transmission space pattern by Δw8.
Just make it bigger. As a result, it is possible to prevent an increase in the light intensity of the light-shielding line pattern portions at both ends and a decrease in the light intensity in the transmission space pattern portions inside the light-shielding line patterns at both ends.
The dimension Δw7 for widening the light-shielding line pattern width w7 at both ends and the dimension Δw8 for widening the transmission space pattern width w8 inside the light-shielding line patterns at both ends are the same as in the case of the fourth embodiment described with reference to FIGS. .05 to 0.2
0) w7 and Δw8 = (0.05 to 0.20) w8. It is not always necessary to set Δw7 = Δw8,
It is not necessary to make w7 / w7 and Δw8 / w8 equal.
By improving the light intensities of the light-shielding line pattern portions at both ends and the transmission space pattern portion inside thereof, the depth of focus for the entire line-and-space pattern including both end portions can be increased. The width of the entire shading line pattern,
The occupied width can be suppressed to a very small increase as compared with increasing the width of the transmission space pattern. In FIG. 12, the width w7 of the light shielding line pattern 34 is drawn smaller than the width w8 of the transmission space pattern 36 between them, but when the light shielding line pattern width w7 is larger than the transmission space pattern width w8. Also, the present invention is effective.

(Embodiment 9) The present invention is also effective in the case of a periodic pattern having a change in the line width in the longitudinal direction, instead of the simple line and space pattern as described above. FIG. 13 shows an embodiment of the present invention for a periodic pattern in which the line width changes in the longitudinal direction. Shading part 3 on the reticle
The transmission patterns 40 having a line width change in the longitudinal direction are periodically arranged with the light shielding pattern 41 therebetween. If the line widths of the transmission patterns 40 are all the same, the same problem as in the space-type line and space pattern occurs when performing oblique incident illumination projection exposure. That is, the light intensity of the transmission pattern portions at both ends becomes lower than the light intensity of the other transmission pattern portions. Therefore, in FIG. 13, only the width of the transmission pattern 40a at both ends of the periodic pattern is set to (w9 + Δw9). The width of the other transparent pattern 40 is w9, and the width of the light shielding pattern 41 separating the transparent pattern 40 is w10. .DELTA.w9 is set to .DELTA.w9 = (0.05 to 0.20) w9 as in the above-mentioned various embodiments. Thereby, the light intensity of the transmission pattern portions at both ends can be improved, and the depth of focus of the entire periodic pattern including both ends can be significantly improved. The occupied width can be suppressed to a very small increase in comparison with increasing the entire transmission pattern width. The size relationship between the width w9 of the transmission pattern 40 and the width w10 of the light shielding pattern 41 is arbitrary. The present invention is effective when w9 = w10, whichever is larger.

(Embodiment 10) FIG. 14 is also an embodiment of the present invention for a periodic pattern in which the line width changes in the longitudinal direction. In the transmissive portion 35 on the reticle, light-shielding patterns 45 having a change in line width in the longitudinal direction are periodically arranged with a transmissive pattern 46 therebetween. In such a pattern, the light blocking pattern 45
If all the line widths are the same, the same problem as in the line-type line-and-space pattern occurs when performing the oblique incident illumination projection exposure. That is, the light intensity of the light-shielding pattern portions at both ends is higher than the light intensity of the other light-shielding pattern portions, and the light is excessively exposed. Since the light intensity is lower than the light intensity, the exposure amount becomes insufficient. Therefore, in this embodiment,
Transmission pattern parts 46 inside the light-shielding patterns at both ends of the periodic pattern
Only the width of a is (w11 + Δw11). The width of the other transmission pattern 46 is w11, and the width of the light shielding pattern 45 is Δw1.
Is 2. Also in this case, Δw11 = (0.05 to 0.2
0) w11. As a result, it is possible to solve the shortage of the exposure amount of the transmission pattern portions inside the light shielding patterns at both ends, and it is possible to significantly improve the depth of focus of the entire periodic pattern including both ends. Further, the occupied width can be suppressed to a very small increase as compared with the case where the entire transmission pattern width is increased. The size relationship between the width w11 of the transmission pattern 24 and the width w12 of the light shielding pattern 23 is arbitrary. The present invention is effective when w11 = w12, whichever is larger.

(Embodiment 11) FIG. 15 is also an embodiment of the present invention for a periodic pattern in which the line width changes in the longitudinal direction. In the transmissive portion 35 on the reticle, light-shielding patterns 45 having a change in line width in the longitudinal direction are periodically arranged with a transmissive pattern 46 therebetween. If the line widths of the light-shielding patterns 45 are all the same, the same problem as in the line-type line-and-space pattern will occur when performing the oblique incident illumination projection exposure. In this embodiment, the width of the light shielding pattern 45a at both ends of the periodic pattern is (w
13 + Δw13). The width of the other light shielding pattern 45 is w13, and the widths of the transmission patterns 46 are all w14. Also in this case, Δw13 = (0.05 to 0.20) w13. As a result, it is possible to prevent the light intensity of the light-shielding pattern portions at both ends from increasing, and it is possible to significantly improve the depth of focus of the entire periodic pattern including both ends. Further, the occupied width can be suppressed to a very small increase as compared with the case where the entire transmission pattern width is increased. The size relationship between the width w13 of the light shielding pattern 45 and the width w14 of the transmission pattern 46 is arbitrary. The present invention is effective when w13 = w14, whichever is larger.

(Embodiment 12) FIG. 16 is also an embodiment of the present invention for a periodic pattern in which the line width changes in the longitudinal direction. In the transmissive portion 35 on the reticle, light-shielding patterns 45 having a change in line width in the longitudinal direction are periodically arranged with a transmissive pattern 46 therebetween. If the line widths of the light-shielding patterns 45 are all the same, the same problem as in the line-type line-and-space pattern will occur when performing the oblique incident illumination projection exposure.

