Chuck, substrate holding device, substrate processing device, and method for manufacturing an article

Abstract

To provide a chuck that can reduce distortion of a substrate by adjusting the height of convex parts on an inner peripheral side and the height of convex parts on an outer peripheral side to have a predetermined relationship.SOLUTION: A chuck is to adsorb and hold a substrate and includes a plurality of convex parts in contact with the rear face of the substrate that is adsorbed and held, an annular partition wall, and a bottom on which the plurality of convex parts and the partition wall are arranged. The plurality of convex parts are formed of a plurality of groups with first convex parts arranged outside the partition wall and second convex parts arranged inside the partition wall and at positions adjacent to the first convex parts across the partition wall as one group. When the height of the first convex parts included in each of the plurality of groups is ho, and the height of the second convex parts included in each of the plurality of groups is hi, hi>ho is satisfied.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a chuck, a substrate holding device, a substrate processing apparatus, and a method for manufacturing an article. [Background technology]

[0002] In recent years, reduction projection exposure tools used in semiconductor device manufacturing and other processes have been increasing in numerical aperture (NA) to accommodate the miniaturization of devices. While increasing NA improves resolution, it also reduces the effective depth of focus. Therefore, to maintain resolution while ensuring sufficient practical depth of focus, efforts have been made to improve wafer flatness (flatness of the substrate surface) by reducing the field curvature of the projection optical system and improving the flatness accuracy of the chuck that holds the wafer (substrate) and compensates for unevenness in wafer (substrate) thickness.

[0003] One of the causes of the reduction in the flatness of the substrate surface is the inclusion of foreign matter between the chuck and the substrate. When a foreign matter is trapped, the substrate in the trapped area becomes deformed and rises, which can cause defects in the formation of patterns on the substrate and reduce yield. In order to stochastically avoid such a reduction in yield due to foreign matter, a pin contact chuck (pin chuck) is used, which uses so-called pins (protrusions) that significantly reduce the contact rate between the chuck and the substrate.

[0004] When this pin chuck is used, the substrate may be deformed and bent (warped) by the vacuum suction force between the convex parts, which may result in a decrease in the flatness of the substrate surface. Various proposals have been made to improve this.

[0005] For example, in Patent Document 1, a ring-shaped partition wall (bank) that surrounds a plurality of convex portions is provided in a pin chuck, and this partition wall is disposed between an outer peripheral convex portion and an inner peripheral convex portion that is adjacent to the outer peripheral convex portion. The partition wall is disposed as close as possible to the outer peripheral convex portion.

[0006] In Patent Document 2, the partition walls are disposed at positions outside the outermost convex portion, or between the outermost convex portion and the convex portion adjacent to the outermost convex portion on the inner circumferential side. The partition walls are disposed at positions within a predetermined range in the outer circumferential direction from the center of the distance between the outermost convex portion and the convex portion adjacent to the outermost convex portion on the inner circumferential side. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 4298078 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-185607 Summary of the Invention [Problem to be solved by the invention]

[0008] When a substrate is vacuum-sucked, the inside of the partition wall is kept at a substantially vacuum pressure, generating a suction force, but the outside of the partition wall is at atmospheric pressure, generating almost no suction force. In Patent Documents 1 and 2, the partition wall is positioned close to the outer peripheral convex portion in order to allow the suction force to act as far as possible on the outside of the substrate. However, because the suction force acts on the outside of the substrate, the flatness of the substrate surface decreases, resulting in a problem of increased distortion of the substrate.

[0009] Therefore, an object of the present invention is to provide a chuck that can reduce distortion of a substrate, for example, by making the heights of the convex portions on the inner periphery and the outer periphery have a predetermined relationship. [Means for solving the problem]

[0010] In order to achieve the above object, a chuck according to one aspect of the present invention includes a plurality of convex portions that come into contact with a back surface of a substrate held by suction, an annular partition wall, and a bottom portion on which the plurality of convex portions and the partition wall are arranged, the plurality of convex portions being configured into a plurality of groups, each group being a first convex portion arranged outside the partition wall and a second convex portion arranged inside the partition wall and adjacent to the first convex portion with the partition wall sandwiched therebetween, and when the height of the first convex portions included in each of the plurality of groups is ho and the height of the second convex portions included in each of the plurality of groups is hi, the hi>ho is satisfied, and the height of the partition wall is such that the height of the first convex portions included in each of the plurality of groups is hi>ho. 1 It is characterized in that it is equal to or less than the height of the convex portion. The substrate may further include a plurality of protrusions that contact the rear surface of the substrate held by suction, an annular partition wall, and a bottom on which the plurality of protrusions and the partition wall are arranged, the plurality of protrusions being configured from a plurality of groups, each group consisting of a first protrusion arranged outside the partition wall and a second protrusion arranged inside the partition wall and adjacent to the first protrusion with the partition wall in between, and the height of the first protrusions included in each of the plurality of groups being ho and the height of the second protrusions included in each of the plurality of groups being hi, such that hi>ho is satisfied, and such that So is a cross-sectional area of ​​the first protrusions included in each of the plurality of groups and Si is a cross-sectional area of ​​the second protrusions included in each of the plurality of groups, such that Si>So is satisfied. The present invention is also characterized in that the substrate includes a plurality of convex portions that contact the back surface of the substrate held by suction, a ring-shaped partition wall, and a bottom on which the plurality of convex portions and the partition wall are arranged, the plurality of convex portions being composed of a plurality of groups, each group consisting of a first convex portion arranged outside the partition wall and a second convex portion arranged inside the partition wall and adjacent to the first convex portion across the partition wall, where ho is the height of the first convex portions included in each of the plurality of groups and hi is the height of the second convex portions included in each of the plurality of groups, and hi>ho is satisfied, the partition wall includes adjacent double partition walls, and the outer partition wall of the double partition wall has a height lower than the second convex portions included in each of the plurality of groups. [Effects of the Invention]

