JP2013073976A - Spatial light modulator, optical device, and exposure device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spatial light modulator ensuring a high resolution by using electrowetting and capable of controlling the phase of light passing through each pixel.SOLUTION: A spatial light modulator 28 for modulating illumination light IL incident to the array surface includes a cell 34 having a barrier 33a in the Z direction traversing the array surface, lower electrodes 60A, 60B and upper electrodes 64A, 64B arranged in the Z direction in the cell 34, and a liquid Lq held between the electrodes 60A, 60B and 64A, 64B in the cell 34. The phase of the illumination light IL reflected in the cell 34 is controlled by controlling the position in the Z direction of the liquid Lq in the cell 34 by a voltage applied to the electrodes 60A, 60B and 64A, 64B.

Description

  The present invention relates to a spatial light modulator that modulates incident light, an optical apparatus and an exposure apparatus that include the spatial light modulator, and a device manufacturing technique that uses the exposure apparatus.

  For example, in a lithography process for manufacturing a device (electronic device or microdevice) such as a semiconductor element or a liquid crystal display element, a predetermined pattern is formed in a lump on a substrate such as a wafer or a glass plate via a projection optical system. An exposure type or scanning exposure type exposure apparatus or the like is used. As these exposure apparatuses, in order to suppress the increase in manufacturing cost by preparing a mask for each of a plurality of types of devices and for each of a plurality of layers of a substrate, and to manufacture each device efficiently, Instead, spatial light modulators with an array of micromirrors, each with a variable tilt angle or height by means of a hinge mechanism, are used to create a reflective variable light / dark pattern on the object plane of the projection optics. Alternatively, a so-called maskless type exposure apparatus that generates a phase pattern is known. Thus, in the method of adjusting the tilt angle of the micromirror using the hinge mechanism, the drive mechanism of the micromirror is complicated, and further, it is difficult to realize a transmission type modulator.

Therefore, as a spatial light modulator that can be used for maskless exposure, so-called electrowetting (electrowetting: electrocapillarity) is used to apply a transparent liquid or an opaque liquid on the optical path of each pixel (optical element). There has been proposed a modulator capable of setting each pixel to a bright state or a dark state by moving (see, for example, Patent Document 1). Electrowetting is a technique for electrically controlling the wettability of the surface, and studies are being made on the transfer of microdroplets and application to displays using colored oil (for example, see Non-Patent Document 1). . The principle of electrowetting is thought to be based on Maxwell stress (electrostatic force). That is, when subjected to a certain dielectric material (dielectric constant epsilon) electrical field (E), the dielectric material is that the direction in εE ^2/2 of the stress acts to reduce the electric field parallel and a dielectric medium. The mechanism for changing the wettability of the surface will be considered with an example of a change in the contact angle of a water drop placed in the air. When an electric potential is applied between a water droplet and an electrode placed under the insulating film, an electric field is formed in the air around the water droplet, and Maxwell stress (electrostatic force) acts in a direction to shrink the air that is a dielectric medium. As a result, stress is exerted on the surface of the water droplets in the vertical outward direction of the water droplets, and is pulled to the air side. This stress varies depending on the location of the water droplet, and the closer to the insulating film, the stronger the electric field, so that it is pulled more strongly. Therefore, the closer to the insulating film, the larger the amount of movement of the surface of the water droplet, and the contact angle of the water droplet appears to decrease.

Special table 2007-515802

Frieder Mugele and Jean-Christophe Baret, “Electrowetting: from basics to applications,” Journal of Physics: Condensed Matter, 17 (2005) R705-R774 (UK)

  In a conventional spatial light modulator using electrowetting, since each pixel is divided only by an electrode, for example, it is difficult to accurately set a plurality of pixels in a row alternately in a bright state and a dark state. It was difficult to increase the resolution. Furthermore, it is difficult for a conventional spatial light modulator using electrowetting to control the phase of light passing through each pixel.

  In view of such circumstances, an aspect of the present invention is a spatial light modulator capable of obtaining a high resolution using electrowetting and controlling the phase of light passing through each pixel (optical element), and the space. An object of the present invention is to provide a technique using an optical modulator.

  According to the first aspect of the present invention, a spatial light modulator for modulating light incident on the array surface is provided. The spatial light modulator includes a cell portion having a partition wall portion along a first direction crossing the arrangement surface, a first electrode and a second electrode disposed in the cell portion along the first direction, and A liquid held between the first electrode and the second electrode in the cell portion, and a voltage applied to the first and second electrodes in the first direction of the liquid in the cell portion. By controlling the position, the phase of the light reflected in the cell part is controlled.

According to the second aspect, the spatial light modulator of the present invention, the first optical system for irradiating illumination light to the cell part of the spatial light modulator, and the light from the cell part as an object And a second optical system for guiding the optical device.
Moreover, according to the 3rd aspect, the 1st exposure apparatus which exposes a board | substrate with exposure light is provided. The exposure apparatus includes a spatial light modulator of the present invention, an illumination optical system that irradiates the exposure light to an array of a plurality of cell portions of the spatial light modulator, and reflected light from the plurality of cell portions on a substrate. And a projection optical system that projects the pattern onto the substrate and exposure control that controls the phase pattern of the reflected light from the plurality of cell portions of the spatial light modulator to control the pattern exposed on the substrate. A device.

  Moreover, according to the 4th aspect, the 2nd exposure apparatus which exposes a board | substrate through a mask with exposure light is provided. This exposure apparatus has the spatial light modulator of the present invention, and an illumination optical system that illuminates the mask with the exposure light via the spatial light modulator, and an incident angle of the exposure light that illuminates the mask. In order to control the distribution, an illumination control device that controls the phase pattern of the reflected light from the plurality of cell units of the spatial light modulator is provided.

  According to a fifth aspect, there is provided a device manufacturing method comprising: forming a pattern of a photosensitive layer on a substrate using the exposure apparatus of the present invention; and processing the substrate on which the pattern is formed. Is provided.

  According to the spatial light modulator of the aspect of the present invention, the position of the liquid in the cell portion in the first direction is controlled by the action of electrowetting by the voltage applied to the first and second electrodes. The phase of light reflected in the portion (light passing through the pixel (optical element) including the cell portion) is controlled. Further, since the pixels are partitioned by the partition walls, the influence of electrostatic force between the pixels and the flow of liquid between the pixels are suppressed, and high resolution can be obtained.

(A) is a figure which shows schematic structure of the spatial light modulator which concerns on 1st Embodiment, (B) is an expansion perspective view which shows a part of main-body part of the spatial light modulator. It is a figure which shows one pixel and control system of the spatial light modulator of FIG. 1 (A). (A) is the expanded sectional view which looked at two pixels of the spatial light modulator of Drawing 1 (A) in the X direction, and (B) is the expanded sectional view which looked at two pixels in the Y direction. (A) is an expanded sectional view which shows the main-body part of the spatial light modulator under manufacture, (B) is an expanded sectional view which shows the state which inject | poured the liquid into the cell part of the main-body part. It is an expansion perspective view which shows one pixel of the spatial light modulator of a 1st modification. (A) is an enlarged sectional view showing a pixel in the first state of the first modified example, and (B) is an enlarged sectional view showing a pixel in the second state of the first modified example. (A) is an enlarged perspective view showing one pixel of the spatial light modulator of the second modification, and (B) is an enlarged perspective view showing one pixel of the spatial light modulator of the third modification. It is a figure which shows schematic structure of the exposure apparatus which concerns on 2nd Embodiment. It is a figure which shows schematic structure of the modification of 2nd Embodiment. It is a flowchart which shows an example of the manufacturing process of an electronic device.

[First Embodiment]
A first embodiment of the present invention will be described with reference to FIGS. 1 (A) to 4 (B). FIG. 1A shows a schematic configuration of a spatial light modulator (SLM) 28 according to this embodiment, and FIG. 1B enlarges a part of the main body 30 of the spatial light modulator 28. And show. The spatial light modulator 28 of the present embodiment includes a main body 30 having pixels 32 as a plurality of optical elements arranged in a two-dimensional array, and illumination light IL that is incident on and reflected from the pixels 32. And a modulation control unit 48 that individually controls the phase of the light, and modulates light incident on each pixel 32 using electrowetting (electrowetting). Illumination light IL is, for example, ArF excimer laser light with a wavelength of 193 nm, KrF excimer laser light with a wavelength of 248 nm, or harmonics of laser light output from a solid-state laser (semiconductor laser or the like). Illumination light IL is, for example, light that is pulsed at a frequency of several kHz or about 1 to 2 MHz. In the following description, the X axis and the Y axis are taken along the first and second arrangement directions in which the plurality of pixels 32 are orthogonal, and the Z axis is taken in the direction orthogonal to the X axis and the Y axis.