In this embodiment, the width of the light shielding patterns 45a at both ends of the periodic pattern is (w15 + Δw15), and the width of the transmission pattern portion 46a inside the light shielding patterns 45a at both ends is (w16 + Δw15).
It is as w16). The width of the other shading pattern 45 is w1
5, the width of the transmission pattern 46 is w16. Again, Δ
Let w15 = (0.05 to 0.20) w15 Δw16 = (0.05 to 0.20) w16. As a result, it is possible to prevent an increase in the light intensity of the light-shielding pattern portions at both ends and to solve the shortage of the exposure amount of the light-transmitting pattern portions inside the light-shielding patterns 45a at both ends. Can be greatly improved. Further, the occupied width can be suppressed to a very small increase as compared with the case where the entire transmission pattern width is increased. The width w15 of the shading pattern 45 and the width w16 of the transmission pattern 46
The size relationship with and is arbitrary. Whichever is larger, w15
The present invention is also effective when = w16. Not necessarily Δw15
And Δw16 do not have to be equal, and Δw15 / w15 and Δw15
It is not necessary to make w16 / w16 equal.

By the way, the present invention is also effective when the patterns are arbitrarily bent while maintaining the parallel state. FIG. 17
20 to 20 are examples of the present invention for a periodic pattern bent in a chevron shape.

(Embodiment 13) FIG. 17 shows a light-shielding portion 31 on a reticle, in which mountain-shaped transmission patterns 50 are periodically formed with light-shielding patterns 51 separated from each other. If the line widths of the transmission patterns 50 are all the same, the same problem as in the space-type line and space pattern occurs when performing oblique incident illumination projection exposure. Therefore, in FIG. 17, only the width of the transmission pattern 50a at both ends of the periodic pattern is set to (w17 + Δw17). The width of the other transparent pattern 50 is w17, the transparent pattern 5
The width of the light-shielding pattern 51 separating 0 is w18. Δw17
Δw17 = (0.05-
0.20) w17. As a result, the light intensity of the transmission pattern portions 50a at both ends can be improved, and the focal depth of the entire periodic pattern including both ends can be significantly improved. The occupied width can be suppressed to a very small increase in comparison with increasing the entire transmission pattern width. The size relationship between the width w17 of the transmission pattern 50 and the width w18 of the light shielding pattern 51 is arbitrary. The present invention is effective when w17 = w18, whichever is larger.

(Embodiment 14) FIG. 18 shows an example in which a mountain-shaped light-shielding pattern 55 is periodically provided with a transmission pattern 56 provided in the transmission portion 35 on the reticle. In such a pattern, if the line widths of the transmission pattern 56 are all the same, the same problem as in the line-type line-and-space pattern occurs when performing the oblique incident illumination projection exposure. Therefore, in the present embodiment, only the width of the transmission pattern portion 56a inside the light shielding patterns at both ends of the periodic pattern is set to (w19 + Δw19). The width of the other transmission pattern 56 is w19, and the width of the light shielding pattern 55 is w20. Also in this case, Δw19 = (0.05 to 0.2
0) Set to w19. As a result, the shortage of the exposure amount of the transmission pattern portion 56a inside the light shielding patterns at both ends can be resolved, and the depth of focus of the entire periodic pattern including both ends can be significantly improved. The occupied width can be suppressed to a very small increase in comparison with increasing the entire transmission pattern width. The size relationship between the width w19 of the transmission pattern 56 and the width w20 of the light shielding pattern 55 is arbitrary. The present invention is effective when w19 = w20, whichever is larger.

(Embodiment 15) FIG. 19 is also an embodiment in which the present invention is applied in the case where mountain-shaped light-shielding patterns 55 are periodically arranged with a transmission pattern 56 being separated in the transmission portion 35 on the reticle. If the line widths of the shading patterns 55 are all the same,
When performing the oblique exposure illumination projection exposure, the same problem as the line type line and space pattern occurs. Therefore, in this embodiment, the widths of the light shielding patterns 55a at both ends of the periodic pattern are (w21 + Δw21), and the widths of the other light shielding patterns 38 are w2.
1. The width of the transmission pattern 39 is all Δw22. Also in this case, Δw21 = (0.05 to 0.20) w21
And As a result, it is possible to prevent an increase in the light intensity of the light shielding pattern portions 55a at both ends, and it is possible to significantly improve the depth of focus of the entire periodic pattern including both ends. The occupied width can be suppressed to a very small increase in comparison with increasing the entire transmission pattern width. The size relationship between the width w21 of the light-shielding pattern 55 and the width w22 of the transmission pattern 56 is arbitrary. The present invention is effective when w21 = w22, whichever is larger.

(Embodiment 16) FIG. 20 is also an embodiment in which the present invention is applied in the case where the mountain-shaped light-shielding patterns 55 are periodically arranged with the transmission pattern 56 in between in the transmission portion 35 on the reticle. If the line widths of the light-shielding pattern 55 and the transmission pattern 56 are all the same, the same problem as in the line-type line-and-space pattern occurs when performing oblique-incidence illumination projection exposure.

In this embodiment, the width of the light shielding pattern 55a at both ends of the periodic pattern is (w23 + Δw23), and the width of the transmission pattern portion 56a inside the light shielding pattern 55a at both ends is (w24 + Δw23).
It is as w24). The width of the other shading pattern 55 is w2
3, the width of the transmission pattern 56 is Δw24. Also in this case,
Δw23 = (0.05 to 0.20) w23 Δw24 = (0.05 to 0.20) w24. As a result, it is possible to prevent an increase in the light intensity of the light-shielding pattern portions at both ends and to eliminate the shortage of the exposure amount of the light-transmitting pattern portions inside the light-shielding patterns 55a at both ends, so that the focal depth of the entire periodic pattern including both ends can be reduced. Can be greatly improved. Compared to increasing the overall transmission pattern width,
Occupied width can be kept very small. The size relationship between the width w23 of the light shielding pattern 55 and the width w24 of the transmission pattern 56 is arbitrary. Whichever is larger, w23 = w24
In this case, the present invention is also effective. Not necessarily Δw23 and Δw
It is not necessary to make 24 equal, and Δw23 / w23 and Δw24 /
It is not necessary to make w24 equal. In each of FIGS. 18 to 20, a mountain-shaped pattern bent at a right angle is shown, but it goes without saying that the angle bent into the mountain may be arbitrary. The present invention is also effective for a periodic pattern in which a combination of two or more patterns is repeated periodically. Examples thereof will be shown below.

