JP2012069654A - Spatial light modulator, luminaire and exposure device, and manufacturing method of device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To configure a spatial light modulator having large area mirror elements arranged densely.SOLUTION: The spatial light modulator comprises multiple mirror elements SEk each having a reflection surface SEA, a base member SVb on which the multiple mirror elements SEk are arranged tiltably around a center, i.e. the vertex SEp in each reflection surface SEA, and multiple voice coil motors SVk which drive the multiple mirror elements SEk, respectively, in the direction perpendicular to the reflection surface SEA on the rear surface of the reflection surface SEA, at multiple positions including the vertex SEp but not on the same straight line.

Description

  The present invention relates to a spatial light modulator, an illumination apparatus and an exposure apparatus, and a device manufacturing method, and more particularly to a spatial light modulator that modulates illumination light using a plurality of mirror elements, and an illumination apparatus including the spatial light modulator. And an exposure apparatus including the illumination apparatus, and a device manufacturing method using the exposure apparatus.

  With so-called device rule (practical minimum line width) miniaturization, high resolution is required for projection exposure apparatuses (so-called steppers, scanning steppers (also called scanners), etc.) used for manufacturing semiconductor elements and the like. It has become.

Conventionally, the resolution of a projection exposure apparatus has been improved by shortening the exposure wavelength, increasing the numerical aperture of the projection optical system (higher NA), and the like. However, shortening the wavelength of illumination light is accompanied by difficulty in developing light sources and glass materials, for example. Further, increasing the NA increases the depth of focus (DOF) of the projection optical system and decreases the imaging performance (imaging characteristics), so there is a limit to increasing the NA. Therefore, it has become essential to reduce the k ₁ factor (so-called Low ₁ ).

Under such circumstances, recently, in order to realize Lowk ₁ , spatial light modulation for modulating light from a light source into illumination light having a complicated shape (intensity distribution) as disclosed in, for example, Patent Document 1 An illumination light source having a more complicated shape (illuminance distribution) is employed as compared with modified illumination such as annular illumination and multipole illumination using a multi-mirror array (SLM: Spatial Light Modulator).

  However, since the conventional spatial light modulator is manufactured by MEMS (Micro Electro Mechanical Systems), each mirror element is too small, the reflected light is blurred by diffraction, interference, etc., and there is an optical problem. It has recently been found. In addition, a spatial light modulator (multi-mirror array) that has a larger mirror element than a MEMS and is driven by a piezoelectric element has been developed. However, since the piezoelectric element is accompanied by hysteresis and / or drift, calibration that frequently detects the relationship between the applied voltage and the driving amount of the mirror element is indispensable, and complicated control by a feedback loop is unavoidable. It was.

US Patent Application Publication No. 2009/0097094

  According to the first aspect of the present invention, a plurality of mirror elements having a reflecting surface and two-dimensionally arranged; and each of the plurality of mirror elements is supported at one point in the same plane as the reflecting surface. A plurality of mirror elements that drive each of the plurality of mirror elements in directions toward and away from the base plate at a plurality of points that are not collinear with the one point on the back surface of the reflecting surface; A spatial light modulator comprising: a drive device;

  According to this, it becomes possible to drive a plurality of mirror elements having a reflecting surface and two-dimensionally arranged at high speed with high response.

  According to a second aspect of the present invention, the spatial light modulator of the present invention disposed on the optical path of an energy beam from a beam source; on the optical path of the energy beam, forward and backward of the optical path of the spatial light modulator And an optical system disposed on at least one of the lighting systems.

  According to this, it is possible to form an illumination light source having a complicated shape (intensity distribution) by modulating the energy beam from the beam source by the spatial light modulator, and the spatial light modulator is created regardless of the MEMS. Therefore, it is possible to prevent the reflected light from being blurred by the individual mirror elements.

  According to a third aspect of the present invention, there is provided an exposure apparatus that exposes an object with an energy beam to form a pattern on the object, the pattern being applied to the energy beam via the spatial light modulator and the optical system. There is provided an exposure apparatus comprising: an illuminating device of the present invention that illuminates with; and a projection system that projects the energy beam through the pattern onto the object.

  According to this, it becomes possible to form a pattern on an object with high resolution and high accuracy.

  According to a fourth aspect of the present invention, there is provided a device manufacturing method comprising: exposing an object using the exposure apparatus of the present invention; and developing the exposed object.

It is a figure which shows schematic structure of the exposure apparatus which concerns on one Embodiment. It is a figure which shows schematic structure of the spatial light modulation unit which comprises the illumination system of FIG. 3A is a diagram showing an arrangement of mirror elements included in the spatial light modulator of FIG. 2, FIG. 3B is a diagram showing a configuration of the mirror elements, and FIG. 3C is a diagram of a mirror element tilting device. It is a figure which shows a structure. 4A is a diagram showing a specific design example of the two-dimensional arrangement of the mirror elements of FIG. 3A, and FIG. 4B is a diagram for explaining the tilting mechanism of the mirror elements having the configuration of FIG. FIG. It is a figure which shows the specific structural example of the microcoil (array) which comprises the tilting apparatus of a mirror element. FIG. 6A is a diagram showing a two-dimensional array (multi-mirror array) of mirror elements according to a modification, and FIG. 6B is a diagram for explaining the configuration of the mirror elements of FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 shows a schematic configuration of an exposure apparatus 100 according to an embodiment. The exposure apparatus 100 is a step-and-scan projection exposure apparatus, a so-called scanner. As will be described later, in the present embodiment, a projection optical system PL is provided. In the following description, a reticle and wafer are arranged in a direction perpendicular to the Z-axis direction parallel to the optical axis AX of the projection optical system PL and in a plane perpendicular to the Z-axis direction. And the direction perpendicular to the Z and Y axes is the X axis direction, and the rotation (tilt) directions around the X, Y, and Z axes are θx, θy, And the θz direction will be described.

