JPH06181167A - Image forming method, fabrication of device employing the method, and photomask employed therein - Google Patents

Abstract

PURPOSE:To enhance resolution by reducing coherence between lumious fluxes emitted from bright parts neighboring through a dark part. CONSTITUTION:Fine slits 21, 23, 25 are provided, respectively, with polarization membranes 121, 123, 125 so that linearly polarized lights having identical polarization direction are projected through the group A fine slits 21, 23, 25. On the other hand, group B fine slits 22, 24 are provided with polarization membranes 122, 124 so that linearly polarized lights having identical polarization direction and crossing perpendicularly with the polarization direction of dirrfacted light projected through the group A fine slit applied with polarization membrane are projected through the group B slits 22, 24. Consequently, neighboring diffracted lights from groups A and B do not interfere each other although they are partially overlapped on an image plane and a series of fine slit 21-25 images of an object is formed at high contrast on the image plane.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an image forming method and a method of manufacturing a semiconductor device using the method.

[0002]

2. Description of the Related Art Higher integration of semiconductor devices such as ICs and LSIs is accelerating more and more, and accompanying this, the progress of fine processing technology of semiconductor wafers is remarkable. The projection exposure technique, which is the center of this fine processing technique, is currently being improved in resolution in order to form an image of a size of 0.5 micron or less.

In order to improve the resolution, there are a method of increasing the numerical aperture (NA) of the projection lens system and a method of shortening the wavelength of the exposure light, but both methods have limitations,
New resolution enhancement methods are needed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming method exhibiting high resolution, a method of manufacturing a device using the method, and a photomask used in the method.

The image forming method of the present invention for achieving the above object is a method for forming an image of a fine pattern, in which coherence between light beams from adjacent bright portions via dark portions is reduced. It has a feature.

The device manufacturing method of the present invention for achieving the above object is a semiconductor device manufacturing method including a step of projecting an image of a fine pattern on a wafer, wherein the light fluxes from the bright portions adjacent to each other through the dark portion are separated from each other. It is characterized by reducing the coherence of.

The photomask of the present invention for achieving the above object is characterized in that it has means for reducing the coherence between the radiation beams from the adjacent bright portions via the dark portions.

In the present invention, the light portion is formed by a light transmitting portion and the dark portion is formed by a light shielding portion (reflection, absorption) like a transmission type mask, and the light portion is formed by a light reflecting portion such as a reflection type mask. There is a form in which the dark part is configured by a light shielding part (transmission, absorption).

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG.
Imaging of a fine pattern will be described with reference to (A) to (C). As shown in FIG. 1 (A), five fine slits 1
The rows 1 to 15 are illuminated with the illumination light 10, and the diffracted light generated in the rows of the fine slits 11 to 15 is incident on the pupil of the projection lens system (not shown). An image of the rows of the fine slits 11 to 15 is formed on. The projection lens system is an aplanatic lens with a numerical aperture of 0.55, the illumination light 10 is coherent illumination, and the illumination light 10 is i-line (wavelength 365 nm), and the image intensity distribution of the fine slit array on the image plane of the projection lens system. And the line width of the fine slits 11 to 15 is 0.5.
The period of the rows of micron and fine slits 11 to 15 is 1.0
The image intensity distribution of the fine slit array on the image plane of the projection lens system at the time of micron shows a high contrast as shown in FIG. 1 (B), but the line width of the fine slits 11 to 15 is 0.3 μm. The intensity distribution of the image of the rows of the fine slits 11 to 15 on the image plane of the projection lens system when the row of the fine slits 11 to 15 has a period of 0.6 μm is shown in FIG.
Shows a low contrast. As described above, when the line width or array period of the fine slits 11 to 15 becomes small, the contrast of the fine slit distribution on the image plane becomes low, because the diffraction angle of the high-order diffracted light from the rows of the fine slits 11 to 15 is small. This is because the higher order diffracted light does not enter the pupil of the projection lens system as it becomes larger. The present invention makes high-order diffracted light incident on the pupil of the projection lens system by making the diffracted light from the adjacent fine slits among the diffracted light from the rows of the fine slits 11 to 15 mutually incoherent.