(Embodiment 17) FIG. 21 shows an embodiment of the present invention in the case of a periodic pattern in which two types of bent patterns are combined. Two types of transmission patterns 6 are included in the light-shielding portion 31.
0 and 61 are periodically arranged, and the end portions of the transmission pattern 60 are located between the transmission patterns 61 with a required space. In the area where the two types of transmission patterns 60 and 61 are close to each other, when the line widths of the transmission patterns 60 and 61 are all the same, the problem similar to that of the space-type line-and-space pattern occurs when performing the oblique incident illumination projection exposure. Cause Therefore,
In FIG. 21, the transmission patterns 60a and 61 at both ends of the periodic pattern are formed.
Only the width of a is (w25 + Δw25). The widths of the other transparent patterns 60 and 61 are w25 and the transparent patterns 60 and 61.
The width of the light-shielding portion 62 separating the two is w26. Δw25 is equal to Δw25 = (0.05 to 0.2) as in the above various embodiments.
0) Set to w25. As a result, the transparent pattern portions 60 at both ends are
It is possible to solve the shortage of the exposure amount of a and 61a, and it is possible to significantly improve the depth of focus of the entire periodic pattern including both ends. The occupied width can be suppressed to a very small increase in comparison with increasing the entire transmission pattern width. The width w25 of the transparent patterns 60 and 61 and the width w of the light shielding portion 62
The size relationship with 26 is arbitrary. Whichever is larger, w
The present invention is also effective when 25 = w26.

(Embodiment 18) FIG. 22 is also an embodiment of the present invention in the case of a periodic pattern in which two types of bent patterns are combined. Two kinds of light-shielding patterns 6 in the transmission part 35.
5, 66 are lined up periodically. The end portion of the light shielding pattern 65 is located between the end portions of the light shielding pattern 66. The part where the two types of shading patterns 65 and 66 come close to each other is the shading pattern 6
If the line widths of 5 and 66 or the width of the transmitting portion 67 between the light shielding patterns 65 and 66 are all equal, the same problem as in the line type line and space pattern occurs when performing oblique incident illumination projection exposure. Therefore, in the present embodiment, only the width of the light-shielding patterns 65a at both ends of the periodic pattern and the transmitting portion 67a inside the 66a is set to (w27 + Δw27). The width of the other transmitting portion 67 is w27, and the width of the light shielding patterns 65 and 66 is w28. Also in this case, Δw27 = (0.05 to 0.20) w27
And As a result, it is possible to eliminate the shortage of the exposure amount of the transmission pattern portion 67a inside the light shielding patterns at both ends, and it is possible to significantly improve the depth of focus of the entire periodic pattern including both ends. The occupied width can be suppressed to a very small increase in comparison with increasing the entire transmission pattern width. The width w27 of the transmitting portion 67 and the width w of the light shielding patterns 65 and 66
The size relationship with 28 is arbitrary. Whichever is larger, w
The present invention is also effective when 27 = w28.

(Embodiment 19) FIG. 23 is also an embodiment of the present invention in the case of a periodic pattern in which two types of bent patterns are combined. Two kinds of light-shielding patterns 6 in the transmission part 35.
5, 66 are lined up periodically. The end portion of the light shielding pattern 65 is located between the end portions of the light shielding pattern 66. The part where the two types of shading patterns 65 and 66 come close to each other is the shading pattern 6
If the line widths of 5 and 66 or the width of the transmission part between the light shielding patterns are all equal, the same problem as the line type line and space pattern occurs when performing the oblique incident illumination projection exposure. Therefore, in this embodiment, only the widths of the light shielding patterns 65a and 66a at both ends of the periodic pattern are set to (w29 + Δw29). The widths of the other light shielding patterns 65 and 66 are w29, and the widths of the transmissive portions 67 separating the light shielding patterns 65 and 66 are all w30. Also in this case, Δw29 = (0.05 to 0.20) w29
And As a result, the light-shielding pattern portions 65a and 66 at both ends are
It is possible to prevent an increase in the light intensity of a and significantly improve the depth of focus of the entire periodic pattern including both ends. The occupied width can be suppressed to a very small increase in comparison with increasing the entire transmission pattern width. The size relationship between the width w29 of the light shielding patterns 65 and 66 and the width w30 of the transmitting portion 67 is arbitrary. The present invention is effective when w29 = w30, whichever is larger.

(Embodiment 20) FIG. 24 is also an embodiment of the present invention in the case of a periodic pattern in which two types of bent patterns are combined. Two kinds of light-shielding patterns 6 in the transmission part 35.
5, 66 are lined up periodically. The end portion of the light shielding pattern 65 is located between the end portions of the light shielding pattern 66. The part where the two types of shading patterns 65 and 66 come close to each other is the shading pattern 6
If the line widths of 5 and 66 or the width of the transmission part between the light shielding patterns are all equal, the same problem as the line type line and space pattern occurs when performing the oblique incident illumination projection exposure. Therefore, in this embodiment, the widths of the light shielding patterns 65a and 66a at both ends of the periodic pattern are set to (w31 + Δw31), and the width of the transmitting portion 67a inside these light shielding patterns 65a and 66a is set to (w32 + Δw32). Other shading patterns 6
The widths of 5 and 66 are w31, and the width of the transmissive portion 67 is w32. Also in this case, Δw31 = (0.05 to 0.20) w31 and Δw32 = (0.05 to 0.20) w32. As a result, it is possible to prevent an increase in the light intensity of the light-shielding pattern portions at both ends and to eliminate the shortage of the exposure amount of the light-transmitting pattern portions 67a inside the light-shielding patterns 65a and 66a at both ends. The depth of focus can be greatly improved. The occupied width can be suppressed to a very small increase in comparison with increasing the entire transmission pattern width. The width w31 of the light-shielding patterns 65 and 66 and the transparent portion 6
The magnitude relationship with the width w32 of 7 is arbitrary. The present invention is effective when w31 = w32, whichever is larger. It is not always necessary to make Δw31 and Δw32 equal, and Δw31
It is not necessary to make / w31 and Δw32 / w32 equal.