  The exposure apparatus 100 includes an illumination system IOP, a reticle stage RST that holds a reticle R, a projection unit PU that projects a pattern image formed on the reticle R onto a wafer W coated with a sensitive agent (resist), and a wafer W. A wafer stage WST to be held and a control system for these are provided.

  The illumination system IOP includes a light source 1, a beam expander 2, a beam splitter BS 1, a spatial light modulation unit 3, a relay optical system 4, and a fly as an optical integrator, which are sequentially arranged on the optical path of the light beam LB emitted from the light source 1. And an illumination optical system including an eye lens 5, a beam splitter BS2, a condenser optical system 6, an illumination field stop (reticle blind) 7, an imaging optical system 8, a bending mirror 9, and the like.

  As an example of the light source 1, an ArF excimer laser (output wavelength 193 nm) is used. The light beam LB emitted from the light source 1 has, for example, a rectangular cross-sectional shape that is long on the X axis.

  The beam expander 2 includes a concave lens 2a and a convex lens 2b. The concave lens 2a has a negative refractive power, and the convex lens 2b has a positive refractive power.

  The light beam LB that has passed through the beam expander 2 enters the beam splitter BS1. A part of the light beam LB reflected by the beam splitter BS1 is received by a detection unit D1 including an imaging element such as a CCD. Thereby, the intensity distribution (including the positional deviation of the light beam LB) of the light beam LB directed to the spatial light modulation unit 3 through the beam splitter BS1 is detected. The detection result is sent to the main controller 20.

  The spatial light modulation unit 3 includes a so-called K prism (hereinafter simply referred to as a prism) 3P, and a reflective spatial light modulator (SLM: Spatial Light) disposed on the lower surface (surface on the −Z side) of the prism 3P. Modulator) 3S. The prism 3P is made of optical glass such as fluorite or quartz glass.

  As shown in an enlarged view in FIG. 2, on the upper surface of the prism 3P, that is, on the side opposite to the spatial light modulator 3S, an incident surface (−Y side surface) and an exit surface (+ Y) parallel to the XZ plane in FIG. V-shaped surfaces (surfaces recessed in a wedge shape) made of surfaces PS1 and PS2 that intersect each other at 60 degrees and intersect each other at 120 degrees are formed. The back surfaces of the surfaces PS1 and PS2 (inner surfaces of the prism 3P) function as reflecting surfaces R1 and R2, respectively.

  The reflecting surface R1 reflects light parallel to the Y axis, which is incident perpendicularly to the incident surface of the prism 3P from the beam expander 2 via the beam splitter BS1, in the direction of the spatial light modulator 3S. The reflected light beam LB reaches the spatial light modulator 3S via the upper surface of the prism 3P, and is reflected toward the reflection surface R2 by the spatial light modulator 3S as will be described later. The reflecting surface R2 of the prism 3P reflects the light that has arrived from the spatial light modulator 3S via the upper surface of the prism 3P and emits it to the relay optical system 4 side.

  The spatial light modulator 3S is a reflective spatial light modulator. The spatial light modulator means an element that processes, displays, and erases spatial information such as an image or patterned data by two-dimensionally controlling the amplitude, phase, or traveling direction of incident light. As the spatial light modulator 3S of the present embodiment, a movable multi-mirror array having a large number of minute mirror elements (mirror elements) SE arranged on a two-dimensional (XY) plane is used. The spatial light modulator 3S includes a large number of mirror elements. In FIG. 2, only the mirror elements SEa, SEb, SEc, and SEd are shown. Details of the configuration of the spatial light modulator 3S will be described later.

  Returning to FIG. 1, the fly-eye lens 5 is a set of a large number of microlens elements having positive refractive power arranged densely in the direction perpendicular to the light beam LB. As the fly-eye lens 5, for example, a cylindrical micro fly-eye lens disclosed in US Pat. No. 6,913,373 can be employed.

  According to the illumination system IOP of the present embodiment, the light beam LB emitted from the light source 1 is incident on the beam expander 2 and passes through the beam expander 2 so that its cross section is enlarged, and a predetermined rectangular cross section is formed. It is shaped into a light beam. The light beam LB shaped by the beam expander 2 enters the spatial light modulation unit 3 via the beam splitter BS1.