[0011] According to the present invention, for example, a chuck is provided that can reduce distortion of a substrate by setting the heights of the convex portions on the inner periphery and the outer periphery to a predetermined relationship. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram illustrating the configuration of an exposure apparatus according to a first embodiment. [Figure 2] FIG. 10 is a diagram illustrating a material mechanics model of a beam with one side fixed and one side free, subjected to a uniformly distributed load. [Figure 3] 1 is a diagram illustrating a substrate holding device according to a first embodiment. [Figure 4] FIG. 10 is a diagram illustrating a material mechanics model for a cantilever beam. [Figure 5] FIG. 1 is a cross-sectional view illustrating a chuck according to a first embodiment. [Figure 6] FIG. 10 is a diagram illustrating a substrate holding device according to a third embodiment. [Figure 7] 1 is a flowchart illustrating a device manufacturing process. [Figure 8] 1 is a flowchart illustrating a wafer process. [Figure 9] FIG. 1 is a diagram illustrating a pin chuck used in a general substrate holding device. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In each drawing, the same reference numerals are used to designate the same members or elements, and redundant descriptions will be omitted or simplified.

[0014] Example 1 1 is a diagram illustrating a schematic configuration of an exposure apparatus 100 according to this embodiment. The exposure apparatus 100 is an apparatus that can irradiate light (exposure light) emitted from a light source onto a resist to harden it, thereby forming a pattern in the hardened material onto which a pattern formed on a reticle 104 has been transferred.

[0015] In the following description, the direction parallel to the optical axis of the light irradiating the resist on the substrate 110 is referred to as the Z-axis direction, and two directions orthogonal to each other in a plane perpendicular to the Z-axis direction are referred to as the X-axis direction and the Y-axis direction. Exposure apparatus 100 of this embodiment is applicable to apparatuses that perform sequential focus driving on multiple pattern formation regions (exposure regions) and apparatuses that perform sequential exposure (projection exposure apparatuses, substrate processing apparatuses), etc. Exposure apparatus 100 of this embodiment will be described below with reference to FIG. 1. Note that exposure apparatus 100 of this embodiment will be described as a step-and-repeat type exposure apparatus.

[0016] The substrate (wafer) 110 is a substrate to be processed, the surface of which is coated with a photosensitive agent (resist) that effectively induces a chemical reaction when exposed to exposure light. The substrate 110 may be made of glass, ceramics, metal, silicon, resin, or the like, and, if necessary, a member made of a material different from the substrate 110 may be formed on the surface. The substrate 110 may also be any of various substrates, such as a gallium arsenide wafer, a composite adhesive wafer, a glass wafer containing quartz, a liquid crystal panel substrate, or a reticle. The outer shape may also be circular or rectangular, in which case the outer shape of the chuck may be adjusted to match the outer shape of the substrate.

[0017] The reticle (master) 104 is placed on a reticle stage 103 that is configured to be movable in a plane perpendicular to the optical axis of the projection optical system 106 and in the direction of this optical axis. The reticle 104 has a rectangular outer periphery and a pattern portion with a three-dimensional pattern (a concave-convex pattern to be transferred to the substrate, such as a circuit pattern) formed on the surface (pattern surface) facing the substrate 110. The reticle 104 is made of a material that can transmit light, such as quartz.

[0018] The exposure apparatus 100 of this embodiment also functions as a substrate processing apparatus, and may include a substrate holding device 101, a substrate stage 102, a reticle stage 103, an illumination optical system 105, a projection optical system 106, an off-axis scope 107, a measurement unit 108, and a control unit 109.

[0019] The substrate holding device 101 may include a chuck 1 for suction-holding the substrate 110, a suction unit (not shown) that is a vacuum source for sucking (exhausting) the space between the back surface of the substrate 110 and the chuck 1, and a control unit (not shown) that controls the suction unit. Details of the substrate holding device 101 in this embodiment will be described later.

[0020] The substrate stage 102 includes a θZ tilt stage that holds the substrate 110 via the substrate holding device 101, an XY stage (not shown) that supports the θZ tilt stage, and a base (not shown) that supports the XY stage. The substrate stage 102 is driven by a driving device (not shown) such as a linear motor. The driving device can be driven in six axial directions: X, Y, Z, θX, θY, and θZ, and is controlled by a control unit 109 (described later). Note that although the driving device is capable of driving in six axial directions, it may also be capable of driving in any one of one to six axial directions.