(Embodiment 21) FIG. 25 is an embodiment of the present invention for another periodic pattern in which two types of patterns are combined. Two types of transmission patterns 70 are provided in the light shielding unit 31,
71 are lined up periodically. The transmission pattern 70 has an inverted L shape, and the transmission pattern 71 has an L shape, and is located between the transmission patterns 70. When the line widths of the transmission patterns 70 and 71 are made uniform, the portion 72 where the two types of transmission patterns 70 and 71 come close to each other has the same problem as the space-type line and space pattern. That is, the light intensity of the transmission pattern portions at both ends becomes lower than the light intensity of the other transmission pattern portions.
Therefore, in FIG. 25, the transmission patterns 70 at both ends of the periodic pattern are formed.
Only the widths of a and 71a are (w33 + Δw33), (w
34 + Δw34). Other transmission patterns 70, 7
The width of 1 is w33, w34, and the light-shielding portions 72a, 72b, 72c that separate the transmission patterns 70, 71 from the middle light-shielding portions 72a, 72b.
Has a width of w35, and the light shielding portion 72c has a width of w36. Δw33
Δw33 = (0.05-
0.20) w33. As a result, it is possible to solve the shortage of the exposure amount of the transmission pattern portions at both ends, and it is possible to significantly improve the depth of focus of the entire periodic pattern including both ends. In addition, the occupied width can be suppressed to an extremely small increase compared to the case where the width w33 of the transmission patterns 70 and 71 is entirely set to the width (w33 + Δw33). Δw34 is Δ
It is sufficient to set w34 = Δw33. The magnitude relationship between the width w33 of the transmissive patterns 70 and 71 and the width w35 of the light shielding portions 72a and 72b is arbitrary. The present invention is effective when w33 = w35, whichever is larger. The size relationship between the widths w33 and w34 of the transparent patterns 70 and 71 is also arbitrary. Further, in FIG. 25, Δw
Although 34 = Δw33 is set, Δw34 <Δw33 is established, and the width of the light shielding portion inside the transmissive patterns 70a and 71a at both ends is set to w35 +
It may be (Δw33-Δw34). In that case, Δw34 =
0 is acceptable.

(Embodiment 22) FIG. 26 is also an embodiment of the present invention for another periodic pattern in which two types of patterns are combined. Two kinds of light-shielding patterns 75 in the transmission part 35,
76 are lined up periodically. The light shielding pattern 75 has an inverted L shape, and the light shielding pattern 76 has an L shape, and is located between the light shielding patterns 75. When the line widths of the light shielding patterns 75 and 76 are made uniform, the portions where the two types of light shielding patterns 75 and 76 are close to each other have the same problem as the line type line and space pattern. That is, the light intensity of the light-shielding pattern portions at both ends becomes higher than the light intensity of the other light-shielding patterns, and at the same time, the light intensity of the transmitting portion inside the light-shielding patterns at both ends becomes lower than the light intensity of the other transmitting pattern portions. Therefore, in this embodiment, only the widths of the transmitting portions 78a and 78b inside the light shielding patterns 75a and 76a at both ends of the periodic pattern are set to (w37 + Δw37).
There is. The widths of the middle transmission parts 78c and 78d of the other transmission parts 78c to 78e are w37, and the widths of the transmission parts 78e are w38,
Light-shielding pattern 75 other than the edge light-shielding patterns 75a and 76a,
The width of 76 is w39 and w40. Also in this case, Δw37 =
(0.05 to 0.20) w37. As a result, the light transmitting patterns 75a and 76a on both ends are provided with the transmitting portions 78a and
The shortage of the exposure amount of 8b can be eliminated, and the depth of focus of the entire periodic pattern including both ends can be significantly improved. Further, compared with the case where the width w37 of the transmissive portions 78c and 78d is entirely set to the width (w37 + Δw37), the occupied width can be suppressed to an extremely small increase. Transmission part 78
The magnitude relationship between the widths w37 and w38 of c, 78d and 78e is arbitrary. The present invention is effective when w37 = w38, whichever is larger. In addition, the width w37 of the transmissive portions 78c and 78d
And the width w39 of the light shielding patterns 75 and 76 are arbitrary. The present invention is effective when w37 = w39, whichever is larger.

(Embodiment 23) FIG. 27 is also an embodiment of the present invention for a periodic pattern in which two types of patterns are combined. Two types of light-shielding patterns 75 and 76 are provided in the transparent portion 35.
Are lined up periodically. The light-shielding pattern 75 has an inverted L shape
The light shielding pattern 76 is L-shaped and is located between the light shielding patterns 75. When the line widths of the light shielding patterns 75 and 76 are made uniform, the portions where the two types of light shielding patterns 75 and 76 are close to each other have the same problem as the line type line and space pattern. That is, the light intensity of the light-shielding pattern portions at both ends becomes higher than the light intensity of the other light-shielding patterns, and at the same time, the light intensity of the transmitting portion inside the light-shielding patterns at both ends becomes lower than the light intensity of the other transmitting pattern portions. Therefore, in this embodiment,
Only the widths of the light shielding patterns 75a and 76a at both ends of the periodic pattern are (w41 + Δw41) and (w42 + Δw42), respectively. The widths of the other light-shielding patterns 75 and 76 are w41, w42,
The width of the transmissive portions 78a and 78b is w43, and the width of the transmissive portion 78e is w44. Also in this case, Δw41 = (0.05 to 0.2
0) w41. As a result, it is possible to prevent the light intensity of the light-shielding pattern portions at both ends from increasing, and it is possible to significantly improve the depth of focus of the entire periodic pattern including both ends. In addition, the entire width w41 of the light shielding pattern portion is the width (w41 + Δ
Compared with w41), the occupied width can be suppressed to a very small increase. Δw42 may be set to Δw42 = Δw41. The width w41 of the light-shielding patterns 75 and 76 and the transparent portion 78
The magnitude relationship with the width w43 of a and 78b is arbitrary. The present invention is effective when w41 = w43, whichever is larger. The size relationship between the width w43 of the transmissive portions 78a and 78b and the width w44 of the transmissive portion 78e is also arbitrary. Further, in FIG. 27, Δw
Although 42 = Δw41 is set, Δw42 <Δw41 is established, and the transmissive portions 78a and 78b inside the light shielding patterns 75a and 76a at both ends are set.
The width may be w43 + (Δw41−Δw42). In that case, Δw42 = 0 may be sufficient.