  For example, as shown in FIG. 2, four parallel light beams L1 to L4 aligned in the Z-axis direction in the light beam LB enter the inside from the incident surface of the prism 3P and are spatially modulated by the reflecting surface R1. Reflected parallel to each other toward the container 3S. The light beams L1 to L4 are incident on the reflecting surfaces of different mirror elements SEa, SEb, SEc, and SEd that are arranged in the Y-axis direction among the plurality of mirror elements SE. Here, the mirror elements SEa, SEb, SEc, SEd are tilted independently by their respective drive units (not shown). For this reason, the light rays L1 to L4 are reflected toward the reflecting surface R2 in different directions. Then, the light beams L1 to L4 (light beam LB) are reflected by the reflecting surface R2 and emitted to the outside of the prism 3P. Here, the air-converted optical path lengths of the light beams L1 to L4 from the −Y side surface (incident surface) to the + Y side surface (outgoing surface) of the prism 3P correspond to the air-converted optical path length when the prism 3P is not provided. Is set equal to Here, the air-converted optical path length is an optical path length L / n obtained by converting an optical path length (L) of light in the medium (refractive index n) into an optical path length in the air (refractive index 1).

  Light rays L1 to L4 (light beam LB) emitted to the outside of the prism 3P are aligned in parallel to the Y axis via the relay optical system 4 and are incident on the fly-eye lens 5 disposed behind the relay optical system 4. To do. Then, each of the light beams L1 to L4 is incident on one of a large number of lens elements of the fly-eye lens 5, whereby the light beam LB is divided (wavefront division). Thereby, a secondary light source (surface light source, that is, an illumination light source) composed of a plurality of light source images is formed on the rear focal plane LPP of the fly-eye lens 5 that coincides with the pupil plane (illumination pupil plane) of the illumination optical system. .

  FIG. 2 schematically shows light intensity distributions SP1 to SP4 corresponding to the light beams L1 to L4 on the rear focal plane LPP of the fly-eye lens 5. Thus, in this embodiment, the light intensity distribution (also referred to as luminance distribution or illumination light source shape) of the secondary light source (illumination light source) is freely set by the spatial light modulator 3S. As the spatial light modulator, the above-described reflective active spatial light modulator, or a transmissive or reflective diffractive optical element as an inactive spatial light modulator can be used. When such an inactive spatial light modulator is used, the secondary light source is controlled by controlling the position and orientation of at least some of the optical members (lens, prism member, etc.) constituting the relay optical system 4. The light intensity distribution of (illumination light source) can be variably set. Further, as the diffractive optical element, for example, controlling the position of the diffractive optical element having a plurality of sections disclosed in US Pat. No. 6,671,035 and US Pat. No. 7,265,816. Thus, the light intensity distribution of the secondary light source (illumination light source) may be variably set. In addition to the above-mentioned active or inactive spatial light modulator, a secondary light source (illumination light source) can be used by using a movable illumination aperture stop disclosed in, for example, US Pat. No. 6,452,662. The light intensity distribution may be set variably.

  In the present embodiment, the secondary light source formed by the fly-eye lens 5 is used as the illumination light source, and the reticle R held on the reticle stage RST described later is Koehler illuminated. For this reason, the surface on which the secondary light source is formed is a conjugate surface with respect to the surface of the aperture stop 41 (aperture stop surface) of the projection optical system PL, and is called a pupil plane (illumination pupil plane) of the illumination optical system. Further, the irradiated surface (the surface on which the reticle R is disposed or the surface on which the wafer W is disposed) is an optical Fourier transform surface with respect to the illumination pupil plane. When the number of wavefront divisions by the fly-eye lens 5 is relatively large, the overall light intensity distribution formed on the entrance surface of the fly-eye lens 5 and the overall light intensity distribution (pupil intensity distribution) of the entire secondary light source. ) And a high correlation. For this reason, the light intensity distribution on the incident surface of the fly-eye lens 5 and the surface optically conjugate with the incident surface is also referred to as the light intensity distribution (luminance distribution or illumination light source shape) of the secondary light source (illumination light source). it can.

  Returning to FIG. 1, the light beam LB emitted from the fly-eye lens 5 enters the beam splitter BS2. A part of the light beam LB reflected by the beam splitter BS2 is received by a detection unit D2 including an image sensor such as a CCD. Thereby, the light intensity distribution of the light beam LB, that is, the light intensity distribution (luminance distribution or illumination light source shape) of the secondary light source (illumination light source) is detected. The detection result is sent to the main controller 20.

  The light beam LB via the beam splitter BS2 is condensed by the condenser optical system 6, and further, the illumination field stop 7, the imaging optical system 8, the folding mirror 9, etc. (hereinafter, from the condenser optical system 6 to the folding mirror 9). Are collectively referred to as a light transmission optical system 10) and emitted from the illumination system IOP. As shown in FIG. 1, the emitted light beam LB is irradiated onto the reticle R as illumination light IL. Here, by restricting (shielding) the light beam LB (illumination light IL) by the illumination field stop 7, a part of the pattern surface (illumination region) of the reticle R is illuminated.

  Reticle stage RST is arranged below (−Z side) illumination system IOP. On reticle stage RST, reticle R is fixed, for example, by vacuum suction. The reticle stage RST can be finely driven in a horizontal plane (XY plane) by a reticle stage drive system (not shown) including a linear motor, for example, and can be driven within a predetermined stroke range in the scanning direction (Y-axis direction). It has become.

  Position information of the reticle stage RST in the XY plane (including rotation information in the θz direction) is transferred to a movable mirror 12 (or an end surface of the reticle stage RST) by a reticle laser interferometer (hereinafter referred to as “reticle interferometer”) 14. For example, it is always detected with a resolution of about 0.25 nm through the formed reflection surface. Measurement information of reticle interferometer 14 is supplied to main controller 20.

