JP7336922B2 - Exposure apparatus and article manufacturing method - Google Patents

Description

The present invention relates to an exposure apparatus and an article manufacturing method.

2. Description of the Related Art Conventionally, an exposure apparatus has been used in which an original (reticle or mask) is illuminated by an illumination optical system and a pattern of the original is projected onto a substrate (wafer) via a projection optical system. With the miniaturization of semiconductor devices, exposure apparatuses are required to achieve high resolution. In order to achieve high resolution, it is necessary to shorten the wavelength of the exposure light, increase the numerical aperture (NA) of the projection optical system (high NA), and deformed illumination (annular illumination, dipole illumination, quadrupole illumination, etc.). ) is valid.

On the other hand, along with the recent increase in the number of layers in the device structure, the exposure apparatus is also required to improve the overlay accuracy. Japanese Patent Application Laid-Open No. 2002-100001 discloses a light shielding portion arranged at a position defocused from a conjugate plane of an illumination target surface of an exposure apparatus toward the light source side, and a light shielding section arranged at a position defocused from the conjugate plane of the illumination target surface toward the illumination target surface side. An exposure apparatus having a light blocking portion is disclosed. The exposure apparatus disclosed in Patent Document 1 is effective in improving overlay accuracy.

JP 2010-73835 A

However, in the exposure apparatus disclosed in Japanese Patent Application Laid-Open No. 2002-200011, the illuminance is lowered by the light shielding portion, and asymmetry (XY asymmetry) of the integrated effective light source occurs. If a large asymmetry occurs in the integrated effective light source, for example, when a line-and-space pattern having the same line width in the vertical direction and the horizontal direction is transferred to a substrate, line-and-space patterns may be generated between the vertical pattern and the horizontal pattern. Width difference occurs.

SUMMARY OF THE INVENTION It is an exemplary object of the present invention to provide an exposure apparatus that is advantageous in suppressing a decrease in illuminance on a surface to be illuminated and occurrence of asymmetry in integrated effective light sources. do.

To achieve the above object, an exposure apparatus as one aspect of the present invention is an exposure apparatus that exposes an original and a substrate while moving the substrate in a scanning direction, wherein the original is covered with light from a light source. an illumination optical system for illuminating an illumination surface, the illumination optical system including: a first light shielding unit arranged at a position away from a conjugate surface of the illumination target surface toward the light source; a second light shielding part arranged at a position away from the surface side; and a masking part arranged between the first light shielding part and the second light shielding part and defining an illumination range of the illuminated surface. , a first distance between the conjugate surface and the first light shielding portion in the direction along the optical axis of the illumination optical system, and a distance between the conjugate surface and the second light shielding portion in the direction along the optical axis; The sum of the second distance between the It is characterized by

Further objects or other aspects of the present invention will be made clear by the embodiments described below with reference to the accompanying drawings.

According to the present invention, for example, it is possible to provide an exposure apparatus that is advantageous in suppressing a decrease in illuminance on a surface to be illuminated and occurrence of asymmetry in integrated effective light sources.

1 is a schematic cross-sectional view showing the configuration of an exposure apparatus as one aspect of the present invention; FIG. FIG. 4 is a diagram for explaining details of a first light shielding unit, a masking unit, and a second light shielding unit; FIG. 4 is a diagram for explaining an integrated effective light source; FIG. It is a figure for demonstrating the function of a 1st light-shielding part and a 2nd light-shielding part. FIG. 4 is a diagram for explaining a configuration for reducing XY asymmetry of integrated effective light sources; It is a figure for demonstrating the specific numerical example regarding a 1st light-shielding part and a 2nd light-shielding part. It is a figure for demonstrating the specific numerical example regarding a 1st light-shielding part and a 2nd light-shielding part.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. In addition, the following embodiments do not limit the invention according to the scope of claims. Although multiple features are described in the embodiments, not all of these multiple features are essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same or similar configurations are denoted by the same reference numerals, and redundant description is omitted.