(Embodiment 24) FIG. 28 is also an embodiment of the present invention for a periodic pattern in which two types of patterns are combined. Two types of light-shielding patterns 75 and 76 are provided in the transparent portion 35.
Are lined up periodically. The light-shielding pattern 75 has an inverted L shape
The light shielding pattern 76 is L-shaped and is located between the light shielding patterns 75. When the line widths of the light shielding patterns 75 and 76 are made uniform, the portions where the two types of light shielding patterns 75 and 76 are close to each other have the same problem as the line type line and space pattern. That is, the light intensity of the light-shielding pattern portions at both ends becomes higher than the light intensity of the other light-shielding patterns, and at the same time, the light intensity of the transmitting portion inside the light-shielding patterns at both ends becomes lower than the light intensity of the other transmitting pattern portions. Therefore, in this embodiment,
The widths of the light-shielding patterns 75a and 76a at both ends of the periodic pattern are set to (w45 + Δw45) and (w46 + Δw46), respectively, and the light-transmitting portions 78a and 7a inside the light-shielding patterns 75a and 76a at both ends are formed.
The width of 8b is (w47 + Δw47). The widths of the other light-shielding patterns 75 and 76 are w45 and w46, and the other transparent portions 7
8c, 78d, and 78e, the width of the transmissive portions 78c and 78d is w47, and the width of the transmissive portion 78e is w48. Also in this case,
Δw45 = (0.05 to 0.20) w45 Δw47 = (0.05 to 0.20) w47. As a result, it is possible to prevent an increase in the light intensity of the light-shielding pattern portions at both ends and to eliminate the insufficient exposure amount of the light-transmitting pattern portions inside the light-shielding patterns 75a and 76a at both ends.
The focal depth of the entire periodic pattern including both ends can be significantly improved. Further, the width w45 of the light shielding pattern portion and the width w47 of the transmitting portion are all the width (w45 +
Compared with Δw45) and (w47 + Δw47), the occupied width can be suppressed to a very small increase. The width w45 of the light shielding patterns 75 and 76 and the width w47 of the transmissive portions 78c and 78d.
The size relationship with and is arbitrary. Whichever is bigger, w45
The present invention is also effective when = w47. Transparent portion 78c,
The magnitude relationship between the width w47 of 78d and the width w48 of the transmissive portion 78e is also arbitrary. It is not always necessary to equalize Δw45 and Δw47, and it is not necessary to equalize Δw45 / w45 and Δw47 / w47.

The present invention can be applied to any periodic pattern and, of course, is not related to the length of the pattern. Therefore, the present invention can be applied to a reticle having a periodic light transmission pattern such as a hole-shaped periodic transmission pattern or a polygonal shape or a circular shape.

(Embodiment 25) FIG. 29 shows an embodiment of the present invention regarding a periodic transmission pattern having a hole shape. Hole-shaped transmission patterns 80 are periodically arranged in the light-shielding portion 31, and when the widths of the transmission patterns 80 are all the same, the same problem as in the space-type line-and-space pattern occurs. Therefore, in FIG. 29, only the width of the transmission patterns 80a at both ends is set to (w49 + Δw49). Other transparent patterns 80
Has a width of w49, and the light-shielding portion 81 separating the transmission pattern 80 has a width of w50. Δw49 is set to Δw49 = (0.05 to 0.20) w49 as in the above-mentioned various embodiments. As a result, it is possible to solve the shortage of the exposure amount of the transmission pattern portions at both ends, and it is possible to significantly improve the depth of focus of the entire periodic pattern including both ends. Also, the entire transmission pattern 8
Compared with increasing the width of 0, the occupied width can be suppressed to a very small increase. Width w49 of transparent pattern 80
And the width w50 of the light shielding portion 81 are arbitrary. The present invention is effective when w49 = w50, whichever is larger.

(Embodiment 26) FIG. 30 shows an embodiment of the present invention for a rectangular or square periodic pattern.
Light-shielding patterns 85 are periodically arranged in the transmissive portion 35. If the widths of the light-shielding patterns 85 or the widths of the transmissive portions 86 between the light-shielding patterns 85 are all equal, the same problem as in the line-type line-and-space pattern occurs when performing the oblique incident illumination projection exposure. Therefore, in this embodiment, only the width of the transmissive portion 86a inside the light shielding pattern 85a at both ends of the periodic pattern is set to (w51 + Δw51). The width of the other transparent portion 86 is w51, and the width of the light shielding pattern 85 is w52. Also in this case, Δw51 = (0.05 to 0.20) w51. As a result, the transparent portions 86a inside the light-shielding patterns 85a at both ends are formed.
Insufficient exposure amount can be eliminated, and the depth of focus of the entire periodic pattern including both ends can be significantly improved.
In addition, as compared with increasing the width of all the transmissive portions 86,
Occupied width can be kept very small. The size relationship between the width w51 of the transmitting portion 86 and the width w52 of the light shielding pattern 85 is arbitrary. The present invention is effective when w51 = w52, whichever is larger.

(Embodiment 27) FIG. 31 is also an embodiment of the present invention for a rectangular or square periodic pattern.
Light-shielding patterns 85 are periodically arranged in the transmissive portion 35. If the widths of the light-shielding patterns 85 or the widths of the transmissive portions 86 between the light-shielding patterns 85 are all equal, the same problem as in the line-type line-and-space pattern occurs when performing the oblique incident illumination projection exposure. Therefore, in this embodiment, only the width of the light shielding pattern 85a at both ends of the periodic pattern is set to (w53 + Δw53). The width of the other light-shielding pattern 85 is w53, and the transmissive portion 86
The width of all is w54. Also in this case, Δw53 = (0.0
5 to 0.20) w53. As a result, it is possible to prevent the light intensity of the light-shielding pattern portions at both ends from increasing, and it is possible to significantly improve the depth of focus of the entire periodic pattern including both ends. Further, the occupied width can be suppressed to a very small increase as compared with the case where the entire light-shielding pattern width is increased. The size relationship between the width w53 of the light shielding pattern 85 and the width w54 of the transmissive portion 86 is arbitrary. Whichever is larger, w53 = w
The present invention is also effective in the case of 54.