  Projection optical system PL is arranged below reticle stage RST (−Z side). As the projection optical system PL, for example, a refractive optical system including a plurality of optical elements (lens elements) arranged along the optical axis AX is used. The projection optical system PL is, for example, both-side telecentric and has a predetermined projection magnification (for example, 1/4 times, 1/5 times, or 1/8 times). Therefore, as described above, when the reticle R is illuminated by the illumination light IL from the illumination system IOP, the pattern surface of the reticle R (the first surface of the projection optical system, the object surface) is projected via the projection optical system PL. A reduced image of the pattern in the illumination area (a reduced image of a part of the pattern) is conjugated to the illumination area on the wafer W (second surface of the projection optical system, image plane) coated with a resist (sensitive agent). Projected onto the irradiation area (exposure area) IA of the illumination light IL.

  Among a plurality of lens elements constituting the projection optical system PL, a plurality of lens elements (not shown) on the object plane side (reticle R side) are controlled by an imaging performance correction controller 48 under the main controller 20. For example, it is a movable lens that can be driven in the Z-axis direction, which is the optical axis direction of the projection optical system PL, and in the tilt direction with respect to the XY plane (that is, the θx and θy directions). An aperture stop 41 that continuously changes the numerical aperture (NA) within a predetermined range is provided in the vicinity of the pupil plane of the projection optical system PL. As the aperture stop 41, for example, a so-called iris stop is used. The aperture stop 41 is controlled by the main controller 20 via the imaging performance correction controller 48.

  Wafer stage WST is driven on stage base 22 with a predetermined stroke in the X-axis direction and Y-axis direction by stage drive system 24 including a linear motor and the like, and in Z-axis direction, θx direction, θy direction, and θz direction. It is driven minutely. On wafer stage WST, wafer W is held by vacuum suction or the like via a wafer holder (not shown).

  Position information (including rotation information (yaw amount (rotation amount in θz direction), pitching amount (rotation amount in θx direction) and rolling amount (rotation amount in θy direction)) of wafer stage WST in the XY plane) is a laser. An interferometer system (hereinafter abbreviated as “interferometer system”) 18 always detects with a resolution of about 0.25 nm, for example, via a movable mirror 16 (or a reflecting surface formed on the end surface of wafer stage WST). The Measurement information of the interferometer system 18 is supplied to the main controller 20.

  Further, the position and the inclination of the surface of the wafer W in the Z-axis direction are such that an imaging light beam for forming images of many pinholes or slits toward the imaging surface of the projection optical system PL with respect to the optical axis AX. It is measured by a focal position detection system having an irradiation system 60a that irradiates from an oblique direction and a light receiving system 60b that receives a reflected light beam of the imaging light beam on the surface of the wafer W. As the focal position detection system (60a, 60b), one having the same configuration as the oblique incidence type multipoint focal position detection system disclosed in, for example, US Pat. No. 5,448,332 is used.

  On the wafer stage WST, a reference plate FP whose surface is flush with the surface of the wafer W is fixed. On the surface of the reference plate FP, a reference mark used for baseline measurement of the alignment system AS, a pair of reference marks detected by a reticle alignment system described later, and the like are formed. In addition, on the wafer stage WST, a luminance distribution measuring device 80 for measuring the pupil luminance distribution on-body is provided.

  An alignment system AS that detects alignment marks and reference marks formed on the wafer W is provided on the side surface of the lens barrel 40 of the projection unit PU. As the alignment system AS, for example, an image processing method in which a mark is illuminated and detected by broadband light such as a halogen lamp and the position of the mark is measured by performing image processing on the detected mark image (image). An FIA (Field Image Alignment) system, which is a kind of imaging type alignment sensor, is used.

  Although not shown in the exposure apparatus 100, TTR (Through The Reticle) alignment using light having an exposure wavelength disclosed in, for example, US Pat. No. 5,646,413 is provided above the reticle stage RST. A pair of reticle alignment systems comprising the system is provided. A detection signal of the reticle alignment system is supplied to main controller 20.

  The control system is mainly configured by a main controller 20 in FIG. The main controller 20 is composed of a so-called workstation (or microcomputer) composed of a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc. Control all over. The main controller 20 includes, for example, a storage device 42 including a hard disk, an input device 45 including a pointing device such as a keyboard and a mouse, a display device 44 such as a CRT display (or liquid crystal display), and a CD (compact disc). , DVD (digital versatile disc), MO (magneto-optical disc) or FD (flexible disc) drive device 46 is connected externally.

  In the storage device 42, information on the illumination light source shape (pupil luminance distribution) in which the imaging state of the projection image projected onto the wafer W by the projection optical system PL is optimum (for example, aberration or line width is within an allowable range), Stored therein is information corresponding to the illumination system IOP, in particular, control information of the mirror element SE of the spatial light modulator 3S, information on the aberration of the projection optical system PL, and the like.

  The drive device 46 is set with an information recording medium (a CD-ROM for convenience in the following description) in which a processing program for adjusting the illumination light source shape is written. Note that these programs may be installed in the storage device 42. Main controller 20 reads these programs onto the memory as appropriate.