Next, an embodiment of the image projection method of the present invention will be described with reference to FIGS. 2 (A), (B)
2A shows an object provided with fine slits (for example, an original plate for manufacturing a semiconductor device), and the row of fine slits in FIG. 2A is an odd number among the rows of fine slits 11 to 15 in FIG. Of the fine slits 11 to 15 and the even numbered slits 12 and 14 of the fine slits 11 to 15 are left.
2 (B), the row of fine slits of FIG. 2 (B) leaves even-numbered slits 12 and 14 among the fine slits 11 to 15 of FIG. 1 (A), and the fine slits of FIG. 1 (A). Odd numbered slits 11, 13, 1 of 11-15
5 is eliminated, and the cycle of each row of fine slits in FIGS. 2A and 2B is twice the cycle of the row of fine slits in FIG. 1A. Therefore, when the rows of the fine slits of FIGS. 2A and 2B are combined with each other, the row of the fine slits of FIG. 1A is obtained.

Consider that the array of fine slits shown in FIGS. 2A and 2B is imaged by a projection lens system. Similar to the simulation described above, the projection lens system is an aplanatic lens having a numerical aperture of 0.55, the illumination is coherent illumination, and the illumination light is an i-line, and the intensity distribution of the image of each row of fine slits on the image plane of the projection lens system. The projection lens when the line widths of the fine slits 11 to 15 are 0.3 μm, and the periods of the fine slit lines 11, 13 and 15 and the fine slit lines 12 and 14 are 1.2 μm. The intensity distributions of the images of the rows of fine slits in FIGS. 2A and 2B on the image plane of the system are as shown in FIGS. 2C and 2D, respectively.

Therefore, if the images of the rows of fine slits shown in FIGS. 2A and 2B are superposed without interfering with each other, the intensity distribution shown in FIG. It is possible to form an image corresponding to a row of fine slits of 3 microns and a period of 0.6 microns.

In this embodiment, by improving an object having a row of fine slits as shown in FIG. 1 (A),
An image having an intensity distribution as shown in FIG. 2E is formed. FIG. 2F shows an object including rows of fine slits 21 to 25 and rows of polarizing films 121 to 125 formed for the respective slits, and each of the fine slits 21 to 25 drawn in a blank portion. Represents a light transmitting part of an object such as an original plate, and each part drawn by a dark part represents a light shielding part of this object.
Here, the fine slits 21 and 2 which are odd-numbered from the right end
3, 25 are group A, and even fine slits 22, 24 from the right end are group B. The A group is in the row of fine slits in FIG. 2A, and the B group is in FIG.
This corresponds to the row of fine slits in (B).

In FIG. 2F, the diffracted lights emitted from the fine slits 21, 23, 25 of the A group become linearly polarized lights whose polarization directions match each other (for example, lights polarized in a direction orthogonal to the paper surface). So that the fine slit 2
Polarizing films 121, 123, and 125 are attached to each of 1, 23, and 25.
Is added. That is, the fine slits 21, 23, 25
Polarizing films 121, 123, 125 having the same polarization direction as each other.
Is provided. On the other hand, the fine slits 22 of the B group,
The respective diffracted lights emitted from 24 have the same polarization direction and are linearly polarized light polarized in a direction orthogonal to the polarization direction of the diffracted light from the fine slits of the A group + the portion of the polarizing film (for example, parallel to the paper surface). The polarizing films 122 and 124 are added to the fine slits 22 and 24, respectively. That is, the polarization films 122 and 124 having the same polarization direction are provided in the fine slits 22 and 24. The diffracted light emitted from the fine slits 21, 23, 25 of the A group and the diffracted light emitted from the fine slits 22, 24 of the B group are mutually incoherent light because their polarization directions are orthogonal to each other. , A and B, adjacent diffracted lights partially overlap with each other on the image plane but do not interfere with each other, and the arrangement intervals of the fine slits of A and B groups are the same as those of the fine slits 21 to 25. When the array period is doubled, the high-order diffracted light from each group enters the pupil of the projection lens system. Therefore, from FIG.
Similarly to the case described using (E), the image of the row of the minute slits 21 to 25 of the object can be formed on the image surface with high contrast.