(Embodiment 28) FIG. 32 shows an embodiment of the present invention for a rectangular or square periodic pattern.
Light-shielding patterns 85 are periodically arranged in the transmissive portion 35. If the widths of the light-shielding patterns 85 or the widths of the transmitting portions 86 between the light-shielding patterns 85 are all equal, a problem similar to that of the line-type line-and-space pattern occurs when performing oblique incident illumination projection exposure. Therefore, in this embodiment, the width of the light-shielding pattern 85a at both ends of the periodic pattern is set to (w55 + Δw55), and the width of the transmissive portion 86a inside the light-shielding pattern 85a at both ends is set to (w
56 + Δw 56). The width of the other light-shielding pattern 85 is w55, and the width of the transmissive portion 86 is w56. Again, Δ
Let w55 = (0.05 to 0.20) w55 Δw56 = (0.05 to 0.20) w56. As a result, it is possible to prevent an increase in the light intensity of the light-shielding pattern portions at both ends and to eliminate the shortage of the exposure amount of the light-transmitting pattern portions inside the light-shielding pattern 85a at both ends. Can be greatly improved. Further, the occupied width can be suppressed to an extremely small increase as compared with the case where the entire light-shielding pattern width and the width of the transmission part are increased. The size relationship between the width w55 of the light-shielding pattern 85 and the width w56 of the transmissive portion 86 is arbitrary. The present invention is effective even when w55 = w56, whichever is larger. It is not always necessary to make Δw55 and Δw56 equal, and Δw
It is not necessary to make 55 / w55 and Δw56 / w56 equal.

In addition to the above, the present invention can be applied to a reticle having an arbitrary periodic pattern. The number of repetitions of the periodic pattern in the line width direction is arbitrary as long as it is 4 or more, and the length in the direction other than the line width and the number of repetitions may be arbitrary. Further, in the above description, only the dimensions of the transmission patterns at both ends of the periodic pattern, or the dimensions of the light shielding patterns at both ends of the periodic pattern and / or the dimensions of the transmission patterns inside the light shielding patterns at both ends are increased. However, it is also possible to increase the size to one more inner pattern at both ends. The occupying width as a whole of the periodic pattern is slightly increased, but the effect of improving the resolution of the end portion, the prevention of the reduction of the resist thickness, and the improvement of the depth of focus by the prevention of the reduction of the line width are equal to or more than those of the above-mentioned embodiment. Will be achieved.

In the present invention, the pattern size to be increased at both ends is compared with the line-and-space pattern having a line-to-space ratio of 1: 1 under the conditions of the annular illumination oblique incidence projection exposure which was used in the experiment. The obtained dimensional increase coefficient k = 0.05 to 0.20 was applied uniformly.

Therefore, the validity of this point will be touched upon.
When oblique incidence exposure is performed, the deterioration at both ends of the periodic pattern becomes more remarkable as the oblique incidence angle is large and the illumination is performed at a specific oblique incidence angle. Therefore, in the case of annular illumination, the larger the average radius of the annular ring and the narrower the annular width, the more noticeable the deterioration of both ends of the periodic pattern. The ring conditions under which the experiment was performed are such that, when the radius of the projection lens aperture stop is 1, the outer radius of the light source image formed at the aperture stop position is 0.6 and the inner radius is 0.5.
Is the condition. In the current projection exposure apparatus, the standard state is the condition that a circular light source image with a radius of 0.5 to 0.6, which is considered to be the most suitable for use in the shape of the end of the pattern and the cross-sectional shape of the pattern, The outer radius of the annular illumination is close to the upper limit. Further, in order to make the illumination unevenness within the entire exposure area to be ± 1.5% or less, which is a practical illumination unevenness, the above-mentioned annular width is required at a minimum. Therefore, the ring illumination conditions used for the experiment are close to the conditions in which deterioration at both ends of the periodic pattern occurs most significantly when grazing incidence projection exposure is practically used. In case of 4 point light source, 2 point light source, 1 point light source,
In order to obtain practical illumination intensity and illumination uniformity, it is necessary to make the size of the light source large, and the light source size is larger than the annular width, so under such practical illumination conditions, Deterioration at both ends of the periodic pattern is not so remarkable as in the annular illumination condition.

Further, in the method using the filter for adjusting the transmittance at the position of the aperture stop of the projection lens, the deterioration at both ends of the periodic pattern is reduced as compared with the case where the filter is not used. The value of the dimensional increase coefficient k is obtained for a line-and-space pattern having a line-to-space ratio of 1: 1, but the light-shielding pattern or the light-transmitting pattern is larger than the light-transmitting pattern or the light-shielding pattern. In the periodic pattern, the end-to-end degradation for the larger size of the light-shielding pattern or the light-transmitting pattern is reduced compared to the case of the line-and-space pattern having a line-to-space ratio of 1: 1. Therefore, the value of the dimension increase coefficient k is on the safe side from the viewpoint of the dimension ratio of the light-shielding pattern to the transmission pattern of the periodic pattern.

By the way, although the upper limit and the lower limit are set in the appropriate range of the dimensional increase of both ends, the lower limit indicates the condition under which the effect can be easily detected. When both sides of the periodic pattern are less deteriorated and the same size increase factor is used, the deterioration at both ends is improved more than in the case of the annular illumination. The upper limit is
This is a limit set in consideration of the influence from both ends to the inside. That is, if the light-shielding portion has a transmission period pattern and the transmission pattern widths on both sides of this transmission period pattern are excessively widened, the light intensity of the light-shielding pattern portion inside the light-shielding portion increases. In addition, there is a shading period pattern in the transmissive part,
If the light-shielding pattern width at both ends of the light-shielding period pattern is too wide,
This causes a problem that the light intensity of the transmission pattern portion inside thereof is lowered. Furthermore, there is a shading period pattern in the transmissive part,
If the width of the inner transparent pattern portions of the light shielding patterns at both ends is excessively widened, disadvantages such as an increase in the light intensity of the inner light shielding pattern portions occur. The adverse effect of increasing the dimension increase coefficient k is greater when the deterioration of both ends of the periodic pattern due to the original oblique incident illumination projection exposure is remarkable. Therefore, if the size increase coefficient k obtained for the above-mentioned annular illumination condition is used in the case of another oblique incident illumination projection exposure, the adverse effect is smaller, and no problem occurs.