Next, the configuration of the spatial light modulator 3S will be described.
FIG. 3A shows an arrangement of 27 mirror elements SEk that are a part of the multi-mirror array SE included in the spatial light modulator 3S. FIG. 3B shows the configuration of each mirror element, taking the mirror element SEk as a representative. 3C shows a driving device (micro voice coil motor (hereinafter referred to as a voice coil motor as appropriate) that drives (tilts) the mirror elements SEk and SEk ′ in FIG. 3A in the θx direction and the θy direction. Or referred to as micro-VCM)) The configuration of SVk, SVk ′ is shown.

  As can be seen from FIGS. 3A to 3C, the spatial light modulator 3S includes a plurality of mirror elements SEk (k = 1 to K) two-dimensionally arranged on a base member (base plate) SVb. A set (multi-mirror array) SE (see FIG. 3A) and two for each mirror element SEk and two-dimensionally arranged voice coil motors SVk (k = 1 to K) on the base member SVb ) (Micro VCM array MVA (see FIG. 3C)). The number K of mirror elements SEk is, for example, 4000 to 10,000.

  As shown in FIG. 3B, each mirror element SEk has a triangular shape (regular triangular shape in the present embodiment), and its upper surface (+ Z side surface) is subjected to mirror surface processing or the like to be a reflective surface. SEA is formed. Note that the mirror element SEk can be configured by attaching a thin plate-like plane mirror on a triangular support member. The size of the mirror element SEk is, for example, about 1 mm on one side.

  As can be seen from FIGS. 3B and 3C, the mirror element SEk is arranged substantially parallel to the base member SVb, and one apex SEp of the triangle is attached to the column SEs fixed on the base member SVb. Fixedly supported. That is, the mirror element SEk is cantilevered on the base member SVb via the support column SEs. One vertex SEp is a fixed fulcrum (end). For this reason, the mirror element SEk can rotate (swing) in the θx direction around the vertex SEp, and can rotate in the θy direction around an axis parallel to the Y axis passing through the vertex SEp. As a result, the mirror element SEk is configured to be tiltable in the θx direction and the θy direction.

  As shown in FIG. 3B, a pair of movers SEm is fixed to the lower surface of the mirror element SEk (the back surface of the reflection surface SEA). Each mover SEm includes a permanent magnet. The pair of movable elements SEm is disposed on the lower surface of the mirror element SEk at each of a plurality of points (locations) including the vertex SEp and not on the same straight line as a whole. In the present embodiment, the two movers SEm are arranged in the vicinity of two vertices of a triangle other than the vertex SEp.

  Opposite each mover SEm, as shown in FIG. 3C, a stator SVk is disposed on the base member SVb. The stator SVk constitutes a voice coil motor SVk together with the opposing movable element SEm, and two stators SVk are provided for each mirror element SEk. Stator SVk includes an iron core SVa and a coil SVc wound around the outer periphery of iron core SVa. A voice coil motor (shown using the same symbol SVk as the stator) drives a portion of the mirror element SEk where the movable element SEm is fixed in a direction (± Z direction) approaching and separating from the stator SVk. The other mirror elements SEk and the driving device (micro VCM) SVk are configured in the same manner as the mirror element SEk and the driving device (micro VCM) SVk.

  Here, by controlling the direction of the current supplied to the coil SVc included in each stator SVk, an attractive force or a repulsive force can be freely generated between the stator SVk and the corresponding movable element SEm. By controlling the magnitude of the current, the magnitude of the attractive force or repulsive force can be controlled. In the present embodiment, the direction and magnitude of the current supplied to the individual coils of the set of voice coil motors SVk (k = 1 to K) (micro VCM array MVA) included in the spatial light modulator 3S are determined by the main controller. 20.

  The plurality of mirror elements SEk (k = 1 to K) having the above-described configuration are two-dimensionally arranged on the base member SVb to form a multi-mirror array SE, as shown in FIG. Here, among the plurality of mirror elements SEk (k = 1 to K), the plurality of mirror elements arranged along the X-axis direction has one vertex SEp of the triangular reflecting surface on one side in the Y-axis direction. And the other side (+ Y side and -Y side). In addition, among a plurality of mirror elements SEk (k = 1 to K), a pair of mirror elements arranged adjacent to each other in the Y-axis direction are mutually adjacent to one vertex SEp on a triangular reflecting surface or one vertex SEp. Are arranged adjacent to each other in the Y-axis direction. With such an arrangement, the plurality of mirror elements SEk (k = 1 to K) are arranged densely.

  Corresponding to the two-dimensional arrangement of the multi-mirror array SE described above, the mover SEm and the stator SVk, that is, the voice coil motor SVk (k = 1 to K), are arranged in a grid pattern on the base member SVb and are micro VCM. An array MVA is configured.

  FIG. 4A shows a specific design example of the multi-mirror array SE (two-dimensional array of mirror elements SEk (k = 1 to K)). In the example shown in FIG. 4A, for example, a mirror member made of a plate member whose surface is mirror-finished (or a plate member to which a thin flat mirror is attached) is subjected to an exposure process, and FIG. In A), a cut pattern indicated by a white portion is formed, and this white portion is formed by etching. In FIG. 4A, reference sign SEn indicates an anchor point fixed to the base member SVb.