FIG. 1 is a schematic cross-sectional view showing the configuration of an exposure apparatus 100 as one aspect of the present invention. The exposure apparatus 100 is a step-and-scan type exposure apparatus (scanner) that exposes the substrate 27 while moving the original 25 and the substrate 27 in the scanning direction (scanning exposure) and transfers the pattern of the original 25 onto the substrate. ). The exposure apparatus 100 includes an illumination optical system 110 that illuminates the original 25 (reticle or mask) with light from the light source 1, a projection optical system 26 that projects the pattern of the original 25 onto a substrate 27 (wafer, glass plate, etc.), have

The light source 1 includes a mercury lamp with a wavelength of about 365 nm, a KrF excimer laser with a wavelength of about 248 nm, an excimer laser such as an ArF excimer laser with a wavelength of about 193 nm, or the like, and emits a light flux (exposure light) for illuminating the original 25 .

Illumination optical system 110 includes routing optical system 2 , exit angle preserving optical element 5 , diffractive optical element 6 , condenser lens 7 , light blocking member 8 , prism unit 10 and zoom lens unit 11 . The illumination optical system 110 includes an optical integrator 12, a diaphragm 13, a condenser lens 14, a first light shielding section 18, a second light shielding section 20, a masking unit 19, a condenser lens 21, and a collimator lens 23. including.

The guiding optical system 2 is provided between the light source 1 and the emission angle preserving optical element 5 and guides the light flux from the light source 1 to the emission angle preserving optical element 5 . The emission angle preserving optical element 5 is provided on the light source side of the diffractive optical element 6, and guides the luminous flux from the light source 1 to the diffractive optical element 6 while maintaining a constant divergence angle. The exit angle preserving optical element 5 includes an optical integrator such as a fly-eye lens, a microlens array, or a fiber bundle. The emission angle preserving optical element 5 reduces the influence of output fluctuations of the light source 1 on the light intensity distribution (pattern distribution) formed by the diffractive optical element 6 .

The diffractive optical element 6 is arranged on a plane having a Fourier transform relationship with the pupil plane of the illumination optical system 110 . The diffractive optical element 6 converts the light intensity distribution of the light flux from the light source 1 onto the pupil plane of the illumination optical system 110 which is conjugate with the pupil plane of the projection optical system 26 and onto the plane conjugate with the pupil plane of the illumination optical system 110 . Diffractive action transforms to form the desired light intensity distribution. The diffractive optical element 6 may be composed of a computer generated hologram (CGH) designed by a computer so as to obtain a desired diffraction pattern on the diffraction pattern surface. In this embodiment, the light source shape formed on the pupil plane of the projection optical system 26 is called an effective light source shape. The term "effective light source" means the light angle distribution on the surface to be illuminated and the conjugate plane of the surface to be illuminated. The diffractive optical element 6 is provided between the exit angle preserving optical element 5 and the condenser lens 7 .

A plurality of diffractive optical elements 6 may be provided in the illumination optical system 110 . For example, each of the plurality of diffractive optical elements 6 is attached (mounted) to one corresponding to a plurality of slots of a turret (not shown). The plurality of diffractive optical elements 6 form different effective light source shapes. These effective source shapes include small circular shapes (relatively small circular shapes), large circular shapes (relatively large circular shapes), annular shapes, dipole shapes, quadrupole shapes, and others. A method of illuminating an illuminated surface with an annular, dipole, or quadrupole effective light source shape is called modified illumination.

A light beam from the exit angle preserving optical element 5 is diffracted by the diffractive optical element 6 and guided to the condenser lens 7 . The condenser lens 7 is provided between the diffractive optical element 6 and the prism unit 10 and condenses the light flux diffracted by the diffractive optical element 6 to form a diffraction pattern (light intensity distribution) on the Fourier transform plane 9 .

The Fourier transform surface 9 is located between the optical integrator 12 and the diffractive optical element 6 and is a surface that has an optical Fourier transform relationship with the diffractive optical element 6 . By replacing the diffractive optical element 6 arranged in the optical path of the illumination optical system 110, the shape of the diffraction pattern formed on the Fourier transform surface 9 can be changed.