[0021] The reticle stage 103 is configured to be movable, for example, within a plane perpendicular to the optical axis of the projection optical system 106 (described later), i.e., within the XY plane, and rotatable in the θZ direction. The reticle stage 103 is driven by a driving device (not shown) such as a linear motor, which is capable of driving in three axial directions, X, Y, and θZ, and is controlled by a control unit 109 (described later). Note that although the driving device is capable of driving in three axial directions, it may also be capable of driving in any one of one to six axial directions.

[0022] The illumination optical system 105 includes a light source (not shown) and illuminates the reticle 104 on which a circuit pattern (reticle pattern) to be transferred is formed. The light source may be, for example, a laser. Usable lasers include an ArF excimer laser with a wavelength of approximately 193 nm, a KrF excimer laser with a wavelength of approximately 248 nm, and an F2 excimer laser with a wavelength of approximately 157 nm. The type of laser is not limited to an excimer laser; for example, a YAG laser may be used. The number of lasers is also not limited. When a laser is used as the light source, it is preferable to use a beam shaping optical system that shapes a parallel beam from the laser light source into a desired beam shape, or an incoherent optical system that converts a coherent laser into an incoherent beam. Furthermore, the usable light source is not limited to a laser; one or more lamps, such as a mercury lamp or a xenon lamp, may also be used.

[0023] Although not shown, the illumination optical system 105 also includes lenses, mirrors, a light integrator, a diaphragm, etc. Generally, the internal optical system is arranged in the following order: a condenser lens, a fly's eye lens, an aperture diaphragm, a condenser lens, a slit, and an imaging optical system. In this case, the light integrator includes a fly's eye lens and an integrator formed by stacking two sets of cylindrical lens array plates.

[0024] The projection optical system 106 forms an image of diffracted light from the pattern on the reticle 104, illuminated by exposure light from the illumination optical system 105, onto the substrate 110 at a predetermined magnification (e.g., 1 / 2, 1 / 4, or 1 / 5), causing interference. The interference image formed on the substrate 110 is substantially identical to the reticle pattern. This interference image is generally called an optical image, and the shape of the optical image determines the line width formed on the substrate 110. The projection optical system 106 can be an optical system consisting of only multiple optical elements, or an optical system consisting of multiple optical elements and at least one concave mirror (catadioptric optical system). Alternatively, the projection optical system 106 can be an optical system consisting of multiple optical elements and at least one diffractive optical element such as a kinoform, or an all-mirror optical system.

[0025] The off-axis scope 107 is used to position the substrate 110 and detect the positions of multiple pattern formation regions on the substrate 110. It can detect and measure the relative position between a reference mark arranged on the substrate stage 102 and a mark formed on the substrate 110 mounted on the substrate stage 102. The measurement unit (surface position measurement means) 108 is a measurement device that can adjust the focus of the projection optical system 106 to the exposure target region of the substrate 110, and constitutes a focusing device that adjusts the focus of the projection optical system 106 to the substrate surface.

[0026] Control unit 109 includes a CPU, memory (storage unit), etc., and is configured as at least one computer, and is connected via lines to each component of exposure apparatus 100. Control unit 109 also performs overall control of the operation and adjustment of each component of exposure apparatus 100 in accordance with a program stored in the memory. Control unit 109 may be configured integrally with other parts of exposure apparatus 100 (in a common housing), or may be configured separately from other parts of exposure apparatus 100 (in a different housing), or may be installed in a location separate from exposure apparatus 100 and controlled remotely.

[0027] Here, the exposure sequence of exposure apparatus 100 will be described below. Note that each operation (process) shown in the exposure sequence is controlled by control unit 109 executing a computer program. When the exposure sequence starts, substrate 110 is set in exposure apparatus 100 automatically or manually by an operator, and then operation of exposure apparatus 100 is started in response to an exposure start command.

[0028] First, a first substrate 110 to be exposed first is loaded into a substrate carrier in the exposure apparatus 100 by a transport mechanism (not shown) (loading step). Next, the substrate 110 is sent onto a chuck 1 mounted on a substrate stage 102 by the transport mechanism, and is held by suction by the substrate holding device 101 (substrate holding step).

[0029] Next, multiple marks formed on the substrate 110 are detected by the off-axis scope 107 mounted on the exposure apparatus 100, and the magnification, rotation, and deviation amounts in the X-axis and Y-axis directions of the substrate 110 are determined, and position correction is performed (alignment process).

[0030] Next, the substrate stage 102 moves the substrate 110 so that the predetermined pattern formation area of ​​the mounted substrate 110 to be exposed first is aligned with the exposure position of the exposure apparatus 100. Next, after focusing by the measurement unit 108, light is irradiated from the light source, passes through the illumination optical system 105 and the reticle (pattern formation unit) 104, is reduced at a predetermined magnification by the projection optical system 106, and is then irradiated onto the resist coated on the substrate 110. The resist coated in the predetermined pattern formation area is exposed for a predetermined time (exposure process). The exposure time is, for example, about 0.2 seconds.

[0031] Next, the substrate stage 102 moves (steps) the substrate 110 to the next pattern formation region on the substrate 110, and exposes it in the same manner as above. The same pattern formation process is repeated sequentially until exposure is completed in all pattern formation regions to be exposed. In this way, the pattern formed on the reticle 104 can be formed on one substrate 110. Then, the substrate 110 is transferred from the chuck 1 to a collection transport hand (not shown) and returned to the substrate carrier in the exposure apparatus 100 (unloading process). After the unloading process of the substrate 110, the substrate 110 is processed, for example, by etching or the like (processing process), and an article can be manufactured by removing unnecessary cured material from the processed substrate 110.