  FIG. 4B schematically shows an enlarged portion within the ellipse of FIG. As shown in FIG. 4B, the mirror element SEk rotates in the θy direction around the perpendicular (reference axis LV) of the base SEo passing through the vertex SEp at the contact (vertex) SEp with the support member SEL. (Actually twisted) and the support member SEL to which the mirror element SEk is connected is connected to the two anchor points (fixed fulcrum) SEk sandwiching the contact (vertex) SEp therebetween (reference line) It rotates in the θx direction about the axis LH) (actually twisted). Thereby, each mirror element SEk (k = 1 to K) can be tilted around the vertex SEp.

  Each mirror element SEk (k = 1 to K) tilts around the vertex SEp by controlling the driving force (attractive force or repulsive force in the Z-axis direction) generated by the corresponding two voice coil motors SVk. Each mirror element SEk is inclined with respect to the reference axis LH by equally controlling the driving force generated by the two voice coil motors SVk, and different from the reference axis LV by making the driving forces of the two voice coil motors SVk different. Lean. In this way, each mirror element SEk (k = 1 to K) tilts around the vertex SEp.

  Further, the stator SVk (k = 1 to K) constituting the micro VCM array MVA is exposed to and etched from the base member SVb, whereby the iron core SVa shown in FIG. 5 is formed on the base member SVb. A pattern corresponding to each of the coils SVc is formed by overlapping a plurality of layers through an insulating layer except for the contact SVc0 of the coil SVc. Here, only the coil SVc may be produced using lithography techniques such as exposure and etching, and the iron core SVa may be arranged in the central space of the produced coil SVc.

  In the exposure apparatus 100, as in a normal scanner, after performing preparatory work such as wafer exchange, reticle exchange, reticle alignment, baseline measurement of the alignment system AS, and wafer alignment (such as EGA), exposure in a step-and-scan manner is performed. Operation is performed. Prior to the exposure operation, main controller 20 sets the illumination light source shape (pupil luminance distribution) using spatial light modulation unit 3 (spatial light modulator 3S). Here, main controller 20 supplies each of the plurality of mirror elements SEk (k = 1 to K) included in spatial light modulator 3S with the amount and direction of inclination and coil SVc which is a stator of voice coil motor SVk. By controlling the magnitude and direction of the current based on the known relationship with the current value, the inclination of each of the mirror elements SEk is controlled in an open loop. In addition, the relationship between each inclination amount and inclination direction of the plurality of mirror elements SEk (k = 1 to K) included in the spatial light modulator 3S and the current value supplied to the coil SVc that is a stator of the voice coil motor SVk. For example, it is desirable to measure and update periodically.

  As described above, in order to form the illumination light source (secondary light source) of the exposure apparatus 100 of the present embodiment, the spatial light modulator 3S provided in the illumination system IOP constitutes the multi-mirror array SE. Since each two micro VCMs are used to drive (tilt drive) each mirror element SEk (k = 1 to K) in the θx direction and θy direction, each mover is moved in the + Z direction and the −Z direction. The plurality of mirror elements SEk arranged two-dimensionally can be driven at high speed with high response. Further, since each mirror element SEk can be manufactured regardless of the MEMS, the reflection surface of each mirror element can be significantly larger than that of a mirror element manufactured by MEMS, and the reflected light is blurred. Can be effectively reduced. In addition, the voice coil motor SVk does not have a hysteresis characteristic unlike a piezo element and the driving amount is uniquely determined with respect to the applied current amount. Therefore, the mirror element SEk (k = 1 to K) with high speed and high accuracy is provided. ) Tilt drive open loop control.

  Further, according to the illumination system IOP according to the present embodiment, the illumination light source having a complicated shape (intensity distribution) can be formed by modulating the light beam LB from the light source 1 by the spatial light modulator 3S.

Further, according to the exposure apparatus 100 of the present embodiment, the illumination light IL from the illumination light source is irradiated onto the reticle R on which the pattern is formed, and the illumination light IL via the reticle R is irradiated to the wafer via the projection optical system PL. A pattern image is formed on the wafer W by projecting onto the wafer W. As a result, it becomes possible to change to Lowk ₁ , and it is also possible to change the illumination conditions in parallel with the scanning exposure, so that the pattern can be formed on the wafer with high resolution and high accuracy.

  In the above embodiment, the case where the reflection surface SEA of the mirror element SEk has a triangular shape has been described. However, the present invention is not limited to this, and the reflection surface may have another polygonal shape such as a quadrangle. FIG. 6A shows, as an example, a multi-mirror array SE composed of a two-dimensional array of rectangular mirror elements SEk (k = 1 to K).

  In the example shown in FIG. 6A, for example, a mirror member made of a plate member whose surface is mirror-finished (or a plate member on which a thin flat mirror is attached) is exposed to light, and FIG. ) Is formed by forming a cut pattern indicated by a white portion and etching the white portion. In FIG. 6A, reference sign SEn indicates an anchor point fixed to the base member SVb.

  FIG. 6B schematically shows an enlarged view of one mirror element SEk constituting the multi-mirror array SE of FIG. The center of each side of the plurality of mirror elements SEk is connected to the linear support member SEL as a vertex SEp. As shown in FIG. 6B, the mirror element SEk rotates in the θy direction about the perpendicular (reference axis LV) of the bottom SEo passing through the contact SEp at the contact SEp with the support member SEL (actually And twisted in the θx direction around the reference axis LH passing through the contact SEp (actually twisted). Thereby, each mirror element SEk (k = 1 to K) can be tilted about the contact SEp. The tilting mechanism of the mirror element SEk is the same as that of the above-described triangular mirror element.