The light blocking member 8 is configured to be movable in a direction perpendicular to the optical axis 1b of the illumination optical system 110, and is arranged upstream of the Fourier transform surface 9 (light source side). The light shielding member 8 is arranged at a position slightly separated (defocused) from the position of the Fourier transform plane 9 .

A prism unit 10 and a zoom lens unit 11 are provided between the Fourier transform surface 9 and the optical integrator 12 and function as a zoom optical system that expands the light intensity distribution formed on the Fourier transform surface 9 . The prism unit 10 guides the light intensity distribution formed on the Fourier transform surface 9 to the zoom lens unit 11 by adjusting the annular rate and the like. Also, the zoom lens unit 11 is provided between the prism unit 10 and the optical integrator 12 . The zoom lens unit 11 includes, for example, a plurality of zoom lenses, and converts the light intensity distribution formed on the Fourier transform plane 9 into a σ value based on the ratio of the NA of the illumination optical system 110 and the NA of the projection optical system 26. is adjusted and led to the optical integrator 12 .

The optical integrator 12 is provided between the zoom lens unit 11 and the condenser lens 14 . The optical integrator 12 includes a fly-eye lens that forms a large number of secondary light sources and guides them to the condenser lens 14 according to the light intensity distribution adjusted for the annular ratio, aperture angle, and σ value. However, the optical integrator 12 may include other optical elements such as an optical pipe, a diffractive optical element, a microlens array, etc. instead of the fly-eye lens. The optical integrator 12 uniformly illuminates the master plate 25 placed on the illuminated surface 24 with the light flux that has passed through the diffractive optical element 6 . A diaphragm 13 is provided between the optical integrator 12 and the condenser lens 14 .

A condenser lens 14 is provided between the optical integrator 12 and the original 25 . As a result, a large number of light fluxes guided from the optical integrator 12 can be condensed to illuminate the master 25 in a superimposed manner. When a light beam enters the optical integrator 12 and is collected by the condenser lens 14, the conjugate plane 19a , which is the focal plane of the condenser lens 14, is illuminated in a substantially rectangular shape.

A half mirror 15 is arranged behind the condenser lens 14 . A part of the exposure light reflected by the half mirror 15 enters the light amount measuring optical system 16 . A sensor 17 for measuring the amount of light is arranged behind the optical system 16 for measuring the amount of light. Based on the amount of light measured by the sensor 17, the amount of exposure during exposure is appropriately controlled.

An X blade and a Y blade are included between the first light shielding part 18 and the second light shielding part 20, specifically, a conjugate plane 19a that is conjugate with the illuminated surface 24 or in the vicinity of the conjugate plane 19a. A masking unit (masking section) 19 is arranged to illuminate with a substantially rectangular light intensity distribution. The vicinity of the conjugate plane 19a means that the X blade and the Y blade of the masking unit 19 are separated from the conjugate plane 19a by a distance necessary to prevent mutual interference. 0.2 mm apart from each other. The masking unit 19 is arranged to define the illumination range of the original 25 (surface to be illuminated 24 ), and is scanned in synchronization with the original stage 29 and the substrate stage 28 . The original stage 29 is a stage that holds and moves the original 25 , and the substrate stage 28 is a stage that holds and moves the substrate 27 .

Two light shielding portions, in this embodiment, a first light shielding portion 18 and a second light shielding portion 20, are provided at positions distant (defocused) from the masking unit 19 (the conjugate surface 19a of the illuminated surface 24). . The first light shielding part 18 is arranged at a position away from the conjugate plane 19a of the illuminated surface 24 toward the light source. The second light shielding part 20 is arranged at a position away from the conjugate plane 19a of the illuminated surface 24 toward the illuminated surface.

The light reflected by the mirror 22 having a predetermined inclination with respect to the light flux from the condenser lens 21 passes through the collimator lens 23 and illuminates the master 25 .

