JP2007220695A - Projection aligner and projection aligning method, and device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To align a fine pattern by projection at high throughput. <P>SOLUTION: The projection aligner which projects a specified pattern on a photosensitive substrate is provided with a lighting optical system to supply a light to a specified pattern, and a projection optical system wherein an image of the specified pattern is formed on the photosensitive substrate by means of an immersion liquid between the photosensitive substrate and the projection optical system. The projection optical system is provided with a border optical member formed of a tesseral crystal material, which positions the optical axis of the projection optical system in nearly parallel to <100> axis of the border optical member or a crystal axis optically equivalent to the <100> axis. The lighting optical system sets a light to the specified pattern to be one with a range of specific incident angle, and it sets the light with a range of specific incident angle to TE polarization for the specified pattern. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a projection exposure apparatus, a projection exposure method, and a device manufacturing method, and more particularly to a projection exposure apparatus and method used when manufacturing microdevices such as semiconductor elements and liquid crystal display elements in a photolithography process. .

  In a photolithography process for manufacturing semiconductor elements, etc., a mask (or reticle) pattern image is projected and exposed on a photosensitive substrate (a wafer coated with a photoresist, a glass plate, etc.) via a projection optical system. An exposure apparatus is used. In the exposure apparatus, as the degree of integration of semiconductor elements and the like is improved, the resolving power (resolution) required for the projection optical system is increasing.

  Therefore, in order to satisfy the requirement for the resolution of the projection optical system, it is necessary to shorten the wavelength λ of the illumination light (exposure light) and increase the image-side numerical aperture NA of the projection optical system. Specifically, the resolution of the projection optical system is represented by k · λ / NA (k is a process coefficient). The image-side numerical aperture NA is n, where n is the refractive index of the medium (usually a gas such as air) between the projection optical system and the photosensitive substrate, and θ is the maximum incident angle on the photosensitive substrate.・ It is expressed by sinθ.

In this case, if the maximum incident angle θ is increased to increase the image-side numerical aperture, the incident angle to the photosensitive substrate and the exit angle from the projection optical system increase, and the reflection loss on the optical surface increases. Thus, a large effective image-side numerical aperture cannot be ensured. Therefore, an immersion technique is known in which an image-side numerical aperture is increased by filling a medium such as a liquid having a high refractive index in the optical path between the projection optical system and the photosensitive substrate (for example, Patent Document 1). ).
International Publication No. WO2004 / 019128 Pamphlet

  In the projection optical system disclosed in the above patent document, pure water is used as the immersion liquid, and a quartz lens is used as a boundary lens in which the object side surface is in contact with gas and the image side surface is in contact with pure water. However, in this conventional configuration, for example, when ArF excimer laser light is used, since the refractive index of pure water as immersion liquid is about 1.5, an image-side numerical aperture of about 1.3 is secured. Was the limit.

  Recently, a liquid having a higher refractive index than pure water has been proposed as the immersion liquid. However, if only the refractive index of the liquid as the immersion liquid is simply set large, the boundary lens (the liquid in the lens in the projection optical system) Not only makes the lens design impossible because the curvature of the convex surface on the object side of the lens on the object side) is too large, but also a sufficiently large effective imaging area on the image plane (an effective still exposure area in the case of an exposure apparatus) ) Is difficult to secure.

  For this reason, it is conceivable to use a crystal optical material having a higher refractive index than quartz as the boundary lens. In the wavelength range of 200 nm or less, such as an ArF excimer laser, intrinsic birefringence (intrinsic birefringence) is exhibited not only in anisotropic crystal materials but also in equiaxed (cubic) crystal optical materials. In addition, a crystal optical material having a sufficiently high transmittance and refractive index in a wavelength region of 200 nm or less such as an ArF excimer laser has not been found.

  Therefore, an object of the present invention is to achieve projection exposure of a fine pattern with high throughput by achieving a large image-side numerical aperture using an immersion projection exposure method. Another object of the present invention is to manufacture a device at low cost by projecting and exposing a fine pattern with high throughput.

In order to achieve the above object, a projection exposure apparatus according to a first embodiment of the present invention is a projection exposure apparatus that projects a predetermined pattern on a photosensitive substrate,
An illumination optical system for supplying illumination light to the predetermined pattern;
A projection optical system that forms an image of the predetermined pattern on the photosensitive substrate via an immersion liquid between the photosensitive substrate and the projection optical system;
The projection optical system includes a boundary optical member that is disposed in contact with the immersion liquid and formed of an equiaxed crystal material,
The optical axis of the projection optical system is positioned substantially parallel to the <100> axis of the boundary optical member or a crystal axis optically equivalent to the <100> axis,
The illumination optical system sets the illumination light for the predetermined pattern to illumination light in a specific incident angle range, and sets the illumination light in the specific incident angle range to TE polarized light for the predetermined pattern. is there.

In order to achieve the above object, a projection exposure method according to a second aspect of the present invention is a projection exposure method for projecting a predetermined pattern onto a photosensitive substrate,
A pattern setting step for setting the predetermined pattern on a predetermined surface;
An illumination step of supplying illumination light to the predetermined pattern;
A projection step of forming an image of the predetermined pattern on the photosensitive substrate via an immersion liquid between the photosensitive substrate and the projection optical system;
In the projecting step, the pattern is projected onto the photosensitive substrate through a boundary optical member that is disposed in contact with the immersion liquid and formed of an equiaxed crystal material,
The optical axis of the projection optical system is positioned substantially parallel to the <100> axis of the boundary optical member or a crystal axis optically equivalent to the <100> axis,
In the illumination step, the illumination light for the predetermined pattern is set to illumination light in a specific incident angle range, and the illumination light in the specific incident angle range is set to TE polarized light for the predetermined surface.

  In the device manufacturing method according to the third aspect of the present invention, a projection exposure step of projecting and exposing the predetermined pattern onto the photosensitive substrate using the projection exposure apparatus of the first embodiment, and developing the photosensitive substrate Developing step.

  In the projection exposure apparatus of the present invention, a liquid having a large refractive index is interposed in the optical path between the boundary lens and the image surface (second surface), and the high refractive index of the liquid that contacts the image side surface of the boundary lens. , The boundary lens is also formed of an equiaxed crystal material having a large refractive index, and the <100> axis of the equiaxed crystal material or an optically equivalent axis to the <100> axis Is set to be parallel to the optical axis of the boundary lens. Then, by supplying illumination light that becomes TE polarized light to the pattern surface to the projection optical system, the crystal material passes through a region that is not substantially affected by the intrinsic birefringence of the equiaxed crystal material. Diffracted light from the pattern can be passed. For this reason, a large image-side numerical aperture can be achieved by an immersion projection exposure method using a high refractive index liquid and a high refractive index material, so that a fine pattern can be projected and exposed with a high throughput, resulting in a low cost. The device can be manufactured.

  A first embodiment according to the present invention will be described below with reference to the drawings. In the present embodiment, the present invention is applied to the case where exposure is performed by a scanning exposure type projection exposure apparatus (scanning stepper) having a step-and-scan method.

