HK1141334A

HK1141334A - Spatial light modulation unit, illumination apparatus, exposure apparatus, and device manufacturing method

Info

Publication number: HK1141334A
Application number: HK10107744.2A
Authority: HK
Inventors: 田中裕久
Original assignee: 株式会社尼康
Priority date: 2007-10-03
Filing date: 2008-10-02
Publication date: 2010-11-05

Description

Spatial light modulation unit, illumination apparatus, exposure apparatus, and device manufacturing method

Technical Field

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

Background

Reflective spatial light modulators are known as conventional spatial light modulators used to form pupil illumination distributions (e.g., dipole, quadrupole, or other distributions) for modified illumination in an exposure apparatus (see, for example, japanese patent laid-open application No. 2002-353105). In laid-open application No. 2002-353105, a reflective spatial light modulator is arranged such that light is obliquely incident to the reflective spatial light modulator so as to separate an optical path incident to the spatial light modulator from an optical path (reflected optical path) exiting from the spatial light modulator without a significant change in the configuration of an illumination optical system in an exposure apparatus.

Disclosure of Invention

However, in the spatial light modulator described in the aforementioned laid-open application No. 2002-353105, the optical path exiting from the spatial light modulator cannot be coaxial with the optical path incident to the spatial light modulator, and therefore it is difficult to form a desired optical path when it is arranged in an optical system.

It is an object of the present invention to provide a spatial light modulation unit that can be arranged in an optical system to form a desired light path.

A spatial light modulation unit according to an embodiment of the present invention is a spatial light modulation unit that can be arranged in an optical system and can be arranged along an optical axis of the optical system, the spatial light modulation unit including: a first folding surface to fold a light ray incident parallel to an optical axis of the optical system; a reflective spatial light modulator to reflect the light folded on the first folding surface; and a second folding surface to fold the light reflected on the spatial light modulator and send the light forward into the optical system; wherein the spatial light modulator applies spatial modulation to the light rays according to a position where the light rays folded on the first folding surface are incident on the spatial light modulator.

The spatial light modulation unit includes a spatial light modulator that applies spatial modulation to a light ray according to a position where the light ray is incident. For this reason, it is capable of forming a desired pupil luminance distribution (e.g., a dipole, quadrupole, or other distribution). In addition to the reflective spatial light modulator, it also comprises a first folding surface and a second folding surface. For this reason, they may be arranged in an optical system to form a desired optical path.

The illumination apparatus according to the embodiment is an illumination apparatus that illuminates a first surface with light supplied from a light source, the illumination apparatus including the aforementioned spatial light modulation unit.

An illumination apparatus according to another embodiment is an illumination apparatus that illuminates an illumination target surface on the basis of light rays from a light source, the illumination apparatus including: a spatial light modulator including a plurality of optical elements that are two-dimensionally arranged and individually controlled; a diffractive optical element arrangeable in the lighting device; a first optical path in which a spatial light modulator may be arranged at a first position; a second optical path in which the diffractive optical element is arrangeable at a second position; a third optical path which is an optical path between the light source and the first optical path and an optical path between the light source and the second optical path; and a fourth optical path that is an optical path between the first optical path and the illumination target surface and an optical path between the second optical path and the illumination target surface; wherein the first optical path and the second optical path are switchable to each other, and wherein an optical axis at an exit of the third optical path is coaxial with an optical axis at an entrance of the fourth optical path.

An illumination apparatus according to still another embodiment is an illumination apparatus that illuminates a first surface with light supplied from a light source, the illumination apparatus including a spatial light modulation unit including: a spatial light modulator that applies spatial modulation to a light ray according to a position at which the light ray is incident; and a diffractive optical element that forms a first pupil luminance distribution with light that has not passed through the spatial light modulator of the spatial light modulation unit;

the illumination apparatus is configured to form a second pupil luminance distribution at least partially overlapping the first pupil luminance distribution with light rays from the spatial light modulator of the spatial light modulation unit.

An exposure apparatus according to an embodiment is an exposure apparatus that projects an image of a first surface onto a second surface, the exposure apparatus including: the lighting device is used for lighting the first surface; and a projection optical system that forms an image of the first surface on the second surface based on light from an illumination area formed on the first surface by the illumination device.

A device manufacturing method according to an embodiment, comprising: a preparation step of preparing a photosensitive substrate; a disposing and projecting step of disposing a photosensitive substrate on the second surface in the aforementioned exposure apparatus, and projecting an image of a predetermined pattern located on the first surface onto the photosensitive substrate to effect exposure thereof; a developing step of developing the photosensitive substrate on which the image of the pattern has been projected to form a mask layer having a shape corresponding to the pattern on a surface of the photosensitive substrate; and a processing step of processing the surface of the photosensitive substrate through the mask layer.

Embodiments of the present invention successfully provide a spatial light modulation unit that can be arranged in an optical system to form a desired light path.

Drawings

Fig. 1 is a configuration diagram schematically showing an exposure apparatus according to a first embodiment.

Fig. 2 is a diagram for explaining the arrangement relationship of the spatial light modulation unit and the diffractive optical unit.

Fig. 3 is a diagram for explaining another arrangement relationship of the spatial light modulation unit and the diffractive optical unit.

Fig. 4 is a diagram for explaining a configuration in an IV-IV cross section of the spatial light modulation unit shown in fig. 2.

Fig. 5 is a partial perspective view of a spatial light modulator provided in the spatial light modulation unit.

Fig. 6 is a diagram showing the shape of an illumination field in the case of annular illumination.

Fig. 7 is a flowchart of a method of manufacturing a semiconductor device.

Fig. 8 is a flowchart of a method of manufacturing a liquid crystal display device.

Fig. 9 is a configuration diagram of a maskless exposure apparatus schematically shown as a modified example of the exposure apparatus according to the first embodiment.

Fig. 10 is a configuration diagram schematically showing an exposure apparatus according to a second embodiment.

Fig. 11 is a diagram for explaining the arrangement of the spatial light modulation unit.

Fig. 12 is a diagram showing a pupil luminance distribution formed by light beams passing through the diffractive optical unit but not the spatial light modulation unit.

Fig. 13 is a diagram showing a pupil luminance distribution formed by light beams that do not pass through the diffractive optical unit but pass through the spatial light modulation unit.

Fig. 14 is a diagram showing pupil luminance distributions resulting from the overlap of the first pupil luminance distribution and the second pupil luminance distribution on the pupil plane.

Fig. 15 is a diagram for explaining the arrangement of another spatial light modulation unit.

Fig. 16 is a diagram for explaining the arrangement of the spatial light modulation unit.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that in the description, the same elements or elements having the same functionality will be denoted by the same reference symbols without redundant description.

(first embodiment)

The configuration of the exposure apparatus EA1 according to the first embodiment will be described with reference to fig. 1. Fig. 1 is a configuration diagram schematically showing an exposure apparatus of a first embodiment.

The exposure apparatus EA1 of the first embodiment has an illumination apparatus IL provided with a spatial light modulation unit SM1, a mask stage (stage) MS supporting a mask M, a projection optical system PL, and a wafer stage WS supporting a wafer W, along an optical axis Ax of the apparatus. The exposure apparatus EA1 illuminates the mask M with an illumination apparatus IL based on light supplied from the light source 1, and projects an image of the first surface, which is the surface Ma on which the pattern of the mask M is formed, onto the second surface, which is the projection surface Wa, on the wafer W using the projection optical system PL. The illumination apparatus IL, which illuminates the surface Ma on which the pattern of the mask M is placed, i.e., the first surface, with light supplied from the light source 1, performs modified illumination (e.g., two-pole, four-pole, or other illumination) with the spatial light modulation unit SM 1.