A projection optical system 26 projects the pattern of the original 25 onto the substrate 27 . The resolution of the pattern of the original 25 depends on the shape of the effective light source. Therefore, by forming an appropriate effective light source distribution in the illumination optical system 110, the resolution of the pattern of the original 25 can be improved.

Details of the first light shielding unit 18, the masking unit 19, and the second light shielding unit 20 will be described with reference to FIG. In FIG. 2, the y direction indicates the scanning direction. Masking unit 19 includes scan masking blades 19d and 19e that move during scan exposure.

The first light shielding part 18 includes a first light shielding member 18a and a second light shielding member 18b, as shown in FIG. An end portion 18aA of the first light shielding member 18a on the side of the second light shielding member and an end portion 18bA of the second light shielding member 18b on the side of the first light shielding member are located within the light beam effective area, and block part of the light beam. The intensity of light reaching the illuminated surface 24 is adjusted. For example, an actuator (not shown) is connected to the first light shielding member 18a. By moving the first light shielding member 18a along the scanning direction (y direction) with such an actuator, the opening width defined by the end 18aA of the first light shielding member 18a and the end 18bA of the second light shielding member 18b is changed. can be changed. Thus, the first light shielding portion 18 constitutes a variable slit. Further, in this embodiment, a first moving unit FMU is provided for moving the first light shielding member 18a and the second light shielding member 18b in the direction along the optical axis 1b of the illumination optical system 110 with respect to the first light shielding unit 18. It is

The second light shielding part 20 includes a third light shielding member 20a and a fourth light shielding member 20b, as shown in FIG. An end portion 20aA of the third light shielding member 20a on the side of the fourth light shielding member and an end portion 20bA of the fourth light shielding member 20b on the side of the third light shielding member are located within the light beam effective area, and block part of the light beam. The intensity of light reaching the illuminated surface 24 is adjusted. An actuator (not shown) is connected to the third light shielding member 20a. By moving the third light shielding member 20a along the scanning direction (y direction) with such an actuator, the opening width defined by the end portion 20aA of the third light shielding member 20a and the end portion 20bA of the fourth light shielding member 20b is changed. can be changed. Thus, the second light shielding section 20 constitutes a variable slit. Further, in this embodiment, a second moving unit SMU is provided for moving the third light shielding member 20a and the fourth light shielding member 20b in the direction along the optical axis 1b of the illumination optical system 110 with respect to the second light shielding unit 20. It is

As shown in FIG. 2, in a plane including the optical axis 1b and parallel to the scanning direction, a first distance between the conjugate surface 19a and the end portion 18aA of the first light shielding member 18a in the direction along the optical axis 1b be d1. In a plane that includes the optical axis 1b and is parallel to the scanning direction, d2 is the second distance between the conjugate surface 19a and the end portion 20aA of the third light shielding member 20a in the direction along the optical axis 1b. In this case, the first distance d1 and the second distance d2 are different values. Further, the distance between the conjugate surface 19a and the end portion 18bA of the second light shielding member 18b is equal to the first distance d1, and the distance between the conjugate surface 19a and the end portion 20bA of the fourth light shielding member 20b is the second distance. equal to d2. Thus, the first light shielding part 18 and the second light shielding part 20 are arranged such that the first distance d1 and the second distance d2 are different.

As shown in FIG. 2, 18c is the middle point between the end 18aA of the first light shielding member 18a and the end 18bA of the second light shielding member 18b in a plane that includes the optical axis 1b and is parallel to the scanning direction. do. Similarly, the middle point between the edge 20aA of the third light shielding member 20a and the edge 20bA of the fourth light shielding member 20b is 20c. S1 is the distance from the midpoint 18c to the end 18aA of the first light shielding member 18a and the end 18bA of the second light shielding member 18b, and the distance from the midpoint 20c to the end 20aA of the third light shielding member 20a and the fourth light shielding member 20b is Let S2 be the distance to the end 20bA. In this case, the distance S1 and the distance S2 are different values. A straight line connecting the middle point 18c and the middle point 20c is parallel to the optical axis 1b.