  In FIG. 1A, the main body 30 of the spatial light modulator 28 is arranged in a two-dimensional lattice shape in the X and Y directions with a base member 31 made of a rectangular box-like insulator having an open top surface. A partition member 33 made of an insulator having a plurality of square openings formed therein, a plurality of connecting portions 33S for supporting the partition member 33 in the base member 31, and an upper surface of the base member 31 and the illumination light IL Has a flat cover glass 35 (see FIG. 1B). In the present embodiment, a plurality of pixels 32 are arranged along a bottom surface (hereinafter referred to as an arrangement surface DP) parallel to the XY plane of the cover glass 35.

  The partition wall member 33 is a set of square cylindrical partition wall portions 33a that are in close contact with each other in the X and Y directions and are arranged at equal pitches (periods) px and py (px = py). The partition wall 33a has an inner surface with a square cross section surrounded by an inner surface along the Z direction perpendicular to the arrangement surface DP, that is, two surfaces parallel to the XZ surface and two surfaces parallel to the YZ surface. The partition portion 33a includes the cell portion 34, and the pixel 32 includes the cell portion 34 and the liquid Lq (see FIG. 1B) that is held in the cell portion 34 and transmits the illumination light IL. Therefore, the arrangement pitch of the plurality of pixels 32 in the X direction and the Y direction is equal to the arrangement pitch px of the cell portions 34.

  The array pitch px of the pixels 32 is, for example, about 10 to 1 μm. As an example, the number of pixels 32 arranged in the X direction is several thousand to several tens of thousands, and the number of arrays in the Y direction is about 1/10 of the number of arrays in the X direction. It is. In FIG. 1A, each pixel 32 is shown enlarged. The number of the pixels 32 arranged in the X direction and the Y direction is arbitrary, the cross-sectional shape of the partition wall 33a (the shape of the pixel 32) may be a rectangle, and the arrangement pitches px and py of the pixels 32 in the X direction and the Y direction are They may be different from each other.

The base member 31 is an insulator made of, for example, a fluoropolymer (fluorine polymer), a material in which an insulating layer such as silicon oxide (SiO ₂ ) or silicon nitride (eg, Si ₃ N ₄ ) is formed on the surface of a silicon substrate, or ceramics. Etc. can be formed. The partition member 33 can be formed from, for example, silicon oxide, silicon nitride, ceramics, or the like. The cover glass 35 is made of a material that transmits the illumination light IL, such as quartz or fluorite (CaF ² ).

  In the present embodiment, each pixel 32 includes a reflecting member 37 having a reflecting surface parallel to the XY plane that reflects the incident illumination light IL through the liquid Lq. Then, by using electrowetting, each pixel 32 changes the phase of the illumination light IL1 incident vertically (in the Z direction) to a first predetermined value like the pixel 32 at the position A1 shown in FIG. And the phase of the incident illumination light IL2 is changed by 180 ° (π (rad)) from the phase δ, as in the pixel 32 at the position A2. And a plurality of states including the second state of reflection. The pixel 32 in the first state is also referred to as a pixel 32 (0), and the pixel 32 in the second state is also referred to as a pixel 32 (π).

  Next, FIG. 2 representatively shows one pixel 32 in the main body 30 of the spatial light modulator 28 of FIG. FIG. 2 also shows a block diagram of the modulation control unit 48 of the spatial light modulator 28. In FIG. 2, the pixel 32 has a cell portion 34 (partition wall portion 33 a) indicated by a two-dot chain line and an inner surface in the ± Y direction on the side opposite to the cover glass 35 of the cell portion 34 (in this embodiment, the + Z direction side). Lower electrodes 60A and 60B made of a pair of provided metal films, insulating thin films (hereinafter referred to as insulating films) 62A and 62B, and insulating films 62A and 62B provided on the surfaces of the lower electrodes 60A and 60B. And a first wire electrode 38 made of a plurality of thin cylindrical or prismatic wires 38a arranged at equal intervals in the X direction. Further, the pixel 32 includes an upper electrode 64A, 64B made of a pair of metal films provided on the inner surface in the ± Y direction at the end of the cell part 34 on the cover glass 35 side (−Z direction side), and the upper electrode 64A. , 64B, and a second wire electrode made up of a plurality of wires 39a having substantially the same shape as, for example, the wires 38a arranged at equal intervals in the X direction between the insulating films 62C, 62D. 39.

  The pixel 32 is a metal elongated in the Y direction in which the width in the X direction disposed between the first and second wire electrodes 38 and 39 in the cell portion 34 is narrower than the width in the X direction on the inner surface of the cell portion 34. In the space including the reflection member 37 that also serves as an electrode made of a flat plate and the reflection member 37 between the wire electrodes 38 and 39 in the cell part 34, the liquid repellency of the wire electrodes 38 and 39 (surface tension of the liquid Lq). And a liquid Lq held so as not to leak. In particular, the diameter (maximum length of the cross section when the wire is a prismatic shape) of the upper wire 39a (here, in the −Z direction) disposed in the region through which the illumination light IL passes is to increase the utilization efficiency of the illumination light IL. Furthermore, it is preferable that the liquid Lq is as thin as possible within a range in which the liquid Lq does not leak due to liquid repellency or surface tension. On the other hand, the diameter of the lower wire 38a in the region where the illumination light IL does not pass may be larger than the diameter of the wire 39a. The electrodes 60A, 60B and 64A, 64B are connected by wiring. The surface of the reflecting member 37 acts as a reflecting surface for the illumination light IL.

  As a material of the insulating films 62A to 62D, for example, a dielectric material such as fluorine-added silicon oxide (SiOF), carbon-added silicon oxide (SiOC), or ceramics can be used. As materials for the electrodes 60A, 60B, 64A, 64B and the reflecting member 37, polysilicon or the like can be used in addition to metal. When the reflection member 37 is polysilicon, a reflection film such as a dielectric multilayer film may be formed on the surface thereof. As a material for the wire electrodes 38 and 39, it is preferable to use a material that is easy to be finely processed, has high conductivity, and has high liquid repellency, such as carbon nanotubes. The wire electrodes 38 and 39 may be formed by coating a metal wire with an insulating film. In the present embodiment, if the widths in the X direction and the Y direction of the inner surface of the cell part 34 are equally a1, the lengths of the electrodes 60A to 64B and the insulating films 62A to 62D in the X direction are substantially equal to a1, and the Y of the reflecting member 37 The length in the direction is equal to a1.

  As an example, if the width a1 is 1 μm (1000 nm), the length a2 of the wire electrodes 38 and 39 in the Y direction is approximately 900 nm, and the diameter of the wires 38a and 39a is approximately 20 nm. However, the diameter of the lower wire 38a may be larger than that. At this time, the thickness (the height in the Y direction) and the width in the Z direction of the electrodes 60A to 64B and the insulating films 62A to 62D are approximately 25 nm and 100 nm, respectively. Further, the width a3 in the X direction of the reflecting member 37 is approximately 400 nm, the thickness of the reflecting member 37 is approximately 50 nm, and the distance a5 in the Z direction between the upper end of the wire electrode 38 and the lower end of the wire electrode 39 is approximately 410 nm. . Further, the depth of the liquid Lq in the cell part 34 (the height in the Z direction) is a4, and the liquid Lq is held at the upper end of the wire electrode 38 as shown in FIG. Assuming that the distance in the Z direction between the upper surface and the lower end of the wire electrode 39 is d, the sum of the depth a4 and the distance d is the distance a5 as follows.

a5 = a4 + d (1)
The interval d is set according to the wavelength of the illumination light IL (details will be described later), and the depth a4 is set based on the equation (1) and the interval d. As an example, the depth a4 is set to about 300 nm. Further, the distance d is smaller than the depth a4, and the distance between the reflecting surface of the reflecting member 37 and the upper end of the wire electrode 38 is set smaller than the depth a4. Therefore, even if the liquid Lq moves between the wire electrodes 38 and 39 in the cell part 34, the reflecting member 37 is always disposed in the liquid Lq.