The illumination apparatus IL has, along the optical axis Ax, a spatial light modulation unit SM1, a diffractive optical unit 2, a zoom optical system 3, a fly eye (fly eye) lens 4, a condensing optical system 5, and a folding mirror 6. Each of the spatial light modulation unit SM1 and the diffractive optical unit 2 is insertable into or retractable from the optical path of the illumination apparatus IL. The spatial light modulation unit SM1 and the diffractive optical unit 2 each form a desired pupil luminance distribution in their far fields.

The fly-eye lens 4 is configured such that a plurality of lens elements are two-dimensionally and densely arranged. The plurality of lens elements forming the fly-eye lens 4 are arranged so that the optical axis of each lens element becomes parallel to the optical axis Ax, which is the optical axis of the illumination apparatus IL including the fly-eye lens 4 and the optical axis of the exposure apparatus. The fly-eye lens 4 divides the wavefront (wave-front) of the incident light to form a secondary light source composed of as many light source images as lens elements on a back focal plane thereof. Since the mask M located on the illumination target surface is illuminated by Koehler (Koehler) illumination in the present example, the plane on which this secondary light source is formed is a plane conjugate to the aperture stop of the projection optical system PL and may be referred to as an illumination pupil plane of the illumination apparatus IL. In general, the illumination target surface (the surface on which the mask M is disposed or the surface on which the wafer W is disposed) becomes an optical fourier transform surface with respect to the illumination pupil plane. The pupil luminance distribution is a luminance distribution on an illumination pupil plane of the illumination apparatus IL or on a plane conjugate to the illumination pupil plane. However, when the number of wavefront divisions by the fly-eye lens 4 is large, the total luminance distribution formed on the entrance surface of the fly-eye lens 4 exhibits a high correlation (correlation) with the total luminance distribution (pupil luminance distribution) of the entire secondary light source, and therefore, the luminance distribution on the entrance surface of the fly-eye lens 4 and on a plane conjugate to the entrance surface may also be referred to as a pupil luminance distribution.

The condensing optical system 5 condenses the light emitted from the fly-eye lens 4 and illuminates the mask M on which a predetermined pattern is formed. The folding mirror 6 is arranged in the condensing optical system 5 and folds an optical path of the light beam passing through the condensing optical system. The mask M is mounted on a mask stage MS.

The projection optical system PL forms an image of the first surface on a projection surface (second surface) Wa of the wafer W mounted on the wafer stage WS based on light from an illumination area formed on a pattern surface (first surface) Ma of the mask M by the illumination device IL.

The arrangement relationship of the spatial light modulation unit SM1 and the diffractive optical unit 2 will be described below with reference to fig. 2 and 3. Fig. 2 is a diagram for explaining the arrangement in the case where the spatial light modulation unit SM1 is inserted along the optical axis Ax of the exposure apparatus EA 1. Fig. 3 is a diagram for explaining an arrangement in a case where the spatial light modulation unit SM1 is located outside the optical axis Ax of the exposure apparatus EA1 and one of the plurality of diffractive optical elements 2b in the diffractive optical unit 2 is inserted along the optical axis Ax of the exposure apparatus EA 1.

As shown in fig. 2 and 3, the diffractive optical unit 2 has a turret part 2a formed with a recess 2c, and a plurality of diffractive optical elements 2b formed on the turret (turret) part 2 a. The diffractive optical element 2b is made by forming a level difference in the turret part 2a with a pitch approximately equal to the wavelength of the exposure light (illumination light), and functions to diffract the incident beam at a desired angle.

As shown in fig. 2, in the fixed state of the diffractive optical unit 2, when the spatial light modulation unit SM1 is arranged to be inserted into the space created by the notch 2c of the diffractive optical unit 2, the spatial light modulation unit SM1 may be arranged on the optical axis Ax of the exposure apparatus EA 1. As shown in fig. 3, in the fixed state of the diffractive optical unit 2, when the spatial light modulation unit SM1 is removed from inside the notch 2c of the diffractive optical unit 2, the spatial light modulation unit SM1 may also be located outside the optical axis Ax of the exposure apparatus EA 1. Alternatively, the diffractive optical unit 2 may be moved in a fixed state of the spatial light modulation unit SM 1. In this way, the spatial light modulation unit SM1 may be arranged along the optical axis Ax of the exposure apparatus EA1 or along the optical axis Ax of the illumination apparatus IL.

Since the spatial light modulation unit SM1 is larger in size and mass than the diffractive optical unit 2, it is not mounted on the same turret part 2a but arranged in the recess 2c of the diffractive optical unit 2. Since a cable for transmitting a drive signal is connected to the spatial light modulation unit SM1, in the configuration in which the unit SM1 is disposed in the recess 2, the unit SM1 does not have to be mounted on the turret while the cable is being pulled (trail).

When the spatial light modulation unit SM1 is removed from the optical axis Ax (as shown in fig. 3), the diffractive optical unit 2 is arranged in a state where its rotational axis is parallel to the optical axis Ax and is eccentric with respect to the optical axis Ax. Next, the diffractive optical unit 2 is rotated so that one of the plurality of diffractive optical elements 2b in the turret member 2a is positioned on the optical axis Ax. In the turret part 2a, as shown in fig. 2 and 3, diffractive optical elements 2b are arranged along the circumferential direction thereof. The diffractive optical element 2b is an element that each diffracts an incident beam to generate a plurality of beams eccentric with respect to the optical axis Ax, and is set to have their respective different diffraction properties (e.g., diffraction angles).

The configuration of the spatial light modulation unit SM1 will be described below with reference to fig. 4 and 5. Fig. 4 is a diagram for explaining a configuration in an IV-IV cross section of the spatial light modulation unit SM1 shown in fig. 2. Fig. 5 is a partial perspective view of the spatial light modulator S1 in the spatial light modulation unit SM 1. For better viewing, fig. 4 is depicted without shading (hashing) the cross-section.

As shown in fig. 4, the spatial light modulation unit SM1 has a prism P1 and a reflective spatial light modulator S1 integrally attached to the prism P1. The prism P1 is made of a glass material (e.g., fluorite). The prism P1 has a shape in which one side surface of a rectangular parallelepiped is pressed into a V-shaped wedge. That is, in the prism P1, one side face of the rectangular parallelepiped is composed of two planes PS1, PS2 (a first plane PS1 and a second plane PS2) intersecting at an obtuse angle, while an intersection line (straight line) P1a therebetween is recessed inside (side). The spatial light modulator S1 is attached to the side facing the two sides that meet at the intersection line P1 a. The optical material forming the prism P1 is not limited to fluorite, but may be silica glass or other optical glass.

The inner surfaces of these two side surfaces which meet at the intersection line P1a serve as the first reflecting surface R11 and the second reflecting surface R12. Accordingly, the first reflective surface R11 is located on the first plane PS 1. The second reflective surface R12 lies on a second plane PS2 intersecting the first plane PS 1. The angle between the first reflective surface R11 and the second reflective surface R12 is an obtuse angle.

The angles herein may be determined, for example, as follows: the angle between the first reflective surface R11 and the second reflective surface R12 is 120 °; the angle between the side face of the prism P1 perpendicular to the optical axis Ax and the first reflection surface R11 is 60 °; an angle between a side surface of the prism P1 perpendicular to the optical axis Ax and the second reflection surface R12 is 60 °.