[0032] While this embodiment is based on the step-and-repeat exposure apparatus described above, it is not limited to this and can also be applied to a scanning exposure apparatus. When applied to a scanning exposure apparatus, the reticle and substrate 110 are scanned synchronously based on the exposure magnification, and exposure is performed during the scan.

[0033] It should be noted that the substrate holding device 101 of this embodiment is not limited to use in the exposure apparatus 100. For example, it can also be used in substrate processing apparatuses including imprint apparatuses (lithography apparatuses), liquid crystal substrate manufacturing apparatuses, magnetic head manufacturing apparatuses, semiconductor inspection apparatuses, liquid crystal substrate inspection apparatuses, magnetic head inspection apparatuses, and in the manufacture of micromachines.

[0034] When the substrate 110 is held by suction on the chuck 1, a foreign object may be trapped between the substrate 110 and the chuck 1. For example, even if the foreign object is only a few micrometers in size, the trapped portion of the substrate 110 may be deformed and partially raised, resulting in defective pattern formation. For example, this may occur when the effective depth of focus is 1 micrometer or less.

[0035] To prevent such pinching by foreign matter, a so-called pin contact chuck (hereinafter referred to as chuck) is used, in which the portion that contacts the back surface of substrate 110 is formed as a pin-shaped protrusion, thereby significantly reducing the contact area with substrate 110. Below, a chuck used in a conventional general substrate holding device will be described with reference to FIG.

[0036] 9A and 9B are diagrams illustrating a chuck 200 used in a general substrate holding device. Fig. 9A is a plan view of the chuck 200 as viewed from the +Z direction. Fig. 9B is a partial cross-sectional view of the chuck 200 shown in Fig. 9A. The substrate holding device illustrated in Fig. 9 can be configured with the chuck 200, a protrusion 201, a partition wall 204, and a suction port 205.

[0037] The protrusions 201 function as a contact surface (a support surface that supports the substrate after it is placed) that comes into contact with the rear surface of the substrate 110. The multiple pin-shaped protrusions 201 can include a pin-shaped protrusion (outer peripheral side protrusion) 202, a pin-shaped protrusion (inner peripheral side protrusion) 203, and multiple pin-shaped protrusions different from the outer peripheral side protrusion 202 and the inner peripheral side protrusion 203.

[0038] The partition wall 204 is provided in an annular shape on the bottom of the chuck 200 so as to be located inside the outer peripheral convex portion 202. The height of the partition wall 204 is formed to be approximately 1 to 2 μm lower than the upper surface of the outer peripheral convex portion 202. The suction port 205 is a through-hole formed in the bottom of the chuck 200, and is connected to a flow path formed by piping or the like that communicates with a vacuum source (suction portion) not shown.

[0039] The outer circumferential side protrusions 202 are arranged outside the partition wall 204 so as to abut against the rear surface of the substrate 110 in the outer circumferential direction. A plurality of outer circumferential side protrusions 202 are arranged on the outer periphery having the same radius as the substrate 110. The outer circumferential side protrusions 202 illustrated in FIG. 9 are protrusions arranged on the outermost side (outermost periphery) of the chuck 200. The inner circumferential side protrusions 203 are arranged inside the partition wall 204 so as to abut against the rear surface of the substrate 110 in the inner circumferential direction. A plurality of inner circumferential side protrusions 203 are arranged on the inner periphery having the same radius as the substrate 110. The inner circumferential side protrusions 203 illustrated in FIG. 9 are arranged adjacent to the outer circumferential side protrusion 202 arranged at the bottom on the outermost side, across the partition wall 204. The plurality of pin-shaped protrusions 201 on the chuck 200 can be arranged in a lattice pattern at predetermined distances (intervals, periods, widths). Furthermore, the outer circumferential side protrusions 202 arranged outside the partition wall 204 and the inner circumferential side protrusions 203 arranged inside the partition wall 204 and adjacent to the outer circumferential side protrusions 202 with the partition wall 204 in between are configured as one group. Then, the plurality of protrusions made up of the outer circumferential side protrusions 202 and the inner circumferential side protrusions 203 are configured as a plurality of groups including each group.

[0040] A method for suctioning the substrate 110 with the chuck 200 configured as described above will be described below. First, the substrate 110 is placed on the protrusions 201 of the chuck 200. This causes the back surface of the substrate 110 to abut against the multiple protrusions 201. Next, a vacuum source (not shown) is activated to vacuum-suck the substrate 110 through the suction ports 205, whereby the substrate 110 is supported and held by suction on the protrusions 201 of the chuck 200. At this time, the substrate 110 is deformed and warped by the vacuum suction force between the protrusions 201. The warping of the substrate 110 reduces the flatness of the substrate 110, resulting in so-called wafer distortion (hereinafter referred to as distortion). This can reduce the flatness of the substrate 110.