The integrated effective light source will be described with reference to FIGS. 3(a) and 3(b). In FIGS. 3A and 3B, the y direction indicates the scanning direction. 3(a) shows an illumination area 24e of the surface to be illuminated 24, and FIG. 3(b) shows an illumination area 19b of a conjugate surface 19a (masking unit 19) that is in a conjugate relationship with the surface to be illuminated 24. .

In exposure, the illumination area 24e is scanned. At this time, the incident angle distribution for illuminating a certain point on the exposure surface is obtained by integrating the incident angle distribution for illuminating each point on a straight line 24f parallel to the scanning direction (y direction) in the illumination area 24e. This is called integrated effective light source. Since the straight line 19c is a set of points on the conjugate plane 19a that are conjugate with each point of the straight line 24e, the integrated effective light source is obtained by integrating the incident angle distribution of the illumination target surface 24 with the light flux passing through each point of the straight line 19c. is equivalent to

The functions of the first light shielding section 18 and the second light shielding section 20 will be described with reference to FIGS. 4(a), 4(b) and 4(c). In FIGS. 4(a), 4(b) and 4(c), the y direction indicates the scanning direction. FIG. 4A is an enlarged view of the vicinity of the optical integrator 12, the condenser lens 14, the first light shielding section 18 and the second light shielding section 20. FIG. FIG. 4(a) shows light rays exiting the optical integrator 12, passing through the condenser lens 14 and points A, B and C on the conjugate plane 19a. Here, points A, B and C are points on the straight line 19 shown in FIG. 3(b). FIG. 4B is a diagram showing effective light sources 24a, 24b and 24c at points A', B' and C' on the illuminated surface 24, respectively. Points A', B' and C' are in a conjugate relationship with points A, B and C of the conjugate plane 19a of the illuminated surface 24, respectively. FIG. 4(c) is a diagram showing an integrated effective light source 24d obtained by integrating all rays passing through a straight line including points A', B' and C' on the illuminated surface 24. FIG.

In this embodiment, in order to facilitate understanding of the invention, a case where the effective light source has a circular shape called conventional illumination will be described as an example. or multipole. The present invention is not limited by the shape of the effective light source formed by the diffractive optical element 6, the prism unit 10, and the like.

Referring to FIG. 4A, a light ray 12a emitted from the optical integrator 12 parallel to the optical axis 1b and directed to a point A on the conjugate plane 19a via the condenser lens 14 is divided into the first light shielding portion 18 and the second light shielding portion 18. The light is not shielded by the light shielding part 20 . Therefore, the effective light source 24a at the point A' on the illuminated surface 24 is substantially circular and substantially symmetrical in the scanning direction, as shown in FIG. 4(b).

On the other hand, a light ray 12b emitted from the optical integrator 12 with an inclination toward the first light shielding member from the optical axis 1b and traveling through the condenser lens 14 toward a point B on the conjugate surface 19a is partially divided into the first light shielding member 18a and the first light shielding member 18a. The light is shielded by the third light shielding member 20a. Therefore, the effective light source 24b at the point B' on the surface to be illuminated 24 has a shape in which both ends in the scanning direction are missing from the circular shape, and the distribution in the x direction (the direction orthogonal to the y direction) and the distribution in the y direction. asymmetry (XY asymmetry).

A light ray 12c emitted from the optical integrator 12 with an inclination from the optical axis 1b to the second light shielding member side and directed to the point C on the conjugate surface 19a via the condenser lens 14 is partially divided into the second light shielding member 18b and the second light shielding member 18b. The light is shielded by the fourth light shielding member 20b. Therefore, the effective light source 24c at the point C' on the surface to be illuminated 24 has a shape in which both ends in the scanning direction are missing in the circular shape, and the distribution in the x direction (direction orthogonal to the y direction) and the distribution in the y direction. asymmetry (XY asymmetry).