The prism P1 is arranged such that the side face to which the spatial light modulator S1 is attached is parallel to the optical axis Ax, the first reflection surface R11 is located on the light source 1 side (upstream in the exposure apparatus EA 1), and the second reflection surface R12 is located on the fly-eye lens 4 side (downstream in the exposure apparatus EA 1). Therefore, as shown in fig. 4, the first reflection surface R11 of the prism P1 is arranged obliquely with respect to the optical axis Ax of the exposure apparatus EA 1. As shown in fig. 4, the second reflection surface R12 of the prism P1 is also disposed obliquely with respect to the optical axis Ax of the exposure apparatus EA1 in the direction opposite to the direction of inclination of the first reflection surface R11.

The first reflection surface R11 of the prism P1 reflects light rays incident parallel to the optical axis Ax of the exposure apparatus EA 1. The spatial light modulator S1 is arranged in an optical path between the first and second reflective surfaces R11 and R12, and reflects light rays reflected on the first reflective surface R11. The second reflection surface R12 of the prism P1 reflects the light reflected on the spatial light modulator S1 and emits the reflected light into the illumination apparatus IL of the exposure apparatus EA1, specifically, into the zoom optical system 3.

Therefore, a ridge line (intersection line) P1a formed by the first plane PS1 and the second plane PS2 is located on the side of the spatial light modulator S1 with respect to the first reflective surface R11 and the second reflective surface R12.

The prism P1 in this example is integrally formed from one optical block, but the prism P1 may be constructed using a plurality of optical blocks.

The spatial light modulator S1 applies spatial modulation to light rays reflected on the first reflective surface R11 according to the position where the light rays are incident on the spatial light modulator S1. As described below, the spatial light modulator S1 includes a large number of micro-mirror elements SE1 arranged two-dimensionally. For this reason, for example, ray L1 in the beam incident on spatial light modulator S1 impinges on mirror element SE1a in the plurality of mirror elements SE1 of spatial light modulator S1, and ray L2 impinges on mirror element SE1b, different from mirror element SE1a, in the plurality of mirror elements SE1 of spatial light modulator S1. The mirror elements SE1a, SE1b apply their respective spatial modulation set according to their position to the rays L1, L2, respectively. The spatial light modulator S1 modulates the light so that the light reflected on the second reflection surface R12 to be emitted into the zoom optical system 3 becomes parallel to the light incident on the first reflection surface R11.

The prism P1 is arranged such that the air equivalent length from the incident positions IP1, IP2 at which the rays L1, L2 are incident into the prism P1 to the outgoing positions OP1, OP2 at which said rays are outgoing from the prism P1 after passing through the mirror elements SE1a, SE1b is equal to the air equivalent length from the positions corresponding to the incident positions IP1, IP2 to the positions corresponding to the outgoing positions OP1, OP2 when the prism P1 is outside the exposure apparatus EA 1. The air equivalent length is an optical path length obtained by reducing an optical path length in an optical system to an optical path length in air having a refractive index of 1, and the air equivalent length of an optical path in a medium having a refractive index of n is obtained by multiplying the optical path length thereof by 1/n.

The spatial light modulator S1 may be arranged at a position optically equivalent to the mounting surface of the diffractive optical element 2b on which the diffractive optical unit 2 is mounted, that is, the position of the mounting surface of the diffractive optical element 2b observed through the second reflection surface R12 when viewed from the exit side (the zoom optical system 3 side) of the spatial light modulation unit SM 1.

As shown in fig. 5, the spatial light modulator S1 is a movable multi-mirror including a mirror element SE1, and the mirror element SE1 is a large number of micro-reflective elements whose planar-shaped reflective surfaces are placed upward. Each mirror element SE1 is movable, and the tilt of its reflective surface (i.e., the angle and direction of tilt of the reflective surface) is independently driven and controlled by a control system (not shown). Each mirror element SE1 can be continuously rotated a desired angle of rotation about each of the axes of rotation along two directions parallel to its reflective surface and perpendicular to each other. That is, with respect to each mirror element SE1, its tilt can be controlled in two dimensions along its reflective surface.

The profile (contourr) of each mirror element SE1 herein is square, but the profile is not limited thereto. However, the profile may be a shape such that the mirror elements can be arranged without a space in terms of light utilization efficiency. The gap between the adjacent mirror elements SE1 can be set to the necessary minimum spacing. Furthermore, the mirror element SE1 may be as small as possible in order to make subtle changes in lighting conditions possible. The shape of the reflective surface of each mirror element SE1 is not limited to a plane, but may be a curved surface such as a concave surface or a convex surface.

An optical path extending from the first reflective surface R11 of the prism P1 to the second reflective surface R12 of the prism P1 and passing through the first position of the spatial light modulator S1 where the spatial light modulation unit SM1 can be arranged is referred to as a first optical path. An optical path extending from a position where the first reflecting surface R11 of the prism P1 can be arranged to a position where the second reflecting surface R12 of the prism P1 can be arranged and passing through a second position where the diffractive optical element 2b of the diffractive optical unit 2 can be arranged is referred to as a second optical path. An optical path from the light source 1 to a position where the first reflection surface R11 of the prism P1 can be arranged is referred to as a third optical path. An optical path from a position where the second reflecting surface R12 of the prism P1 can be arranged to the illumination target surface is referred to as a fourth optical path.

That is, the first optical path is an optical path through which light passes only when the illumination target surface is illuminated with light from the light source 1 that has passed through the spatial light modulator S1. The second optical path is an optical path through which light passes only when the illumination target surface is illuminated with light from the light source 1 that has passed through the diffractive optical element 2 b. The third optical path is an optical path between the light source 1 and the first optical path and a path between the light source 1 and the second optical path. The fourth optical path is an optical path between the first optical path and the illumination target surface and an optical path between the second optical path and the illumination target surface. The optical path is a path intended for light to pass through in the use state.

As described above, the spatial light modulation unit SM1 and the diffractive optical unit 2 are arranged such that their insertion can be switched from one to the other with respect to the optical axis Ax of the apparatus. That is, the first optical path and the second optical path are switchable. In addition, the optical axis Ax of the device at the exit of the third optical path is coaxial with the optical axis Ax of the device at the entrance of the fourth optical path.

The first reflective surface R11 of the prism P1 serves as a first optical surface to direct light from the third optical path to the spatial light modulator S1, and the second reflective surface R12 of the prism P1 serves as a second optical surface to direct light that has passed through the spatial light modulator S1 to the fourth optical path. Since the first optical surface and the second optical surface are both reflective surfaces of the prism P1 in the spatial light modulation unit SM1 that can be inserted into or retracted from the optical path of the illumination apparatus IL, the first optical surface and the second optical surface can be integrally inserted into or retracted from the optical path of the illumination apparatus IL. Furthermore, the spatial light modulator S1 may also be inserted into or retracted from the optical path of the illumination device IL.

The first reflection surface R11 of the prism P1 may be regarded as a first folding surface that folds light rays incident parallel to the optical axis to a direction different from the incident direction, and the second reflection surface R12 of the prism P1 may be regarded as a second folding surface that folds light rays reflected on the spatial light modulator S1 to the optical path of the illumination apparatus IL. The first and second folded surfaces may be reflective, refractive, or diffractive surfaces.

The spatial light modulation unit SM1 enables the modified illumination to form a desired pupil luminance distribution, e.g., circular, annular, dipole or quadrupole illumination. Fig. 6 is a diagram showing the shape of the illumination field in the far field of the spatial light modulation unit SM1 (or on the optical fourier transform surface of the spatial light modulation unit SM1) in the case of ring illumination. The shaded area in fig. 6 is the illumination field.

A method of manufacturing a device using the exposure apparatus EA1 of the present embodiment will be described below with reference to a flowchart shown in fig. 7. The first step S301 in fig. 7 is to deposit a metal film on each wafer in a batch of wafers. The next step S302 is to apply a photoresist to the metal film on each wafer in the batch. That is, steps S301 and S302 correspond to the step of preparing the photosensitive substrate, i.e., the wafer W.

The subsequent step S303 sequentially transfers the image of the pattern on the mask M into each shot (shot) region on each wafer in the lot through the projection optical system PL using the exposure apparatus EA1 of the foregoing embodiment.

In step S303, first, a wafer W is arranged on the wafer stage WS. Light is emitted from the light source 1 along the optical axis Ax to the spatial light modulation unit SM1 or the diffractive optical unit 2. The light is spatially modulated during its passage through the spatial light modulation unit SM1 or the diffractive optical element 2. In the exposure apparatus EA1, the spatial light modulation unit SM1 and the diffractive optical unit 2 can be inserted into or retracted from the optical axis Ax according to the shape of the modified illumination to be desired.

The light rays spatially modulated by the spatial light modulation unit SM1 or the diffractive optical unit 2 travel through the zoom optical system 3 to form, for example, a circular ring-shaped (annular shape) illumination field centered on the optical axis Ax on the incident surface of the fly-eye lens 4 as a wavefront division type optical integrator. The light incident on the fly-eye lens 4 undergoes wavefront division in the fly-eye lens 4. This results in the formation of a secondary light source composed of as many light source images as the lens elements in the fly-eye lens 4 on the back focal plane of the fly-eye lens 4.

The light emitted from the fly-eye lens 4 is incident on the condensing optical system 5. The condensing optical system 5 and the fly-eye lens 4 function to uniformly illuminate the pattern surface Ma of the mask M. In this way, an image of the pattern surface Ma is formed on the surface of the wafer W, i.e., the projection surface Wa, based on the light from the illumination area formed on the pattern surface Ma of the mask M by the illumination apparatus IL. Accordingly, an image of the pattern surface Ma on the first surface is projected onto the wafer W disposed on the second surface to effect exposure thereof.

The subsequent step S304 will effect the development of the photoresist on the wafers in the lot. This step results in forming a mask layer having a shape corresponding to the pattern surface Ma on the projection surface Wa of the wafer W.

Step S305 is to process the projected surface Wa of the wafer W through the mask layer formed in step S304. Specifically, etching is performed on the wafers in the lot using the resist pattern as a mask, whereby a circuit pattern corresponding to the pattern on the mask is formed in each irradiated area on each wafer. Thereafter, a device such as a semiconductor device is manufactured by including a step of forming a circuit pattern in an upper layer. The above semiconductor device manufacturing method permits us to manufacture a semiconductor device having an extremely fine circuit pattern with high throughput.

The exposure apparatus of the foregoing embodiment is also applicable to manufacturing a liquid crystal display device as a microdevice by forming a predetermined pattern (circuit pattern, electrode pattern, etc.) on a plate (glass substrate). An example of the method in this case will be described below with reference to the flowchart of fig. 8. In fig. 8, a pattern forming step S401 is to perform a so-called photolithography process of transferring the pattern of a mask onto a photosensitive substrate (a resist-coated glass substrate, or the like) using the exposure apparatus of the foregoing embodiment to effect exposure thereof. The photolithography process results in the formation of a predetermined pattern including a large number of electrodes and other objects on the photosensitive substrate. Thereafter, the exposed substrate is processed by including a developing step, an etching step, a resist removing step, and other steps, thereby forming a predetermined pattern on the substrate, followed by the next color filter forming step S402.

The next color filter forming step S402 is to form a color filter in which a large number of groups of three dots corresponding to R (red), G (green), and B (blue) are arrayed in a matrix form, or a plurality of filter groups of three stripes R, G and B are arrayed in the horizontal scanning line direction. After the color filter forming step S402 is completed, a cell assembling step S403 is performed. In the cell assembly step S403, a liquid crystal panel (liquid crystal cell) is assembled using a substrate having a predetermined pattern obtained in the pattern formation step S401, a color filter obtained in the color filter formation step S402, and the like.

In the cell assembly step S403, a liquid crystal panel (liquid crystal cell) is manufactured, for example, by pouring liquid crystal between the substrate having the predetermined pattern obtained in the pattern formation step S401 and the color filter obtained in the color filter formation step S402. Thereafter, a module assembling step S404 is performed to attach components such as a circuit for a display operation of the assembled liquid crystal panel (liquid crystal cell) and a backlight, thereby completing the liquid crystal display device. The above-described manufacturing method of the liquid crystal display device permits us to manufacture the liquid crystal display device having an extremely fine circuit pattern with high throughput. The present embodiment is not limited to the manufacturing process applied to semiconductor devices and liquid crystal display devices, but can also be widely applied to, for example, plasma displays and other manufacturing processes, and manufacturing processes of various devices (e.g., micro-machines, MEMS (micro-electro-mechanical systems), thin film magnetic heads, DNA chips, and the like).

The spatial light modulator S1 of the spatial light modulation unit SM1 applies spatial modulation to the light rays according to the position where the light rays are incident. For this reason, a desired pupil luminance distribution (e.g., a dipole, quadrupole, annular, or other distribution) can be formed.

The spatial light modulating cell SM1 has a first reflective surface R11 and a second reflective surface R12 in addition to the spatial light modulator S1. For this reason, they may be arranged in an optical system to form a desired optical path.

The spatial light modulator S1 in the exposure apparatus EA1 of the present embodiment can modulate light so that the optical path of light reflected on the second reflection surface R12 to be emitted from the spatial light modulation unit SM1 into the zoom optical system 3 coincides with the optical path of incident light incident on the first reflection surface R11. That is, the optical path of the light incident on the spatial light modulation cell SM1 coincides with the optical path of the light exiting from the spatial light modulation cell SM 1. For this reason, in the case of inserting the spatial light modulation unit SM1, or in the case of inserting the diffractive optical unit 2, the optical path is not changed, whereby the spatial light modulation unit SM1 can be freely inserted into the optical axis Ax of the exposure apparatus EA1 or retracted from the optical axis Ax of the exposure apparatus EA 1.

Specifically, between the case where the spatial light modulation cell SM1 is inserted and the case where the spatial light modulation cell SM1 is located outside the optical axis Ax, the air equivalent length of the light passing through the optical path does not change. For this reason, the exposure apparatus EA1 permits the spatial light modulation cell SM1 to be inserted or retracted without any change in configuration.

Since the optical path on the exit side of the spatial light modulation unit SM1 coincides with the optical path on the entrance side, the configuration of the illumination apparatus IL using the spatial light modulation unit SM1 can be shared with the illumination optical system using the diffractive optical unit 2. This permits cost reduction.

Fig. 9 shows a schematic configuration diagram of a maskless exposure apparatus EA2 that is a modified example of the exposure apparatus EA1 according to the first embodiment. The exposure apparatus EA2 of this modified example is different from the exposure apparatus EA1 of the first embodiment in that it has the spatial light modulation unit SM2 instead of having a mask.

The spatial light modulation unit SM2 (similar to the spatial light modulation unit SM1) has first and second reflective surfaces R21, R22 and a spatial light modulator S2. The illumination apparatus IL of the exposure apparatus EA2 illuminates the reflection surface (first surface) of the spatial light modulator S2 in the spatial light modulation unit SM 2. The projection optical system PL forms an image of the first surface on the projection surface Wa (second surface) on the wafer W based on light from the illumination area formed on the reflection surface (first surface) of the spatial light modulator S2 by the illumination device IL.

(second embodiment)

The configuration of the exposure apparatus EA3 according to the second embodiment will be described with reference to fig. 10. Fig. 10 is a configuration diagram schematically showing an exposure apparatus of the second embodiment.

The exposure apparatus EA3 of the second embodiment has a light source 11, an illumination apparatus IL provided with a spatial light modulation unit SM1, a mask stage MS supporting a mask M, a projection optical system PL, and a wafer stage WS supporting a wafer W, along an optical axis Ax of the apparatus.

The illumination apparatus IL has, along the optical axis Ax, a polarization state control unit 12, a depolarizer (depolarizer)13 that is insertable into or retractable from the optical path of the illumination apparatus IL, a spatial light modulation unit SM1, a diffractive optical unit 2, a relay (relay) optical system 15, an afocal optical system 17, a polarization conversion element 18, a conical turning mirror (conicalaxicon) system 19, a zoom optical system 21, a folding mirror 22, a micro fly's eye lens 23, a condensing optical system 24, an illumination field stop (mask) 25, an imaging optical system 26, and a folding mirror 27. Each of the spatial light modulation unit SM1 and the diffractive optical unit 2 used to form the desired pupil luminance distribution can be inserted into or retracted from the optical path of the illumination apparatus IL.

An almost parallel beam emitted from the light source 11 travels through the polarization state control unit 12 having a quarter wave plate (wave plate) and a half wave plate rotatable about the optical axis Ax to be converted into a light beam in a predetermined polarization state, and then travels through the spatial light modulation unit SM1 or the diffractive optical unit 2 and enters the afocal optical system 17 through the relay optical system 15. In the case where the mask M is illuminated with light in an unpolarized state, the beam from the light source 11 that has passed through the polarization state control unit 12 travels through the depolarizer 13 inserted into the optical path of the illumination apparatus IL, and then enters the spatial light modulation unit SM1 or the diffractive optical unit 2. With respect to such a polarization state control unit 12 and a depolarizer 13, reference may be made to U.S. patent publication No. 2006/0170901a 1.

The afocal optical system 17 is an afocal system (afocal optical element) set so that the following occurs: its front focus position substantially coincides with the position of the predetermined plane 16 indicated by the broken line in the drawing, and its back focus position substantially coincides with the position of the predetermined plane 20 indicated by the broken line in the drawing. On the other hand, as indicated by a broken line in the drawing, the spatial light modulation unit SM1 or the diffractive optical unit 2 is arranged at a position conjugate to the position of the predetermined plane 16.

Therefore, the almost parallel beam incident to the spatial light modulation unit SM1 or the diffractive optical unit 2 as the beam conversion element forms, for example, a ring-shaped (annular) light intensity distribution on the pupil plane of the afocal optical system 17 as the relay optical system, and thereafter is emitted from the afocal optical system 17 as the almost parallel beam. The polarization conversion element 18 and the conical turning mirror system 19 are arranged at or near the pupil position of the afocal optical system in the optical path between the front lens unit 17a and the rear lens unit 17b of the afocal optical system 17.

The conical turning mirror system 19 is composed of the following components arranged in the order named from the light source side: a first prism member 19a, a plane of which is on the light source side and a concave conical-shaped refractive surface is on the mask side; and a second prism member 19b, one plane of which is on the mask side and a convex conical-shaped refractive surface is on the light source side. The concave conical-shaped refracting surface of the first prism member 19a and the convex conical-shaped refracting surface of the second prism member 19b are complementarily formed so that they can contact each other. At least one of the first and second prism members 19a and 19b is configured to be movable along the optical axis Ax so that an interval between the concave conical-shaped refractive surface of the first prism member 19a and the convex conical-shaped refractive surface of the second prism member 19b is variable. By the action of the axicon cone system 19, both the annular ratio (inside/outside diameter) and the size (outside diameter) of the annular secondary light source are varied without having to change the width of the secondary light source.

When the concave conical refractive surface of the first prism member 19a contacts the convex conical refractive surface of the second prism member 19b, the conical turning mirror system 19 acts as a plane-parallel plate and does not affect the annular secondary light source formed. However, when the concave conical refractive surface of the first prism member 19a is separated from the convex conical refractive surface of the second prism member 19b, the conical turning mirror system 19 acts as a so-called beam expander. Thus, the angle of the incident beam to the predetermined plane 20 varies according to the change in the pitch of the conical turning mirror system 19.

The polarization conversion element 18 has the following functions: the incident light in the linear polarization state is converted into light in a circumferential polarization state with a polarization direction substantially along a circumferential direction, or converted into light in a radial polarization state with a polarization direction substantially along a radial direction. With respect to such a polarization conversion element 18, reference may be made to the aforementioned U.S. patent publication No. 2006/0170901a 1.

The beam having passed through the afocal optical system 17 travels through a zoom optical system 21 to vary the σ value, and passes through a folding mirror 22 to enter a micro fly-eye lens (or fly-eye lens) 23 as an optical integrator. The micro fly-eye lens 23 is an optical element composed of a large number of micro lenses having positive refractive power, which are vertically and horizontally and densely arranged. In general, micro fly's eye lenses are made, for example, by etching a plane-parallel plate to form groups of micro lenses.

Each microlens forming the micro fly-eye lens is smaller than each lens element forming the fly-eye lens. The micro fly-eye lens is different from the fly-eye lens composed of lens elements isolated from each other because a large number of micro lenses (micro refractive surfaces) are integrally formed without being isolated from each other. However, the micro fly-eye lens is an optical integrator of the same wavefront division type as the fly-eye lens because lens elements having positive refractive power are arranged horizontally and vertically.

The position of the predetermined plane 20 is located in the vicinity of the front focus position of the zoom optical system 21, and the incident surface of the micro fly-eye lens 23 is located in the vicinity of the rear focus position of the zoom optical system 21. By the action of the zoom optical system 21, both the width and the size (outer diameter) of the annular secondary light source are changed, while the annular ratio of the annular secondary light source is unchanged. The zoom optical system 21 keeps the predetermined plane 20 and the incident surface of the micro fly-eye lens 23 in a substantially fourier transform relationship, and in turn keeps the pupil plane of the afocal optical system 17 and the incident surface of the micro fly-eye lens 23 substantially optically conjugate with each other.

Thus, for example, a ring-shaped illumination field centered on the optical axis Ax is formed on the incident surface of the micro fly-eye lens 23 as if on the pupil plane of the afocal optical system 17. The overall shape of this annular illumination field varies similarly depending on the focal length of the zoom optical system 21. Each microlens forming the micro fly-eye lens 23 has a cross section of a rectangular shape similar to the shape of the illumination field to be formed on the mask M (and thus similar to the shape of the exposure area to be formed on the wafer W).

The beam incident on the micro fly-eye lens 23 is two-dimensionally divided by a large number of micro lenses, and a secondary light source having a light intensity distribution approximately equal to an illumination field formed by the incident beam (that is, a secondary light source composed of a substantially surface illuminant of a ring shape centered on the optical axis Ax) is formed on or near the back focal plane of the micro fly-eye lens 23 (and thus on the illumination pupil plane). The beam from the secondary light source formed on or near the back focal plane of the micro fly-eye lens 23 travels through the condenser optical system 24 to illuminate the mask shutter 25 overlappingly.

In this way, an illumination field of a rectangular shape according to the shape and focal length of each microlens forming the micro fly-eye lens 23 is formed on the mask shutter 25 as an illumination field stop. The beams having passed through the rectangular apertures (light transmitting portions) of the mask shutters 25 are subjected to the condensing action of the imaging optical system 26 to overlappingly illuminate the mask M formed with the predetermined pattern. That is, the imaging optical system 26 forms an image of the rectangular aperture of the mask shutter 25 on the mask M.

The beam transmitted by the pattern of the mask M held on the mask stage MS travels through the projection optical system PL to form an image of the mask pattern on the wafer (photosensitive substrate) W held on the wafer stage WS. In this way, by performing a single exposure or a scanning exposure to simultaneously two-dimensionally drive and control the wafer stage WS in a plane perpendicular to the optical axis Ax of the projection optical system PL and thus the wafer W, the pattern of the mask M is sequentially transferred into each of the exposure regions on the wafer W.

The afocal optical system (relay optical system) 17, the conical axicon system 19, and the zoom optical system (magnification-varying optical system) 21 constitute a shaping optical system for changing the size and shape of a secondary light source (substantial surface illuminant) formed on the illumination pupil plane, which is arranged in the optical path between the spatial light modulation unit SM1 or the diffractive optical unit 2 and the micro fly-eye lens (optical integrator) 23.

The spatial light modulation unit SM1 is arranged to be switchable with the diffractive optical unit 2 in fig. 10, but it may be arranged, for example, on the plane 16 indicated by the dotted line in fig. 10. The position of the plane 16 corresponds to a position optically conjugate to the position of the diffractive optical element 2.

In this case, as shown in fig. 11, the spatial light modulation unit SM1 may be arranged on the optical axis Ax such that only a portion of the beam emitted from the light source 11 passes through the unit. In the spatial light modulation unit SM1 shown in fig. 11, when compared with the arrangement shown in fig. 4, for example, the spatial light modulator S1 is arranged to be moved to the light source 11 side with respect to the first reflection surface R11 and the second reflection surface R12 in the direction along the optical axis Ax. In this arrangement, for example, the rays L1, L3 in the light beam emitted from the light source 11 are incident on the afocal optical system 17 without entering the inside of the prism P1 in the spatial light modulation unit SM 1. On the other hand, rays L2 and L4 in the light beam emitted from the light source 11 are incident into the prism P1 of the spatial light modulation unit SM1, reflected on the first reflection surface R11, the spatial light modulator S1, and the second reflection surface R12, and thereafter emitted from the prism P1 to enter the afocal optical system 17.

In this case, the spatial light modulator S1 may be fixed, for example, at the position of the plane 16 indicated by the dotted line in fig. 10. Then, as is apparent from fig. 11, it is possible to simultaneously use a first optical path which is an optical path from the first reflection surface R11 of the prism P1 to the second reflection surface R12 of the prism P1 and an optical path extending through the first position where the spatial light modulator S1 can be arranged, and a second optical path which is an optical path from the position where the first reflection surface R11 of the prism P1 can be arranged to the position where the second reflection surface R12 of the prism P1 can be arranged (in the case where the spatial light modulation unit SM1 is arranged at the position of the plane 16 so as to be switchable with the diffractive optical unit 2) and an optical path where the diffractive optical element 2b of the diffractive optical unit 2 can be arranged. In this case, an optical path from the light source 11 to a position where the first reflection surface R11 of the prism P1 can be arranged serves as a third optical path. In the case where the spatial light modulation unit SM1 is arranged at the position of the plane 16 so as to be switchable with the diffractive optical unit 2, an optical path from the position of the second reflection surface R12 where the prism P1 can be arranged to the illumination target surface serves as a fourth optical path.

When the spatial light modulation unit SM1 is arranged at the position of the predetermined plane 16 as shown in fig. 11 and is configured to reflect only a part of the beam by the spatial light modulator S1 of the spatial light modulation unit SM1, it becomes possible to perform correction of the pupil intensity as shown in fig. 12 to 14, for example. Fig. 12 shows a pupil luminance distribution formed by a beam passing through the diffractive optical unit 2 but not passing through the spatial light modulation unit SM 1. Fig. 13 shows a pupil luminance distribution formed by a beam that does not pass through the diffractive optical unit 2 but passes through the spatial light modulation unit SM 1. Fig. 14 shows a pupil luminance distribution obtained by superimposing the pupil luminance distribution of fig. 12 on the pupil luminance distribution of fig. 13. The shading in fig. 12 to 14 indicates the luminance level on the pupil plane (the darker the shading, the higher the luminance).

Specifically, as shown in fig. 12, the diffractive optical unit 2 forms a first pupil luminance distribution in which the luminance decreases from left to right on the plane of the drawing with light rays that do not pass through the spatial light modulator S1 of the spatial light modulating unit SM 1. On the other hand, as shown in fig. 13, the spatial light modulator S1 of the spatial light modulating unit SM1 forms a substantially uniform second pupil luminance distribution with high luminance, which at least partially overlaps the first pupil luminance distribution. As shown in fig. 14, an overall almost uniform pupil luminance distribution can be obtained by superimposing the first pupil luminance distribution having uneven luminance on the second pupil luminance distribution to emphasize a low-luminance portion in the first pupil luminance distribution. The above example is related to the generation of an overall almost uniform pupil luminance distribution, but the pupil luminance distribution to be generated is not limited to an almost uniform distribution. As an example, it is also possible to change the pupil luminance distribution to a non-uniform distribution in order to adjust the transfer state of the pattern of the mask M.

In the spatial light modulation cell SM1, the air equivalent length of the light passing through the optical path does not change between the case of inserting the spatial light modulation cell SM1 and the case of retracting the spatial light modulation cell SM1 from the optical axis Ax. For this reason, the air equivalent length of the rays LI, L3 is equal to that of the rays L2, L4, and thus it is easy to combine and handle the ray passing through the spatial light modulation unit SM1 and the ray not passing therethrough.

In the case where the spatial light modulation cell SM1 is inserted at the position of the predetermined plane 16, it is also possible to use another spatial light modulation cell SM3, for example, based on the configurations shown in fig. 15 and 16. Fig. 15 is a diagram showing the arrangement in the case where the spatial light modulation unit SM3 is arranged such that the first reflection surface R31 and the second reflection surface R32 of the spatial light modulation unit SM3 intersect the optical axis Ax. Fig. 16 is a diagram showing the arrangement in the case where the spatial light modulation unit SM3 is arranged such that the first reflection surface R31 and the second reflection surface R32 of the spatial light modulation unit SM3 do not intersect with the optical axis Ax.

The spatial light modulation unit SM3 has a V-shaped prism (reflection member) P3 and a spatial light modulator S3. Unlike the spatial light modulation unit SM1, the spatial light modulator S3 is not integrally configured with the prism P3.

Surfaces provided on the prism P3 and reflecting by a pair of surfaces adjoining at a predetermined angle of an obtuse angle correspond to the first reflecting surface R31 and the second reflecting surface R32. As shown in fig. 15 and 16, the positional relationship between the prism P3 and the spatial light modulator S3 can be relatively changed in the direction intersecting the optical axis Ax. That is, the prism P3 is moved to make the first reflection surface R31 and the second reflection surface R32 intersect with the optical axis Ax while keeping the spatial light modulator S3 fixed.

The spatial light modulator S1 in the exposure apparatus EA3 according to the present embodiment may modulate light so that an optical path of light reflected on the second reflection surface R12 to be emitted toward the relay optical system 15 in the spatial light modulation unit SM1 may coincide with an optical path of light incident on the first reflection surface R11. That is, the optical path of the light incident on the spatial light modulation cell SM1 coincides with the optical path of the light exiting from the spatial light modulation cell SM 1. For this reason, in the case of inserting the spatial light modulation unit SM1, or in the case of inserting the diffractive optical unit 2, the optical path is not changed, whereby the spatial light modulation unit SM1 can be freely inserted into the optical axis Ax of the exposure apparatus EA3 or retracted from the optical axis Ax of the exposure apparatus EA 3.

Since the optical path of the light incident to the spatial light modulation cell SM1 coincides with the optical path of the light exiting from the spatial light modulation cell SM1, the spatial light modulation cell SM1 can be inserted into the position of the predetermined plane 16 or retracted from the position of the predetermined plane 16 without significant change in the configuration of the illumination apparatus IL.

Specifically, between the case where the spatial light modulation cell SM1 is inserted and the case where the spatial light modulation cell SM1 is located outside the optical axis Ax, the air equivalent length of the light passing through the optical path does not change. Therefore, in the exposure apparatus EA3, the spatial light modulation unit SM1 can be inserted and retracted without any change in the configuration of the illumination apparatus IL.

Since the optical path on the exit side of the spatial light modulation cell SM1 can be made to coincide with the optical path on the incident side, the configuration of the illumination apparatus IL using the spatial light modulation cell SM1 can be shared with the illumination optical system using the diffractive optical unit 2. This permits cost reduction.

The embodiments of the present invention have been described above, but it is noted that the present invention is not limited to the above-described embodiments but can be modified in many ways. For example, in the above-described embodiments, the spatial light modulator having a plurality of reflective elements which are two-dimensionally arranged and individually controlled is a spatial light modulator in which, for example, the tilt of a two-dimensionally arranged reflective surface can be individually controlled. This type of spatial light modulator may be a spatial light modulator selected from among the spatial light modulators disclosed, for example, in: japanese patent laid-open application No. 10-503300 (translation of PCT application) and its corresponding European patent application publication No. EP779530, Japanese patent laid-open application No. 2004-78136 and its corresponding U.S. patent No. 6,900,915, Japanese patent laid-open application (translation of PCT application) No. 2006-524349 and its corresponding U.S. patent No. 7,095,546, and Japanese patent laid-open application No. 2006-113437. In such spatial light modulators, light beams having passed through individual reflection surfaces of the spatial light modulator are incident at a predetermined angle to a distribution forming optical system, and a predetermined light intensity distribution according to a plurality of control signals to a plurality of optical elements can be formed on an illumination pupil plane.

The spatial light modulator may also be, for example, a spatial light modulator in which the heights of two-dimensionally arranged reflective surfaces can be individually controlled. This type of spatial light modulator may be a spatial light modulator selected from among the spatial light modulators disclosed, for example, in: japanese patent laid-open application No. 6-281869 and its corresponding U.S. patent No. 5,312,513, and Japanese patent laid-open application (translation of PCT application) No. 2004-520618 and its corresponding U.S. patent No. 6,885,493, FIG. 1 d. Such spatial light modulators can exert the same effect as a diffractive surface on incident light when forming a two-dimensional height distribution.

The above-described spatial light modulator having a plurality of reflective surfaces arranged two-dimensionally can be modified, for example, in accordance with the disclosure in japanese patent laid-open application (translation of PCT application) No. 2006-513442 and its corresponding U.S. patent No. 6,891,655 or in japanese patent laid-open application (translation of PCT application) No. 2005-524112 and its corresponding U.S. patent laid-open application No. 2005/0095749.

The air equivalent length of the light passing through the optical unit with the spatial light modulating cells SM1, SM2 inserted may be made different from the air equivalent length of the light passing through the optical path with the spatial light modulating cells SM1, SM2 located outside the optical axis Ax. The shapes of the prisms P1, P2 in the spatial light modulation cells SM1, SM2 are not limited to the shapes shown in the embodiment and the modified examples.

It is also possible to provide pupil luminance distribution measuring means for measuring the pupil luminance distribution formed by the spatial light modulating cells SM1, SM2 in the illumination apparatus IL or in the exposure apparatuses EA1, EA2, EA 3. As for the configuration in which the pupil luminance distribution measuring device is incorporated in the illumination apparatus IL, reference may be made to, for example, japanese patent laid-open application No. 2006-54328, and as for the configuration in which the pupil luminance distribution measuring device is incorporated in the exposure apparatuses EA1, EA2, EA3, reference may be made to, for example, U.S. patent laid-open application No. 2006/0170901a 1. In order to adjust the pupil luminance distribution formed by the spatial light modulation units SM1, SM2 to a desired pupil luminance distribution based on the measurement results obtained by such pupil luminance distribution measuring apparatus, it is also possible to correct a plurality of drive signals to the spatial light modulation units SM1, SM 2.

In the above-described embodiments, the light sources 1, 11 may be, for example, an ArF excimer laser light source supplying a pulsed laser light having a wavelength of 193nm, or a KrF excimer laser light source supplying a pulsed laser light having a wavelength of 248 nm. Not necessarily limited to these light sources, it is also possible, for example, to use another suitable light source, for example F₂Laser light sources or ultra-high pressure mercury lamps. The above-described embodiments show the application of the present invention to a scanning exposure apparatus, but are not necessarily limited thereto, and the present invention can also be applied to an exposure apparatus of a single exposure type that performs projection exposure in a state where a reticle (mask) and a wafer (photosensitive substrate) are fixed with respect to a projection optical system.

In the foregoing embodiment, it is also possible to apply a technique of filling the inside of an optical path between the projection optical system and the photosensitive substrate with a medium (generally, a liquid) having a refractive index of more than 1.1, which is a so-called liquid immersion (immersion) method. In this case, it is also possible to adopt one of the following techniques as a technique for filling the inside of the optical path between the projection optical system and the photosensitive substrate with the liquid: techniques for partially filling an optical path with a liquid, as disclosed in international publication WO 99/49504; a technique of moving a stage for holding a substrate to be exposed in a liquid bath, as disclosed in Japanese patent laid-open application No. 6-124873; a technique of forming a liquid pool of a predetermined depth on a stage and holding a substrate therein, as disclosed in japanese patent laid-open application No. 10-303114; and so on.

In the foregoing embodiments, it is also possible to apply the so-called polarized illumination method disclosed in U.S. patent publication nos. 2006/0203214, 2006/0170901, and 2007/0146676.

The present invention is not limited to the above-described embodiments, but may be carried out in various configurations without departing from the spirit and scope of the invention.

Note that the above-described embodiments are described only for easy understanding of the present invention and not for limiting the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design changes and equivalents falling within the technical scope of the present invention. Each of the constituent elements and others in the above-described embodiments may be used in any combination or the like.

Claims

1. A spatial light modulation unit that can be arranged in an optical system and can be arranged along an optical axis of the optical system, comprising:

a first folding surface to fold a light ray incident parallel to the optical axis of the optical system;

a reflective spatial light modulator to reflect the light rays folded on the first folding surface; and

a second folding surface to fold the light reflected on the spatial light modulator and send the light forward into the optical system;

wherein the spatial light modulator applies spatial modulation to the light rays folded on the first folding surface according to a position where the light rays are incident on the spatial light modulator.

2. The spatial light modulation unit according to claim 1, wherein the second folding surface comprises a reflective surface.

3. The spatial light modulation unit according to claim 2, wherein the first folding surface comprises a reflective surface.

4. The spatial light modulation unit according to claim 3, wherein the first folding surface and the second folding surface comprise respective internal reflection surfaces thereof.

5. The spatial light modulation unit according to claim 4, wherein the first reflection surface and the second reflection surface are reflection surfaces of a prism, and wherein the spatial light modulator is integrally attached to the prism.

6. The spatial light modulation unit according to claim 4 or 5, wherein an air equivalent length from an incident position to the prism to an exit position from the prism is equal to an air equivalent length from a position corresponding to the incident position to a position corresponding to the exit position in a case where the prism is arranged outside the optical system.

7. The spatial light modulation unit according to any one of claims 1 to 6, wherein the spatial light modulator is relatively movable with respect to the first folding surface and the second folding surface in a direction along the optical axis of the optical system.