  FIG. 1 is a partially cutaway view showing a schematic configuration of the projection exposure apparatus of this example. In FIG. 1, the projection exposure apparatus of this example includes an illumination optical system ILS and a projection optical system 25. ing. The former illumination optical system ILS includes a plurality of optical members arranged along the optical axes (illumination system optical axes) AX1 to AX4 from the exposure light source 1 (light source) to the condenser lens 20 (details will be described later). The illumination field of exposure on the pattern surface (reticle surface) of the reticle R as a mask is illuminated with a uniform illuminance distribution with exposure illumination light (exposure light) as an exposure beam from 1. The latter projection optical system PL reduces the pattern in the illumination field of the reticle R1 (or R2) at the projection magnification M (M is a reduction magnification such as 1/4 or 1/5) under the illumination light. The obtained image is projected onto an exposure area on one shot area on the wafer W coated with a photoresist as a substrate to be exposed (substrate) or a photoreceptor. Reticle R1 (or R2) and wafer W can also be regarded as a first object and a second object, respectively. The wafer W is a disk-shaped substrate having a diameter of about 200 to 300 mm, such as a semiconductor (silicon or the like) or SOI (silicon on insulator). The projection optical system PL of this example is a refractive optical system, for example, but a catadioptric system or the like can also be used.

  Hereinafter, in FIG. 1, regarding the projection optical system PL, the reticle R1 (or R2), and the wafer W, the Z axis is parallel to the optical axis AX5 of the projection optical system PL, and the plane is perpendicular to the Z axis (XY plane). The Y axis is taken along the scanning direction of the reticle R and the wafer W during scanning exposure (direction parallel to the paper surface of FIG. 1), and the X axis is taken along the non-scanning direction (direction perpendicular to the paper surface of FIG. 1). Take and explain. In this case, the illumination field on reticle R1 (or R2) is an elongated area in the X direction, which is the non-scanning direction, and the exposure area on wafer W is an elongated area conjugate with the illumination field. Further, the optical axis AX5 of the projection optical system PL coincides with the illumination system optical axis AX4 on the reticle R1 (or R2).

  First, the reticle R1 (or R2) on which the pattern to be exposed and transferred is sucked and held on the reticle stage RS, and the reticle stage RS moves at a constant speed in the Y direction on the reticle base (not shown) and is synchronized. The reticle R1 (or R2) is scanned by finely moving in the X direction, the Y direction, and the rotation direction around the Z axis so as to correct the error. The X- and Y-direction positions and the rotation angle of the reticle stage RS are measured by a movable mirror RSM and a laser interferometer RIF provided thereon. Based on this measurement value and control information from the main control system (not shown), the reticle stage drive system (not shown) controls the position and speed of the reticle stage RS via a drive mechanism (not shown) such as a linear motor. To do. A reticle alignment microscope (not shown) for reticle alignment is disposed above the periphery of the reticle R1 (or R2).

  On the other hand, the wafer W is sucked and held on the wafer stage WS via a wafer holder (not shown), and the wafer stage WS can move on the wafer base (not shown) at a constant speed in the Y direction, It is placed so that it can be stepped in the direction. The wafer stage WS also incorporates a Z leveling mechanism for aligning the surface of the wafer W with the image plane of the projection optical system PL based on a measurement value of an autofocus sensor (not shown). The X- and Y-direction positions and the rotation angle of the wafer stage WS are measured by a movable mirror WSM and a laser interferometer WIF provided thereon. Based on this measurement value and control information from the main control system (not shown), the wafer stage drive system (not shown) controls the position and speed of the wafer stage WS via a drive mechanism (not shown) such as a linear motor. To do. In addition, in the vicinity of the projection optical system PL, for example, an FIA (Fie1d Image A1ignment) type alignment sensor (not shown) is used in the off-axis method for detecting the position of the alignment mark on the wafer W for wafer alignment. Is arranged.

  Prior to exposure by the projection exposure apparatus of this example, alignment of reticle R1 is performed by the above-described reticle alignment microscope (when double exposure is performed, alignment of reticle R2 in addition to reticle R1 is also performed), and wafer The alignment of the wafer W is performed by detecting the position of the alignment mark formed together with the circuit pattern in the previous exposure process on W by an alignment sensor (not shown). Thereafter, in a state where the illumination field IL on the reticle R1 is irradiated with the illumination light IL, the reticle stage RS and the wafer stage WS are driven to synchronously scan the reticle R1 and one shot area on the wafer W in the Y direction. And the operation of stopping the emission of the illumination light IL, driving the wafer stage WS, and moving the wafer W stepwise in the X and Y directions are repeated. The ratio of the scanning speed of reticle stage RS and wafer stage ws during the synchronous scanning is such that the projection magnification of projection optical system PL is maintained in order to maintain the imaging relationship between reticle R and wafer W via projection optical system PL. Equal to M. By these operations, the pattern image of the reticle R1 is exposed and transferred to all shot areas on the wafer W by the step-and-scan method. In the case of performing double exposure, the reticle stage RS and the wafer stage WS are driven in a state in which the illumination field IL on the reticle R2 is irradiated with the illumination light IL following the transfer of the pattern image of the reticle R1. The operation of synchronously scanning the reticle R2 and one shot area on the wafer W in the Y direction, and stopping the emission of the illumination light IL, driving the wafer stage WS to step the wafer W in the X and Y directions. Repeat the operation.

Next, the configuration of the illumination optical system of the present embodiment will be described in detail. In FIG. 1, an ArF (argon fluorine) excimer laser (wavelength 193 nm) is used as the exposure light source 1 of the present embodiment. The exposure light source 1 is a laser light source such as KrF (krypton fluorine) excimer laser (wavelength 248 nm), F ₂ (fluorine molecule) laser (wavelength 157 nm), or Kr ₂ (krypton molecule) laser (wavelength 146 nm). Etc. can also be used. These laser light sources (including the exposure light source 1) are narrow band lasers or wavelength-selected lasers, and the illumination light IL emitted from the exposure light source 1 is linearly polarized by the narrow band or wavelength selection. The polarization state is mainly composed of. Hereinafter, in FIG. 1, the illumination light IL immediately after being emitted from the exposure light source 1 will be described assuming that the main component is linearly polarized light whose polarization direction (electric field direction) matches the X direction in FIG. 1.

  The illumination light IL emitted from the exposure light source 1 travels along the illumination system optical axis AX1, is reflected by the optical path bending mirror 2, and then enters the polarization control member 3 as a polarization control mechanism. The illumination light IL emitted from the polarization control member 3 is incident on a diffractive optical element (DOE) 41 along the illumination system optical axis AX2. The diffractive optical element 41 is composed of a phase type diffraction grating, and the incident illumination light IL is diffracted in a predetermined direction and travels.