Considering an integrated effective light source 24d obtained by integrating all the luminous fluxes passing through a straight line including points A, B, and C in this way, the integrated effective light source 24d is an XY asymmetric light source as shown in FIG. 4(c). have sex.

A configuration for reducing the XY asymmetry of the integrated effective light source 24d will be described with reference to FIGS. 5(a) and 5(b). FIG. 5(a) is a diagram showing an illumination distribution 24ee (illumination region 24e) that illuminates the illuminated surface 24 and is formed by the light flux that illuminates the conjugate plane 19a at the maximum angle θ0. By the condenser lens 21 and the collimator lens 23, the distribution of the conjugate plane 19a is imaged on the illuminated surface 24 at the imaging magnification β.

Let θ0 be the maximum incident angle of the light flux that illuminates the conjugate plane 19a. A light ray having an angle of θ0 passing through the end portion 18aA of the first light shielding member 18a and a light ray having an angle of −θ0 passing through the end portion 20aA of the third light shielding member 20a intersect at a point 19aa on the conjugate plane 19a. A distance S1 and a second distance S2 are determined. As described above, the first distance S1 is the distance from the midpoint 18c to the edge 18aA of the first light shielding member 18a, and the second distance S2 is the distance from the midpoint 20c to the edge of the third light shielding member 20a. distance up to 20aA. Let 19bb be the point where the straight line connecting the end 18aA of the first light shielding member 18a and the end 20aA of the third light shielding member 20a intersects the conjugate plane 19a, and let S be the distance between the points 19bb and 19cc. Let 24g, 24h and 24i be the points on the illuminated surface 24 corresponding to the points 19aa, 19bb and 19cc on the conjugate surface 19a, respectively.

Since the light rays that illuminate the area inside the point 24g on the illuminated surface 24 are not blocked by the first light shielding member 18a and the third light shielding member 20a, the intensity thereof is constant. In addition, since the light rays illuminating the area outside the point 24h on the illuminated surface 24 are blocked by the first light shielding member 18a and the third light shielding member 20a, the intensity thereof becomes zero. The other end of the illumination distribution 24ee is shielded by the second light shielding member 18b and the fourth light shielding member 20b and has a similar shape. Therefore, the illumination distribution 24ee has a shape close to a trapezoid. Let w0 and w100 be the lower and upper bases of the trapezoid, respectively.

The effective light source that illuminates the points between the points 24i and 24g on the illuminated surface 24 is substantially circular, like the effective light source at the point A' described above. An effective light source that illuminates a point between points 24g and 24h on the illuminated surface 24 has a large XY asymmetry, similar to the effective light source at point B' described above. In addition, at a point between the points 24g and 24h on the surface to be illuminated 24, both the first light shielding section 18 and the second light shielding section 20 block light, so that the illuminance decreases. Therefore, by increasing the ratio of w100 to w0 and decreasing the distance between the points 24g and 24h, it is possible to suppress the decrease in illuminance and the generation of XY asymmetry of the integrated effective light source 24d.

The lower base w0 of the illumination distribution 24ee is expressed as w0=2βS. On the other hand, the upper base w100 of the illumination distribution 24ee is expressed as w100=2β(S1−d1×tan θ0)=2β(S2−d2×tan θ0). Therefore, the ratio w100/w0 of the upper base w100 to the lower base w0 is expressed as w100/w0=(S1−d1×tan θ0)/S=(S2−d2×tan θ0)/S.

Points 19aa and 19bb on the conjugate plane 19a are represented by points where a straight line passing through the end portion 18aA of the first light shielding member 18a intersects the conjugate plane 19a. Therefore, when d1< d2 , w100/w0 approaches 1 as d1 decreases, and becomes 1 when d1=0. When d1>d2, w100/w0 approaches 1 as d2 decreases, and becomes 1 when d2=0.

As described above, the scan masking blades 19 d and 19 e are arranged between the first light shielding section 18 and the second light shielding section 20 . The scan masking blades 19d and 19e move during scanning exposure and thus require a certain amount of space. Therefore, the distance between the first light shielding part 18 and the second light shielding part 20 in the direction along the optical axis 1b cannot be made smaller than the predetermined value D. The predetermined value D is expressed as D=d1+d2 using a first distance d1 between the first light shielding portion 18 and the conjugate surface 19a and a second distance d2 between the second light shielding portion 20 and the conjugate surface 19a. be. Generally, the predetermined value D is 5 mm or more and 20 mm or less.

FIG. 5B is a diagram showing an illumination distribution 24ee that illuminates the surface to be illuminated 24 formed by the light flux that illuminates the conjugate surface 19a at the maximum angle θ0 when the first distance d1 and the second distance d2 are equal. is. Since there is a condition of D=d1+d2, the first distance d1 shown in FIG. 5(b) is larger than the first distance d1 shown in FIG. 5(a). Therefore, w100/w0 becomes smaller as shown in FIG. 5(b).

Specific numerical examples regarding the first light shielding portion 18 and the second light shielding portion 20 will be described below. FIG. 6 shows the relationship between w100/w0 and d1/d2 with D=8 [mm], S=5 [mm], and θ0=0.4 [rad]. In FIG. 6, the vertical axis indicates w100/w0, and the horizontal axis indicates d1/d2. As shown in FIG. 6, the relationship between w100/w0 and d1/d2 is represented by a quadratic expression, and is minimized at d1=d2.

If the integrated effective light source 24d has XY asymmetry, correcting the XY asymmetry reduces the illuminance. If the XY asymmetry needs to be 15% or less in order to reduce such a decrease in illuminance, it is preferable to set w100/w0 to 0.7 or more. Referring to FIG. 6, it can be seen that d2/d1>2 or d2/d1<1/2 is required to make w100/w0 equal to or greater than 0.7.

Next, the conditions for the maximum and minimum values of d2/d1 will be described with reference to FIG. Points C' and B' shown in FIG. 4(b), which correspond to the slanted portions of the illumination distribution 24ee, have a ray centroid shift (deviation of the centroid ray) in the scanning direction. The ray centroid shift affects the registration accuracy, so it is not preferable, but the ray centroid shift can be controlled by the ratio of d1 and d2.

Assuming conventional illumination, FIG. It shows the ray centroid shift. In FIG. 7, the vertical axis indicates the ray barycenter shift, and the horizontal axis indicates d1/d2. Referring to FIG. 7, the ray center-of-gravity shift has a minimum value, specifically 0, when d 1 /d 2 =1 . This means that no ray centroid shift occurs. In order to improve the superimposition accuracy, it is preferable to reduce the ray barycentric shift to less than half that of the conventional configuration in which the light blocking portion is arranged only on the upstream side of the conjugate plane of the surface to be illuminated. Referring to FIG. 7, it can be seen that 1/4<d2/d1<4 is required in order to make the ray center-of-gravity shift less than half that of the conventional configuration.

Therefore, the condition that the first distance d1 from the conjugate plane 19a to the first light shielding part 18 and the second distance d2 from the conjugate plane 19a to the second light shielding part 20 should satisfy is d1≠d2, more preferably 1 /4<d2/d1<1/2 or 2<d2/d1<4. Thus, it is preferable that one of the first distance d1 and the second distance d2 is larger than twice the other distance and smaller than four times.

Further, in the present embodiment, as described above, the actuator for moving the first light shielding member 18a along the scanning direction and the first light shielding portion 18 (the first light shielding member 18a and the second light shielding member 18b) are arranged along the optical axis 1b. A first moving unit FMU is provided for moving in the direction along. Similarly, an actuator for moving the third light shielding member 20a along the scanning direction and a second movement for moving the second light shielding portion 20 (the third light shielding member 20a and the fourth light shielding member 20b) in the direction along the optical axis 1b A partial SMU is provided. By having such a drive mechanism, it is possible to set the optimum d1, d2 , S1 and S2 depending on the illumination mode, further reducing (suppressing) the ray centroid shift, the decrease in illuminance, and the XY asymmetry in the effective light source. )can do.