[0041] Using the arrangement position of the partition wall 204 illustrated in FIG. 9(B) as an example, the flatness and distortion of the substrate 110 at the outer peripheral convex portion 202 will be described below with reference to FIG. 2 based on a material mechanics model. FIG. 2 is a diagram illustrating a material mechanics model of a beam that is fixed on one side and free on the other side and receives a uniformly distributed load. The material mechanics model of the deflection state of the substrate 110 in the outer peripheral region (outer periphery) of the chuck 200 corresponds to the model illustrated in FIG. 9(B). Note that, as illustrated in FIG. 9(B), the partition wall 204 is arranged closer to the outer peripheral convex portion 202 than the inner peripheral convex portion 203.

[0042] The Young's modulus of the substrate 110 is E, and the thickness of the substrate 110 is h. Next, the distance between the outer circumferential convex portion 202 and the inner circumferential convex portion 203 included in the above-mentioned multiple groups is L. Furthermore, the acting force per unit length is w, the deflection is y, and the radial position of the inner circumferential convex portion 204 as a reference is x. Note that the distance L may be calculated by averaging the distances between the outer circumferential convex portion 202 and the inner circumferential convex portion 203 of each group included in the multiple groups.

[0043]

number

[0044]

number

[0045]

number

[0046]

number

[0047]

number

[0048] As an example, substituting the design values ​​of a typical chuck, E = 160 GPa, Pv = 0.1 MPa, L = 2 mm, and h = 0.7 mm, into the above equation (5) yields dx = 1.29 nm. For example, if the tolerance for overlay error relative to an ideal horizontal reference is 1.5 nm, only 0.29 nm of tolerance remains. Furthermore, even if the tolerance for overlay error relative to an ideal horizontal reference is, for example, 3 nm or 5 nm, a distortion of 1.29 nm significantly impacts the process of forming a pattern on a substrate. Therefore, in order to perform processes such as pattern formation after the substrate 110 is chucked and held, the substrate 110 must be chucked and held in a state with reduced distortion.

[0049] Therefore, in this embodiment, a chuck capable of reducing distortion can be provided by setting a predetermined relationship between the heights of the inner peripheral side convex portion 4 and the outer peripheral side convex portion 3, which will be described later. The substrate holding device 101 of this embodiment will be described in detail below with reference to FIGS.

[0050] 3A and 3B are diagrams illustrating a substrate holding device 101 according to this embodiment. FIG. 3A is a plan view of the substrate holding device 101 as viewed from the +Z direction. FIG. 3B is a partial cross-sectional view of the substrate holding device 101 of FIG. 3A. The substrate holding device 101 according to this embodiment will be described in detail below with reference to FIG. 3. The substrate holding device 101 according to this embodiment may include a chuck 1, a suction unit (not shown), and a control unit.

[0051] The chuck 1 is configured in a circular shape with a diameter smaller than that of the substrate 110, and may include a plurality of pin-shaped protrusions 2, a partition (first partition) 5, and a suction port (first suction port) 6. The chuck 1 is placed on a substrate stage 102.

[0052] The protrusions 2 are pin-shaped protrusions arranged in plurality on the bottom of the chuck 1, and when the substrate 110 is placed on the chuck 1, the back surface of the substrate 110 abuts against the upper surfaces of the protrusions 2. The protrusions 2 are arranged in a grid pattern on the bottom of the chuck 1 at a predetermined distance L (mm). The diameter of the protrusions 2 varies depending on the specifications of the chuck 1, but a typical diameter is about φ0.2 mm. The protrusions 2 may be arranged in a grid pattern other than a concentric pattern, or may be arranged at an angle, for example, in a 60-degree staggered grid pattern. They may also be arranged randomly, or a combination of these.

[0053] The protrusions 2 may include a plurality of pin-shaped protrusions (outer peripheral protrusions, first protrusions) 3, a plurality of pin-shaped protrusions (inner peripheral protrusions, second protrusions) 4, and a plurality of pin-shaped protrusions (third protrusions) different from the outer peripheral protrusions 3 and the inner peripheral protrusions 4. The outer peripheral protrusions 3 are arranged outside the partition wall 5 so as to abut against the rear surface of the substrate 110 in the outer peripheral direction. The outer peripheral protrusions 3 are protrusions arranged in plurality on the outer periphery with the same radius as the substrate 110. The outer peripheral protrusions 3 illustrated in FIG. 3 are arranged on the outermost side (outermost periphery) of the chuck 1. The inner peripheral protrusions 4 are arranged inside the partition wall 5 so as to abut against the rear surface of the substrate 110 in the inner peripheral direction. The inner peripheral protrusions 4 are arranged in plurality on the inner periphery with the same radius as the substrate 110. The inner peripheral protrusions 4 are arranged adjacent to the outer peripheral protrusion 3 arranged at the bottom of the outermost side, across the partition wall 5. In this embodiment, the plurality of protrusions 2 excluding the third protrusion are configured to be composed of a plurality of groups, each group consisting of an outer circumferential side protrusion 3 arranged outside the partition wall 5 and an inner circumferential side protrusion 4 arranged inside the partition wall 5 at a position adjacent to the outer circumferential side protrusion 3 across the partition wall 5. As will be described later, the outer circumferential side protrusions 3 included in each of the plurality of groups have a height lower than that of the inner circumferential side protrusions 4.