  In the above embodiment, the plurality of mirror elements SEk (k = 1 to K) of the spatial light modulator 3S are fixed to the column SEs on the base member SVb, for example, by fixing the vertex SEp in the reflection surface SEA. Although it is configured to be tiltable about the vertex SEp, it can be configured to be tiltable by supporting the mirror element SEk using a plurality of elastic members such as leaf springs instead. In this case, at least three voice coil motors SVk (k = 1 to K) for each of the plurality of mirror elements SEk (k = 1 to K) are placed on the base member SVb at three points that are not on the same straight line. Deploy. By independently controlling the three voice coil motors SVk, the inclination (θx and θy) and the surface position (Z) of the reflection surface of the mirror element SEk can be controlled.

  In the above embodiment, one spatial light modulation unit (spatial light modulator) is used, but a plurality of spatial light modulation units (spatial light modulators) can also be used. As an illumination optical system for an exposure apparatus using a plurality of spatial light modulation units, for example, an illumination optical system disclosed in US Patent Application Publication No. 2009/0109417 and US Patent Application Publication No. 2009/0128886 is used. Can be adopted.

  In the above embodiment, the case where the exposure apparatus is a scanning stepper has been described. However, the present invention is not limited to this, and a stationary exposure apparatus such as a stepper may be used. The above-described embodiment can also be applied to a step-and-stitch reduction projection exposure apparatus that synthesizes a shot area and a shot area.

  In addition, as disclosed in, for example, US Pat. No. 6,590,634, US Pat. No. 5,969,441, US Pat. No. 6,208,407, a plurality of wafers. The above-described embodiment can also be applied to a multi-stage type exposure apparatus including a stage. Further, as disclosed in, for example, US Pat. No. 7,589,822, an exposure including a measurement stage including a measurement member (for example, a reference mark and / or a sensor) separately from the wafer stage. The above embodiment can also be applied to an apparatus.

  In the above embodiment, the case where the exposure apparatus 100 is a dry-type exposure apparatus that exposes the wafer W without using liquid (water) has been described. As disclosed in US Pat. No. 1,420,298, WO 2004/055803, US Pat. No. 6,952,253, and the like, an immersion optical path including illumination light path between the projection optical system and the wafer. The above embodiment can also be applied to an exposure apparatus that forms a space and exposes the wafer with illumination light through the liquid in the projection optical system and the immersion space.

  In addition, the projection optical system of the above embodiment may be not only a reduction system but also an equal magnification and an enlargement system, and the projection optical system may be not only a refraction system but also a reflection system or a catadioptric system. The image may be an inverted image or an erect image.

  In the above embodiment, a so-called polarized illumination method disclosed in US Patent Application Publication No. 2006/0170901 or US Patent Application Publication No. 2007/0146676 can also be applied.

The light source of the exposure apparatus is not limited to the ArF excimer laser, but is a KrF excimer laser (output wavelength 248 nm), F ₂ laser (output wavelength 157 nm), Ar ₂ laser (output wavelength 126 nm), Kr ₂ laser (output wavelength 146 nm). It is also possible to use a pulse laser light source such as a super high pressure mercury lamp that emits bright lines such as g-line (wavelength 436 nm) and i-line (wavelength 365 nm). A harmonic generator of a YAG laser or the like can also be used. In addition, as disclosed in, for example, US Pat. No. 7,023,610, a single wavelength laser beam in an infrared region or a visible region oscillated from a DFB semiconductor laser or a fiber laser is used as vacuum ultraviolet light. For example, a harmonic that is amplified by a fiber amplifier doped with erbium (or both erbium and ytterbium) and wavelength-converted into ultraviolet light using a nonlinear optical crystal may be used.

  Further, as disclosed in, for example, International Publication No. 2001/035168, an exposure apparatus (lithography system) that forms a line-and-space pattern on a wafer W by forming interference fringes on the wafer W. You may apply the said embodiment.

  Further, as disclosed in, for example, US Pat. No. 6,611,316, two reticle patterns are synthesized on a wafer via a projection optical system, and 1 on the wafer by one scan exposure. The above embodiment may be applied to an exposure apparatus that performs double exposure of two shot areas almost simultaneously.

  In the above embodiment, the object on which the pattern is to be formed (the object to be exposed to which the energy beam is irradiated) is not limited to the wafer, but may be another object such as a glass plate, a ceramic substrate, a film member, or a mask blank. good.

  The use of the exposure apparatus is not limited to the exposure apparatus for semiconductor manufacturing, but for example, an exposure apparatus for liquid crystal that transfers a liquid crystal display element pattern to a square glass plate, an organic EL, a thin film magnetic head, an image sensor (CCD, etc.), micromachines, DNA chips and the like can also be widely applied to exposure apparatuses. Further, in order to manufacture reticles or masks used in not only microdevices such as semiconductor elements but also light exposure apparatuses, EUV exposure apparatuses, X-ray exposure apparatuses, electron beam exposure apparatuses, etc., glass substrates or silicon wafers, etc. The above embodiment can also be applied to an exposure apparatus that transfers a circuit pattern.