The method for manufacturing an article according to the embodiment of the present invention is suitable for manufacturing articles such as flat panel displays, liquid crystal display elements, semiconductor elements, and MEMS. This manufacturing method includes a step of exposing a substrate coated with a photosensitive agent using the exposure apparatus 100 described above and a step of developing the exposed photosensitive agent. Also, the circuit pattern is formed on the substrate by performing an etching process or an ion implantation process on the substrate using the pattern of the developed photosensitive agent as a mask. By repeating these steps of exposure, development, etching, etc., a circuit pattern consisting of a plurality of layers is formed on the substrate. In the post-process, the substrate on which the circuit pattern is formed is diced (processed), and chip mounting, bonding, and inspection processes are performed. Such manufacturing methods may also include other well-known steps (oxidation, deposition, deposition, doping, planarization, resist stripping, etc.). The method for manufacturing an article according to the present embodiment is advantageous in at least one of performance, quality, productivity and production cost of the article as compared with conventional methods.

The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the claims are appended to make public the scope of the invention.

Reference Signs List 100: exposure device 110: illumination optical system 18: first light shielding unit 19: masking unit 19a: conjugate surface 20: second light shielding unit 24: surface to be illuminated 25: original plate 27: substrate

Claims (8)

An exposure apparatus that exposes a substrate while moving the original and the substrate in a scanning direction,
an illumination optical system that illuminates the illuminated surface of the original with light from a light source;
The illumination optical system is
a first light shielding part arranged at a position away from the conjugate plane of the illuminated surface toward the light source;
a second light shielding part arranged at a position away from the conjugate plane toward the surface to be illuminated;
a masking part disposed between the first light shielding part and the second light shielding part and defining an illumination range of the illuminated surface;
including
a first distance between the conjugate plane and the first light shielding part in the direction along the optical axis of the illumination optical system, and a distance between the conjugate plane and the second light shielding part in the direction along the optical axis The sum of the second distance is 5 mm or more and 20 mm or less,
An exposure apparatus, wherein the first light shielding section and the second light shielding section are arranged such that the first distance is different from the second distance. 2. An exposure apparatus according to claim 1, wherein one of said first distance and said second distance is greater than two times and less than four times the other distance. An exposure apparatus that exposes a substrate while moving the original and the substrate in a scanning direction,
an illumination optical system that illuminates the illuminated surface of the original with light from a light source;
The illumination optical system is
a first light shielding part arranged at a position away from the conjugate plane of the illuminated surface toward the light source;
a second light shielding part arranged at a position away from the conjugate plane toward the surface to be illuminated;
a masking part disposed between the first light shielding part and the second light shielding part and defining an illumination range of the illuminated surface;
including
a first distance between the conjugate plane and the first light shielding part in the direction along the optical axis of the illumination optical system, and a distance between the conjugate plane and the second light shielding part in the direction along the optical axis and the second distance, one of which is larger than twice and smaller than four times the other distance. a first moving unit that moves the first light shielding unit in a direction along the optical axis;
a second moving unit that moves the second light shielding unit in a direction along the optical axis;
4. An exposure apparatus according to any one of claims 1 to 3, further comprising: a changing unit that changes the light angle distribution formed on the surface to be illuminated by the illumination optical system;
3. The first light shielding section and the second light shielding section are moved using the first moving section and the second moving section according to the light angle distribution changed by the changing section. 5. The exposure apparatus according to 4. 6. The exposure apparatus according to any one of claims 1 to 5 , wherein the masking section is arranged on the conjugate plane or in the vicinity of the conjugate plane. 7. The exposure apparatus according to claim 1, wherein each of said first light shielding section and said second light shielding section includes a variable slit. exposing a substrate using the exposure apparatus according to any one of claims 1 to 7 ;
developing the exposed substrate;
producing an article from the developed substrate;
A method for manufacturing an article, comprising:

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