[0054] At least one partition wall 5 is arranged in a circular ring shape on the bottom of the chuck 1 so as to surround a portion of the plurality of protrusions 2. The suction port 6 is a through-hole formed in the chuck 1, and in this embodiment, functions as a suction port when a suction unit (described later) sucks (exhausts) the space between the back surface of the substrate 110 and the chuck 1. Note that, although only one suction port 6 is provided in FIG. 3 , this is not limiting and one or more suction ports 6 may be formed in the chuck 1.

[0055] The suction unit is a vacuum source (not shown) configured to be able to suck the space between the backside of the substrate 110 and the chuck 1 by vacuum suction or the like. The suction unit starts operating in response to a signal from the control unit 109, and sucks the space between the backside of the substrate 110 and the chuck 1 via a flow path such as a pipe connected to the suction unit and the suction port 6, thereby adsorbing the substrate 110 to the chuck 1. Note that the suction unit is not limited to being arranged in the substrate holding device 101, and may be arranged outside the substrate holding device 101 or outside the exposure apparatus 100.

[0056] Next, the height of the outer circumferential projections 3 included in each of the aforementioned multiple groups (hereinafter, multiple groups) is defined as ho. The height of the inner circumferential projections 4 included in each of the multiple groups is defined as hi. A desirable value of ho will be described below with reference to FIGS. 4 and 5. In this embodiment, ho is the average height of the outer circumferential projections 3 included in each of the multiple groups, and hi is the average height of the inner circumferential projections 4 included in each of the multiple groups. FIG. 4 illustrates a material mechanics model for a cantilever beam in this embodiment when the outer circumferential projections 3 are eliminated. FIG. 5 illustrates a cross-sectional view of the chuck 1 of this embodiment.

[0057] FIG. 5 shows a model 2min of the deflection of the substrate 110 when the outer peripheral convex portion 3 as shown in FIG. 4 is eliminated, and a model 2j of the deflection of the substrate 110 when ho=hi.

[0058] 5, the slope of the deflection model is dy / dx, the deflection is y, the radial position of the inner circumferential convex portion 4 as a reference is x, and the distance between the outer circumferential convex portion 3 and the inner circumferential convex portion 4 included in each of the multiple groups is L. As a result, the slope dy / dx with respect to u=x / L can be expressed by the following equation (6), and the deflection y can be expressed by the following equation (7).

number

[0059] And when u=1, y max can be expressed by the following equation (8).

number

number

[0060] The height of the partition walls 5 is set lower than that of the inner circumferential side convex portions 4 included in each of the multiple groups, but equal to or lower than that of the outer circumferential side convex portions 3 included in each of the multiple groups. If the partition walls 5 were set higher than the outer circumferential side convex portions 3 included in each of the multiple groups, the partition walls 5 would perform the same function as the outer circumferential side convex portions 3 included in each of the multiple groups. The partition walls 5 are arranged closer to the outer circumferential side convex portions 3 included in each of the multiple groups than to the inner circumferential side convex portions 4 included in each of the multiple groups. The arrangement position of the partition walls 5 is determined by comparing the average positions of the convex portions included in each of the multiple groups. The partition walls 5 are preferably arranged as close as possible to the outer circumferential side convex portions 3 included in each of the multiple groups. In this embodiment, the partition walls 5 are arranged so that u≈1.

[0061] In this embodiment, hi-ho<(PvL 4 ) / (Eh 3 By setting the height hi relative to ho so as to satisfy the above condition, distortion can be reduced. This makes it possible to provide a chuck that can adsorb and hold the substrate 110 in an optimal state when performing processes such as pattern formation.

[0062] For example, if Pv = 0.1013 MPa, L = 2 mm, and E = 160 GPa are substituted into the above formula (8), ymax = 44.3 nm when h = 0.7 mm. In this case, distortion can be reduced by designing hi-ho to be smaller than about 45 nm.

[0063] <Example 2> The substrate holding device 101 of this embodiment is a substrate holding device in which the cross-sectional area of ​​the outer circumferential convex portion 3 included in each of the plurality of groups (hereinafter, the plurality of groups) shown in embodiment 1 is smaller than the cross-sectional area of ​​the inner circumferential convex portion 4 included in each of the plurality of groups. Note that the configuration of the substrate holding device 101 is similar to that of the substrate holding device 101 of embodiment 1, and therefore, explanations of overlapping parts will be omitted.

[0064] In this embodiment, if the cross-sectional area of ​​the outer circumferential convex portions 3 included in each of the multiple groups is So and the cross-sectional area of ​​the inner circumferential convex portions 4 included in each of the multiple groups is Si, the outer circumferential convex portions 3 and the inner circumferential convex portions 4 are designed and processed so that Si > So. This reduces the processing resistance of the outer circumferential convex portions 3 during processing, making it easier to process the convex portions. Note that in this embodiment, So is the average value of the cross-sectional areas of the outer circumferential convex portions 3 included in each of the multiple groups, and Si is the average value of the cross-sectional areas of the inner circumferential convex portions 4 included in each of the multiple groups.

[0065] Furthermore, the reduction in processing resistance increases the amount of removal of the outer peripheral convex portions 3 included in each of the multiple groups, which ultimately contributes to hi>ho. Furthermore, the vertical rigidity of the outer peripheral convex portions 3 included in each of the multiple groups becomes smaller than that of the inner peripheral convex portions 4 included in each of the multiple groups. This increases the amount of vertical compression of the substrate 110 when sucked by the suction unit, which ultimately contributes to hi>ho. Note that, while lapping may be considered as an example of processing the convex portions 2, other methods may be used as long as they are capable of processing Si>So.