  The diffraction angle and direction of each diffracted light from the diffractive optical element 41 correspond to the position of the illumination light IL on the pupil plane 15 of the illumination optical system ILS and the incident angle and direction of the illumination light IL to the reticle R. A plurality of diffractive optical elements 41 and other diffractive optical elements 42 having a diffractive action different from that are arranged on a turret-like member (not shown). Then, for example, the turret-shaped member is driven by an exchange mechanism under the control of the main control system, and the diffractive optical element 41 or the like at an arbitrary position on the turret-shaped member is moved to a position on the illumination system optical axis AX2. By loading, the incident angle range and direction of the illumination light to the reticle R (or the position of the illumination light on the pupil plane) can be set to a desired range according to the pattern of the reticle R. .

  Illumination light (diffracted light) IL emitted from the diffractive optical element 41 passes through relay lenses 51 and 52 along the illumination system optical axis AX2, and is reflected by the mirror 6 for bending the optical path. Is incident on a fly-eye lens 7 which is an activating member). The illumination light IL emitted from the fly-eye lens 7 reaches the mirror 11 for bending the optical path through the relay lenses 81 and 82, the field stop 9 and the condenser lens 10 along the illumination system optical axis AX3, and is reflected there. The illumination light IL illuminates the reticle R1 through the condenser lens 12 along the illumination system optical axis AX4. The pattern on the reticle R1 thus illuminated is projected and transferred onto the wafer W by the projection optical system PL as described above.

Note that the relay lenses 51 and 52 described above may be a zoom optical system for finely adjusting the incident angle range of the illumination light to the reticle R.
If necessary, the field stop 9 can be a scanning type, and scanning can be performed in synchronization with the scanning of the reticle stage RS and the wafer stage WS. In this case, the field stop may be divided into a fixed field stop and a movable field stop.

  In this configuration, the exit-side surface of the fly-eye lens 7 is located in the vicinity of the pupil plane of the illumination optical system. The pupil plane is connected to reticle R1 (or R2) via optical members (relay lenses 81 and 82, field stop 9, condenser lenses 10 and 12, and mirror 11) in the illumination optical system from the pupil plane to reticle R. ) Acts as an optical Fourier transform surface for the pattern surface (reticle surface). In other words, the illumination light emitted from one point on the pupil plane becomes a substantially parallel light beam and irradiates the reticle R1 (or R2) at a predetermined incident angle and incident direction. The incident angle and the incident direction are determined according to the position of the luminous flux on the pupil plane.

  The optical path bending mirrors 2, 6, and 11 are not essential in terms of optical performance. However, if the illumination optical system is arranged on a straight line, the overall height (height in the Z direction) of the exposure apparatus increases. In order to save space, they are arranged at appropriate positions in the illumination optical system. The illumination system optical axis AX1 coincides with the illumination system optical axis AX2 by reflection of the mirror 2, the illumination system optical axis AX2 coincides with the illumination system optical axis AX3 by reflection of the mirror 6, and the illumination system optical axis AX3 The reflection of the mirror 11 coincides with the illumination system optical axis AX4.

  Next, the configuration of the projection optical system PL of this embodiment will be described in detail. The projection optical system PL of the present embodiment is composed of a plurality of optical elements (LS1, LS2,... BL) including a boundary lens BL as a boundary optical element provided at the front end portion on the wafer W side. Exposure light (illumination light) from the illumination optical system enters the projection optical system PL from the object plane side, passes through a plurality of optical elements (LS1, LS2,...), And then from the image plane side of the projection optical system PL. It is injected and reaches the wafer W. Specifically, the exposure light EL passes through the boundary lens BL after passing through each of the plurality of optical elements (LS1, LS2,...), And is a liquid interposed between the boundary lens BL and the wafer W. Through the wafer W.

  In the present embodiment, the boundary optical element is a plano-convex boundary lens formed of an equiaxed crystal material having optical transparency to exposure light (illumination light), and the <100> axis is It forms so that it may become an optical axis. Instead of the above-described configuration, the boundary optical element may be configured by a parallel plane plate formed of the above crystal material and a plano-convex shape boundary lens. In this case, the plane parallel plate and the boundary lens There is liquid between them.

  Further, as the plurality of optical elements (LS1, LS2,...) Other than the boundary optical element, for example, quartz glass or fluorite can be applied. When applying fluorite as a plurality of optical elements other than the boundary optical element, for example, a correction method using clocking disclosed in US Pat. No. 6,788,389 can be applied.

  In the present embodiment, the plurality of optical elements LS1 and LS2 are driven by optical element control units LC1 and LC2 controlled by a main control system (not shown), and their positions and postures can be adjusted. The wavefront aberration of the projection optical system PL can be controlled by adjusting the positions and postures of the plurality of optical elements LS1 and LS2.

  As the liquid in the present embodiment, for example, a high refractive index liquid having a refractive index greater than 1.5 with respect to the wavelength of exposure light (illumination light) is used. In this case, if only the refractive index of the liquid as the immersion liquid is set to a large value, the curvature of the convex surface on the object side of the boundary lens BL becomes too large, which makes it impossible to design the lens, and it is sufficient on the image plane. It becomes impossible to ensure a large effective imaging area (an effective still exposure area in the case of an exposure apparatus). Therefore, in the present embodiment, the boundary lens is formed of an optical material having a refractive index greater than 1.8, corresponding to the high refractive index of the liquid in contact with the image side surface of the boundary lens BL. As a result, in the projection optical system according to the present embodiment, a relatively large effective result is obtained while a liquid is interposed in the optical path between the image plane and an effective image-side numerical aperture greater than 1.4, for example, is ensured. An image area can be secured.

  Here, as the high refractive index liquid in this embodiment, for example, Delphi (a compound based on a cyclic hydrocarbon skeleton having a refractive index of 1.63 for ArF excimer laser light) by Mitsui Chemicals, Inc., HIF-001 by JSR Corporation. (Refractive index for ArF excimer laser light is 1.64), IF131 (refractive index for ArF excimer laser light is 1.642) and IF132 (refractive index for ArF excimer laser light) by EI DuPont de Nemours & Company 1.644), IF175 (refractive index with respect to ArF excimer laser light is 1.664), and the like.

Examples of the equiaxed crystal material forming the boundary optical element include LuAG (Lutetium Alminum Garnet), a refractive index of 2.1 for ArF excimer laser light, and MgO (magnesium oxide). , The refractive index for ArF excimer laser light is 1.96), CaO (calcium oxide, refractive index for ArF excimer laser light is 2.7), spinel ([crystalline magnesium aluminum spinel] MgAl ₂ O ₄ , for ArF excimer laser light) A refractive index of 1.87) can be used.

  FIG. 2 shows the crystal axis orientation of the equiaxed (cubic) crystal material as described above. The coordinate system in FIG. 2 is a cubic XYZ coordinate system, which is different from the apparatus coordinate system in FIG. Referring to FIG. 2, the crystal axis of the equiaxed crystal material is defined based on a cubic XYZ coordinate system. That is, the <100> axis is defined along the + X axis, the <010> axis is defined along the + Y axis, and the <001> axis is defined along the + Z axis.

  Further, the <101> axis in the direction forming 45 ° with the <100> axis and the <001> axis in the XZ plane, and the <110> axis in the direction forming 45 ° with the <100> axis and the <010> axis in the XY plane. However, in the YZ plane, the <011> axis is defined in a direction forming 45 ° with the <010> axis and the <001> axis. Furthermore, the <111> axis is defined in a direction that makes an equal acute angle with respect to the + X axis, + Y axis, and + Z axis.

  In FIG. 2, only the crystal axes in the space defined by the + X axis, the + Y axis, and the + Z axis are illustrated, but the crystal axes are similarly defined in other spaces. In the present invention, when it is necessary to strictly define the relative crystal axis orientation, for example, a plurality of crystal axes optically equivalent to <011> are expressed as <011>, <0-11>, <110. > And the like (listed) with different codes and arrangement positions. However, when it is not necessary to strictly define the relative crystal axis orientation, a plurality of optically equivalents such as <011>, <0-11>, <110> are represented by the notation <011>. The crystal axes are collectively represented.

  By the way, in order to improve the resolution of the projection optical system PL, an image side aperture which is the product of the sine of the maximum incident angle of the light beam on the wafer W and the medium interposed between the wafer W and the projection optical system PL. The number is for example 1. It is necessary to expand to the extent. In this case, considering that the boundary lens is formed of, for example, the above-mentioned LuAG as an equiaxed crystal material, since the refractive index of LuAG with respect to the exposure light (illumination light) is 2.1, it passes through the boundary lens. The angle range of the luminous flux with respect to the optical axis, in other words, the angle range with respect to the <100> axis is −45 to +45 degrees.

  In an equiaxed crystal material, birefringence is almost zero (minimum) at the <111> axis and optically equivalent crystal axes (<-111>, <1-11>, <11-1>). It is. Similarly, birefringence is almost zero (minimum) in the <100> axis, the <010> axis, and the <001> axis. On the other hand, the birefringence is maximum on the <110> axis, the <101> axis, the <011> axis, and the optically equivalent <-110> axis, <-101> axis, and <01-1> axis. In other words, birefringence varies depending on the incident angle of an equiaxed crystal material.

  As described above, when considering a light beam having a very wide angle range with respect to the optical axis, the influence of birefringence differs depending on the angle of the light beam passing through the equiaxed crystal material with respect to the optical axis. Become.

  FIG. 3 is a diagram showing the distribution of the H polarization wavefront of the projection optical system PL in which only the boundary lens BL is formed of an equiaxed crystal material and the other optical elements are formed of an amorphous material such as quartz glass. 3A is a plan view indicated by contour lines, and FIG. 3B is a bird's eye view. Note that the H-polarized wavefront in FIG. 3 is the exit of the projection optical system PL for H-polarized light having a polarization direction in the horizontal direction in the figure of the light beam reaching a predetermined image point to be evaluated in the image plane of the projection optical system PL. The difference between the phase distribution at the pupil and the average wavefront of the light beam reaching a predetermined image point to be evaluated in the image plane of the projection optical system PL is shown. The H-polarization wavefront shown in FIG. 3A has partial regions + Ri, + Le whose phases are advanced in the left-right direction in the figure with the optical axis position interposed therebetween, and the phases are delayed in the vertical direction in the figure with the optical axis position interposed therebetween. And a partial region M (Up and -Lo) that includes the optical axis and extends in the direction of ± 45 degrees in the drawing.

  Here, the light beam that passes through the partial region + Ri is a light beam that travels substantially along the <110> axis of the equiaxed crystal material, and the light beam that passes through the partial region + Le is approximately that of the equiaxed crystal material. It is a light beam traveling along the <1-10> axis. The light beam passing through the partial region -Up is a light beam traveling substantially along the <010> axis of the equiaxed crystal material, and the light beam passing through the partial region -Lo is formed of the equiaxed crystal material. The light beam travels substantially along the <10-1> axis. The light beam passing through the partial region M1 is approximately the <111> axis of the equiaxed crystal material and the optically equivalent crystal axes (<-111>, <1-11>, <11-1>). ) Along the light beam.

  FIG. 4 shows the distribution of the V polarization wavefront of the projection optical system PL in which only the boundary lens BL is formed of an equiaxed crystal material and the other optical elements are formed of an amorphous material such as quartz glass. 4A is a plan view indicated by contour lines, and FIG. 4B is a bird's eye view. Note that the V-polarization wavefront in FIG. 4 is the emission of the projection optical system PL for the V-polarized light having the polarization direction in the vertical direction in the drawing of the light beam reaching the predetermined evaluation target image point in the image plane of the projection optical system PL. The difference between the phase distribution at the pupil and the average wavefront of the light beam reaching a predetermined image point to be evaluated in the image plane of the projection optical system PL is shown. The V-polarized wavefront shown in FIG. 4A has partial regions -Ri, -Le whose phases are delayed in the horizontal direction in the figure with the optical axis position interposed therebetween, and phases in the vertical direction in the figure with the optical axis position interposed therebetween. It typically has a partial area + Up, + Lo that is advanced, and an X-shaped partial area M2 (substantially no phase advance / delay) that includes the optical axis and extends in the direction of ± 45 degrees in the drawing.

  Here, the light beam passing through the partial region -Ri is a light beam that travels substantially along the <110> axis of the equiaxed crystal material, and the light beam passing through the partial region -Le is the equiaxed crystal material. Is a light beam traveling substantially along the <1-10> axis. The light beam passing through the partial region + Up is a light beam traveling substantially along the <010> axis of the equiaxed crystal material, and the light beam passing through the partial region + Lo is approximately < 10-1> A light beam traveling along the axis. The light beam passing through the partial region M2 is approximately the <111> axis of the equiaxed crystal material and the crystal axes (<-111>, <1-11>, <11-1>) optically equivalent thereto. ) Along the light beam.

  3 and 4, in the case of H-polarized light, only the region in which the light beam passing through the boundary lens BL corresponds to the partial regions -Up, -Lo (that is, the region where the extreme value of the change rate of the phase delay is taken). In the case of V-polarized light, the light beam passing through the boundary lens BL passes only through the region corresponding to the partial regions -Ri, -Le (that is, the region that takes the extreme value of the change rate of the phase delay). It can be understood that the diffracted light from the reticle pattern may be controlled. In the case of using H-polarized light, if the light beam passing through the boundary lens BL is set so as to pass only through the region corresponding to the partial regions + Ri, + Le, the polarization direction of the light beam reaching the wafer W is relative to the wafer surface. Since it becomes p-polarized light, it is not preferable. When V-polarized light is used, if the light beam passing through the boundary lens BL is set so as to pass only the region corresponding to the partial regions + Up, + Lo, the polarization direction of the light beam reaching the wafer W Becomes p-polarized with respect to the wafer surface.