  An electronic device such as a semiconductor element includes a step of designing a function and performance of the device, a step of manufacturing a reticle based on the design step, a step of manufacturing a wafer from a silicon material, and a part of the lithography system of the above-described embodiment. A lithography step for transferring a mask (reticle) pattern onto a wafer by the exposure apparatus (pattern forming apparatus) and its exposure method, a development step for developing the exposed wafer, and exposure of portions other than the portion where the resist remains It is manufactured through an etching step for removing a member by etching, a resist removing step for removing a resist that has become unnecessary after etching, a device assembly step (including a dicing process, a bonding process, and a packaging process), an inspection step, and the like. In this case, in the lithography step, the exposure method described above is executed using the exposure apparatus that constitutes a part of the lithography system of the above embodiment, and a device pattern is formed on the wafer, so that a highly integrated device is produced. It can be manufactured with good performance.

  As described above, the spatial light modulator of the present invention is suitable for forming an illumination light source (secondary light source). The illumination device of the present invention is suitable as an illumination system for an exposure apparatus. The exposure apparatus of the present invention is suitable for transferring illumination light from an illumination light source and transferring a pattern onto an object. The device manufacturing method of the present invention is suitable for manufacturing micro devices.

  DESCRIPTION OF SYMBOLS 1 ... Light source, 2 ... Beam expander, 3S ... Spatial light modulator, 4 ... Relay optical system, 5 ... Fly eye lens, 6 ... Condenser optical system, 7 ... Illumination field stop, 8 ... Imaging optical system, 9 ... Bending mirror, 20 ... main control device, 100 ... exposure device, IOP ... illumination system, MVA ... micro VCM array, PL ... projection optical system, PU ... projection unit, R ... reticle, RST ... reticle stage, SE ... mirror array , SEk: mirror element, SVk: voice coil motor, W: wafer, WST: wafer stage.

Claims (18)

A plurality of mirror elements having a reflecting surface and two-dimensionally arranged;
A base plate for supporting each of the plurality of mirror elements at one point in the same plane as the reflecting surface;
A plurality of driving devices for driving each of the plurality of mirror elements in a direction approaching and separating from the base plate at each of a plurality of points that are not collinear with the one point on the back surface of the reflecting surface;
A spatial light modulator.   Each of the plurality of driving devices is disposed on the base plate so as to oppose the mover provided at each of the plurality of points on the back surface of the reflection surface of the mirror element. The spatial light modulator according to claim 1, comprising a stator.   The spatial light modulator according to claim 2, wherein the plurality of stators are arranged in a lattice pattern on the base plate. Each of the plurality of movers includes a permanent magnet,
The spatial light modulator according to claim 2, wherein each of the plurality of stators includes a coil.   5. The spatial light modulator according to claim 4, wherein each of the plurality of stators further includes an iron core around which the coil is wound.   The spatial light modulator according to claim 4 or 5, wherein the coil is manufactured by laminating a plurality of coil patterns on the base plate via an insulating layer except for a contact point.   The spatial light modulator according to any one of claims 1 to 6, wherein the plurality of mirror elements are two-dimensionally arranged in a first direction and a second direction orthogonal to the first direction.   The spatial light modulator according to claim 7, wherein the reflection surface of the mirror element has a polygonal shape. The reflection surface of the mirror element is triangular,
The spatial light modulator according to claim 8, wherein the one point of the mirror element coincides with one vertex of the triangular reflecting surface.   The spatial light according to claim 9, wherein a plurality of points that are not collinear with the one point on the back surface of the reflecting surface of the mirror element are set in the vicinity of a vertex different from the one vertex of the triangular reflecting surface. Modulator.   Among the plurality of mirror elements, the plurality of mirror elements arranged along the first direction alternately position the one vertex of the triangular reflecting surface on one side and the other side of the second direction. The spatial light modulator according to claim 9 or 10.   Among the plurality of mirror elements, the pair of mirror elements arranged adjacent to each other in the second direction has the one vertex of the triangular reflecting surface, or the bottoms corresponding to the one vertex, The spatial light modulator as described in any one of Claims 9-11 arrange | positioned adjacent to the 2nd direction. The plurality of mirror elements arranged in the first direction are connected to a support member extending in the first direction at the one point,
The spatial light modulator according to claim 7, wherein the support member is supported on the base plate at a point different from the one point.   The spatial light modulator according to claim 13, wherein the plurality of mirror elements are arranged on the base plate by arranging the support members in parallel.   The spatial light modulator according to any one of claims 1 to 14, wherein the array of the plurality of mirror elements is formed by etching at least one mirror member. A spatial light modulator according to any one of the preceding claims, disposed on the optical path of an energy beam from a beam source;
And an optical system disposed on at least one of the front and rear of the optical path of the spatial light modulator on the optical path of the energy beam. An exposure apparatus that exposes an object with an energy beam to form a pattern on the object,
The illumination device according to claim 16, wherein a pattern is illuminated with the energy beam through the spatial light modulator and the optical system;
A projection system for projecting the energy beam through the pattern onto the object;
An exposure apparatus comprising: Exposing an object using the exposure apparatus of claim 17;
Developing the exposed object. A device manufacturing method comprising: