WO2014073548A1 - Spatial-light-modulating optical system, illumination optical system, exposure device, and method for producing device - Google Patents

Abstract

This illumination optical system can achieve a desired pupil intensity distribution by suppressing the effect of unneeded light not from a mirror element of a spatial light modulator. The present invention is provided with: a spatial light modulator having a plurality of mirror elements that are arrayed in a predetermined plane and are controlled individually; and a distribution formation optical system that causes light that has traversed the spatial light modulator to be distributed at a predetermined light strength distribution at the illumination pupil of the illumination optical system. The direction of any given pair of opposing edges of two adjacent mirror elements of the plurality of mirror elements of the spatial light modulator, and the direction of the line of intersection between a predetermined plane and a plane perpendicular to the predetermined plane containing the axis line of an entering light beam entering to the spatial light modulator intersect at a required angle that is not 0°.

Description

Spatial light modulation optical system, illumination optical system, exposure apparatus, and device manufacturing method

The present invention relates to a spatial light modulation optical system, an illumination optical system, an exposure apparatus, and a device manufacturing method.

In an exposure apparatus used for manufacturing a device such as a semiconductor element, a light source emitted from a light source is a secondary light source (generally a surface light source consisting of a number of light sources via a fly-eye lens as an optical integrator). Form a predetermined light intensity distribution in the illumination pupil. Hereinafter, the light intensity distribution in the illumination pupil is referred to as “pupil intensity distribution”. The illumination pupil is a position where the illumination surface becomes the Fourier transform plane of the illumination pupil by the action of the optical system between the illumination pupil and the illumination surface (a mask or a wafer in the case of an exposure apparatus). Defined.

After the light from the secondary light source is collected by the condenser optical system, the mask on which a predetermined pattern is formed is illuminated in a superimposed manner. The light transmitted through the mask forms an image on the wafer via the projection optical system, and the mask pattern is projected and exposed (transferred) onto the wafer. The pattern formed on the mask is miniaturized, and it is indispensable to obtain a uniform illuminance distribution on the wafer in order to accurately transfer the fine pattern onto the wafer.

Conventionally, there has been proposed an illumination optical system capable of continuously changing the pupil intensity distribution (and consequently the illumination condition) without using a zoom optical system (see, for example, Patent Document 1). In a conventional illumination optical system, an incident light flux is made minute for each reflecting surface by using a movable multi-mirror configured by a large number of minute mirror elements that are arranged in an array and whose tilt angle and tilt direction are individually driven and controlled. By dividing the light into units and deflecting, the cross section of the light beam is converted into a desired shape or a desired size, and thus a desired pupil intensity distribution is realized.

US Patent Application Publication No. 2009/0116093

Since the conventional illumination optical system uses a spatial light modulator having a large number of minute mirror elements whose postures are individually controlled, the degree of freedom in changing the shape and size of the pupil intensity distribution is high. However, not only the reflected light from the mirror element but also the reflected light from the surface of the substrate supporting the mirror element, for example, may reach the illumination pupil. In this case, it becomes difficult to form a desired pupil intensity distribution due to the influence of reflected light (generally unnecessary light) from other than the mirror elements.

The present invention has been made in view of the foregoing problems, and provides an illumination optical system capable of realizing a desired pupil intensity distribution while suppressing the influence of unnecessary light from other than the mirror elements of the spatial light modulator. The purpose is to do. The present invention also provides an exposure apparatus that can perform good exposure under appropriate illumination conditions using an illumination optical system that realizes a desired pupil intensity distribution while suppressing the influence of unnecessary light. With the goal.

In order to solve the above problems, in the first embodiment, in a spatial light modulation optical system including a spatial light modulator having a plurality of mirror elements arranged on the first surface and individually controlled,
An incident-side optical system that irradiates light to the plurality of mirror elements of the spatial light modulator;
Of the plurality of mirror elements of the spatial light modulator, the direction of any pair of edges facing each other in two adjacent mirror elements is perpendicular to the first surface including the optical axis of the incident side optical system. A spatial light modulation optical system characterized by intersecting with a second surface is provided.
In the second embodiment, in a spatial light modulation optical system including a spatial light modulator having a plurality of mirror elements arranged on a predetermined surface and individually controlled,
Of the plurality of mirror elements of the spatial light modulator, the direction of an arbitrary pair of edges facing each other in two adjacent mirror elements passes between the pair of any facing edges and is substantially the same as the predetermined surface. Provided is a spatial light modulation optical system characterized by an angle at which unnecessary light reflected by parallel plane portions is reduced.

In the third embodiment, in the illumination optical system that illuminates the illuminated surface with light from the light source,
A spatial light modulation optical system of the first form or the second form;
There is provided an illumination optical system comprising: a distribution forming optical system that distributes light having passed through the spatial light modulator to an illumination pupil of the illumination optical system with a predetermined light intensity distribution.

In a fourth aspect, there is provided an exposure apparatus comprising the illumination optical system of the third aspect for illuminating a predetermined pattern, and exposing the predetermined pattern onto a substrate.

In the fifth embodiment, an exposure apparatus that exposes a predetermined pattern on a substrate,
An exposure apparatus comprising the spatial light modulation optical system of the first form or the second form is provided.

In a sixth embodiment, using the exposure apparatus of the fourth embodiment or the fifth embodiment, exposing the predetermined pattern to a photosensitive substrate;
Developing the photosensitive substrate having the predetermined pattern transferred thereon, and forming a mask layer having a shape corresponding to the predetermined pattern on the surface of the photosensitive substrate;
And processing the surface of the photosensitive substrate through the mask layer. A device manufacturing method is provided.

In the seventh embodiment, in a spatial light modulation method for spatially modulating incident light using a spatial light modulator having a plurality of mirror elements arranged on a predetermined surface and individually controlled,
Among the plurality of mirror elements of the spatial light modulator, the predetermined plane includes a direction of an arbitrary pair of edges facing each other in two adjacent mirror elements and an axis of an incident light beam incident on the spatial light modulator. A spatial light modulation method is provided in which the direction of the line of intersection between the plane perpendicular to the predetermined plane and the predetermined plane intersects at a required angle other than 0 °.
In an eighth aspect, in a spatial light modulation method for spatially modulating incident light using a spatial light modulator having a plurality of mirror elements arranged on the first surface and individually controlled,
Irradiating light to the plurality of mirror elements of the spatial light modulator via an incident side optical system;
Reflecting the light at the plurality of mirror elements of the spatial light modulator;
Including
Of the plurality of mirror elements of the spatial light modulator, the direction of any pair of edges facing each other in two adjacent mirror elements is perpendicular to the first surface including the optical axis of the incident side optical system. A spatial light modulation method characterized by intersecting a second surface is provided.
In the ninth embodiment, in a spatial light modulation method for spatially modulating incident light using a spatial light modulator having a plurality of mirror elements arranged on a predetermined surface and individually controlled,
Irradiating light to the plurality of mirror elements of the spatial light modulator via an incident side optical system;
Reflecting the light at the plurality of mirror elements of the spatial light modulator;
Of the plurality of mirror elements of the spatial light modulator, unnecessary light that passes between any pair of opposing edges in two adjacent mirror elements and is reflected by a surface portion substantially parallel to the predetermined surface is reduced. To do
The spatial light modulation method characterized by including.

In the illumination optical system of the present invention, it is possible to realize a desired pupil intensity distribution while suppressing the influence of unnecessary light from other than the mirror elements of the spatial light modulator. In the exposure apparatus of the present invention, the illumination optical system that realizes a desired pupil intensity distribution while suppressing the influence of unnecessary light is favorable under appropriate illumination conditions realized according to the mask pattern characteristics. Exposure can be performed, and as a result, a good device can be manufactured.

It is a figure which shows schematically the structure of the exposure apparatus concerning embodiment. It is a figure explaining the structure and effect | action of a spatial light modulator. It is a fragmentary perspective view of the principal part of a spatial light modulator. It is a figure which shows roughly the characteristic principal part structure in embodiment. It is a figure which shows a mode that light injects in the direction which cross | intersects the direction of the edge of a mirror element. FIG. 6 is a cross-sectional view taken along line AA of FIG. It is a figure which shows schematically the structure of the exposure apparatus concerning a modification. It is a figure which shows roughly the characteristic principal part structure in the modification of FIG. It is a figure explaining the necessity of the light beam conversion element in the modification of FIG. It is a flowchart which shows the manufacturing process of a semiconductor device. It is a flowchart which shows the manufacturing process of liquid crystal devices, such as a liquid crystal display element.

Hereinafter, embodiments will be described with reference to the accompanying drawings. FIG. 1 is a view schematically showing a configuration of an exposure apparatus according to the embodiment. In FIG. 1, the Z-axis is along the normal direction of the transfer surface (exposure surface) of the wafer W, which is a photosensitive substrate, and the Y-axis is in the direction parallel to the paper surface of FIG. In the W transfer surface, the X axis is set in a direction perpendicular to the paper surface of FIG.

Referring to FIG. 1, in the exposure apparatus of this embodiment, exposure light (illumination light) is supplied from a light source LS. As the light source LS, for example, an ArF excimer laser light source that supplies light with a wavelength of 193 nm, a KrF excimer laser light source that supplies light with a wavelength of 248 nm, or the like can be used. Light emitted from the light source LS in the + Z direction is incident on the optical path bending mirror 2 via the beam transmission unit 1. The light reflected by the optical path bending mirror 2 enters the spatial light modulator 3.

As will be described later, the spatial light modulator 3 individually controls the postures of a plurality of mirror elements arranged in a predetermined plane and individually controlled based on a control signal from the control system CR. And a driving unit for driving. The beam transmitting unit 1 guides the incident light beam from the light source LS to the spatial light modulator 3 while converting the incident light beam into a light beam having a cross section having an appropriate size and shape, and arranges a plurality of mirror elements of the spatial light modulator 3. The position variation and the angle variation of the light incident on the surface (hereinafter referred to as “spatial light modulator array surface”) are actively corrected.

The light emitted in the + Z direction from the spatial light modulator 3 enters the pupil plane 4 c of the relay optical system 4 via the front lens group 4 a of the relay optical system 4. The front lens group 4a is set so that its front focal position substantially coincides with the position of the array surface of the spatial light modulator 3, and its rear focal position substantially coincides with the position of the pupil plane 4c. As will be described later, the light having passed through the spatial light modulator 3 variably forms a light intensity distribution according to the postures of the plurality of mirror elements on the pupil plane 4c.

The light that forms the light intensity distribution on the pupil plane 4c is incident on the relay optical system 5 via the rear lens group 4b of the relay optical system 4 in which the front focal position is set on the pupil plane 4c. The relay optical system 5 has a front focal position located near the rear focal position of the rear lens group 4b, and a rear focal position located near the incident surface of the micro fly's eye lens 7. The rear focal position of the side lens group 4b and the incident surface of the micro fly's eye lens 7 are set optically in a Fourier transform relationship between the arrangement surface of the spatial light modulator 3 and the incident surface of the micro fly's eye lens 7. is doing.

The light that has passed through the relay optical system 5 is reflected in the + Y direction by the optical path bending mirror 6 and enters the micro fly's eye lens (or fly eye lens) 7. The rear lens group 4b and the relay optical system 5 set the pupil plane 4c and the incident surface of the micro fly's eye lens 7 optically conjugate. Therefore, the light that has passed through the spatial light modulator 3 is light corresponding to the light intensity distribution formed on the pupil plane 4c on the incident surface of the micro fly's eye lens 7 disposed at a position optically conjugate with the pupil plane 4c. Form an intensity distribution.

The micro fly's eye lens 7 is an optical element made up of a large number of micro lenses having positive refractive power, which are arranged vertically and horizontally and densely. The micro fly's eye lens 7 is configured by forming a micro lens group by etching a plane parallel plate. Has been. In a micro fly's eye lens, unlike a fly eye lens composed of lens elements isolated from each other, a large number of micro lenses (micro refractive surfaces) are integrally formed without being isolated from each other. However, the micro fly's eye lens is the same wavefront division type optical integrator as the fly's eye lens in that the lens elements are arranged vertically and horizontally. In other words, the micro fly's eye lens 7 is an optical integrator that includes a plurality of wavefront division surfaces arranged in parallel in a plane that crosses the optical axis.

A rectangular minute refracting surface as a unit wavefront dividing surface in the micro fly's eye lens 7 is a rectangular shape similar to the shape of the illumination field to be formed on the mask M (and the shape of the exposure region to be formed on the wafer W). It is. For example, a cylindrical micro fly's eye lens can be used as the micro fly's eye lens 7. The configuration and operation of the cylindrical micro fly's eye lens are disclosed in, for example, US Pat. No. 6,913,373.

The light beam incident on the micro fly's eye lens 7 is two-dimensionally divided by a large number of microlenses, and the light intensity distribution on the rear focal plane or in the vicinity of the illumination pupil is almost the same as the light intensity distribution formed on the incident plane. A secondary light source (substantially surface light source consisting of a large number of small light sources: pupil intensity distribution) is formed. The light from the secondary light source formed on the illumination pupil immediately after the micro fly's eye lens 7 illuminates the mask blind 9 in a superimposed manner via the condenser optical system 8.

Thus, in the mask blind 9 as the illumination field stop, a rectangular illumination field corresponding to the shape and focal length of the rectangular minute refractive surface of the micro fly's eye lens 7 is formed. Note that an opening having a shape corresponding to the secondary light source is located at the rear focal plane of the micro fly's eye lens 7 or at a position in the vicinity thereof, that is, at a position optically conjugate with an entrance pupil plane of the projection optical system PL described later. You may arrange | position the illumination aperture stop which has (light transmissive part).

The light that passes through the rectangular opening (light transmitting portion) of the mask blind 9 receives the light condensing action of the imaging optical system 10 and is an optical path bending mirror 11 arranged in the optical path of the imaging optical system 10. After that, the mask M on which a predetermined pattern is formed is illuminated in a superimposed manner. That is, the imaging optical system 10 forms an image of the rectangular opening of the mask blind 9 on the mask M.

The light transmitted through the mask M held on the mask stage MS forms a mask pattern image on the wafer (photosensitive substrate) W held on the wafer stage WS via the projection optical system PL. In this way, batch exposure or scan exposure is performed while the wafer stage WS is two-dimensionally driven and controlled in a plane (XY plane) orthogonal to the optical axis AX of the projection optical system PL, and thus the wafer W is two-dimensionally driven and controlled. As a result, the pattern of the mask M is sequentially exposed in each exposure region of the wafer W.

The exposure apparatus of the present embodiment includes a first pupil intensity distribution measurement unit DTr that measures a pupil intensity distribution on the exit pupil plane of the illumination optical system based on light that passes through the illumination optical system (1 to 11), and a projection optical system. A second pupil intensity distribution measurement unit DTw that measures a pupil intensity distribution on the pupil plane of the projection optical system PL (an exit pupil plane of the projection optical system PL) based on light via the PL, and first and second pupil intensity distributions And a control system CR that controls the spatial light modulator 3 based on the measurement result of at least one of the measurement units DTr and DTw and controls the overall operation of the exposure apparatus.

The first pupil intensity distribution measurement unit DTr includes, for example, an imaging unit having a photoelectric conversion surface disposed at a position optically conjugate with the exit pupil position of the illumination optical system, and each point on the surface to be irradiated by the illumination optical system. Is measured (pupil intensity distribution formed at the exit pupil position of the illumination optical system by the light incident on each point). In addition, the second pupil intensity distribution measurement unit DTw includes an imaging unit having a photoelectric conversion surface arranged at a position optically conjugate with the pupil position of the projection optical system PL, for example, and includes each image plane of the projection optical system PL. A pupil intensity distribution related to the points (pupil intensity distribution formed by light incident on each point at the pupil position of the projection optical system PL) is measured.

For details on the configuration and operation of the first and second pupil intensity distribution measurement units DTr and DTw, reference can be made to, for example, US Patent Publication No. 2008/0030707. As the pupil intensity distribution measuring unit, the disclosure of US Patent Publication No. 2010/0020302 can be referred to.

In the present embodiment, the secondary light source formed by the micro fly's eye lens 7 is used as a light source, and the mask M (and thus the wafer W) disposed on the irradiated surface of the illumination optical system is Koehler illuminated. For this reason, the position where the secondary light source is formed is optically conjugate with the position of the aperture stop AS of the projection optical system PL, and the formation surface of the secondary light source can be called the illumination pupil plane of the illumination optical system. Further, the image of the formation surface of the secondary light source can be called an exit pupil plane of the illumination optical system. Typically, the irradiated surface (the surface on which the mask M is disposed or the surface on which the wafer W is disposed when the illumination optical system including the projection optical system PL is considered) is optical with respect to the illumination pupil plane. A Fourier transform plane. The pupil intensity distribution is a light intensity distribution (luminance distribution) on the illumination pupil plane of the illumination optical system or a plane optically conjugate with the illumination pupil plane.

When the number of wavefront divisions by the micro fly's eye lens 7 is relatively large, the overall light intensity distribution formed on the incident surface of the micro fly's eye lens 7 and the overall light intensity distribution (pupil intensity distribution) of the entire secondary light source. ) And a high correlation. For this reason, the incident surface of the micro fly's eye lens 7 and a surface optically conjugate with the incident surface, for example, the pupil plane 4c, can also be called illumination pupil planes, and the light intensity distribution on these planes is also the pupil intensity distribution. Can be called. In the configuration of FIG. 1, the condensing optical system including the relay optical systems 4 and 5 and the micro fly's eye lens 7 are based on the light beam that has passed through the spatial light modulator 3 and the pupil intensity is applied to the illumination pupil immediately after the micro fly's eye lens 7. A distribution forming optical system that forms a distribution, that is, a distribution forming optical system that distributes light having passed through the spatial light modulator 3 to the illumination pupil immediately after the micro fly's eye lens 7 with a predetermined light intensity distribution.

Next, the configuration and operation of the spatial light modulator 3 will be specifically described. As shown in FIG. 2, the spatial light modulator 3 includes a plurality of mirror elements 3a arranged in a predetermined plane, a base 3b holding the plurality of mirror elements 3a, and a cable (not shown) connected to the base 3b. ), And a drive unit 3c that individually controls and drives the postures of the plurality of mirror elements 3a. In FIG. 2, the optical path from the spatial light modulator 3 to the pupil plane 4c of the relay optical system 4 is shown.

In the spatial light modulator 3, the attitude of the plurality of mirror elements 3a is changed by the action of the drive unit 3c that operates based on a command from the control system CR, and each mirror element 3a is set in a predetermined direction. . As shown in FIG. 3, the spatial light modulator 3 includes a plurality of minute mirror elements 3a arranged two-dimensionally, and the spatial modulation corresponding to the incident position of the incident light can be varied. Is applied and injected. For ease of explanation and illustration, FIG. 2 and FIG. 3 show a configuration example in which the spatial light modulator 3 includes 4 × 4 = 16 mirror elements 3a. The number of mirror elements 3a is typically large, typically about 4000 to 100,000.

Referring to FIG. 2, among the light beams incident on the spatial light modulator 3, the light beam L1 is incident on the mirror element SEa of the plurality of mirror elements 3a, and the light beam L2 is incident on the mirror element SEb different from the mirror element SEa. To do. Similarly, the light beam L3 is incident on a mirror element SEc different from the mirror elements SEa and SEb, and the light beam L4 is incident on a mirror element SEd different from the mirror elements SEa to SEc. The mirror elements SEa to SEd give spatial modulations set according to their positions to the lights L1 to L4.

In the spatial light modulator 3, the optical axis AX <b> 2 of the optical path between the optical path bending mirror 2 and the spatial light modulator 3 in the reference state in which the reflecting surfaces of all the mirror elements 3 a are set along one plane. The configuration is such that the light beam incident along the parallel direction travels in a direction parallel to the optical axis AX3 of the optical path between the spatial light modulator 3 and the relay optical system 4 after being reflected by the spatial light modulator 3. Has been. Further, as described above, the array plane of the plurality of mirror elements 3a of the spatial light modulator 3 and the pupil plane 4c of the relay optical system 4 are optically positioned in a Fourier transform relationship via the front lens group 4a. ing.

Accordingly, the light reflected by the plurality of mirror elements SEa to SEd of the spatial light modulator 3 and given a predetermined angular distribution forms the predetermined light intensity distributions SP1 to SP4 on the pupil plane 4c, and thus the micro fly's eye A light intensity distribution corresponding to the light intensity distributions SP1 to SP4 is formed on the incident surface of the lens. That is, the front lens group 4a determines the angle that the plurality of mirror elements SEa to SEd of the spatial light modulator 3 gives to the emitted light on the pupil plane 4c that is the far field (Fraunhofer diffraction region) of the spatial light modulator 3. Convert to position. Thus, the light intensity distribution (pupil intensity distribution) of the secondary light source formed by the micro fly's eye lens 7 is the light intensity formed on the incident surface of the micro fly's eye lens 7 by the spatial light modulator 3 and the relay optical systems 4 and 5. The distribution corresponds to the distribution.

As shown in FIG. 3, the spatial light modulator 3 is a large number of minute reflecting elements regularly and two-dimensionally arranged along one plane with a planar reflecting surface as the upper surface. A movable multi-mirror including a mirror element 3a. Each mirror element 3a is movable, and the inclination of the reflection surface, that is, the inclination angle and the inclination direction of the reflection surface are independently controlled by the action of the drive unit 3c that operates based on a control signal from the control system CR. Each mirror element 3a can be rotated continuously or discretely by a desired rotation angle with two directions parallel to the reflecting surface and orthogonal to each other as rotation axes. That is, it is possible to two-dimensionally control the inclination of the reflecting surface of each mirror element 3a.

When the reflecting surface of each mirror element 3a is discretely rotated, the rotation angle is set in a plurality of states (for example,..., -2.5 degrees, -2.0 degrees,... 0 degrees, +0.5 degrees) ... +2.5 degrees,. Although FIG. 3 shows a mirror element 3a having a square outer shape, the outer shape of the mirror element 3a is not limited to a square. However, from the viewpoint of light utilization efficiency, the shape can be arranged so that the gap between the mirror elements 3a is reduced (a shape that can be packed most closely). Further, from the viewpoint of light utilization efficiency, the interval between two adjacent mirror elements 3a can be minimized.

In the present embodiment, as the spatial light modulator 3, for example, a spatial light modulator that continuously changes the directions of a plurality of mirror elements 3a arranged two-dimensionally is used. As such a spatial light modulator, for example, European Patent Publication No. 779530, US Pat. No. 5,867,302, US Pat. No. 6,480,320, US Pat. No. 6,600,591 U.S. Patent No. 6,733,144, U.S. Patent No. 6,900,915, U.S. Patent No. 7,095,546, U.S. Patent No. 7,295,726, U.S. Patent No. 7, No. 424,330, U.S. Pat. No. 7,567,375, U.S. Patent Publication No. 2008/0309901, U.S. Pat. Publication No. 2011/0181852 and U.S. Pat. Publication No. 2011/188017. A spatial light modulator can be used. Note that the orientations of the plurality of mirror elements 3a arranged two-dimensionally may be controlled to have a plurality of discrete stages.

In the spatial light modulator 3, the attitude of the plurality of mirror elements 3a is changed by the action of the drive unit 3c that operates according to the control signal from the control system CR, and each mirror element 3a is set in a predetermined direction. The The light reflected at a predetermined angle by each of the plurality of mirror elements 3 a of the spatial light modulator 3 forms a desired pupil intensity distribution on the illumination pupil immediately after the micro fly's eye lens 7. As described above, the spatial light modulator 3 variably forms a pupil intensity distribution on the illumination pupil immediately after the micro fly's eye lens 7. Furthermore, the position of another illumination pupil optically conjugate with the illumination pupil immediately after the micro fly's eye lens 7, that is, the pupil position of the imaging optical system 10 and the pupil position of the projection optical system PL (the aperture stop AS is disposed). The desired pupil intensity distribution is also formed at the (position).

In the exposure apparatus, in order to transfer the pattern of the mask M onto the wafer W with high accuracy and faithfully, it is important to perform exposure under appropriate illumination conditions according to the pattern characteristics of the mask M, for example. In the illumination optical system (1 to 11) of the present embodiment, since the spatial light modulator 3 in which the postures of the plurality of mirror elements 3a are individually changed is used, the pupil formed by the action of the spatial light modulator 3 is used. The intensity distribution can be changed freely and quickly.

However, as described above, in an illumination optical system configured by a normal design using a reflective spatial light modulator having a plurality of mirror elements, not only specularly reflected light (0th-order light) from the mirror elements but also Reflected light (0th-order light, diffracted light) from the surface of the substrate supporting the mirror element also reaches the illumination pupil. In this case, it becomes difficult to form a desired pupil intensity distribution due to the influence of reflected light (unnecessary light) from other than the mirror element, mainly due to the influence of zero-order light from the surface of the substrate.

Hereinafter, in order to facilitate understanding of the description, as shown in FIGS. 1 and 2, a local coordinate system (x1, y1, z1) in the spatial light modulator 3 is set. In the local coordinate system (x1, y1, z1), the x1 axis is set in the direction parallel to the X axis on the arrangement plane of the spatial light modulator 3, and the y1 axis is set in the direction orthogonal to the x1 axis on the arrangement plane. Further, as shown in FIG. 4, the plurality of mirror elements 3a have a rectangular reflecting surface having edges along the x1 direction (X direction) and the y1 direction, and the spatial light modulator 3 extends along the x1 direction. Assume that the rectangular effective reflection region 3d has a long side and a short side along the y1 direction.

In the present embodiment, as shown in FIG. 4, among a plurality of mirror elements 3 a of the spatial light modulator 3, the direction of a pair of edges (y1 direction) facing each other in two adjacent mirror elements 3 a and the spatial light modulation. The direction of the axis of the incident light beam incident on the device 3 (the direction of the optical axis AX2) intersects the XY plane at an angle α ′. Here, the axis of the incident light beam is defined as a line connecting the center of the light quantity in the cross section of the incident light beam, or a line connecting the outline center in the cross section of the incident light beam. The outer shape center is defined as, for example, the center of gravity of the outer shape obtained by connecting the points where the intensity peak is half value (or other appropriate value) in the cross section of the incident light beam.

Therefore, as shown in FIG. 5, between the pair of edges 51 and 52 extending in the y1 direction in two adjacent mirror elements 3a, a direction intersecting the y1 direction at an angle α (arrow F1 in FIG. 5). The light beam enters along the direction indicated by. This crossing angle α is a space where zero-order light passing between the pair of edges 51 and 52 and reflected by the surface of the base 3b (not shown in FIG. 5) passes between the edges 51 and 52. The angle is not emitted from the light modulator 3.

FIG. 6 is a cross-sectional view taken along line AA in FIG. 5, and is a diagram for explaining the minimum value α _m of the crossing angle α. 5 and 6, the width dimension between the pair of edges 51 and 52 is B, the thickness of each mirror element 3a is D, and the surface 3ba of each mirror element 3a and the base 3b (spatial light modulator) 3 is a plane portion substantially parallel to the array plane 3), and G is the incident angle of light on the surface 3ba, the minimum value α _m of the angle α satisfies the following formula (1a). .
B / sin (α _m ) = 2 × (D + G) × tan β (1a)

That is, the zero-order light that passes between the pair of edges 51 and 52 and is reflected by the surface of the base 3 b is not passed through the edges 51 and 52 and emitted from the spatial light modulator 3. Therefore, the angle α at which the direction of the incident light beam intersects the y1 direction in the x1y1 plane needs to satisfy the following conditional expression (1).
α ≧ sin ⁻¹ [B / {2 × (D + G) × tan β}] (1)

As described above, in this embodiment, the optical path bending mirror 2 that deflects the incident light and guides it to the spatial light modulator 3 is the incident side optical system that guides the incident light beam to the spatial light modulator 3, that is, spatial light modulation. An incident side optical system for irradiating light to the plurality of mirror elements 3a of the container 3 is configured. The relay optical system 4 constitutes an emission side optical system into which light from the plurality of mirror elements 3 a of the spatial light modulator 3 enters. As shown in FIG. 4, the plane including the incident optical axis AX <b> 1 to the optical path bending mirror 2 and the incident optical axis AX <b> 2 from the optical path bending mirror 2 to the spatial light modulator 3 is from the spatial light modulator 3. A plane perpendicular to the arrangement plane of the spatial light modulator 3 including the emission optical axis AX3 and the y1 direction intersects at an angle α ′ corresponding to the required angle α. In other words, the plane including the optical axis AX1 on the incident side of the optical path bending mirror 2 and the optical axis AX2 on the exit side of the optical path bending mirror 2 intersects the y1 direction that is the direction of the edge.

Then, as shown in FIG. 5, the y1 direction which is the direction of the pair of edges 51 and 52 facing each other in the two adjacent mirror elements 3a and the axis of the incident light beam incident on the spatial light modulator 3 (on the optical axis AX2). And a direction perpendicular to the arrangement plane of the spatial light modulator 3 and the direction of the intersection line (corresponding to the direction line F1 in FIG. 5) intersects at a required angle α. In other words, the y1 direction that is the direction of the edge is a surface (second surface) that includes the optical axis AX2 of the incident-side optical system (2) and is perpendicular to the array surface (first surface) of the spatial light modulator 3. ). Therefore, in the present embodiment, the zero-order light that passes between the pair of opposing edges 51 and 52 in the two adjacent mirror elements 3a and is reflected by the surface 3ba of the base 3b is reflected between the edges 51 and 52. The light is not emitted from the spatial light modulator 3 after passing through, and thus does not reach the illumination pupil immediately after the micro fly's eye lens 7.

As a result, in the illumination optical system (1 to 11) of the present embodiment, it is possible to achieve a desired pupil intensity distribution while suppressing the influence of unnecessary light from other than the mirror element 3a of the spatial light modulator 3. In the exposure apparatus (1 to WS) of this embodiment, the pattern of the mask M to be transferred is used by using the illumination optical system (1 to 11) that realizes a desired pupil intensity distribution while suppressing the influence of unnecessary light. The fine pattern can be accurately transferred to the wafer W under appropriate illumination conditions realized according to the characteristics.

In the above-described embodiment, as shown in FIG. 4, the incident optical axis AX1 to the optical path bending mirror 2, the incident optical axis AX2 from the optical path bending mirror 2 to the spatial light modulator 3, and the spatial light modulation. The emission optical axis AX3 from the device 3 is not included in one plane. However, without being limited to this, in the configuration in which the incident optical axes AX1 and AX2 and the emission optical axis AX3 are included in one plane, the influence of unnecessary light from other than the mirror element 3a of the spatial light modulator 3 is suppressed. Variations that can be made are also possible.

FIG. 7 is a drawing schematically showing a configuration of an exposure apparatus according to a modification. The modification of FIG. 7 has a configuration similar to that of the embodiment of FIG. However, in the modification of FIG. 7, the incident optical axes AX1 and AX2 and the exit optical axis AX3 are included in one plane (YZ plane), and between the beam transmitting unit 1 and the optical path bending mirror 2. 1 is different from the embodiment of FIG. 1 in that a diffractive optical element 21 and a relay optical system 22 are provided in the optical path. Therefore, in FIG. 7, the same reference numerals as those in FIG. 1 are given to elements having the same functions as the components shown in FIG. Hereinafter, the configuration and operation of the modified example of FIG. 7 will be described focusing on the differences from the embodiment of FIG.

In the modification of FIG. 7, the incident light axis AX1 to the optical path bending mirror 2 and the spatial light modulation from the optical path bending mirror 2 are the same as in the case of a normal design using a spatial light modulator having a number of mirror elements. The optical axis AX2 incident on the optical device 3 and the optical axis AX3 emitted from the spatial light modulator 3 are included in one plane (YZ plane). However, as shown in FIG. 8, the spatial light modulator 3 is installed in such a posture that the long side of the rectangular effective reflection region 3d is inclined with respect to the X direction. In FIG. 8, a local coordinate system (x2, y2) on the array surface of the spatial light modulator 3 is set. In the local coordinate system (x2, y2), the x2 axis in the long side direction of the rectangular effective reflection region 3d on the arrangement surface of the spatial light modulator 3 is perpendicular to the x2 axis on the arrangement surface (of the effective reflection region 3d). The y2 axis is set in the short side direction.

Specifically, the spatial light modulator 3 is obtained by rotating the rectangular effective reflection region 3d by a required angle α from the normal arrangement in which the long side is parallel to the X direction around the normal of the arrangement surface. It is installed at. That is, the direction of the line of intersection between one YZ plane including the incident optical axes AX1 and AX2 and the outgoing optical axis AX3 and the array surface of the spatial light modulator 3 is the required angle α with respect to the y2 direction on the array surface. Tilted. FIG. 8 shows an angle α ″ formed by one YZ plane including the incident optical axes AX1 and AX2 and the outgoing optical axis AX3 and the y2 direction in the XY plane. This angle α ″ is an array. This corresponds to the required angle α on the surface. In other words, the optical axis AX1 on the entrance side of the optical path bending mirror 2, the optical axis AX2 on the exit side of the optical path folding mirror 2, and the optical axis AX3 of the exit side optical system (4) are one plane. (YZ plane), and the direction of the line of intersection between this one plane and the array plane of the spatial light modulator 3 is inclined by a required angle with respect to the y2 direction (edge direction) on the array plane.

Thus, also in the modified example of FIG. 7, the y2 direction that is the direction of a pair of edges facing each other in the two adjacent mirror elements 3a and the axis of the incident light beam incident on the spatial light modulator 3 (on the optical axis AX2). The plane perpendicular to the array plane of the spatial light modulator 3 and the direction of the intersection line of the array plane intersect at a required angle α. Therefore, the zero-order light that passes between a pair of opposing edges in the two adjacent mirror elements 3a and is reflected by the surface of the substrate passes through the pair of edges and is emitted from the spatial light modulator 3. Therefore, the illumination pupil just after the micro fly's eye lens 7 is not reached.

However, simply installing the spatial light modulator 3 in such a posture that the long side of the rectangular effective reflection region 3d is inclined with respect to the X direction covers the entire effective reflection region 3d as shown in FIG. As the illumination light beam, a light beam 53 having a rectangular cross section needs to be incident on the spatial light modulator 3, and a relatively large light amount loss occurs in the spatial light modulator 3. Therefore, in the modification of FIG. 7, the diffractive optical element 21 and the relay optical system 22 are attached in order from the light incident side in the optical path between the beam transmitter 1 and the optical path bending mirror 2. .

Specifically, the diffractive optical element 21 is disposed at or near the front focal position of the relay optical system 22, and the array surface of the spatial light modulator 3 is disposed at or near the rear focal position of the relay optical system 22. . That is, the diffractive optical element 21 is disposed at a position that is optically Fourier-transformed with the arrangement surface of the spatial light modulator 3. Thus, the light beam incident on the diffractive optical element 21 is converted into a light beam that matches the shape of the effective reflection region 3d of the spatial light modulator 3 installed in an inclined posture, and has a rectangular shape without substantial loss of light amount. The effective reflection area 3d is illuminated.

In the modification of FIG. 7, the incident light beam is converted into a light beam that matches the shape of the effective reflection area 3 d of the spatial light modulator 3 and emitted as a light beam conversion element that is optically aligned with the arrangement surface of the spatial light modulator 3. A diffractive optical element 21 disposed at a position having a Fourier transform relationship is used. However, the present invention is not limited to a diffractive optical element, and other suitable optical elements as a light beam conversion element, for example, a fly-eye lens disposed at a position optically Fourier-transformed with the arrangement surface of a spatial light modulator. Such a wavefront division type optical integrator can also be used. In this case, the optical integrator is installed in such a posture that the short side of the rectangular unit wavefront dividing surface is inclined by an angle corresponding to the required angle α with respect to the Y direction.

In the above-described embodiments and modifications, the present invention is described by taking a spatial light modulator in which a plurality of mirror elements have a rectangular reflecting surface as an example. However, the present invention is not limited to the rectangular shape, and the present invention can be similarly applied to a spatial light modulation optical system including a spatial light modulator including a plurality of mirror elements having a hexagonal reflecting surface, for example. . What is important in the present invention is that the direction of an arbitrary pair of edges facing each other in two adjacent mirror elements of the plurality of mirror elements of the spatial light modulator and the axis of the incident light beam incident on the spatial light modulator. In addition, the direction perpendicular to the arrangement plane and the direction of the intersection line of the arrangement plane intersect at a required angle α that is not 0 °.

In the above-described embodiment and modification, a pupil intensity distribution is formed in the illumination pupil immediately after the micro fly's eye lens 7 based on the light beam that has passed through the spatial light modulator 3, and the mask M is formed by light from this pupil intensity distribution. Lighting up. However, the present invention is not limited to this, and the present invention can be similarly applied to an exposure apparatus in which the spatial light modulator of the spatial light modulation optical system is used as a mask. In this case, as an example, the exposure apparatus includes a projection optical system that projects light from the spatial light modulator onto the substrate, and the spatial light modulator is disposed on the object plane of the projection optical system.

In the above-described embodiment, as the spatial light modulator having a plurality of mirror elements that are two-dimensionally arranged and individually controlled, the directions (angle: inclination) of the plurality of two-dimensionally arranged reflecting surfaces are individually set. The controllable spatial light modulator 3 is used. However, the present invention is not limited to this. For example, a spatial light modulator that can individually control the height (position) of a plurality of two-dimensionally arranged reflecting surfaces can be used. As such a spatial light modulator, for example, the spatial light modulator disclosed in FIG. 1d of US Pat. No. 5,312,513 and US Pat. No. 6,885,493 can be used. In these spatial light modulators, by forming a two-dimensional height distribution, an action similar to that of the diffractive surface can be given to incident light. The spatial light modulator having a plurality of reflection surfaces arranged two-dimensionally as described above is modified in accordance with the disclosure of, for example, US Pat. No. 6,891,655 and US Patent Publication No. 2005/0095749. May be.

In the above-described embodiment, a variable pattern forming apparatus that forms a predetermined pattern based on predetermined electronic data can be used instead of a mask. As the variable pattern forming apparatus, for example, a spatial light modulation element including a plurality of reflection elements driven based on predetermined electronic data can be used. An exposure apparatus using a spatial light modulator is disclosed, for example, in US Patent Publication No. 2007/0296936. In addition to the non-light-emitting reflective spatial light modulator as described above, a transmissive spatial light modulator may be used, or a self-luminous image display element may be used.

The exposure apparatus of the above-described embodiment is manufactured by assembling various subsystems including the respective constituent elements recited in the claims of the present application so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. Is done. In order to ensure these various accuracies, before and after assembly, various optical systems are adjusted to achieve optical accuracy, various mechanical systems are adjusted to achieve mechanical accuracy, and various electrical systems are Adjustments are made to achieve electrical accuracy. The assembly process from the various subsystems to the exposure apparatus includes mechanical connection, electrical circuit wiring connection, pneumatic circuit piping connection and the like between the various subsystems. Needless to say, there is an assembly process for each subsystem before the assembly process from the various subsystems to the exposure apparatus. When the assembly process of the various subsystems to the exposure apparatus is completed, comprehensive adjustment is performed to ensure various accuracies as the entire exposure apparatus. The exposure apparatus may be manufactured in a clean room where the temperature, cleanliness, etc. are controlled.

Next, a device manufacturing method using the exposure apparatus according to the above-described embodiment will be described. FIG. 10 is a flowchart showing a manufacturing process of a semiconductor device. As shown in FIG. 10, in the semiconductor device manufacturing process, a metal film is vapor-deposited on a wafer W to be a substrate of the semiconductor device (step S40), and a photoresist, which is a photosensitive material, is applied on the vapor-deposited metal film. (Step S42). Subsequently, using the exposure apparatus of the above-described embodiment, the pattern formed on the mask (reticle) M is transferred to each shot area on the wafer W (step S44: exposure process), and the transfer of the wafer W after the transfer is completed. Development, that is, development of the photoresist to which the pattern has been transferred is performed (step S46: development process).

Thereafter, using the resist pattern generated on the surface of the wafer W in step S46 as a mask, processing such as etching is performed on the surface of the wafer W (step S48: processing step). Here, the resist pattern is a photoresist layer in which unevenness having a shape corresponding to the pattern transferred by the exposure apparatus of the above-described embodiment is generated, and the recess penetrates the photoresist layer. is there. In step S48, the surface of the wafer W is processed through this resist pattern. The processing performed in step S48 includes, for example, at least one of etching of the surface of the wafer W or film formation of a metal film or the like. In step S44, the exposure apparatus of the above-described embodiment performs pattern transfer using the wafer W coated with the photoresist as a photosensitive substrate.

FIG. 11 is a flowchart showing a manufacturing process of a liquid crystal device such as a liquid crystal display element. As shown in FIG. 11, in the manufacturing process of the liquid crystal device, a pattern formation process (step S50), a color filter formation process (step S52), a cell assembly process (step S54), and a module assembly process (step S56) are sequentially performed. In the pattern forming process of step S50, a predetermined pattern such as a circuit pattern and an electrode pattern is formed on the glass substrate coated with a photoresist as the plate P using the projection exposure apparatus of the above-described embodiment. The pattern forming step includes an exposure step of transferring the pattern to the photoresist layer using the projection exposure apparatus of the above-described embodiment, and development of the plate P on which the pattern is transferred, that is, development of the photoresist layer on the glass substrate. And a developing step for generating a photoresist layer having a shape corresponding to the pattern, and a processing step for processing the surface of the glass substrate through the developed photoresist layer.

In the color filter forming process in step S52, a large number of sets of three dots corresponding to R (Red), G (Green), and B (Blue) are arranged in a matrix or three R, G, and B A color filter is formed by arranging a plurality of stripe filter sets in the horizontal scanning direction. In the cell assembly process in step S54, a liquid crystal panel (liquid crystal cell) is assembled using the glass substrate on which the predetermined pattern is formed in step S50 and the color filter formed in step S52. Specifically, for example, a liquid crystal panel is formed by injecting liquid crystal between a glass substrate and a color filter. In the module assembling process in step S56, various components such as an electric circuit and a backlight for performing the display operation of the liquid crystal panel are attached to the liquid crystal panel assembled in step S54.

In addition, the present invention is not limited to application to an exposure apparatus for manufacturing a semiconductor device, for example, an exposure apparatus for a display device such as a liquid crystal display element formed on a square glass plate or a plasma display, It can also be widely applied to an exposure apparatus for manufacturing various devices such as an image sensor (CCD, etc.), micromachine, thin film magnetic head, and DNA chip. Furthermore, the present invention can also be applied to an exposure process (exposure apparatus) when manufacturing a mask (photomask, reticle, etc.) on which mask patterns of various devices are formed using a photolithography process.

In the above-described embodiment, ArF excimer laser light (wavelength: 193 nm) or KrF excimer laser light (wavelength: 248 nm) is used as the exposure light. However, the present invention is not limited to this, and other appropriate laser light sources are used. For example, the present invention can also be applied to an F ₂ laser light source that supplies laser light having a wavelength of 157 nm.

In the above-described embodiment, a so-called immersion method is applied in which the optical path between the projection optical system and the photosensitive substrate is filled with a medium (typically liquid) having a refractive index larger than 1.1. You may do it. In this case, as a technique for filling the liquid in the optical path between the projection optical system and the photosensitive substrate, a technique for locally filling the liquid as disclosed in International Publication No. WO99 / 49504, a special technique, A method of moving a stage holding a substrate to be exposed as disclosed in Kaihei 6-124873 in a liquid tank, or a predetermined stage on a stage as disclosed in Japanese Patent Laid-Open No. 10-303114. A method of forming a liquid tank having a depth and holding the substrate therein can be employed. Here, the teachings of WO99 / 49504, JP-A-6-124873 and JP-A-10-303114 are incorporated by reference.