  Hereinafter, the control of the diffracted light from the reticle pattern will be specifically described with reference to FIG. FIG. 5 is a schematic diagram illustrating a state of diffracted light from the reticle pattern, and FIG. 5A is a plan view illustrating a state of light amount distribution in an exit pupil (hereinafter referred to as illumination pupil) of the illumination optical system. FIG. 5B is a diagram schematically showing the optical path of the diffracted light from the reticle pattern, and FIG. 5C shows the state of the V polarization wavefront at the exit pupil PLP of the projection optical system PL and the exit pupil. It is a figure which superimposes and shows the state of the diffracted light to pass.

  As shown in FIG. 5A, a bipolar secondary light source (DPR, DPL) having a symmetrical light intensity distribution with the optical axis sandwiched between two positions decentered from the optical axis AX on the illumination pupil. It is formed. The light from the secondary light source is linearly polarized light having a polarization direction in the vertical direction on the paper surface in FIG. Then, as shown in FIG. 5B, the illumination light ILR from one pole DPR of the secondary light source travels in an oblique direction with respect to the reticle R on which a pattern PA having a pitch in the horizontal direction in the drawing is formed. The illumination light ILL from another pole DPL travels in an oblique direction symmetrical to the illumination light ILR across an optical axis (not shown) and reaches the reticle R. At this time, a line segment connecting the two poles of the secondary light source (DPR, DPL) is a direction corresponding to the pitch direction of the pattern PA on the reticle R.

  The illumination light ILR through the pattern PA of the reticle R is diffracted by the pattern PA, and enters the projection optical system PL as first-order diffracted light ILR (1) and zero-order diffracted light ILR (0). Further, the illumination light ILL via the pattern PA of the reticle R is diffracted by the pattern PA, and becomes −1st order diffracted light ILL (−1) and 0th order diffracted light ILL (0) and enters the projection optical system PL. .

  Each diffracted light incident on the projection optical system PL reaches the pupil plane PLP of the projection optical system PL. This pupil plane PLP is a plane optically equivalent to the exit pupil plane of the projection optical system PL. FIG. 5C shows the distribution of the V polarization wavefront W (V) on the pupil plane PLP of the projection optical system PL (the exit pupil plane of the projection optical system PL) and the distribution of diffracted light passing through the pupil plane PLP. It is the figure displayed repeatedly. Here, on the pupil plane PLP, the diffracted light passing region DER on the right side in the drawing is a region through which the 0th-order diffracted light ILL (0) and the first-order diffracted light ILR (1) pass through the pupil plane PLP. The left diffracted light passage region DEL is a region where the −1st order diffracted light ILL (−1) and the 0th order diffracted light ILR (0) pass through the pupil plane PLP. The distribution of the V polarization wavefront W (V) is the same as the polarization wavefront distribution shown in FIG. The A-A ′ arrow view of the distribution of the V-polarized wavefront W (V) in FIG. 5C corresponds to the V-polarized wavefront W (V) shown in FIG.

  Now, referring back to FIG. 5B, each diffracted light passing through the pupil plane PLP is emitted from the projection optical system PL and reaches the wafer W, and forms an image of the pattern PA on the wafer W by two-beam interference. To do. Here, each diffracted light is TE polarized light with respect to the wafer W (pattern PA).

  At this time, as described above with reference to FIGS. 4A and 4B, each diffracted light takes an extreme value of the phase lag change rate on the pupil plane PLP (ie, a region with a small phase lag change rate). ), The pattern PA can be imaged substantially without being affected by the polarization wavefront aberration. In this way, the pattern pitch of the reticle R and the pattern direction (in the pattern pitch direction) so that the diffracted light is concentrated in the region of the polarization wavefront on the exit pupil of the projection optical system where the rate of change of phase lag is small. By setting the parameters (outer diameter, annular ratio) of dipole illumination, the imaging performance is prevented from deteriorating due to the birefringence of the equiaxed crystal material that forms the boundary lens. be able to.

  In this embodiment, in order to increase the refractive index of the optical member in contact with the immersion liquid, the optical member is made of an equiaxed crystal material, and the transmittance of the equiaxed crystal material having a high refractive index is lowered. For this reason, only the optical member in contact with the immersion liquid is made of an equiaxed crystal material having a high refractive index. Thereby, the transmittance of the projection optical system PL itself can be kept high, and the pattern can be transferred with high throughput under stable imaging performance. In addition, when an equiaxed crystal material having a high refractive index is applied to an optical member other than the optical member in contact with the immersion liquid, irradiation fluctuation is likely to occur, so that stable imaging performance may not be realized. .

  In the description of FIG. 5 described above, the case of using the V-polarized light has been described. However, the same applies to the case of dipole illumination using the H-polarized light. Furthermore, when performing dipole illumination using V-polarized light and dipole illumination using H-polarized light simultaneously, that is, in the case of quadrupole illumination using circumferentially polarized light (TE polarized light with respect to the wafer W surface and pattern PA surface). Even so, it is possible to prevent the deterioration of the imaging performance due to the birefringence of the equiaxed crystal material forming the boundary lens.

  In the case of dipole illumination using H-polarized light, dipole illumination using V-polarized light, or quadrupole illumination using circumferentially polarized light, the diffracted light from the reticle pattern passes through the partial areas M1 and M2. In other words, the diffracted light from the reticle pattern passing through the boundary lens is approximately the <111> axis of the equiaxed crystal material and the crystal axes (<-111>, <1-11>, < 11-1>).

In the above-described embodiment, the polarization wavefront distribution of the projection optical system PL is a distribution having a higher-order component with respect to the pupil radius, so that the degree of freedom for the pattern pitch is small.
Here, the second embodiment is an embodiment in which the state of the wavefront aberration (average wavefront) of the projection optical system PL is controlled to control the distribution of the polarization wavefront of the projection optical system and to improve the degree of freedom with respect to the pattern. explain. In the second embodiment, members and the like having the same functions as those in the first embodiment are denoted by the same reference numerals.

  In the second embodiment, the wavefront of the projection optical system PL is controlled by controlling the positions and postures of the plurality of movable lenses LS1 and LS2 in the projection optical system PL of the projection exposure apparatus of the first embodiment shown in FIG. Change the aberration from the reference state. Specifically, by controlling the positions and postures of the plurality of movable lenses LS1 and LS2, a predetermined amount of spherical aberration is generated in the wavefront aberration of the projection optical system PL.

  Hereinafter, the second embodiment will be described with reference to FIGS. 6 and 7. 6A and 6B are diagrams showing the distribution of the H polarization wavefront of the projection optical system PL in a state where a predetermined amount of spherical aberration is generated. FIG. 6A is a plan view indicated by contour lines, and FIG. It is a bird's-eye view. The H-polarization wavefront in FIG. 6 is the same as in FIG. 3 for the H-polarized light having the polarization direction in the horizontal direction in the figure of the light beam reaching the predetermined image point to be evaluated in the image plane of the projection optical system PL. The difference between the phase distribution at the exit pupil of the projection optical system PL and the average wavefront of the light beam reaching a predetermined image point to be evaluated in the image plane of the projection optical system PL is shown.

  7 is a diagram showing the distribution of the V-polarized wavefront of the projection optical system PL in a state where the same spherical aberration as that in FIG. 6 is generated, and FIG. 7A is a plan view indicated by contour lines, FIG. 7 (b) is a bird's-eye view. Note that the V-polarization wavefront in FIG. 7 is the same as in FIG. 4 for the V-polarized light having the polarization direction in the vertical direction in the figure of the light beam reaching the predetermined image point to be evaluated in the image plane of the projection optical system PL. The difference between the phase distribution at the exit pupil of the projection optical system PL and the average wavefront of the light beam reaching a predetermined image point to be evaluated in the image plane of the projection optical system PL is shown.

  The H-polarized wavefront shown in FIG. 6A has a shape extending in the horizontal direction in the figure and has a region FLV including the optical axis, and the wavefronts in the region FLV are substantially in phase. And it has the partial area | region where the phase has advanced in the left-right direction in the figure on both sides of this area | region FLV.

  Further, the V-polarized wavefront shown in FIG. 7A has a shape extending in the vertical direction in the drawing and has a region FLV including the optical axis, and the wavefronts in the region FLV are substantially in phase. And it has the partial area | region where the phase has advanced in the up-down direction in the figure on both sides of this area | region FLV.

  Here, the wavefront aberration of the projection optical system PL for H-polarization corresponds to the H-polarization wavefront shown in FIGS. 6A and 6B, and the wavefront aberration of the projection optical system PL for V-polarization is FIG. In order to correspond to the V-polarized wavefront shown in a) and (b), the diffracted light from the pattern illuminated with H-polarized light passes only through the region FLH, and the diffracted light from the pattern illuminated with V-polarized light is only in the region FLV. If the illumination condition and the pattern direction (direction perpendicular to the pattern pitch, for example, the V / H direction) are controlled so as to pass through, the pattern image can be transferred onto the wafer W without being affected by the birefringence of the boundary lens. it can.

  FIG. 8 is a schematic diagram showing a state of diffracted light from a reticle pattern having a predetermined pitch, and FIG. 8A is a plan view showing a light amount distribution state and a polarization state in the illumination pupil. FIG. 8B is a diagram in which the state of the H polarization wavefront at the exit pupil PLP of the projection optical system PL and the state of the diffracted light passing through the exit pupil are superimposed, and FIG. 8C is the exit of the projection optical system PL. It is a figure which superimposes and shows the state of the V polarization wave front in the pupil PLP, and the state of the diffracted light which passes the said exit pupil.

In FIG. 8, the diffracted light DEF from the reticle pattern passes through a substantially equiphase region FLH of the H polarization wavefront.
FIG. 9 is a schematic diagram showing a state of diffracted light from a reticle pattern having a different pitch from the example of FIG. 8, and FIG. 9A is a plan view showing a state of light quantity distribution in the illumination pupil. FIG. 9B is a diagram showing the state of the H-polarized wavefront at the exit pupil PLP of the projection optical system PL and the state of the diffracted light passing through the exit pupil, and FIG. It is a figure which shows the state of the V polarization wave front in exit pupil PLP of system PL, and the state of diffracted light which passes the exit pupil concerned.

Also in FIG. 9, the diffracted light DEF from the reticle pattern passes through a substantially equiphase region FLH of the V-polarized wavefront, although the position is different from that in FIG.
As is apparent from FIGS. 8 and 9, in the second embodiment, the state of the diffracted light from the reticle pattern passing through the exit pupil PLP of the projection optical system PL has changed due to the difference in the pitch of the reticle pattern and the like. Even in this case, the diffracted light passes through the almost equiphase region of each polarization wavefront, so that the compound of the equiaxed crystal material forming the boundary lens does not depend on the pattern pitch or the like. Deterioration of imaging performance due to the influence of refraction can be prevented.

In particular, the second embodiment is effective in the case where patterns of various pitches are mixed in the reticle pattern or in the case of multiple exposure.
In the first and second embodiments described above, an example in which the dipole illumination method and the quadrupole illumination method are applied has been described. However, the small σ linear polarization illumination method (the numerical aperture NAi of the illumination system and the aperture of the projection optical system) Number NAp
A combination with a linearly polarized illumination method in which the σ value indicating the ratio is 0.4 or less is also effective.

  In the second embodiment described above, the wavefront aberration (scalar amount) of the projection optical system PL is controlled by changing the position / posture of a part of the plurality of lens elements constituting the projection optical system PL. Even if the wavefront aberration (scalar amount) of the projection optical system PL is controlled by processing the optical surfaces of a plurality of optical elements (lenses, reflectors, parallel plane plates) constituting the projection optical system PL into an aspherical shape. good. In this case, in order to eliminate the image plane position dependency of the wavefront aberration of the projection optical system PL, it is preferable to perform aspheric processing on two or more optical surfaces.

  As an aspherical surface, an aspherical surface rotationally symmetric with respect to the optical axis (an aspherical surface having an infinitely rotationally symmetric shape), a 2θ aspherical surface (aspherical surface having a rotationally symmetric shape with respect to the optical axis, When a spherical surface is approximated by a Zernike polynomial, among the functions of each term of the Zernike polynomial, a shape having a coefficient for a function having sin 2θ or cos 2θ, or a 4θ aspherical surface (aspherical surface having a shape rotationally symmetric twice with respect to the optical axis) When the aspheric surface is approximated by a Zernike polynomial, a shape having a coefficient for a function having sin 4θ or cos 4θ among the functions of each term of the Zernike polynomial can be applied.

  In the first and second embodiments described above, the present invention is applied to the immersion exposure apparatus using a high refractive index liquid and a high refractive index material, but the present invention is not limited thereto. For example, when a lens near the wafer W is formed of fluorite, which is an equiaxed crystal material, in order to reduce problems due to energy concentration, the optical axis of the lens near the wafer W and <100> of fluorite. The present invention can also be applied when the axis is substantially coincident.

Now, as shown in FIG. 10, in each of the above-described embodiments and modifications, when the dipole illumination method or the quadrupole illumination method is used, each of the plurality of poles of the light amount distribution formed on the illumination pupil has an optical axis. When the opening angle with respect to is θ,
45 ° <θ
Is preferably satisfied. If this condition is not satisfied, the diffracted light passing through the exit pupil of the projection optical system PL will pass through a portion deviated from the equiphase portion of the polarization wavefront of each polarization state, resulting in degradation of imaging performance. Therefore, it is not preferable.

  Further, in addition to the above-described various illumination methods, for example, a progressive focus exposure method disclosed in JP-A-4-277612 and JP-A-2001-345245, or exposure light with multiple wavelengths (for example, two wavelengths) is used. It is also effective to apply a multi-wavelength exposure method that obtains the same effect as the progressive focus exposure method.

  In the present embodiment, the optical element BL is attached to the tip of the projection optical system PL, and the optical characteristics of the projection optical system PL, for example, aberration (spherical aberration, coma aberration, etc.) can be adjusted by this lens. The optical element attached to the tip of the projection optical system PL may be an optical plate used for adjusting the optical characteristics of the projection optical system PL. Alternatively, it may be a plane parallel plate that can transmit the exposure light EL.

When the pressure between the optical element at the tip of the projection optical system PL generated by the flow of the liquid LQ and the substrate P is large, the optical element is not exchangeable but the optical element is moved by the pressure. It may be fixed firmly so that there is no.

  The substrate of each of the above embodiments is not only a semiconductor wafer for manufacturing a semiconductor device, but also a glass substrate for a display device, a ceramic wafer for a thin film magnetic head, or an original mask or reticle used in an exposure apparatus. (Synthetic quartz, silicon wafer) or the like may be used.

  In each of the embodiments described above, the step-and-scan type scanning exposure apparatus (scanning stepper) that scans and exposes the pattern of the reticle by synchronously moving the reticle and the wafer is applied as the exposure apparatus. The present invention can also be applied to a step-and-repeat projection exposure apparatus (stepper) in which a reticle pattern is collectively exposed while the reticle and the wafer are stationary, and the wafer is sequentially moved stepwise.

  Further, as the exposure apparatus EX, a reduced image of the first pattern is projected with the first pattern and the substrate P being substantially stationary (for example, a refraction type projection optical system that does not include a reflecting element at 1/8 reduction magnification). The present invention can also be applied to an exposure apparatus that performs batch exposure on a wafer using the above. In this case, after that, a reduced image of the second pattern is partially exposed to the first pattern and collectively exposed onto the substrate P by using the projection optical system in a state where the second pattern and the wafer are substantially stationary. The present invention can also be applied to a stitch type batch exposure apparatus. Further, the stitch type exposure apparatus can be applied to a step-and-stitch type exposure apparatus in which at least two patterns are partially overlapped and transferred on the substrate P, and the wafer is sequentially moved.

  The present invention can also be applied to a twin stage type exposure apparatus disclosed in Japanese Patent Application Laid-Open No. 10-163099, Japanese Patent Application Laid-Open No. 10-214783, and Japanese Translation of PCT International Publication No. 2000-505958.

  In the above-described embodiment, an exposure apparatus that locally fills the liquid between the projection optical system PL and the substrate P is employed. However, the present invention is disclosed in Japanese Patent Laid-Open No. 6-124873. It is also applicable to an immersion exposure apparatus that moves a stage holding a substrate to be exposed in a liquid tank.

  The type of the projection exposure apparatus is not limited to an exposure apparatus for manufacturing a semiconductor element that exposes a semiconductor element pattern on a wafer. An exposure apparatus for manufacturing a liquid crystal display element or a display, a thin film magnetic head, an image sensor (CCD) ) Or an exposure apparatus for manufacturing reticles or masks.

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

  In the exposure apparatus of the above-described embodiment, the reticle (mask) is illuminated by the illumination device (illumination process), and the transfer pattern formed on the mask is exposed to the photosensitive substrate using the projection optical system (exposure process). Thus, a micro device (semiconductor element, imaging element, liquid crystal display element, thin film magnetic head, etc.) can be manufactured. Hereinafter, referring to the flowchart of FIG. 11 for an example of a method for obtaining a semiconductor device as a micro device by forming a predetermined circuit pattern on a wafer or the like as a photosensitive substrate using the exposure apparatus of the present embodiment. I will explain.

  First, in step 301 of FIG. 11, a metal film is deposited on one lot of wafers. In the next step 302, a photoresist is applied onto the metal film on the one lot of wafers. Thereafter, in step 303, using the exposure apparatus of the present embodiment, the image of the pattern on the mask is sequentially exposed and transferred to each shot area on the wafer of one lot via the projection optical system. Thereafter, in step 304, the photoresist on the one lot of wafers is developed, and in step 305, the resist pattern is etched on the one lot of wafers to form a pattern on the mask. Corresponding circuit patterns are formed in each shot area on each wafer.

  Thereafter, a device pattern such as a semiconductor element is manufactured by forming a circuit pattern of an upper layer. According to the semiconductor device manufacturing method described above, a semiconductor device having an extremely fine circuit pattern can be obtained with high throughput. In steps 301 to 305, a metal is deposited on the wafer, a resist is applied on the metal film, and exposure, development, and etching processes are performed. Prior to these processes, on the wafer. It is needless to say that after forming a silicon oxide film, a resist may be applied on the silicon oxide film, and steps such as exposure, development, and etching may be performed.

  In the exposure apparatus of this embodiment, a liquid crystal display element as a micro device can be obtained by forming a predetermined pattern (circuit pattern, electrode pattern, etc.) on a plate (glass substrate). Hereinafter, an example of the technique at this time will be described with reference to the flowchart of FIG. In FIG. 12, in a pattern forming process 401, a so-called photolithography process is performed in which the exposure pattern of the present embodiment is used to transfer and expose a mask pattern onto a photosensitive substrate (such as a glass substrate coated with a resist). By this photolithography process, a predetermined pattern including a large number of electrodes and the like is formed on the photosensitive substrate. Thereafter, the exposed substrate undergoes steps such as a developing step, an etching step, and a resist stripping step, whereby a predetermined pattern is formed on the substrate, and the process proceeds to the next color filter forming step 402.

  Next, in the color filter forming step 402, a large number of sets of three dots corresponding to R (Red), G (Green), and B (Blue) are arranged in a matrix or three of R, G, and B A color filter is formed by arranging a plurality of stripe filter sets in the horizontal scanning line direction. Then, after the color filter forming step 402, a cell assembly step 403 is executed. In the cell assembly step 403, a liquid crystal panel (liquid crystal cell) is assembled using the substrate having the predetermined pattern obtained in the pattern formation step 401, the color filter obtained in the color filter formation step 402, and the like.

  In the cell assembly step 403, for example, liquid crystal is injected between the substrate having the predetermined pattern obtained in the pattern formation step 401 and the color filter obtained in the color filter formation step 402, and a liquid crystal panel (liquid crystal cell) is obtained. ). Thereafter, in a module assembling step 404, components such as an electric circuit and a backlight for performing a display operation of the assembled liquid crystal panel (liquid crystal cell) are attached to complete a liquid crystal display element. According to the above-described method for manufacturing a liquid crystal display element, a liquid crystal display element having an extremely fine circuit pattern can be obtained with high throughput.

In the above-described embodiment, the ArF excimer laser light source is used. However, the present invention is not limited to this, and other appropriate light sources such as an F ₂ laser light source can also be used. Furthermore, in the above-described embodiment, the present invention is applied to the projection optical system mounted on the exposure apparatus. However, the present invention is not limited to this and is applied to other general projection optical systems. Can also be applied.