  In the present embodiment, the reflective member 37 is grounded as an example during normal use of the spatial light modulator 28. Here, the grounded potential (ground level) is set to 0V. Further, the lower wire electrode 38 has a potential close to the potential of the lower electrodes 60A and 60B between the potential of the reflective member 37 and the potential of the lower electrodes 60A and 60B. Between the potential and the potential of the upper electrodes 64A and 64B, the potential is close to the potential of the upper electrodes 64A and 64B. In the present embodiment, when the pixel 32 is set to the first state, the potentials of the upper electrodes 64A and 64B are set to 0V (ground level), and a positive voltage (+ V1) is applied to the lower electrodes 60A and 60B. To do. When the liquid Lq is pure water, the voltage V1 is about 150V, for example. At this time, the potential of the upper wire electrode 39 is 0V, and the potential of the lower wire electrode 38 is between 0V and 150V. Since the liquid Lq is always in contact with the reflecting member 37, the potential is almost 0V. Therefore, the electric field is almost zero at the upper part of the liquid Lq, but the electric field is not zero at the lower part. As a result, Maxwell stress acts on the lower part of the liquid Lq, and the liquid Lq moves in the direction of the lower wire electrode 38. When the droplet moves and comes into contact with the lower wire electrode 38, the wire in contact with the liquid Lq is at the same potential as the liquid Lq, so that no force acts between the wire and the liquid Lq. When all the wires are finally contacted, the liquid Lq stops.

On the other hand, when the pixel 32 is set to the second state, a positive voltage (+ V1) is applied to the upper electrodes 64A and 64B, and the potentials of the lower electrodes 60A and 60B are set to 0V. The principle of operation is the reverse of the above.
In this way, by changing the potentials of the lower electrodes 60A and 60B and the upper electrodes 64A and 64B to + V1 and 0V, respectively, and conversely to the case of 0V and + V1, the Z of the liquid Lq in the cell part 34 is changed. The position in the direction changes by the distance d.

  Since the liquid Lq is driven in the Z direction by the electrostatic force between the wire electrodes 38 and 39 as described above, it is preferable that the liquid Lq transmits the illumination light IL and has a high dielectric constant (relative dielectric constant). That is, as the dielectric constant is higher, the potential of the reflecting member 37 is more easily transmitted to the entire liquid Lq, the electric field in the surrounding space becomes stronger, and Maxwell stress becomes larger. When the illumination light IL is ArF excimer laser light (wavelength 193 nm), the liquid Lq is, for example, pure water (refractive index = 1.44, relative permittivity (for example, 100 Hz or more) = 80), or decalin (decalin ( Refractive index = 1.60, relative dielectric constant = about 10) can be used. Pure water is preferable as the liquid Lq in that the relative dielectric constant is high and the voltage V1 can be reduced. Further, as will be described later, since the interval d can be reduced as the refractive index n of the liquid Lq is increased, decalin is preferable as the liquid Lq in that the height of the cell portion 34 can be reduced (the pixel 32 can be reduced in size). However, the liquid Lq has a refractive index and a dielectric constant smaller than pure water, but fluorine oil such as Fluorinert (registered trademark), hydrofluoroether (HFE), or perfluoropolyether (PFPE) can also be used. It is.

The partition member 33 in which the plurality of pixels 32 (in a state not filled with the liquid Lq), the reflection member 37 (grounded electrode), the wiring for the electrodes 60A to 64B, and the like of the present embodiment are formed by, for example, MEMS (Microelectromechanical). Systems: micro-electromechanical systems) technology. Moreover, parts other than the partition member 33 can be manufactured, for example by the manufacturing process of a normal semiconductor device.
Next, in FIG. 2, the modulation control unit 48 is a control unit 52 that is a part of a computer that controls the distribution of the states (first state or second state) of the plurality of pixels 32 in FIG. .., And the same number of amplifiers 55A, 55B, 55C,... As each pixel 32 that amplifies the output of the SRAM 54, and each pixel 32. And a signal line for grounding the reflective member 37. Outputs of the amplifiers 55A and 55B and the like are supplied to the lower electrodes 60A and 60B of the corresponding pixel 32 (cell part 34) via signal lines and wiring provided on the partition wall member 33, respectively. In the present embodiment, the voltage + V1 (first state) or 0 V (second state) is applied to the lower electrodes 60A and 60B. Note that a shift register can be used instead of the SRAM 54.

  Further, the modulation control unit 48 includes a switching unit 56 that is provided corresponding to each pixel 32 and converts the output of the corresponding amplifier 55A, 55B,. The output of the switching unit 56 is supplied to the upper electrodes 64 </ b> A and 64 </ b> B of the corresponding pixel 32 (cell unit 34) via the signal line and the wiring provided in the partition wall member 33. The switching unit 56 supplies the voltage + V1 to the upper electrodes 64A, 64B when the outputs of the amplifiers 55A, 55B,... (Ie, the potentials of the lower electrodes 60A, 60B) are 0 V, and the outputs of the amplifiers 55A, 55B,. When 0 is + V1, 0 V is supplied to the upper electrodes 64A and 64B.

  Next, FIG. 3A is an enlarged cross-sectional view of the two pixels 32 at positions A1 and A2 in the main body 30 of the spatial light modulator 28 of FIG. ) Is an enlarged cross-sectional view of the two pixels 32 as viewed in the Y direction. For convenience of explanation, the relationship between positions A1 and A2 in FIGS. 3A and 3B is different from the positional relationship in FIG. 3A, in order to facilitate the manufacture of the main body 30 as described later, the distance from the lower end of the lower wire electrode 38 in the cell part 34 to the bottom surface of the cell part 34 is set within the cell part 34. It is set to be the same as the height of the liquid Lq held in (the height a4 in FIG. 2). Further, a shallow box-shaped storage part 66 having an open top made of an insulator is placed on the bottom surface of the partition member 33 in the base member 31, and an electrode 67 made of a metal film is provided on the inner surface of the storage part 66, An insulating film 68 is provided so as to cover the electrode 67. A plurality of height adjusting portions 69 for adjusting the height of the storage portion 66 are provided on the bottom surface in the base member 31 when the main body portion 30 is manufactured. The height adjusting unit 69 is moved in the Z direction by a driving mechanism (not shown) including, for example, a piezo element disposed below the storage unit 31. When the main body 30 is manufactured, a predetermined amount of the same liquid as the liquid Lq is supplied to the inner surface of the storage section 66, and the electrode 67 is set to a predetermined potential (details will be described later).

  In FIG. 3A, the illumination light that passes through the cover glass 35 and enters each pixel 32 passes through the gap between the upper wire electrodes 39 and the liquid Lq and enters the reflecting member 37, and the reflecting member 37. The illumination light reflected by the light passes through the gap between the liquid Lq and the wire electrode 39 and is emitted through the cover glass 35. Therefore, the space between the lower end of the wire electrode 39 above each pixel 32 and the reflecting surface of the reflecting member 37 is an optical path length variable unit 34a in which the optical path length of the illumination light reciprocating in the space, and thus the phase is adjusted. is there. In the pixel 32 in the first state at the position A1, the liquid Lq is held at the upper end of the wire electrode 38, and the distance d between the upper surface of the liquid Lq and the lower end of the wire electrode 39 is higher than the height of the optical path length variable portion 34a. It is set narrowly.

  Then, as indicated by the pixel 32 at the position A1, when the pixel 32 is set to the first state, the potentials of the upper electrodes 64A and 64B are set to 0 V (ground level), and the lower electrodes 60A and 60B are positively connected. (+ V1) is applied. At this time, the upper wire electrode 39 becomes substantially 0 V, and the potential of the lower wire electrode 38 becomes a value close to the voltage (+ V1), so that an electrostatic force attracting force acts between the liquid Lq and the wire electrode 38. To do. Furthermore, when the liquid Lq comes into contact with each wire of the wire electrode 38, the potential of the wire in contact with the liquid Lq becomes the same, and no force acts between the wire and the liquid Lq. Then, when all the wires are finally contacted, the liquid Lq stops. Since the liquid Lq does not leak outside the wire electrode 38, the liquid Lq is stably held at the upper end of the wire electrode 38.

  On the other hand, as shown by the pixel at position A2, when the pixel 32 is set to the second state, a positive voltage (+ V1) is applied to the upper electrodes 64A and 64B, and the potentials of the lower electrodes 60A and 60B are set to 0V. Set to. At this time, since the potential of the lower wire electrode 38 becomes approximately 0 V and the potential of the wire electrode 39 becomes a potential close to the voltage (+ V1), an electrostatic force attracting force acts between the liquid Lq and the wire electrode 39. To do. As shown in FIG. 3B, the liquid Lq moves to the lower end of the wire electrode 39 through the side surface of the reflecting member 37 by electrowetting. Further, when the liquid Lq comes into contact with the entire wire electrode 39, the liquid Lq stops and the liquid Lq is stably held at the lower end of the wire electrode 39. As described above, the position of the liquid Lq in the Z direction changes by the distance d in the cell portion 34 between the first state and the second state. Each pixel 32 is switched to the first state or the second state at high speed only by switching the voltages of the lower electrodes 60A and 60B and the upper electrodes 64A and 64B to (+ V1, 0) or (0, + V1). Can do.

  In the present embodiment, the phase of the illumination light IL2 reflected by the pixel 32 (π) in the second state with respect to the amount of change in the phase of the illumination light IL1 reflected by the pixel 32 (0) in the first state. The amount of change is different by 180 ° (π). Assuming that the wavelengths of the illumination lights IL1 and IL2 are λ and the refractive index of the liquid Lq is n, the conditions for setting the pixels 32 in the first state and the second state are as follows in the liquid Lq with the interval d as follows: The difference between the amount of change in the phase of the illumination light traveling back and forth and the amount of change in the phase of the illumination light traveling back and forth in the air at the interval d is λ / 2 in terms of the optical path length.

2d (n−1) = λ / 2 (2)
From the equation (2), the distance d is as follows.
d = λ / {4 (n−1)} (3)
It can be seen from the equation (3) that the distance d can be reduced as the refractive index n increases. As an example, when the wavelength λ is 193 nm (ArF excimer laser light) and the liquid Lq is pure water (refractive index n = 1.44), the distance d is 110 nm from the equation (3).

  In this embodiment, when the spatial light modulator 28 is used, the SRAM 54 of the modulation control unit 48 in FIG. 2 stores in advance a digital data corresponding to the state of all the pixels 32 in a time-series pattern. The control unit 52 causes the amplifier 55A or the like to output data at a corresponding series of addresses in the SRAM 54 at a predetermined driving frequency (for example, 1 to 2 MHz or the like). In response to this, for example, as shown in FIG. 1A, a plurality of pixels 32 arranged in a two-dimensional array form a pixel 32 (0) in the first state or a second shaded line. It is set to one of the pixels 32 (π) in the state. Therefore, the arrangement of the plurality of pixels 32 in the first state or the second state can be set to an arbitrary arrangement with one pixel 32 as a unit at a predetermined time interval.

  Next, regarding an example of the manufacturing method of the main body 30 of the spatial light modulator 28 of this embodiment, refer to the enlarged cross-sectional views of FIGS. 4A and 4B corresponding to FIGS. 3A and 3B. To explain. First, the part except the cover glass 35 and the liquid Lq of the main body 30 of the spatial light modulator 28 as shown in FIG. At this stage, the storage portion 66 is lowered to the bottom surface in the base member 31. Next, in all the cell portions 34, the potentials of the lower electrodes 60A and 60B, the reflecting member 37, and the upper electrodes 64A and 64B are set to the ground level (0 V), and the electrode 67 on the storage portion 66 side is equivalent to, for example, + V1. Apply a high voltage. Thereafter, for example, a predetermined amount of the liquid Lq is injected into the storage unit 66 via an injector (not shown) capable of measuring the injection amount. The amount of the liquid Lq in the cell part 34 of each pixel 32 in FIG. 2 is b, the number of the pixels 32 in the main body part 30 is N1, and the area outside the partition member 33 in the storage part 66 (the area in the cell part 34 is If the area (unit) is N2, the predetermined amount is approximately b (N1 + N2).

  Next, as shown in FIG. 4 (A), the storage portions until the insulating film 68 of the storage portion 66 contacts the bottom surface of each cell portion 34 in the base member 31 via the plurality of height adjustment portions 69. 66 is raised. At this time, in each cell part 34, the liquid Lq is hold | maintained between the insulating film 68 of the storage part 66, and the lower wire electrode 38, respectively. In this state, the potential of the electrode 67 of the storage unit 66 is switched to the ground level, and the potentials of the upper electrodes 64A and 64B and the reflection member 37 in FIG. 3A are switched to a voltage higher than + V1, for example. At this time, as shown in FIG. 4B, the liquid Lq below the wire electrode 38 moves above the wire electrode 38 by electrowetting in each cell portion 34. Thereafter, the storage unit 66 is lowered to the bottom surface in the base member 31 via the height adjusting unit 69, the storage unit 66 is fixed, and the liquid in the storage unit 66 is sucked. Then, the main body 30 of the spatial light modulator 28 can be manufactured by fixing the cover glass 35 to the upper surface of the base member 31 by bonding or the like.

  According to the manufacturing method of the main body 30 of the spatial light modulator 28 of the present embodiment, by using the storage unit 66 that can be moved up and down, between the wire electrodes 38 and 39 in the cell part 34 of each pixel 32 of the main body 30. A target amount of liquid Lq can be sealed in the space. In addition, the manufacturing method of the main-body part 30 is arbitrary, For example, you may supply the liquid Lq into each cell part 34 from upper direction.

The effects and the like of this embodiment are as follows.
(1) The spatial light modulator 28 that modulates the illumination light IL incident on the array surface DP of the present embodiment includes a cell unit 34 having a partition wall 33a along the Z direction across the array surface DP, And lower electrodes 60A and 60B and upper electrodes 64A and 64B arranged along the Z direction, and a reflecting member 37 arranged between the lower electrodes 60A and 60B and the upper electrodes 64A and 64B. Further, the spatial light modulator 28 is applied to the liquid Lq held between the lower electrodes 60A and 60B and the upper electrodes 64A and 64B in the cell part 34, and the lower electrodes 60A and 60B and the upper electrodes 64A and 64B. And a modulation control unit 48 that controls the position of the liquid Lq in the cell part 34 in the Z direction by voltage, and the illumination light IL reflected by the reflecting member 37 in the cell part 34 by the position of the liquid Lq in the Z direction. Is controlling the phase.

  According to this spatial light modulator 28, the voltage applied to the lower electrodes 60A and 60B and the upper electrodes 64A and 64B (the potential between the electrodes 60A and 60B and the electrodes 64A and 64B) is based on the action of electrowetting. The position of the liquid Lq in the cell part 34 in the Z direction is controlled by the electrostatic force, and the illumination light IL reflected by the reflecting member 37 in the cell part 34 (illumination light IL passing through the pixel 32 including the cell part 34). Is controlled. Further, since the pixel 32 is partitioned by the cell portion 34 (partition wall portion 33a), the influence of electrostatic force between the pixels 32 and the flow of the liquid Lq between the pixels 32 are suppressed, and high resolution is obtained.

  (2) Further, in the present embodiment, in the cell part 34, the lower electrodes 60A and 60B are arranged at equal intervals in the X direction within the XY plane perpendicular to the Z direction via the insulating films 62A and 62B. A first wire electrode 38 made of a plurality of wires 38a is connected to the upper electrodes 64A and 64B via insulating films 62C and 62D from a plurality of wires 39a arranged at equal intervals in the X direction within the XY plane. A second wire electrode 39 is connected. The liquid Lq is held between the wire electrode 38 and the wire electrode 39 in the cell portion 34 so as not to leak due to the liquid repellency (surface tension of the liquid Lq) of the wire electrodes 38 and 39. In this case, the wire electrodes 38 and 39 enable air flow necessary when the liquid Lq moves in the Z direction, and the wire electrode 39 can increase the transmittance of the illumination light IL. Therefore, the Z position of the liquid Lq between the wire electrodes 38 and 39 can be controlled at high speed to control the phase of the reflected light of the illumination light IL from the reflecting member 37, and the use efficiency of the illumination light IL can be increased.

  Note that at least one of the wire electrodes 38 and 39 may be a mesh-like two-dimensional grid electrode. Furthermore, since the lower wire electrode 38 may shield the illumination light IL, the wire electrode 38 may be a two-dimensional lattice-shaped electrode having a small aperture ratio.

(3) Since the pixels 32 of the spatial light modulator 28 are a two-dimensional array, for example, when applied to an exposure apparatus, a pattern with a large area can be exposed or illuminated. In the spatial light modulator 28, the pixels 32 may be arranged in a line (one dimension) in the X direction or the Y direction.
In the above embodiment, the following modifications are possible.
First, in the above embodiment, the liquid Lq is held between the first and second wire electrodes 38 and 39 in the cell portion 34 of each pixel 32. As another configuration, as shown by one pixel 32A in the main body 30A of the spatial light modulator 28A of the first modified example of FIG. 5, a reflection member is provided between the wire electrodes 38 and 39 in the cell portion 34. A first wire member 70 for holding liquid in which wires 70a having substantially the same shape as the wires 38a are arranged at equal intervals in the X direction below the wires 37a, and wires 72a having substantially the same shape as the wires 39a are provided above the reflecting members 37. And a second wire member 72 for holding liquid arranged at equal intervals in the X direction, and the liquid Lq may be held between the first and second wire members 70 and 72. As the material of the wire members 70 and 72, it is preferable to use a material having high liquid repellency, such as a carbon nanotube, similarly to the wire electrodes 38 and 39.

  6A and 6B are cross-sectional views of the pixel 32A in FIG. 5 as viewed in the Y direction. 5 and 6A and 6B, parts corresponding to those in FIGS. 2 and 3B are denoted by the same reference numerals, and detailed description thereof is omitted. In FIG. 5, in this modification, the first wire electrode 38 is directly connected to the lower electrodes 60A and 60B, the second wire electrode 39 is directly connected to the upper electrodes 64A and 64B, and the reflecting member 37 is grounded (grounded). Level is 0). Moreover, the 1st and 2nd wire members 70 and 72 are being fixed to the cell part 34 which is an insulator. In other words, the wire members 70 and 72 are supported in an electrically insulated state (floating state). As a modulation control unit of this modification, a control unit similar to the modulation control unit 48 of FIG. 2 can be used.

  In FIG. 6A, the Z-direction interval between the upper end of the first wire member 70 and the lower end of the second wire member 72 is the same as the interval a5 between the wire electrodes 38 and 39 in FIG. . In this modification, since the wire members 70 and 72 have liquid repellency, the liquid Lq is held between the wire members 70 and 72 in the cell portion 34. In a state where the liquid Lq is held at the upper end of the first wire member 70, the distance d between the upper surface of the liquid Lq and the lower end of the second wire member 72 is a value determined by the above equation (3). When the width (a1) in the X direction and the Y direction in the cell part 34 is approximately 1000 nm, the distance between the wire electrode 38 and the wire member 70 and the distance between the wire electrode 39 and the wire member 72 are each approximately 50 nm, for example.

  As shown in FIG. 6A, when the pixel 32A of this modification is set to the first state (pixel 32A (0)) similar to the above embodiment, the upper electrodes 64A and 64B of FIG. Then, the potential of the wire electrode 39 is set to 0 V (ground level), and a positive voltage (+ V2) is applied to the wire electrode 38 via the lower electrodes 60A and 60B of FIG. The reflection member 37 is always grounded. When the liquid Lq is pure water, the voltage V2 may be about 50V, for example, about 1/3 of the voltage V1 of the above embodiment. At this time, the liquid Lq is sucked by the electrostatic force in the direction of the wire electrode 38. However, since the liquid Lq does not leak to the outside of the wire member 70 due to the liquid repellency (surface tension of the liquid Lq) of the wire member 70, the liquid Lq is stably held at the upper end of the wire member 70. The illumination light IL1 incident through the gap between the wire electrode 39 and the wire member 72 and the liquid Lq is reflected by the reflecting member 37, and is emitted through the gap between the liquid Lq, the wire member 72, and the wire electrode 39.

  On the other hand, as shown in FIG. 6B, when the pixel 32A is set to the second state (pixel 32A (π)), a positive voltage (on the wire electrode 39 via the upper electrodes 64A and 64B in FIG. + V2) is applied, and the potential of the wire electrode 38 is set to 0 V via the lower electrodes 60A and 60B of FIG. Then, the liquid Lq is sucked by electrostatic force in the direction of the wire electrode 39. However, since the liquid Lq does not leak to the outside of the wire member 72 due to the liquid repellency (surface tension of the liquid Lq) of the wire member 72, the liquid Lq is stably held at the lower end of the wire member 72. The illumination light IL2 incident through the gap between the wire electrode 39 and the wire member 72 and the liquid Lq is reflected by the reflecting member 37, and is emitted through the gap between the liquid Lq, the wire member 72, and the wire electrode 39. At this time, the optical path length of the illumination light IL2 is different from the optical path length of the illumination light IL1 by 2d (n−1) (n is the refractive index of the liquid Lq), and the interval d satisfies the above-described formula (3). Therefore, the phase of the reflected illumination light IL2 is 180 ° different from that of the illumination light IL1 in FIG.

  In this modification, each pixel 32A has the voltage of the first wire electrode 38 (lower electrodes 60A, 60B) and the second wire electrode 39 (upper electrodes 64A, 64B) set to (+ V2, 0) or (0, + V2). ), It is possible to switch to the first state or the second state at high speed. Moreover, since the electrically insulated wire members 70 and 72 for holding the liquid Lq are provided between the wire electrodes 38 and 39, the wire electrodes 38 and 39 (electrodes 60A to 64B) are provided. The voltage applied to can be reduced, and the configuration of the modulation control unit becomes easy.

In this modification, at least one of the wire members 70 and 72 may be a mesh-like two-dimensional lattice member. Furthermore, since the lower wire member 70 may shield the illumination light IL, a two-dimensional lattice-like member having a small aperture ratio can be used as the wire member 70.
Next, in the above-described embodiment and its modification, the reflecting member 37 is disposed in each of the pixels 32 and 32A in order to reflect the illumination light IL. However, as shown in the second modified example in FIG. 7A and the third modified example in FIG. 7B, the reflecting member 37 can be omitted. 7A and 7B, portions corresponding to those in FIGS. 2 and 5 are denoted by the same reference numerals, and detailed description thereof is omitted.

First, FIG. 7A shows one pixel 32B in the main body 30B of the spatial light modulator 28B of the second modification. In the pixel 32B of this modification, the reflective member 37 is omitted from the pixel 32 of FIG. 2, and a metal liquid Lqm that is a metal that becomes a liquid at a temperature close to room temperature is held instead of the liquid Lq. Other configurations are the same as those of the spatial light modulator 28 of FIG.
That is, in FIG. 7A, the metal liquid Lqm is held between the wire electrodes 38 and 39 in the cell portion 34 of the pixel 32B. As the metal liquid Lqm, for example, mercury (Hg, melting point: −38.8 ° C.) or gallium (Ga, melting point: 29.8 ° C.) can be used. Mercury is preferred as the metal liquid Lqm in that it becomes liquid at room temperature. When the temperature of the cell part 34 can be set to 30 ° C. or higher, gallium can be used as the metal liquid Lqm.

  In this modification, since the surface of the metal liquid Lqm becomes the reflecting surface 74 that reflects the incident illumination light IL, the reflecting member 37 in FIG. 2 can be omitted. In the first state, the potential of the lower electrodes 60A and 60B (wire electrode 38) is made higher than that of the upper electrodes 64A and 64B (wire electrode 39) of the pixel 32B, so that the metal liquid Lqm becomes the first wire electrode. It is attracted to the side 38 by electrostatic force. At this time, since the wire electrode 38 has liquid repellency (surface tension of the metal liquid Lqm), the metal liquid Lqm is held at the upper end of the wire electrode 38. In this first state, the distance in the Z direction between the surface of the metal liquid Lqm (reflection surface 74) and the lower end of the wire electrode 39 is defined as d.

  In the second state, the potential of the upper electrodes 64A and 64B (wire electrode 39) of the pixel 32B is made higher than the potential of the lower electrodes 60A and 60B (wire electrode 38), so that the metal liquid Lqm becomes the second wire. The electrode 39 is attracted by an electrostatic force. At this time, since the wire electrode 39 has liquid repellency (surface tension of the metal liquid Lqm), the metal liquid Lqm is held at the lower end of the wire electrode 39. In the first state and the second state, the optical path length of the illumination light IL (wavelength λ) incident and reflected on the pixel 32B changes by 2d. Accordingly, the condition of the interval d for the phase of the illumination light IL reflected in the first state and the second state to be different by 180 ° (π) is as follows.

2d = λ / 2, that is, d = λ / 4 (4)
According to the second modification, the reflection member 37 can be omitted, the configuration of the pixel 32B can be simplified, the area of the reflection surface 74 can be made larger than that of the reflection member 37, and the utilization efficiency of the illumination light IL can be increased. Furthermore, the potential difference between the wire electrodes 38 and 39 required for moving the metal liquid Lqm in the Z direction by electrowetting can be reduced. Further, the distance d in the equation (4) can be made smaller than that in the embodiment of FIG.

  Next, FIG. 7B shows one pixel 32C in the main body 30C of the spatial light modulator 28C of the third modification. The pixel 32C of this modification example is the same as the pixel 32A of the modification example of FIG. 5 except that the reflection member 37 is omitted and used between the wire members 70 and 72 in the modification example of FIG. 7A instead of the liquid Lq. It holds metal liquid Lqm. Other configurations are the same as those of the spatial light modulator 28A of FIG. That is, in FIG. 7B, the metal liquid Lqm is held between the wire members 70 and 72 in the cell portion 34 of the pixel 32C, and the surface of the metal liquid Lqm is a reflection surface 74 for the illumination light IL.

  In this modification, the pixel 32C is formed by increasing the potential of the wire electrode 38 with respect to the wire electrode 39 in the first state and increasing the potential of the wire electrode 39 with respect to the wire electrode 38 in the second state. The first state or the second state can be set. At this time, the configuration can be simplified as compared with the pixel 32A of FIG. 5, the area of the reflection surface 74 can be increased, and the utilization efficiency of the illumination light IL can be increased. Furthermore, since there is no reflecting member 37, there is little pressure loss when the liquid moves in the Z direction, and therefore the potential difference between the wire electrodes 38 and 39 required for moving the metal liquid Lqm in the Z direction can be reduced.

[Second Embodiment]
Hereinafter, a second embodiment will be described with reference to FIG. 8, parts corresponding to those in FIGS. 1A to 2 are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 8 shows a schematic configuration of a maskless exposure apparatus EX according to the present embodiment. In FIG. 8, an exposure apparatus EX includes an exposure light source 2 that emits pulsed light, an illumination optical system ILS that illuminates a surface to be irradiated with exposure illumination light (exposure light) IL from the light source 2, and substantially A mask pattern generating spatial light modulator 28 having a main body 30 having a plurality of pixels 32 arranged in a two-dimensional array on the irradiation surface or a surface in the vicinity thereof, and a modulation control unit 48. . Further, the exposure apparatus EX receives illumination light IL having a variable phase distribution generated by the plurality of pixels 32 of the spatial light modulator 28, and a spatial image (device pattern) formed corresponding to the phase distribution. ) On the surface of the wafer W (substrate), a wafer stage WST for positioning and moving the wafer W, a main control system 40 comprising a computer for overall control of the operation of the entire apparatus, and various controls. System.

  Hereinafter, in FIG. 8, the Z axis is set in parallel to the optical axis AX of the projection optical system PL, and in a direction parallel to the paper surface of FIG. 8 in a plane perpendicular to the Z axis (almost horizontal in this embodiment). The Y axis will be described by setting the X axis in a direction perpendicular to the paper surface of FIG. In addition, the angles around the X axis, the Y axis, and the Z axis are also called angles in the θx direction, the θy direction, and the θz direction, respectively. The relationship between the coordinate system (X, Y, Z) and the main body 30 of the spatial light modulator 28 is the same as in the example of FIG. In the present embodiment, the wafer W is scanned in the Y direction (scanning direction) during exposure.

  As the light source 2, an ArF excimer laser light source (wavelength 193 nm) is used. As the light source 2, a KrF excimer laser light source, a solid pulse laser light source that generates harmonics of laser light output from a YAG laser or a solid-state laser (semiconductor laser or the like), or the like can also be used. The solid-state pulse laser light source can emit laser light with a wavelength of 193 nm (various wavelengths other than this) and a pulse width of about 1 ns at a frequency of about 1 to 2 MHz.

In the present embodiment, a power source unit 42 is connected to the light source 2. The main control system 40 supplies a light emission trigger pulse TP instructing the pulse emission timing and the light amount (pulse energy) to the power supply unit 42. In synchronization with the light emission trigger pulse TP, the power supply unit 42 causes the light source 2 to emit pulses at the instructed timing and light quantity.
Illumination light IL made up of pulse laser light having a rectangular cross-sectional shape emitted from the light source 2 and a substantially parallel light beam is a beam expander 4 made up of a pair of lenses, and a polarization control optical system 6 that controls the polarization state of the illumination light IL. Then, the light enters the array of a plurality of minute pixels 12 (optical elements corresponding to the pixels 32 in FIG. 2) of the main body 10 having the base member 11 of the spatial light modulator 9 for the illumination system via the mirror 8A. The polarization control optical system 6 includes, for example, a half-wave plate that rotates the polarization direction of the illumination light IL, a quarter-wave plate for converting the illumination light IL into circularly polarized light, and the illumination light IL that is randomly polarized (non-polarized light). This is an optical system in which a wedge-shaped birefringent prism or the like for conversion into (1) can be installed interchangeably.

  The spatial light modulator 9 has substantially the same configuration as the spatial light modulator 28, the main body 10 of the spatial light modulator 9 corresponds to the main body 30, and the modulation control unit 49 corresponds to the modulation control unit 48. . The pixels 12 (cell part) of the spatial light modulator 9 are arranged in a two-dimensional array along a plane (array plane) inclined in the θx direction with respect to the XY plane, and the phase of the input illumination light IL is respectively input. Control and reflect. By controlling the phase distribution of the reflected illumination light IL in this way, the pupil plane of the illumination optical system ILS is used, for example, when switching diffractive optical elements (DOE) having various characteristics. Can be controlled to an arbitrary distribution such as a circular shape for normal illumination, an annular shape for annular illumination, and a dipole or quadrupolar shape for multipolar illumination.

  For example, before the exposure of one lot of wafers is started, the illumination system control unit 41 sends a plurality of pixels 12 corresponding to each illumination condition to the modulation control unit 49 of the spatial light modulator 9 under the control of the main control system 40. The phase distribution information of the illumination light IL set by the array is supplied. In response to this, the modulation controller 49 controls each pixel 12 of the spatial light modulator 9 to the first state (phase 0) or the second state (phase π). Each pixel 12 may be set to a state in which the phase of the reflected light is changed in a phase other than the first or second state.

  The illumination light IL reflected by the spatial light modulator 9 is guided to the incident surface of the microlens array 16 along the Y axis (optical axis AXI) via the relay optical system 14 including the lenses 14a and 14b and the mirror 8B. . The illumination light IL incident on the microlens array 16 is two-dimensionally divided (wavefront division) by a large number of minute lens elements constituting the microlens array 16, and the illumination optical system that is the rear focal plane of each lens element. A secondary light source (surface light source) is formed on the pupil surface of the ILS (hereinafter referred to as illumination pupil surface IPP). Note that a fly-eye lens or the like can be used instead of the microlens array 16.

  The illumination light IL from the secondary light source formed on the illumination pupil plane IPP is incident on the half mirror 24 via the first relay lens 18A, the field stop 20, the second relay lens 18B, and the condenser optical system 22, Illumination light IL reflected by the mirror 24 in the + Z direction is incident on an irradiated surface (a surface on which a designed transfer pattern is arranged) parallel to the XY plane. Reflecting surfaces of a large number of pixels 32 (optical elements having the cell portions 34 in FIG. 2) arranged in a two-dimensional array of spatial light modulators 28 are arranged along the irradiated surface or a surface in the vicinity thereof. The The illumination optical system ILS includes the optical members from the beam expander 4 to the condenser optical system 22. Note that a quarter-wave plate may be disposed between the polarization beam splitter and the spatial light modulator 28 with the half mirror 24 as a polarization beam splitter and the polarization state of the illumination light IL input thereto as S polarization. . Thereby, almost all of the illumination light IL reflected by the spatial light modulator 28 passes through the polarization beam splitter and travels toward the projection optical system PL, so that the utilization efficiency of the illumination light IL can be improved.