[0066] As described above, in this embodiment, the outer circumferential convex portions 3 included in each of the plurality of groups and the inner circumferential convex portions 4 included in each of the plurality of groups are processed so that Si>So. This improves processing accuracy and shortens processing time, and further reduces distortion as in Example 1. This makes it possible to provide a chuck that can suction and hold the substrate 110 in an optimal state when performing processes such as pattern formation.

[0067] Example 3 The substrate holding device 101 of this embodiment is a substrate holding device further provided with an auxiliary partition (second partition) 7 as a partition different from the partition 5 in the chuck 1 of Embodiment 1, and a suction port (second suction port) 8 as a suction port different from the suction port 6. That is, in Embodiment 3, the first partition is configured to be composed of two adjacent partitions, and the outer partition of the two partitions is referred to as the auxiliary partition (second partition). The substrate holding device 101 of this embodiment will be described below with reference to FIG. 6. FIG. 6 is a diagram illustrating the substrate holding device 101 of this embodiment. FIG. 6(A) is a plan view of the substrate holding device 101 as viewed from the +Z direction. FIG. 6(B) is a partial cross-sectional view of the substrate holding device 101 of FIG. 6(A). Note that the configuration of the substrate holding device 101 of this embodiment is similar to that of the substrate holding device 101 of Embodiment 1, and therefore, description of overlapping parts will be omitted.

[0068] The chuck 1 of this embodiment includes a plurality of pin-shaped protrusions 2, a partition wall 5, and a suction port 6, similar to the first embodiment, and may further include an auxiliary partition wall 7 and a suction port 8.

[0069] The auxiliary partition wall 7 is disposed between the partition wall 5 and the inner circumferential convex portion 4 disposed adjacent to the partition wall 5 on the inner circumferential side. The auxiliary partition wall 7 is preferably disposed at a position closer to the inner circumferential convex portion 4 disposed adjacent to the partition wall 5 on the inner circumferential side than the center position of the distance L. For example, the auxiliary partition wall 7 is disposed so that u<0.5 is satisfied. Note that the partition wall 5 is disposed so that u≈1, as in Example 1.

[0070] The height of the auxiliary partition wall 7 is formed to be lower than the height of the inner circumferential convex portions 4 included in each of the multiple groups. The height of the inner circumferential convex portions 4 included in each of the multiple groups is, for example, an average height. Furthermore, the height of a specific inner circumferential convex portion 4 may be lower than the height of the outer circumferential convex portion 3, which is the lowest height among the inner circumferential convex portions 4 included in each of the multiple groups. Furthermore, the height of the auxiliary partition wall 7 may be formed to be lower by approximately 1 to 2 μm from the top surfaces of the multiple convex portions 2. Even if the height of the auxiliary partition wall 7 is formed to be lower by approximately 1 to 2 μm, with a gap of approximately 1 to 2 μm, the decrease in vacuum pressure when the suction unit sucks the space (area) between the back surface of the substrate 110 and the chuck 1 to suction and hold the substrate 110 is slight and does not pose a problem. Furthermore, even if foreign matter such as dust or particles with a diameter smaller than the difference of approximately 1 to 2 μm adheres to the auxiliary partition wall 7, the probability that the adhered foreign matter will come into contact with the back surface of the substrate 110 is very low. Therefore, forming the height of the auxiliary partition wall 7 to be lower by approximately 1 to 2 μm from the top surfaces of the multiple convex portions 2 does not pose a problem.

[0071] The suction port 8 has the same function as the suction port 6 of Example 1, and is formed between the partition wall 5 and the auxiliary partition wall 7. The suction port 8 is connected to the suction unit by a flow path such as a pipe, similar to the suction port 6 of Example 1. Furthermore, the suction unit in the substrate holding device 101 of this example may be provided with valves (switching valves) (not shown) that open and close the flow paths for suction, in the flow paths connecting the suction port 6 and the suction port 8 to the suction unit, respectively. In this example, the valve arranged between the suction port 6 and the suction unit is referred to as a first valve, and the valve arranged between the suction port 8 and the suction unit is referred to as a second valve.

[0072] In this embodiment, when the substrate 110 is held by suction on the chuck 1, it is sucked through the suction ports 6 and 8. The suction process of the substrate 110 in this embodiment will be described below. The suction process is controlled by a control unit (not shown) of the substrate holding device 101 executing a computer program.

[0073] First, a control unit (not shown) sends an operation command to the suction unit to start suction (exhaust). When the suction unit starts suction, the space between the back surface of the substrate 110 and the chuck 1 is sucked through suction ports 6 and 8. As a result, the area inside the partition wall 5 on the substrate 110 becomes the suction area, generating a larger suction force and making it possible to correct the warpage even in a substrate with a large warpage. Note that distortion occurs when the warpage of the substrate 110 is corrected and suction is completed.

[0074] Next, the control unit (not shown) controls the second valve to stop suction of the region through suction port 8. As a result, the space between partition wall 5 and auxiliary partition wall 7 is opened to the atmosphere from suction port 8, and the suctioned region transitions to a region inside auxiliary partition wall 7, which is the region through suction port 6, on substrate 110, thereby reducing distortion. Note that various controls in these suction processes may be performed by control unit 109.