FIG. 3 is a schematic view showing a reduced projection exposure apparatus for manufacturing a semiconductor device. In FIG. 3, reference numeral 301 is a light source unit including an ultra-high pressure mercury lamp, 302 is an optical integrator including a fly-eye lens, 303 is an illumination lens system,
304 is a reticle on which a circuit pattern including a grid pattern is formed, 305 is a reduced projection lens system with a magnification of 1/5 or 1/10, 306 is a semiconductor wafer, 307 is a stage on which the wafer 306 is placed and moves, 308 Indicates an aperture stop.

The exposure light emitted from the light source section 301 is an integrator 302, an aperture stop 308, and an illumination lens system 303.
The reticle 304 is illuminated via. The diffracted light from the circuit pattern of the reticle 304 enters the pupil of the projection lens system 305, and the diffracted light that passes through the projection lens system 305 causes
An image of the circuit pattern is projected on the wafer 308 placed on the stage 307. The position of the aperture stop 308 placed close to the light exit surface of the integrator 302 and the pupil of the projection lens system 305 are in an optically conjugate relationship, and the aperture of the aperture stop 308 prevents the light from the integrator 302 from being emitted. Only the portion of the reticle 304 suitable for image formation is selected, and the illumination lens system 303
And is used for projection exposure.

A resist (photosensitive material) is coated on the wafer 306, and the resist on the wafer 306 is exposed by the circuit pattern image, and the circuit pattern is transferred to the wafer 306.

The reticle 304 and the wafer 306 are aligned in a predetermined relationship by moving a stage 307 on which the wafer 306 is placed. Wafer 30
When the exposure of the first area (shot area) of 6 is completed,
By moving the stage 307, the wafer 306 is moved in the horizontal direction by a predetermined amount, and the second wafer 306 is moved there.
The area (shot area) is exposed (step-and-repeat exposure).

The lattice pattern portion of the reticle 304 has the structure shown in FIG. 2 (F). The reticle 304 has a row of fine slits 21 to 25 having a line width of several microns and a polarizing film provided for each fine slit. Equipped with. FIG. 4A is a plan view of the reticle 304 seen from the light source section 301 side.
An example of the polarization direction of each polarization film (not shown) is shown in FIG.
This is indicated by an arrow in (C). The polarization directions of the polarizing film for the rows of fine slits 21, 23, 25 and the polarizing film for the rows of fine slits 22, 24 of the reticle 304 are the polarization directions of the light from the rows of the fine slits 21, 23, 25. Since it suffices that the polarization directions of the light from the rows of the fine slits 22 and 24 are orthogonal to each other, it is possible to set other than the configurations shown in FIGS. 4B and 4C.

Since the lattice pattern portion of the reticle 304 has the structure shown in FIG. 2F, diffraction from the adjacent fine slits of the lattice pattern of the reticle 304 is performed as described with reference to FIG. Since the lights become incoherent with each other, a high-contrast lattice-shaped pattern image can be formed on the wafer 306.

FIG. 5 shows a state in which two types of fine slit rows (51 to 55 and 56-59) in which the longitudinal directions of the fine slits are orthogonal to each other are provided on the reticle 304, which was used in this embodiment. The method can be applied to a reticle having a plurality of fine slit rows in which the longitudinal directions of the fine slits are different from each other, and has an excellent advantage that the resolution can be improved regardless of the directionality of the fine slits on the reticle. There is. Therefore, the method used in this example is
As shown in FIG. 6, a reticle 30 having vertical and horizontal fine slit rows 30, 31 and diagonal fine slit rows 32, 33.
It can also be applied to 4. When using the aperture stop 308 shown in FIG. 7 and projecting the image of the pattern of the reticle 304 of FIG. 6, a polarizing film is added to all of the fine slit rows 30, 31, 32, 33 of the reticle 304. Alternatively, the polarizing film may be added only to the diagonal fine slit rows 32 and 33. Incidentally, in FIG. 7, the blank portions 71 to 74
Is a circular aperture, and the shaded portion is a light shielding portion. By using the aperture stop of FIG. 7, the reticle 304 can be obliquely illuminated from four directions by the four light fluxes from the circular apertures 71 to 74.

In the apparatus of FIG. 3, an ultraviolet laser such as a KrF excimer laser may be used as the light source of the light source section 301.

The apparatus shown in FIG. 3 is an apparatus for performing projection exposure with a projection lens system, but the present invention can be applied to an apparatus for performing projection exposure with a projection mirror system and an apparatus for performing projection exposure with a projection mirror and lens system.

FIG. 8 is a diagram showing another example of the photomask of the present invention. The photomask of this embodiment has openings 810 to 810.
A periodic pattern A composed of 830 and a periodic pattern B composed of openings 811 to 815 are provided. Further, the phase shift method is applied to each of the periodic pattern A and the periodic pattern B, and hatched portions 810 and 830 in FIG.
And 811, 813, and 815 have a phase of transmitted light of 180
A phase shifter that changes the degree is attached. Then, in the present embodiment, a polarizing device 821 that converts non-polarized light that enters the periodic pattern A into a linearly polarized state, and a polarizing device 8 that converts light that enters the periodic pattern B into a linearly polarized state.
22 is attached. Here, the polarization devices 821 and 8
A polarizing plate or the like is used for 22, and the polarization direction of light transmitted through both is the direction of each arrow in FIG. However, these polarization directions do not necessarily have to be the directions shown by the arrows, and may be orthogonal to each other.

FIG. 9 is a sectional view of a portion indicated by a chain line 825 in FIG. Reference numerals 831, 832, and 833 in FIG. 9 denote phase shifters attached to the openings 811, 813, and 815, respectively.

The effect of attaching the polarization devices 821 and 822 will be described. If exposure is performed without attaching 821 and 822, accurate pattern transfer cannot be performed. The reason is that the light transmitted through the opening 830 and the opening 81
This is because the coherence of light transmitted through 1 to 815 is high.

However, in this embodiment, the light transmitted through the periodic pattern A is linearly polarized light polarized in the arrow direction,
By making the light passing through the periodic pattern B linearly polarized light polarized in the arrow direction, the light passing through the periodic pattern A and the light passing through the periodic pattern B do not interfere with each other. Therefore, the periodic pattern A and the periodic pattern B are formed on the image plane.
At the boundary of, the pattern (image) is not deformed by the light interference, and as shown in FIG. 10, a light intensity distribution that almost faithfully reproduces the pattern on the photomask on the image plane can be obtained.

Although the exposure method / apparatus using the photomask shown in FIG. 8 is not particularly mentioned in this embodiment, the exposure method / apparatus shown in FIG.
The photomask can also be used for any exposure method such as reduction / magnification / enlargement projection exposure and contact exposure.

In the present embodiment, the case where two periodic patterns are present close to each other as a pattern on the photomask has been described, but various pattern shapes other than the above,
And applicable to pattern arrangement. This is true not only when the phase shift method is applied to the pattern on the photomask of this embodiment, but also when the polarization devices 821 and 822 are applied to the normal pattern to which the phase shift method is not applied. .

In the present embodiment, description has been made assuming a polarizing plate as the polarizing device. However, other polarizing devices having the ability to convert incident light into a substantially linearly polarized state, for example, It may be a special diffraction grating or the like.

In order to suppress image deformation due to optical interference,
It is known that a method of shifting the phase of light passing through adjacent patterns by about 90 degrees is effective. Therefore, in the next embodiment, a method in which the present invention is applied to a more complicated pattern by using the method together will be described.

In this embodiment, the pattern on the photomask shown in FIG. 11 is considered. 841-84 in the figure
4, 851 to 853 and 861 to 864 are openings. FIG. 12 shows the intensity distribution of light formed on the image plane when the photomask of FIG. 11 is illuminated with light having high coherence. FIG. 12 shows the same light intensity distribution as in FIG. 10 in contour lines. From Figure 12, even where the light intensity should be zero,
It can be seen that the effect of interference is such that the light intensity does not become zero and the image contrast deteriorates. With respect to the pattern of the photomask of FIG. 11, openings 841 to 844, 851 to 853,
A description will be given of the configuration of the photomask in which the light transmitted through each of 861 to 864 does not interfere with the adjacent portions.

First, considering the four openings 841 to 844, if the phases of the light transmitted therethrough are alternately different by 90 degrees, the light transmitted through the adjacent portions of the openings 841 to 844 interfere with each other. Will not do. Opening 85
1 to 853 and openings 861 to 864 can be similarly performed. Next, the openings 841 to 844 and the openings 851 to 853, or the 851 to 853 and the openings 861 to 861.
In order to prevent transmitted lights from interfering with each other in the adjacent portions between 864, the present invention is applied and the openings 841 to
It suffices that the polarization directions of the light transmitted through the 844, the openings 851 to 853, and the openings 861 to 864 are adjacent to each other and orthogonal to each other.

FIG. 13 shows an example of the structure of a photomask which satisfies all the above conditions. Opening 8 indicated by diagonal lines in the figure
41, 843, 851, 853, 861, 863,
A phase object is attached that changes the phase of the transmitted light by 90 degrees. Further, reference numerals 870, 871 and 872 denote polarizing devices such as polarizing plates, which function to convert incident light into linearly polarized light having a polarization plane in the direction shown by the arrow.

FIG. 14 shows a light intensity distribution on the image plane formed by using the photomask shown in FIG. In this case, the influence of the interference of the light transmitted through the adjacent openings is suppressed, and the openings 841 to 844, 851 to 853 of the pattern,
The images of 861 to 864 are almost faithfully reproduced.

Although no particular reference was made to the exposure method using the photomask of this embodiment, any exposure method such as reduction / magnification / enlargement projection exposure and contact exposure can be applied.

In the present embodiment, description has been made assuming a polarizing plate as the polarizing device. However, other polarizing devices having the ability to convert incident light into a substantially linearly polarized state, for example, It may be a special diffraction grating or the like.

In the embodiment described above, the polarizing plate is used to make the polarization directions of the light beams from the adjacent openings orthogonal to each other. However, for example, linearly polarized light such as laser light is used as the light for illuminating the photomask or reticle. A member having an optical property of making 90 ° the polarization direction of the linearly polarized light line to one of the adjacent openings by using light, for example, a λ / 2 plate made of an electro-optical crystal such as quartz or another film. The polarization directions of the light illuminating one of the adjacent openings and the light illuminating the other are orthogonal to each other (for example, the polarizing plate or λ /
The object of the present invention can be achieved even if the two plates are distributed.

Next, an embodiment of a method of manufacturing a semiconductor device using the projection exposure apparatus of FIG. 3 and the above-mentioned various photomasks or reticles 304 will be described. FIG. 15 shows a semiconductor device (I
A manufacturing flow of a semiconductor chip such as C and LSI, a liquid crystal panel and a CCD) will be shown. In step 1 (circuit design), the circuit of the semiconductor device is designed. In step 2 (mask fabrication), a mask (reticle 3
04) is produced. On the other hand, step 3 (wafer manufacturing)
Then, a wafer (wafer 30
6) is manufactured. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by the lithography technique using the mask and the wafer prepared above. The next step 5 (assembly) is called a post-process, which is a process of making chips by using the wafer prepared in step 4, and includes an assembly process (dicing, bonding), a packaging process (chip encapsulation) and the like. Including. In step 6 (inspection), the semiconductor device manufactured in step 5 undergoes inspections such as an operation confirmation test and a durability test. Through these steps, the semiconductor device is completed and shipped (step 7).

FIG. 16 shows the detailed flow of the wafer process. In step 11 (oxidation), the surface of the wafer (wafer 306) is oxidized. Step 12 (CV
In D), an insulating film is formed on the surface of the wafer. In step 13 (electrode formation), electrodes are formed on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted in the wafer. Step 15 (resist processing)
Then, a resist (photosensitive material) is applied to the wafer. In step 16 (exposure), the projection exposure apparatus exposes the wafer with an image of the circuit pattern of the mask (reticle 304). In step 17 (development), the exposed wafer is developed. In step 18 (etching), parts other than the developed resist are scraped off. In step 19 (resist stripping), the resist that is no longer needed after etching is removed. By repeating these steps, a circuit pattern is formed on the wafer.

By using the manufacturing method of this embodiment, it becomes possible to manufacture a highly integrated semiconductor device, which has been difficult in the past.

[0042]

As described above, according to the present invention, the coherence between the light beams from the adjacent bright portions through the dark portion is reduced, so that the interference between the adjacent bright portion images partially overlapping on the image plane is prevented. A fine pattern image can be formed with high contrast without being generated.

[Brief description of drawings]

FIG. 1 is an explanatory diagram related to image formation of a fine pattern,
(A) shows an array of fine slits, (B) shows a light intensity distribution on the image plane when a fine slit array having a line width of 0.5 microns and a period of 1.0 micron is imaged, (C).
Indicates a light intensity distribution on the image plane when a fine slit array having a line width of 0.3 micron and a period of 0.6 micron is imaged.

FIG. 2 is an explanatory view showing an embodiment of the present invention, (A)
And (B) show a state in which one fine slit row is decomposed into a pair of fine slit rows having a double period, and (C) shows the light intensity on the image plane when the fine slit row of (A) is imaged. Shows the distribution, (D) shows the light intensity distribution on the image plane when the fine slit array of (B) is imaged, and (E) shows the light intensity distribution of (C) and the light intensity distribution of (D). Shows the distribution of
(F) shows a fine slit array provided with a polarizing film that produces the light intensity distribution of (E) on the image plane.

FIG. 3 is a diagram showing a reduction projection exposure apparatus for manufacturing a semiconductor device.

4A and 4B are explanatory views showing a reticle applied to the exposure apparatus of FIG. 3, in which FIG. 4A is a plan view, and FIGS. 4B and 4C respectively show polarization directions of a polarizing film attached to each slit of a slit row. An example is shown.

FIG. 5 is a plan view showing a reticle including both vertical and horizontal slit rows.

FIG. 6 is a plan view showing a reticle including vertical, horizontal, and diagonal slit rows.

FIG. 7 is a diagram showing an example of an aperture of an aperture stop of an illumination system of an exposure apparatus.

FIG. 8 is a diagram showing another example of the photomask of the present invention.

9 is a cross-sectional view of the photomask of FIG.

10 is a diagram showing an intensity distribution of an image by exposure through the photomask of FIG.

FIG. 11 is an explanatory diagram showing an example of a pattern configuration of a photomask.

FIG. 12 is a diagram showing an intensity distribution of an image by exposure through the photomask of FIG.

13 is a diagram showing an example in which the present invention is applied to the photomask of FIG.

FIG. 14 is a diagram showing an intensity distribution of an image by exposure through the photomask of FIG.

FIG. 15 is a flowchart showing manufacturing steps of a semiconductor device.

16 is a flow chart diagram showing details of a wafer process during the process of FIG.

[Explanation of symbols]

21, 22, 23, 24, 25 Fine slits 121, 122, 123, 124, 125, 821, 8
22 Polarizing film A, B Periodic pattern

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location 7352-4M H01L 21/30 311 W

Claims (13)

[Claims] 1. A method of forming an image of a fine pattern, which reduces coherence between light beams from adjacent bright portions via dark portions. 2. The light fluxes from the respective bright portions are made incoherent with each other by making the polarization planes of the light fluxes from the adjacent bright portions orthogonal to each other.
Image formation method. 3. The image forming method according to claim 1, wherein the bright portion is a light transmitting portion and the dark portion is a light shielding portion. 4. The image forming method according to claim 1, wherein the bright portion comprises a light reflecting portion and the dark portion comprises a light shielding portion. 5. A device manufacturing method including a step of projecting an image of a fine pattern onto a wafer, wherein coherence between light fluxes from adjacent bright portions via dark portions is reduced. Production method. 6. The light fluxes from the respective bright portions are made incoherent with each other by making the polarization planes of the light fluxes from the adjacent bright portions orthogonal to each other.
Device manufacturing method. 7. The method of manufacturing a device according to claim 5, wherein the bright portion is a light transmitting portion and the dark portion is a light shielding portion. 8. The device method according to claim 5, wherein the bright portion is constituted by a light reflecting portion, and the dark portion is constituted by a light shielding portion. 9. A photomask provided with a means for reducing coherence between radiation beams from adjacent bright portions via a dark portion. 10. The photomask according to claim 9, wherein the bright portion is a light transmitting portion and the dark portion is a light shielding portion. 11. The photomask according to claim 9, wherein the bright portion is a light reflecting portion and the dark portion is a light shielding portion. 12. The coherent means comprises a polarizing means provided on at least one of the adjacent bright portions so that the polarization direction of the radiation beam from one of the adjacent bright portions is orthogonal to the polarization direction of the radiation beam from the other. The photomask according to claim 9. 13. The second polarized light, wherein the polarizing means determines a polarization direction orthogonal to the first polarizing means provided on one of the adjacent bright portions and the first polarizing film provided on the other of the adjacent bright portions. The photomask according to claim 13, further comprising a film.