1 is a drawing schematically showing a configuration of an exposure apparatus according to a first embodiment of the present invention. It is a figure explaining the crystal axis orientation of an equiaxed crystal system. It is a figure which shows the H polarization wave front in the exit pupil of a projection optical system, (a) is a top view, (b) is a bird's-eye view. It is a figure which shows the V polarization wave front in the exit pupil of a projection optical system, (a) is a top view, (b) is a bird's-eye view. It is a figure which shows the state of the diffracted light which passes a projection optical system, (a) is a figure which shows light quantity distribution in an illumination pupil, (b) shows the optical path of the diffracted light of the pattern from a reticle schematically. (C) is a figure which shows the position of the diffracted light which passes the exit pupil of a projection optical system. It is a figure which shows the H polarization wave front in the exit pupil of the projection optical system concerning 2nd Embodiment, (a) is a top view, (b) is a bird's-eye view. It is a figure which shows the V polarization wave front in the exit pupil of the projection optical system concerning 2nd Embodiment, (a) is a top view, (b) is a bird's-eye view. It is a figure which shows the state of the diffracted light which passes the projection optical system concerning 2nd Embodiment, (a) is a figure which shows light quantity distribution in an illumination pupil, (b) passes the exit pupil of a projection optical system. FIG. 4C is a diagram illustrating the position of the V-polarized diffracted light passing through the exit pupil of the projection optical system. It is a figure which shows the state of the diffracted light which passes the projection optical system concerning 2nd Embodiment, (a) is a figure which shows light quantity distribution in an illumination pupil, (b) passes the exit pupil of a projection optical system. FIG. 4C is a diagram illustrating the position of the V-polarized diffracted light passing through the exit pupil of the projection optical system. It is a figure for demonstrating the preferable opening angle range of each pole in a dipole illumination method or a quadrupole illumination method. It is a flowchart of the method at the time of obtaining the semiconductor device as a device. It is a flowchart of the method at the time of obtaining the flat panel display as a device.

Explanation of symbols

PL: projection optical system BL: boundary lens IL: immersion liquid R (R1, R2): reticle W: wafer

Claims (16)

In a projection exposure apparatus that projects a predetermined pattern on a photosensitive substrate,
An illumination optical system for supplying illumination light to the predetermined pattern;
A projection optical system that forms an image of the predetermined pattern on the photosensitive substrate via an immersion liquid between the photosensitive substrate and the projection optical system;
The projection optical system includes a boundary optical member that is disposed in contact with the immersion liquid and formed of an equiaxed crystal material,
The optical axis of the projection optical system is positioned substantially parallel to the <100> axis of the boundary optical member or a crystal axis optically equivalent to the <100> axis,
The illumination optical system sets the illumination light for the predetermined pattern to illumination light in a specific incident angle range, and sets the illumination light in the specific incident angle range to TE polarized light for the predetermined pattern. A projection exposure apparatus. The illumination optical system supplies illumination light to a pattern group having a pitch in a first direction along a plane that includes the first direction and is perpendicular to the predetermined plane;
A first surface including the <110> axis of the boundary optical member of the projection optical system or a crystal axis optically equivalent to the <110> axis and the optical axis, or the boundary optical of the projection optical system The boundary optics so as to allow diffracted light from the pattern group to pass along a second surface including the <001> axis of the member or a crystal axis optically equivalent to the <001> axis and the optical axis. The projection exposure apparatus according to claim 1, wherein the member is positioned. The illumination optical system supplies illumination light to a pattern group having a pitch in a first direction along a plane that includes the first direction and is perpendicular to the predetermined plane;
The diffracted light from the pattern group is passed along a plane including the <111> axis of the boundary optical member of the projection optical system or a crystal axis optically equivalent to the <111> axis and the optical axis. The projection exposure apparatus according to claim 1, wherein the boundary optical member is positioned as described above.   2. The predetermined pattern includes a first pattern group having a pitch in a first direction and a second pattern having a pitch in a second direction orthogonal to the first direction. The projection exposure apparatus according to any one of claims 3 to 4.   The projection exposure apparatus according to any one of claims 1 to 4, wherein the illumination light in the specific incident angle range is dipole illumination light or quadrupole illumination light. Each pole of the dipole illumination light or the quadrupole illumination light has an opening angle with respect to the optical axis on the exit pupil of the illumination optical system as θ,
45 ° <θ
The projection exposure apparatus according to claim 5, wherein:   The projection exposure apparatus according to claim 1, wherein the projection optical system includes a wavefront aberration control unit that controls a wavefront aberration of the projection optical system.   The projection exposure apparatus according to claim 7, wherein the wavefront aberration control unit controls at least one of a position and a posture of at least a part of the optical member constituting the projection optical system.   8. The projection exposure apparatus according to claim 7, wherein the wavefront aberration control means is an aspherical surface formed on at least two of the optical surfaces of the optical member constituting the projection optical system.   2. The optical member constituting the projection optical system, wherein a member formed of the equiaxed crystal material is only an optical member in contact with the immersion liquid. The projection exposure apparatus according to claim 9. The boundary optical member in the projection optical system includes a first boundary optical member and a second boundary optical member,
A first immersion liquid is filled between the first optical member and the photosensitive substrate,
11. The projection exposure apparatus according to claim 1, wherein a second immersion liquid is filled between the first optical member and the second optical member. In a projection exposure method for projecting a predetermined pattern on a photosensitive substrate,
A pattern setting step for setting the predetermined pattern on a predetermined surface;
An illumination step of supplying illumination light to the predetermined pattern;
A projection step of forming an image of the predetermined pattern on the photosensitive substrate via an immersion liquid between the photosensitive substrate and the projection optical system;
In the projecting step, the pattern is projected onto the photosensitive substrate through a boundary optical member that is disposed in contact with the immersion liquid and formed of an equiaxed crystal material,
The optical axis of the projection optical system is positioned substantially parallel to the <100> axis of the boundary optical member or a crystal axis optically equivalent to the <100> axis,
In the illumination step, the illumination light for the predetermined pattern is set to illumination light in a specific incident angle range, and the illumination light in the specific incident angle range is set to TE polarized light with respect to the predetermined surface. Projection exposure method. In the pattern setting step, a pattern group having a pitch in the first direction is set,
In the illumination step, the illumination light is supplied along a plane that includes the first direction and is perpendicular to the predetermined plane;
In the projecting step, the <110> of the boundary optical member, a first surface including a crystal axis optically equivalent to the <110> axis and the optical axis, or <001> of the boundary optical member or the 13. The projection exposure method according to claim 12, wherein diffracted light from the pattern group is allowed to pass along a second surface including a crystal axis optically equivalent to a <001> axis and the optical axis. . In the pattern setting step, a pattern group having a pitch in the first direction is set,
In the illumination step, the illumination light is supplied along a plane that includes the first direction and is perpendicular to the predetermined plane;
In the projection step, diffracted light from the pattern group is allowed to pass along a plane including the optical axis and the <111> axis of the boundary optical member or a crystal axis optically equivalent to the <111> axis. The projection exposure method according to claim 12.   The said predetermined pattern is comprised from the 1st pattern group which has a pitch in a 1st direction, and the 2nd pattern which has a pitch in the 2nd direction orthogonal to the said 1st direction. The projection exposure method according to claim 14. A projection exposure step of projecting and exposing the predetermined pattern on the photosensitive substrate using the projection exposure apparatus according to any one of claims 1 to 11,
A device manufacturing method comprising: a developing step of developing the photosensitive substrate.

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