8. The spatial light modulation unit according to claim 3, wherein the first folding surface and the second folding surface comprise their respective surface reflection surfaces.

9. The spatial light modulation unit according to claim 8, wherein the first folding surface and the second folding surface are a pair of reflection surfaces provided on a reflection member at a predetermined angle.

10. The spatial light modulation unit according to claim 9, wherein the reflection member and the spatial light modulator are arranged in a positional relationship relatively changeable in a direction intersecting the optical axis of the optical system.

11. The spatial light modulation unit according to any one of claims 1 to 7, wherein the first folding surface and the second folding surface are arranged in a positional relationship with the spatial light modulator to be relatively changeable in a direction intersecting the optical axis of the optical system.

12. The spatial light modulation unit according to any one of claims 1 to 11, wherein the spatial light modulator comprises a plurality of reflective elements arranged two-dimensionally; and is

Wherein the plurality of reflective elements are controllable independently of each other.

13. The spatial light modulation unit of claim 12, wherein each of the plurality of reflective elements of the spatial light modulator comprises a reflective surface, and

wherein the tilt of the reflective surfaces of the reflective elements can be independently controlled.

14. The spatial light modulation unit according to any one of claims 1 to 13, wherein the spatial light modulator modulates light rays so that the light rays folded on the second folding surface to be emitted into the optical system become parallel to the incident light rays to the first folding surface.

15. A spatial light modulation unit that can be arranged in an optical system and can be arranged along an optical axis of the optical system, comprising:

a first reflecting surface arranged obliquely with respect to the optical axis of the optical system;

a second reflecting surface arranged obliquely with respect to the optical axis of the optical system; and

a spatial light modulator provided such that it can be arranged in an optical path between the first and second reflective surfaces;

wherein the spatial light modulator applies spatial modulation to light in the spatial light modulator according to where the light is incident on the spatial light modulator.

16. The spatial light modulation unit according to claim 15, wherein the first reflective surface is located on a first plane, and

wherein the second reflective surface lies on a second plane that intersects the first plane.

17. The spatial light modulation unit according to claim 16, wherein a ridgeline formed by the first plane and the second plane is located on a spatial light modulator side with respect to the first reflection surface and the second reflection surface, and wherein an angle between the first reflection surface and the second reflection surface is an obtuse angle.

18. An illumination device for illuminating a first surface with light supplied from a light source, said illumination device comprising:

the spatial light modulation unit of any one of claims 1-17.

19. The illumination apparatus according to claim 18, characterized in that it further comprises a diffractive optical element to form a desired pupil luminance distribution,

wherein the spatial light modulator may be arranged at a position conjugate to the diffractive optical element.

20. The illumination apparatus according to claim 18, characterized in that it further comprises a diffractive optical element which forms a desired pupil luminance distribution and which can be mounted on a predetermined mounting surface,

wherein the spatial light modulator may be arranged at a position optically equivalent to the predetermined mounting surface.

21. The illumination device according to claim 19 or 20, wherein the diffractive optical element is insertable into or retractable from an optical path of the illumination device.

22. An illumination apparatus for illuminating a surface to be illuminated on the basis of light from a light source, said illumination apparatus comprising:

a spatial light modulator including a plurality of optical elements that are two-dimensionally arranged and individually controlled;

a diffractive optical element arrangeable in the lighting device;

a first optical path in which the spatial light modulator may be arranged at a first position;

a second optical path in which the diffractive optical element is arrangeable at a second position;

a third optical path that is an optical path between the light source and the first optical path and an optical path between the light source and the second optical path; and is

A fourth optical path that is an optical path between the first optical path and the illumination target surface and an optical path between the second optical path and the illumination target surface;

wherein the first optical path and the second optical path are switchable with each other, and wherein an optical axis at an exit of the third optical path is coaxial with an optical axis at an entrance of the fourth optical path.

23. A lighting device as recited in claim 22, wherein the lighting device comprises: a first optical surface that directs light from the third optical path to the spatial light modulator; and a second optical surface that guides the light that has passed through the spatial light modulator to the fourth optical path.

24. The illumination device as recited in claim 23, wherein the first optical surface and the second optical surface are insertable into or retractable from an optical path of the illumination device.

25. The illumination device as recited in claim 24 wherein the first optical surface and the second optical surface are integrally insertable into or retractable from the optical path of the illumination device.

26. The illumination device according to any of claims 22 to 25, wherein the spatial light modulator is insertable into or retractable from an optical path of the illumination device.

27. The illumination apparatus according to any one of claims 22 to 25, wherein the spatial light modulator is fixed at a predetermined position.

28. A lighting device as recited in any one of claims 22-26, wherein the first optical path and the second optical path are used simultaneously.

29. The illumination apparatus of any of claims 23-27, wherein the first optical surface and the second optical surface comprise their respective reflective surfaces.

30. The illumination apparatus according to any one of claims 22 to 29, wherein the spatial light modulator comprises a plurality of reflective elements arranged two-dimensionally, and

31. The illumination apparatus of claim 30, wherein each of the reflective elements of the spatial light modulator comprises a reflective surface, and

32. An exposure apparatus for projecting an image of a first surface onto a second surface, the exposure apparatus comprising:

the illumination apparatus of any one of claims 18 to 31, which illuminates the first surface; and

a projection optical system that forms the image of the first surface on the second surface based on light rays from an illumination area formed on the first surface by the illumination device.

33. An exposure apparatus for projecting an image of a first surface onto a second surface, the exposure apparatus comprising:

an illumination device to illuminate the first surface;

the spatial light modulation unit of any one of claims 1-17; and

a projection optical system that forms the image of the first surface on the second surface based on light rays from an illumination area formed on the first surface by the illumination device;

wherein the spatial light modulators of the spatial light modulating cells are arranged on the first surface.

34. A device manufacturing method, comprising:

a preparation step of preparing a photosensitive substrate;

a disposing and projecting step of disposing the photosensitive substrate on the second surface in the exposure apparatus according to claim 32 or 33, and projecting an image of a predetermined pattern on the first surface onto the photosensitive substrate to effect exposure thereof;

a developing step of developing the photosensitive substrate including the projected image of the pattern to form a mask layer having a shape corresponding to the pattern on a surface of the photosensitive substrate; and

a processing step of processing the surface of the photosensitive substrate through the mask layer.

35. An illumination device for illuminating a first surface with light supplied from a light source, said illumination device comprising:

the spatial light modulation unit of any one of claims 1-17; and

a diffractive optical element that forms a first pupil luminance distribution with light that does not pass through the spatial light modulator of the spatial light modulation unit;

wherein a second pupil luminance distribution that at least partially overlaps with the first pupil luminance distribution is formed with light from the spatial light modulator of the spatial light modulation unit.

36. An illumination device for illuminating a first surface with light supplied from a light source, said illumination device comprising:

a spatial light modulation unit including a spatial light modulator that applies spatial modulation to a light ray according to a position at which the light ray is incident; and

37. The illumination apparatus according to claim 36, wherein the spatial light modulator comprises a plurality of reflective elements arranged two-dimensionally, and

38. The illumination apparatus of claim 37, wherein each of the reflective elements of the spatial light modulator comprises a reflective surface, and

39. An exposure apparatus for projecting an image of a first surface onto a second surface, the exposure apparatus comprising:

the illumination device recited in claim 36 which illuminates said first surface; and

40. A device manufacturing method, comprising:

a preparation step of preparing a photosensitive substrate;

a disposing and projecting step of disposing the photosensitive substrate on the second surface in the exposure apparatus according to claim 39, and projecting an image of a predetermined pattern on the first surface onto the photosensitive substrate to effect exposure thereof;