Similarly, there is no problem in using the present invention as a reticle used for conventional normal illumination projection exposure which is not oblique incidence illumination. Although the deterioration of both ends of the periodic pattern is originally small, the application of the present invention can further prevent the deterioration of both ends of the periodic pattern.

Further, according to the present invention, when the pattern size at both ends of the periodic pattern is increased in the range of k = 0.05 to 0.10. Position is (pattern line width) ×
Only (0.025-0.10) moves. In the case of a semiconductor integrated circuit pattern or the like, the alignment accuracy with a pattern already formed on the substrate to be exposed requires about 1/5 or less of the pattern line width. If the size increase amount of the pattern at both ends of the pattern is set to the above range of k = 0.05 to 0.10. It is also possible to apply the present invention only to a reticle having a fine pattern of interest without changing the reticle of the other layer that overlaps. As a matter of course, if the reticles of other overlapping layers are designed in consideration of the positional deviation due to the dimension increase of both end patterns,
It is clear that a value of k larger than 0.10.

The present invention described above is effective for the periodic pattern close to the minimum size obtained by performing the oblique incident illumination projection exposure, so that the projection exposure can be easily performed normally including the patterns at both ends. It is not necessary to apply even to a large periodic pattern. Therefore, when one reticle has various large and small periodic patterns, the present invention may be applied only to patterns having small periods. When the exposure wavelength is λ and the numerical aperture of the projection exposure optical system is NA, the pattern dimension d is converted to the transfer dimension on the substrate to be exposed, and when the periodic pattern is approximately d <0.75λ / NA, Especially effective.

Further, in the case where one reticle has various periodic patterns of different sizes, the dimension for increasing the line width is determined for the periodic pattern having the minimum line width, which is a problem, and the increased dimension is set for other cycles. You may apply uniformly to both ends of a pattern. Since the degree of deterioration at both ends of the periodic pattern decreases as the line width increases, there is no problem even if the dimension increase coefficient k decreases as the line width increases. On the other hand, it is possible to reduce the man-hours for designing the pattern.

[0086]

As described above, according to the exposure original drawing substrate of the present invention, the resolution at both ends of the periodic pattern is improved, the resist thickness is prevented from being reduced, and the line is prevented when the oblique incident illumination projection exposure is performed. The width can be prevented from decreasing. Therefore, the depth of focus for the entire periodic pattern including both ends can be improved. Further, the present invention is particularly effective for a periodic pattern close to the minimum dimension obtained by performing the oblique incident illumination projection exposure, and by increasing only the dimension of both end portions patterns, the periodic pattern close to the minimum dimension in the central portion is obtained. Since the pattern can be used, it is possible to achieve further miniaturization.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of pattern arrangement in a reticle of the present invention.

2A and 2B are diagrams showing calculation results of a light intensity distribution on a wafer in the case of the embodiment of FIG.

FIG. 3 is a diagram showing another embodiment of pattern arrangement in the reticle of the present invention.

4A and 4B are diagrams showing calculation results of a light intensity distribution on a wafer in the case of the embodiment of FIG.

FIG. 5 is a diagram showing yet another embodiment of pattern arrangement in the reticle of the present invention.

6A and 6B are diagrams showing calculation results of a light intensity distribution on a wafer in the case of the embodiment of FIG.

FIG. 7 is a diagram showing an embodiment of pattern arrangement in a reticle for simultaneously carrying out the invention described with reference to FIGS. 3 and 4 and the invention described with reference to FIGS. 5 and 6;

8A and 8B are diagrams showing calculation results of a light intensity distribution on a wafer in the case of the embodiment of FIG.

FIG. 9 is a diagram showing an embodiment of the present invention in the case where the ratio of the light-shielding line pattern width and the transmission space pattern width is not 1: 1.

FIG. 10 is a diagram showing an embodiment of the present invention in the case where the ratio of the light-shielding line pattern width and the transmission space pattern width is not 1: 1.

FIG. 11 is a diagram showing an embodiment of the present invention in the case where the ratio of the light-shielding line pattern width and the transmission space pattern width is not 1: 1.

FIG. 12 is a diagram showing an embodiment of the present invention in the case where the ratio between the light-shielding line pattern width and the transmission space pattern width is not 1: 1.

FIG. 13 is a diagram showing an embodiment of the present invention for a periodic pattern having a change in line width in the longitudinal direction.

FIG. 14 is a diagram showing an embodiment of the present invention for a periodic pattern having a change in line width in the longitudinal direction.

FIG. 15 is a diagram showing an embodiment of the present invention for a periodic pattern having a change in line width in the longitudinal direction.

FIG. 16 is a diagram showing an embodiment of the present invention for a periodic pattern having a change in line width in the longitudinal direction.

FIG. 17 is a diagram showing an example of the present invention with respect to a periodic pattern bent in a chevron shape.

FIG. 18 is a diagram showing an example of the present invention with respect to a periodic pattern bent in a chevron shape.

FIG. 19 is a diagram showing an example of the present invention for a periodic pattern bent in a chevron shape.

FIG. 20 is a diagram showing an example of the present invention with respect to a periodic pattern bent in a chevron shape.

FIG. 21 is a diagram showing an example of the present invention in the case of a periodic pattern in which two types of bent patterns are combined.

FIG. 22 is a diagram showing an embodiment of the present invention in the case of a periodic pattern in which two types of bent patterns are combined.

FIG. 23 is a diagram showing an embodiment of the present invention in the case of a periodic pattern in which two types of bent patterns are combined.

FIG. 24 is a diagram showing an example of the present invention in the case of a periodic pattern in which two types of bent patterns are combined.

FIG. 25 is a diagram showing an embodiment of the present invention in the case of a periodic pattern in which another two types of patterns are combined.

FIG. 26 is a diagram showing an embodiment of the present invention in the case of a periodic pattern in which another two types of patterns are combined.

FIG. 27 is a diagram showing an example of the present invention in the case of a periodic pattern in which another two types of patterns are combined.