  As an example, the illumination light IL from the illumination optical system ILS illuminates a rectangular illumination area 26A elongated in the X direction on the array of the many pixels 32 of the spatial light modulator 28 with a substantially uniform illuminance distribution. The illumination optical system ILS, the half mirror 24, and the main body 30 of the spatial light modulator 28 are supported by a frame (not shown). As an example, the exposure pattern control unit 43 under the control of the main control system 40 is set in the modulation control unit 48 of the spatial light modulator 28 by the array of pixels 32 every time the illumination light IL having a predetermined number of pulses is emitted. Information on the phase distribution of the light IL is supplied. In response to this, the modulation controller 48 controls each pixel 32 of the spatial light modulator 28 to the first state (phase 0) or the second state (phase π). Instead of the spatial light modulators 9 and 28, spatial light modulators similar to the spatial light modulators 28A to 28C of the above modification may be used.

  The illumination light IL reflected by the array of a large number of pixels 32 in the illumination area 26A of the spatial light modulator 28 enters the projection optical system PL via the half mirror 24. Projection optical system PL having optical axis AX supported by a column (not shown) is a double-sided telecentric reduction projection optical system. The projection optical system PL converts a reduced image of the aerial image corresponding to the phase distribution of the illumination light IL set by the spatial light modulator 28 into an exposure area 26B (an illumination area 26A and an illumination area 26A) in one shot area of the wafer W. To a region conjugate to The projection magnification β of the projection optical system PL is, for example, about 1/10 to 1/100, and the resolution (half pitch or line width) is, for example, about the width of the image of the pixel 32 of the spatial light modulator 28. For example, if the width of the pixel 32 is about several μm and the projection magnification β of the projection optical system PL is about 1/100, the resolution of the projection optical system PL is about several tens of nm.

  The wafer W (substrate) includes, for example, a surface of a circular flat base material such as silicon or SOI (silicon on insulator) applied with a photoresist (photosensitive material) with a thickness of about several tens to 200 nm. . Further, when the exposure apparatus EX is of an immersion type, for example, as disclosed in US Patent Application Publication No. 2007/242247, a space between the optical member at the tip of the projection optical system PL and the wafer W is disclosed. A local liquid immersion device for supplying and recovering a liquid (for example, pure water) that transmits the illumination light IL is provided. In the case of the immersion type, the resolution can be further increased.

  In FIG. 8, wafer W is attracted and held on the upper surface of wafer stage WST via a wafer holder (not shown), and wafer stage WST performs step movement in the X and Y directions on a guide surface (not shown), and Y Move at a constant speed in the direction. The position of wafer stage WST in the X and Y directions, the rotation angle in the θz direction, and the like are formed by laser interferometer 45, and this measurement information is supplied to stage control system 44. Stage control system 44 controls the position and speed of wafer stage WST via drive system 46 such as a linear motor based on control information from main control system 40 and measurement information from laser interferometer 45. In order to perform alignment of the wafer W, an alignment system (not shown) for detecting the position of the alignment mark on the wafer W is also provided.

When the wafer W is exposed, after the wafer W is aligned, the illumination condition of the illumination optical system ILS is set using the spatial light modulator 9. Then, in order to perform exposure on the shot areas arranged in a line in the Y direction on the surface of the wafer W, the wafer W is positioned at the scanning start position. Thereafter, scanning of the wafer W at a constant speed in the + Y direction is started.
Next, the main control system 40 corresponds to the aerial image formed in the exposure area 26B in the modulation control section 48 via the exposure pattern control section 43 according to the relative position of the exposure area 26B of the wafer W to the shot area. Information on the phase distribution of the illumination light IL on the reflecting surface of the spatial light modulator 28 is supplied, and a light emission trigger pulse TP is supplied to the power supply unit 42. As a result, a target aerial image is sequentially exposed in the exposure area 26B according to the position in the Y direction. By repeating this operation until the shot area crosses the exposure area 26B, the entire aerial image (circuit pattern) is exposed in the shot area.

  Thereafter, in order to expose a shot area adjacent to the shot area of the wafer W, the main control system 40 sends the illumination light IL to the modulation controller 48 via the exposure pattern controller 43 while scanning the wafer W in the same direction. And the light emission trigger pulse TP is supplied to the power supply unit 42. In this manner, exposure can be continuously performed from the first shot area to the next shot area. When shifting to exposure of a row including shot regions adjacent to the wafer W in the X direction, the wafer stage WST is driven to move the wafer W stepwise in the X direction (non-scanning direction orthogonal to the scanning direction). . Then, the scanning direction of the wafer W with respect to the exposure region 26B is set to the opposite −Y direction, and the phase distribution of the illumination light IL is reversed from the main control system 40 to the modulation control unit 48 via the exposure pattern control unit 43. By supplying information and supplying the light emission trigger pulse TP to the power supply unit 42, it is possible to continuously expose a series of shot regions in adjacent columns. In this exposure, it is also possible to expose different aerial images to a plurality of shot areas. Each shot area may be exposed by a plurality of scans. Thereafter, the photoresist on the wafer W is developed, so that a resist pattern is formed in each shot area of the wafer W.

The effects and the like of this embodiment are as follows.
(1) In the first aspect, the exposure apparatus EX that exposes the wafer W of the present embodiment with the illumination light IL includes the spatial light modulator 28 and the plurality of cell units 34 (pixels 32) of the spatial light modulator 28. An illumination optical system ILS that irradiates the array with illumination light IL, a projection optical system PL that guides illumination light from the plurality of cell units 34 to the wafer W and projects a pattern onto the wafer W, and a pattern that is exposed to the wafer W In order to control, an exposure pattern control unit 43 that controls the phase of illumination light reflected by the plurality of cell units 34 of the spatial light modulator 28 is provided.

  According to the exposure apparatus EX of the first aspect, since the spatial light modulator 28 is provided, an arbitrary pattern can be exposed on the wafer W by a maskless method. In the case of performing exposure in the maskless manner as described above, for example, U.S. Pat. No. 6,900,915 and U.S. Pat. No. 7,095,546 are used instead of the spatial light modulator 9 in the illumination optical system ILS. Or a spatial light modulator having a large number of micromirrors each having a variable tilt angle about two orthogonal axes, as disclosed in US Pat. Appln. No. 2005/0095749. You can also. Further, instead of the spatial light modulator 9, a plurality of diffractive optical elements (DOE) may be switched and used.

  (2) In addition, the cell portion 34 (pixel 32) of the spatial light modulator 28 is provided in a rectangular region whose longitudinal direction is the X direction, and the wafer W is in the Y direction orthogonal to the X direction on the image plane of the projection optical system PL. The exposure pattern control unit 43 includes a pattern (phase distribution) formed by a plurality of pixels 32 according to the movement of the wafer W by the wafer stage WST. Is moved in the Y direction. Thereby, the entire surface of the wafer W can be efficiently exposed by a maskless method.

  (3) Further, in the second aspect, the exposure apparatus EX that exposes the wafer W with the illumination light IL through the mask pattern of the present embodiment has the spatial light modulator 9, and the spatial light modulation with the illumination light IL. In order to control the illumination optical system ILS that illuminates the mask pattern via the device 9 and the distribution of the incident angles of the illumination light IL that illuminates the mask pattern (light quantity distribution on the illumination pupil plane IPP), the spatial light modulation And an illumination system control unit 41 that controls the phase of the illumination light IL reflected by a plurality of cell units (pixels 12) of the device 9.

  According to the exposure apparatus EX of the second aspect, since the spatial light modulator 9 is used in the illumination optical system ILS, the mask pattern can be obtained only by controlling the phase distribution of the illumination light IL by the spatial light modulator 9. The distribution of the incident angles of the illumination light IL that illuminates the light (the light amount distribution on the illumination pupil plane IPP) can be controlled to an arbitrary distribution. In the exposure apparatus EX according to the second aspect, instead of the spatial light modulator 28 for setting a mask pattern (phase pattern), a reticle stage that can reciprocate at least in the Y direction, and a reticle stage are mounted. Thus, a reticle on which a transfer pattern is formed may be used.

  Next, in the present embodiment, the following modifications are possible. First, in the present embodiment, the wafer W is continuously moved by scanning and exposing the wafer W. In addition, each shot area of the wafer W is divided into a plurality of partial areas in the Y direction, and when the partial area in the exposure area 26B of the projection optical system PL reaches, the illumination light IL is emitted by a predetermined number of pulses. The partial area may be exposed with the reflected light from the array of pixels 32 of the spatial light modulator 28. Thereafter, the wafer W is moved stepwise in the Y direction, and after the next partial area reaches the exposure area 26B, the partial area is similarly exposed. This method is substantially a step-and-repeat method, but different patterns are exposed to adjacent partial areas.