In the above-described embodiment, the so-called polarization illumination method disclosed in US Publication Nos. 2006/0170901, 2007/0146676, 2007/0195305, and 2010/0165318 is applied. Is also possible. Here, the teachings of US Patent Publication No. 2006/0170901, US Patent Publication Nos. 2007/0146676, 2007/0195305 and 2010/0165318 are incorporated by reference.

In the above-described embodiment, the present invention is applied to the illumination optical system that illuminates the mask (or wafer) in the exposure apparatus. However, the present invention is not limited to this, and an object other than the mask (or wafer) is used. The present invention can also be applied to a general illumination optical system that illuminates the irradiation surface.

The invention can also be described according to the following clauses.
1. In a spatial light modulation optical system including a spatial light modulator having a plurality of mirror elements arranged on a predetermined surface and individually controlled,
Among the plurality of mirror elements of the spatial light modulator, the predetermined plane includes a direction of an arbitrary pair of edges facing each other in two adjacent mirror elements and an axis of an incident light beam incident on the spatial light modulator. A spatial light modulation optical system characterized in that the direction of the line of intersection between the plane perpendicular to the predetermined plane and the predetermined plane intersects at a required angle other than 0 °.
2. The required angle is such that unnecessary light that passes between any pair of facing edges and is reflected by a surface portion substantially parallel to the predetermined surface passes between the pair of edges and exits from the spatial light modulator. The spatial light modulation optical system according to clause 1, wherein the angle is not set.
3. The width dimension between any pair of facing edges is B, the thickness of each mirror element is D, the distance between each mirror element and the surface portion is G, and the incident angle of light to the surface portion is Where β is the required angle α,
α ≧ sin ⁻¹ [B / {2 × (D + G) × tan β}]
3. The spatial light modulation optical system according to clause 2, wherein the condition is satisfied.
4). 4. The spatial light modulation optical system according to any one of clauses 1 to 3, further comprising an incident side optical system that guides the incident light beam to the spatial light modulator.
5. The incident-side optical system has an optical path bending mirror that deflects incident light and guides it to the spatial light modulator,
The plurality of mirror elements have a rectangular reflecting surface having an edge along the first direction;
A plane including the incident optical axis to the optical path bending mirror and the incident optical axis from the optical path bending mirror to the spatial light modulator has an emission optical axis from the spatial light modulator and the first direction. The spatial light modulation optical system according to clause 4, wherein the optical system intersects with a plane perpendicular to the predetermined plane at an angle corresponding to the required angle.
6). The incident-side optical system has an optical path bending mirror that deflects incident light and guides it to the spatial light modulator,
The plurality of mirror elements have a rectangular reflecting surface having an edge along the first direction;
The incident optical axis to the optical path bending mirror, the incident optical axis from the optical path bending mirror to the spatial light modulator, and the outgoing optical axis from the spatial light modulator are included in one plane, 5. The spatial light modulation optical system according to clause 4, wherein the direction of the line of intersection between one plane and the predetermined plane is inclined by the required angle with respect to the first direction.
7). 7. The spatial light modulation according to clause 6, wherein the incident-side optical system includes a light beam conversion element that converts an incident light beam into a light beam that matches a shape of an effective reflection region of the spatial light modulator and emits the light beam. Optical system.
8). The clause 7 is characterized in that the light beam conversion element has a diffractive optical element disposed at a position optically Fourier-transformed with the predetermined surface in the optical path ahead of the optical path bending mirror. Spatial light modulation optical system.
9. The light beam conversion element includes a wavefront splitting type optical integrator disposed in a position optically Fourier-transformed with the predetermined surface in the optical path in front of the optical path bending mirror. 8. The spatial light modulation optical system according to 7.
10. 10. The spatial light modulation optical system according to any one of clauses 5 to 9, wherein the spatial light modulator has a rectangular effective reflection region having a short side along the first direction.
11. 11. The spatial light modulation optical system according to any one of clauses 1 to 10, wherein the spatial light modulator has a drive unit that individually controls and drives the postures of the plurality of mirror elements.
12 12. The spatial light modulation optical system according to clause 11, wherein the driving unit changes the directions of the plurality of mirror elements continuously or discretely.
13. In the illumination optical system that illuminates the illuminated surface with light from the light source,
The spatial light modulation optical system according to any one of clauses 1 to 12,
An illumination optical system comprising: a distribution forming optical system that forms a predetermined light intensity distribution in an illumination pupil of the illumination optical system based on light that has passed through the spatial light modulator.
14 14. The illumination optical system according to clause 13, wherein the distribution forming optical system includes an optical integrator and a condensing optical system disposed in an optical path between the optical integrator and the spatial light modulation optical system. system.
15. Clause 13, wherein the illumination pupil is used in combination with a projection optical system that forms a surface optically conjugate with the irradiated surface, and the illumination pupil is optically conjugate with an aperture stop of the projection optical system. Or the illumination optical system of 14.
16. 16. An exposure apparatus comprising the illumination optical system according to any one of clauses 13 to 15 for illuminating a predetermined pattern, and exposing the predetermined pattern onto a substrate.
17. The exposure according to clause 16, further comprising a projection optical system that forms an image of the predetermined pattern on the substrate, wherein the illumination pupil is at a position optically conjugate with an aperture stop of the projection optical system. apparatus.
18. An exposure apparatus that exposes a substrate with a predetermined pattern,
An exposure apparatus comprising the spatial light modulation optical system according to any one of clauses 1 to 12.
19. A projection optical system for projecting light from the spatial light modulator of the spatial light modulation optical system onto the substrate;
19. The exposure apparatus according to clause 18, wherein the spatial light modulator is disposed on an object plane of the projection optical system.
20. Using the exposure apparatus according to any one of clauses 16 to 19, exposing the predetermined pattern onto a photosensitive substrate;
Developing the photosensitive substrate having the predetermined pattern transferred thereon, and forming a mask layer having a shape corresponding to the predetermined pattern on the surface of the photosensitive substrate;
Processing the surface of the photosensitive substrate through the mask layer. A device manufacturing method comprising:
21. In a spatial light modulation method of spatially modulating incident light using a spatial light modulator having a plurality of mirror elements arranged on a predetermined surface and individually controlled,
Among the plurality of mirror elements of the spatial light modulator, the predetermined plane includes a direction of an arbitrary pair of edges facing each other in two adjacent mirror elements and an axis of an incident light beam incident on the spatial light modulator. A spatial light modulation method characterized in that the direction of the line of intersection between the plane perpendicular to the predetermined plane and the predetermined plane intersects at a required angle other than 0 °.

1 Beam Transmitter 3 Spatial Light Modulator 4, 5 Relay Optical System 7 Micro Fly Eye Lens (Optical Integrator)
8 Condenser optical system 9 Mask blind 10 Imaging optical system LS Light source DTr, DTw Pupil intensity distribution measuring unit CR Control system M Mask MS Mask stage PL Projection optical system W Wafer WS Wafer stage

Claims (24)

1. In a spatial light modulation optical system including a spatial light modulator having a plurality of mirror elements arranged on the first surface and individually controlled,
   An incident-side optical system that irradiates light to the plurality of mirror elements of the spatial light modulator;
   Of the plurality of mirror elements of the spatial light modulator, the direction of any pair of edges facing each other in two adjacent mirror elements is perpendicular to the first surface including the optical axis of the incident side optical system. A spatial light modulation optical system characterized by intersecting the second surface.
2. The intersection angle between the direction of the line of intersection of the first surface and the second surface and the direction of the edge is a surface portion that passes between the pair of opposing edges and is substantially parallel to the first surface. 2. The spatial light modulation optical system according to claim 1, wherein the reflected unnecessary light passes through the pair of edges and is not emitted from the spatial light modulator. 3.
3. The width dimension between any pair of facing edges is B, the thickness of each mirror element is D, the distance between each mirror element and the surface portion is G, and the incident angle of light to the surface portion is Where β is the crossing angle α,
   α ≧ sin ⁻¹ [B / {2 × (D + G) × tan β}]
   The spatial light modulation optical system according to claim 2, wherein the following condition is satisfied.
4. An emission-side optical system on which light from the plurality of mirror elements is incident;
   The incident-side optical system has an optical path bending mirror that deflects incident light and guides it to the spatial light modulator,
   The plurality of mirror elements have a rectangular reflecting surface having an edge along the first direction;
   The plane including the optical axis on the incident side of the optical path bending mirror and the optical axis on the exit side of the optical path bending mirror in the incident side optical system intersects the first direction. Item 4. The spatial light modulation optical system according to any one of Items 1 to 3.
5. An emission-side optical system on which light from the plurality of mirror elements is incident;
   The incident-side optical system has an optical path bending mirror that deflects incident light and guides it to the spatial light modulator,
   The plurality of mirror elements have a rectangular reflecting surface having an edge along the first direction;
   The optical axis on the incident side of the optical path bending mirror, the optical axis on the output side of the optical path bending mirror, and the optical axis of the output optical system in the incident side optical system are included in one plane. 4. The spatial light modulation according to claim 1, wherein a direction of an intersection line between one plane and the first surface is inclined by a predetermined angle with respect to the first direction. 5. Optical system.
6. The spatial light according to claim 5, wherein the incident-side optical system includes a light beam conversion element that converts an incident light beam into a light beam that matches a shape of an effective reflection region of the spatial light modulator and emits the light beam. Modulation optical system.
7. 7. The light beam converting element includes a diffractive optical element disposed at a position optically Fourier-transformed with the first surface in an optical path in front of the optical path bending mirror. The spatial light modulation optical system described in 1.
8. The light beam conversion element is disposed at a position optically Fourier-transformed with the first surface in the optical path in front of the optical path bending mirror, and is in a plane crossing the optical axis of the incident side optical system. The spatial light modulation optical system according to claim 6, further comprising an optical integrator including a plurality of wavefront division surfaces arranged in parallel.
9. 9. The spatial light modulation optical system according to claim 4, wherein the spatial light modulator includes a rectangular effective reflection region having a short side along the first direction. 10.
10. In a spatial light modulation optical system including a spatial light modulator having a plurality of mirror elements arranged on a predetermined surface and individually controlled,
    Of the plurality of mirror elements of the spatial light modulator, the direction of an arbitrary pair of edges facing each other in two adjacent mirror elements passes between the pair of any facing edges and is substantially the same as the predetermined surface. A spatial light modulation optical system, characterized in that the angle is such that unnecessary light reflected by parallel plane portions is reduced.
11. The direction of the edge and the direction of the intersection of the plane perpendicular to the predetermined plane including the axis of the incident light beam incident on the spatial light modulator and the predetermined plane intersect at a required angle other than 0 °. The spatial light modulation optical system according to claim 10.
12. The spatial light modulation optical system according to any one of claims 1 to 11, wherein the spatial light modulator includes a drive unit that individually controls and drives the postures of the plurality of mirror elements.
13. The spatial light modulation optical system according to claim 12, wherein the driving unit changes the directions of the plurality of mirror elements continuously or discretely.
14. In the illumination optical system that illuminates the illuminated surface with light from the light source,
    The spatial light modulation optical system according to any one of claims 1 to 13,
    An illumination optical system, comprising: a distribution forming optical system that distributes light having passed through the spatial light modulator to an illumination pupil of the illumination optical system with a predetermined light intensity distribution.
15. The distribution forming optical system includes: an optical integrator having a plurality of wavefront splitting surfaces arranged in parallel in a plane crossing the optical axis of the distribution forming optical system; and an optical path between the optical integrator and the spatial light modulation optical system The illumination optical system according to claim 14, further comprising a condensing optical system disposed therein.
16. The projection pupil is used in combination with a projection optical system that forms a surface optically conjugate with the irradiated surface, and the illumination pupil is at a position optically conjugate with an aperture stop of the projection optical system. The illumination optical system according to 14 or 15.
17. An exposure apparatus comprising the illumination optical system according to any one of claims 14 to 16 for illuminating a predetermined pattern, and exposing the predetermined pattern onto a substrate.
18. The projection optical system for forming an image of the predetermined pattern on the substrate is provided, and the illumination pupil is at a position optically conjugate with an aperture stop of the projection optical system. Exposure device.
19. An exposure apparatus that exposes a substrate with a predetermined pattern,
    An exposure apparatus comprising the spatial light modulation optical system according to any one of claims 1 to 13.
20. A projection optical system for projecting light from the spatial light modulator of the spatial light modulation optical system onto the substrate;
    The exposure apparatus according to claim 19, wherein the spatial light modulator is disposed on an object plane of the projection optical system.
21. Using the exposure apparatus according to any one of claims 17 to 20, exposing the predetermined pattern to a photosensitive substrate;
    Developing the photosensitive substrate having the predetermined pattern transferred thereon, and forming a mask layer having a shape corresponding to the predetermined pattern on the surface of the photosensitive substrate;
    Processing the surface of the photosensitive substrate through the mask layer. A device manufacturing method comprising:
22. In a spatial light modulation method of spatially modulating incident light using a spatial light modulator having a plurality of mirror elements arranged on a predetermined surface and individually controlled,
    Among the plurality of mirror elements of the spatial light modulator, the predetermined plane includes a direction of an arbitrary pair of edges facing each other in two adjacent mirror elements and an axis of an incident light beam incident on the spatial light modulator. A spatial light modulation method characterized in that the direction of the line of intersection between the plane perpendicular to the predetermined plane and the predetermined plane intersects at a required angle other than 0 °.
23. In a spatial light modulation method of spatially modulating incident light using a spatial light modulator having a plurality of mirror elements arranged on the first surface and individually controlled,
    Irradiating light to the plurality of mirror elements of the spatial light modulator via an incident side optical system;
    Reflecting the light at the plurality of mirror elements of the spatial light modulator;
    Including
    Of the plurality of mirror elements of the spatial light modulator, the direction of any pair of edges facing each other in two adjacent mirror elements is perpendicular to the first surface including the optical axis of the incident side optical system. A spatial light modulation method characterized by intersecting the second surface.
24. In a spatial light modulation method of spatially modulating incident light using a spatial light modulator having a plurality of mirror elements arranged on a predetermined surface and individually controlled,
    Irradiating light to the plurality of mirror elements of the spatial light modulator via an incident side optical system;
    Reflecting the light at the plurality of mirror elements of the spatial light modulator;
    Of the plurality of mirror elements of the spatial light modulator, unnecessary light that passes between any pair of opposing edges in two adjacent mirror elements and is reflected by a surface portion substantially parallel to the predetermined surface is reduced. To do
    A spatial light modulation method comprising:

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