FIG. 28 is a diagram showing an embodiment of the present invention in the case of a periodic pattern in which another two types of patterns are combined.

FIG. 29 is a view showing an example of the present invention regarding a hole-shaped periodic transmission pattern.

FIG. 30 is a diagram showing an embodiment of the present invention for a rectangular or square periodic pattern.

FIG. 31 is a diagram showing an embodiment of the present invention for a rectangular or square periodic pattern.

FIG. 32 is a diagram showing an embodiment of the present invention for a rectangular or square periodic pattern.

FIG. 33 is a diagram showing a projection exposure optical system of a conventional projection exposure apparatus.

FIG. 34 is a diagram showing an example of a basic periodic pattern on a reticle used in the case of conventional normal illumination.

FIG. 35 is a diagram showing an example of a basic periodic pattern on a reticle used in the case of conventional normal illumination.

FIGS. 36 (a) and 36 (b) are diagrams showing the conventional normal exposure light intensity distributions for 12 lined space-type line-and-space patterns having a line width of 0.35 μm on the substrate to be exposed. . It is a figure which compared the difference of a light intensity distribution between a circular illumination and grazing incidence projection exposure.

FIGS. 37 (a) and 37 (b) are light intensity distributions of conventional annular illumination oblique incidence projection exposure for 12 space type line-and-space patterns having a line width of 0.35 μm arranged on the substrate to be exposed. FIG.

38A and 38B are diagrams showing light intensity distributions of conventional normal exposure with respect to twelve space type line-and-space patterns having a line width of 0.35 μm arranged on the substrate to be exposed. .

FIGS. 39 (a) and 39 (b) are light intensity distributions of conventional annular illumination oblique incidence projection exposure with respect to 12 space type line-and-space patterns having a line width of 0.35 μm arranged on the substrate to be exposed. FIG.

40 is a pattern in which the resist remains and causes non-resolution when an experiment for actually transferring a pattern using a positive resist is performed under the exposure condition whose light intensity distribution is shown in FIG. It is the figure shown by the trace of a cross section.

41 is a pattern in which the resist remains and causes non-resolution when an experiment for actually transferring a pattern using a positive resist is performed under the exposure condition whose light intensity distribution is shown in FIG. 37. It is the figure shown by the trace of a section.

FIG. 42 shows an example in which the light intensity distribution is shown in FIG. 38. When a pattern is actually transferred using a positive resist, the resist remains and non-resolution occurs, or the resist thickness decreases. FIG. 7 is a diagram showing how the pattern is formed by tracing a cross section of the formed pattern.

FIG. 43 shows an example of the light intensity distribution shown in FIG. 39. When a pattern is actually transferred using a positive resist, the resist remains to cause non-resolution, and the resist thickness decreases. FIG. 7 is a diagram showing how the pattern is formed by tracing a cross section of the formed pattern.

[Explanation of symbols]

 1 Mercury Lamp 2 Elliptical Concave Mirror 3 Collimator Lens 5 Fly's Eye Lens 6 First Reflecting Mirror 8 Condensing Lens System 9 Reticle 11 Projection Lens 12 Wafer 13 Aperture Aperture 20 Light-Shielding Part 21 Transmission Space Pattern 23 Transmission Part 24 Light-shielding Line Pattern 25 Transmission Space Pattern 28 Reticle 30 Original substrate 31 Light-shielding part 32 Light-shielding line pattern 33 Transparent space pattern 34 Light-shielding line pattern 35 Transparent part 36 Transparent space pattern 40 Transparent pattern 41 Light-shielding pattern 45 Light-shielding pattern 46 Transparent pattern 50 Transparent pattern 51 Light-shielding pattern 55 Light-shielding pattern 56 Transmission pattern 60 Transmission pattern 61 Transmission pattern 62 Light-shielding portion 65 Light-shielding pattern 66 Light-shielding pattern 67 Transmission portion 70 Transmission pattern 71 Transmission pattern 72a Light-shielding portion 80 Transmission pattern 81 Light-shielding portion 85 Light-shielding pattern 86 Transparent part

Claims (6)

[Claims] 1. A master pattern for exposure used for forming a latent image of a fine pattern such as a semiconductor integrated circuit on a master substrate by projection exposure and transfer onto a photosensitive material formed on a substrate to be exposed. In the substrate, the exposure original drawing substrate is characterized in that the pattern width is made larger than the pattern widths of the other parts in the periodic fine pattern only at both ends or near both ends of the periodic fine pattern existing on the original drawing substrate. . 2. The exposure original drawing substrate according to claim 1, wherein the exposure original drawing substrate is used when performing projection exposure with oblique incidence illumination. 3. The exposure original drawing substrate according to claim 1, wherein a periodic pattern formed of a transmission pattern is present in the light-shielding portion of the original substrate, and the transmission pattern width at least at both ends of the periodic transmission pattern is: An exposure original drawing substrate, which is formed to be wider than the width of other transmission patterns in the periodic pattern. 4. The exposure original drawing substrate according to claim 1, wherein a periodic pattern made of a light shielding pattern is present in a transmissive portion of the original substrate, and at least inside the light shielding patterns at both ends of the periodic light shielding pattern. The exposure original drawing substrate, wherein the width of the existing transmissive portion is formed larger than the width of the other transmissive portions between the light shielding patterns in the periodic pattern. 5. The exposure original drawing substrate according to claim 1, wherein a periodic pattern made of a light shielding pattern is present in a transmitting portion of the original substrate, and a light shielding pattern width at least at both ends of the periodic light shielding pattern is: An exposure original drawing substrate, which is formed to be wider than the width of other light-shielding patterns in the periodic pattern. 6. The exposure original drawing substrate according to claim 1, wherein a periodic pattern made of a light shielding pattern is present in a transmissive portion of the original substrate, and a light shielding pattern width at least at both ends of the periodic light shielding pattern is: The width of the other light-shielding patterns in the periodic pattern is formed to be larger, and the width of the transmissive portions inside the light-shielding patterns at the both ends is formed to be larger than the width of the other transmissive portions between the light-shielding patterns in the periodic pattern. An original substrate for exposure, which is characterized in that