  In the above embodiment, the telecentric projection optical system PL is used on the object side and the image plane side. In addition, as shown in the exposure apparatus EXA of the modification example of FIG. 9, it is also possible to use a non-telecentric projection optical system PLA on the object side. In FIG. 9, the illumination optical system ILSA of the exposure apparatus EXA includes a main body ILSB including optical members from the light source 2 to the first relay lens 18A in FIG. 8, and a field in which the illumination light IL from the main body ILSB is sequentially irradiated. A diaphragm 20, a mirror 8C, a second relay lens 18B, a condenser optical system 22, and a mirror 8D are provided. The illumination optical system ILSA irradiates the array of pixels 32 (cell part 34) of the spatial light modulator 28 arranged on the object plane of the projection optical system PLA with the illumination light IL at an incident angle β in the θx direction. The projection optical system PLA forms a predetermined aerial image on the surface of the wafer W by the illumination light IL reflected obliquely from the array of pixels 32. The incident angle β is, for example, several deg (°) to several tens deg. The expression (3) is set so that the phase difference between the illumination light reflected by the pixel 32 in the first state and the illumination light reflected by the pixel 32 in the second state becomes 180 ° according to the incident angle β. ) Or the value of the interval d in the cell part 34 of the formula (4) may be adjusted. Other configurations and operations are the same as those in the above embodiment.

  Further, instead of the microlens array 16 which is the wavefront division type integrator of FIG. 8, a rod type integrator as an internal reflection type optical integrator may be used. In this case, in FIG. 8, a condensing optical system is added to the spatial light modulator 9 side of the relay optical system 14 to form a conjugate surface of the reflection surface of the spatial light modulator 9, and the incident end is near the conjugate surface. A rod-type integrator may be arranged so that is positioned.

In addition, a relay optical system for forming an image of the illumination field stop disposed on the exit end face of the rod-type integrator or in the vicinity of the exit end face on the reflection surface of the spatial light modulator 9 is disposed. In this configuration, the secondary light source is formed on the pupil plane of the relay optical system 14 and the condensing optical system (a virtual image of the secondary light source is formed near the incident end of the rod integrator).
In the case of manufacturing an electronic device (or micro device), as shown in FIG. 10, the electronic device performs step 221 for designing the function / performance of the electronic device, and forms mask pattern data based on this design step. In step 222, which is stored in the main control system of the exposure apparatuses EX, EXA, step 223, in which a substrate (wafer) which is the base material of the device is manufactured and resist is applied, and the exposure apparatuses EX, EXA (or exposure method) described above A step of exposing a spatial image of a phase distribution generated by the spatial light modulator 28 (or mask pattern) onto a substrate (sensitive substrate), a step of developing the exposed substrate, a heating (curing) of the developed substrate, an etching step, etc. Substrate processing step 224 including, device assembly step (dicing process, bonding process, package Including processed processes such extent) 225, and an inspection step 226, and the like.

This device manufacturing method includes a step of exposing the wafer W using the exposure apparatus of the above-described embodiment, and a step of processing the exposed wafer W (step 224). Therefore, an electronic device can be efficiently manufactured with high accuracy.
Further, the present invention is not limited to the application to the manufacturing process of a semiconductor device. For example, a manufacturing process such as a liquid crystal display element and a plasma display, an imaging element (CMOS type, CCD, etc.), a micromachine, a MEMS ( (Microelectromechanical systems), thin film magnetic heads, and various devices (electronic devices) such as DNA chips can be widely applied.

  In addition, the spatial light modulators 28 and 28A to 28C of the above-described embodiment and its modifications can be used for optical devices such as projectors other than the exposure device. The optical device includes a spatial light modulator 28 (or 28A to 28C), an illumination system (first optical system) that irradiates illumination light to a plurality of cell units 34 (pixels 32) of the spatial light modulator 28, and An imaging optical system (second optical system) for guiding the light modulated by the cell portions 34 (pixels 32) to the image plane (the surface of the object). According to this optical device, for example, high resolution can be obtained.

  In addition, this invention is not limited to the above-mentioned embodiment, A various structure can be taken in the range which does not deviate from the summary of this invention.

  EX, EXA ... exposure apparatus, ILS, ILSA ... illumination optical system, PL, PLA ... projection optical system, W ... wafer, Lq ... liquid, Lqm ... liquid metal, 28 ... spatial light modulator, 30 ... main body, 32 ... Pixel, 34 ... cell part, 37 ... reflecting member, 38 ... wire electrode, 39 ... wire electrode, 48 ... modulation control part, 54 ... SRAM, 60A, 60B ... lower electrode, 64A, 64B ... upper electrode

Claims (14)

A spatial light modulator that modulates light incident on the array surface,
A cell part having a partition part along a first direction crossing the arrangement surface;
A first electrode and a second electrode disposed in the cell portion along the first direction;
A liquid held between the first electrode and the second electrode in the cell portion,
The phase of the light reflected in the cell unit is controlled by controlling the position of the liquid in the cell unit in the first direction by the voltage applied to the first and second electrodes. Light modulator. A reflective part fixed to secure a gap through which the liquid passes between the first and second electrodes in the cell part and between the partition part;
The phase of light reflected in the reflection unit by controlling the thickness of the liquid between the reflection unit in the cell unit and the first electrode by the voltage applied to the first and second electrodes. The spatial light modulator according to claim 1, wherein the spatial light modulator is controlled.   The spatial light modulator according to claim 2, wherein the reflection unit also serves as an electrode to which a voltage between two voltages applied to the first and second electrodes is applied.   4. The device according to claim 1, wherein at least one of the first and second electrodes includes a one-dimensional or two-dimensional grid-like electrode disposed in a plane perpendicular to the first direction. The spatial light modulator according to one item. Third and fourth electrodes disposed proximate to the first and second electrodes of the cell portion;
First and second insulating films provided between the third and fourth electrodes and the first and second electrodes, respectively,
5. The spatial light modulator according to claim 1, wherein the voltages of the first and second electrodes are controlled by a voltage applied to the third and fourth electrodes. 6.   Arranged in a plane perpendicular to the first direction, at least one of the position in the cell portion away from the first electrode toward the second electrode and the position away from the second electrode toward the first electrode. The spatial light modulator according to claim 1, further comprising a one-dimensional or two-dimensional lattice-shaped conductive member.   The spatial light modulator according to claim 1, wherein the liquid is a liquid metal that reflects incident light.   The first and second electrodes have a first set of voltages that change the phase of light reflected in the cell portion by a first phase, or the phase of light reflected in the cell portion. The spatial light modulation according to any one of claims 1 to 7, wherein any one of a plurality of sets of voltages including a second set of voltages that are changed by a second phase different from the phase by 180 ° is provided. vessel.   The spatial light modulator according to claim 1, wherein the partition wall is formed in a frame shape. A plurality of the cell portions arranged along the arrangement surface in a two-dimensional or one-dimensional array;
The first electrode, the second electrode, and the liquid provided corresponding to each of the plurality of cell portions;
A control unit for controlling the voltage of the first and second electrodes corresponding to each other independently of each other, and controlling the phase of light reflected by the cell unit;
The spatial light modulator according to claim 1, wherein the spatial light modulator is provided. The spatial light modulator according to any one of claims 1 to 10,
A first optical system for irradiating illumination light to the cell portion of the spatial light modulator;
An optical device comprising: a second optical system that guides light from the cell unit to an object. In an exposure apparatus that exposes a substrate with exposure light,
A spatial light modulator according to claim 10;
An illumination optical system for irradiating the exposure light to the array of the plurality of cell portions of the spatial light modulator;
A projection optical system that guides reflected light from the plurality of cell portions onto the substrate and projects a pattern on the substrate;
An exposure control device for controlling a phase pattern of reflected light from the plurality of cell portions of the spatial light modulator in order to control a pattern exposed to the substrate;
An exposure apparatus comprising: In an exposure apparatus that exposes a substrate with exposure light through a mask,
An illumination optical system comprising the spatial light modulator according to claim 10 and illuminating the mask with the exposure light via the spatial light modulator;
An illumination control device that controls a phase pattern of reflected light from the plurality of cell units of the spatial light modulator in order to control a distribution of incident angles of the exposure light that illuminates the mask;
An exposure apparatus comprising: Forming a pattern of a photosensitive layer on a substrate using the exposure apparatus according to claim 12 or 13,
Processing the substrate on which the pattern is formed;
A device manufacturing method including:

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