[0075] Once the substrate 110 has been corrected, there is a low probability that it will return to its original state even if the suction force on the outer periphery (outer periphery) of the substrate 110 is stopped or reduced, so distortion is kept small.

[0076] As described above, in this embodiment, in addition to reducing distortion, it is possible to reduce warpage of the substrate 110, similar to the first embodiment. As a result, it is possible to provide a chuck that can suction and hold the substrate 110 in an optimal state when performing processes such as pattern formation.

[0077] Furthermore, in some substrates 110 with large warpage, the warpage may return to normal when the suction port 8 is opened to the atmosphere. In this case, a negative pressure of approximately α × minus 1 atmosphere (α is an integer smaller than 1) may be applied by the suction unit via the suction port 8 depending on the state of the warpage of the substrate 110. Alternatively, before the suction unit sucks the space between the back surface of the substrate 110 and the chuck 1, the pressure from the suction port 8 may be set to a negative pressure of approximately minus 1 atmosphere, and the pressure from the suction port 8 may be set to a negative pressure of α × minus 1 atmosphere (α is an integer smaller than 1). This eliminates the need to switch between before and after the correction of the substrate 110, and prevents the warpage from returning to normal.

[0078] Furthermore, for example, the present embodiment may be combined with the substrate holding device 101 of the second embodiment, or the second embodiment may be combined with the substrate holding device 101 of the third embodiment.

[0079] In the above-described embodiments, the protrusions 2 are arranged in a grid pattern at predetermined intervals on the bottom of the chuck 1, but this is not limiting. For example, the distance between the protrusions 2 may be set arbitrarily on both the inner and outer circumferential sides of the substrate 110. Furthermore, the distance between the protrusions 2 does not need to be uniform, and may be non-uniform.

[0080] Furthermore, although the chuck 1 in each of the above embodiments is of a vacuum chucking type, it is not limited to this and may be of an electrostatic chuck type, or may be a chuck that combines a vacuum chucking type with an electrostatic chuck type, etc. In such cases, the vacuum pressure P in the present embodiment may be replaced by the chucking force of the other type or by the vacuum pressure added thereto.

[0081] Furthermore, although a pin chuck is used as the chuck 1 in each of the above-described embodiments, the chuck 1 is not limited to this, and other shapes may be used. For example, a so-called ring-shaped chuck may be used, in which concentric annular recesses serving as suction grooves and concentric annular protrusions serving as substrate support surfaces are alternately arranged. Furthermore, the partitions are not limited to the partitions 5 and auxiliary partitions 7, and partitions other than the partitions 5 and auxiliary partitions 7 may be arranged on the chuck 1.

[0082] <Example of article manufacturing method> Next, an embodiment of a device manufacturing method using exposure apparatus 100 of each of the above-mentioned embodiments will be described. Figure 7 shows the manufacturing flow of a microdevice (semiconductor chips such as ICs and LSIs, liquid crystal panels, CCDs, thin-film magnetic heads, micromachines, etc.). In step 1 (circuit design), the device pattern is designed.

[0083] In step 2 (mask production), a mask (mold, model) is produced on which the designed pattern is formed. Meanwhile, in step 3 (wafer production), a wafer (substrate) is manufactured using materials such as silicon or glass. Step 4 (wafer processing), known as the front-end process, uses the prepared mask and wafer to form the actual circuit on the wafer using lithography technology.

[0084] The next step, assembly, is called the post-process and involves turning the wafers produced in step 4 into semiconductor chips, including assembly processes (dicing, bonding) and packaging (chip encapsulation). Step 6 (inspection) involves testing the semiconductor devices produced in step 5 to confirm their operation and durability. After these processes, the semiconductor devices are completed and then shipped (step 7).

[0085] Figure 8 shows a detailed flow of the above wafer process. In step 11 (oxidation), the wafer surface is oxidized. In step 12 (CVD), an insulating film is formed on the wafer surface. In step 13 (electrode formation), electrodes are formed on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted into the wafer. In step 15 (resist processing), resist is applied to the wafer. In step 16 (exposure), the circuit pattern of the mask is aligned and printed onto multiple pattern formation areas on the wafer using the projection exposure system described above. In step 17 (development), the exposed wafer is developed. In step 18 (etching), the parts other than the developed resist image are removed. In step 19 (resist removal), the resist that is no longer needed after etching is completed is removed. By repeating these steps, multiple circuit patterns are formed on the wafer.

[0086] As described above, according to the device manufacturing method using the chuck 1 of this embodiment, distortion and warpage of the substrate are suppressed, and therefore the precision and yield of the device are improved, and highly integrated devices that have been difficult to manufacture in the past can be manufactured stably and at low cost.

[0087] <Other Examples> The present invention has been described in detail above based on its preferred embodiments, but the present invention is not limited to the above embodiments, and various modifications are possible based on the gist of the present invention, and these modifications are not excluded from the scope of the present invention.

[0088] Furthermore, a computer program that realizes part or all of the functions of the above-described embodiments of the control may be supplied to the substrate holding device 101, the substrate processing apparatus, etc. via a network or various storage media. Then, a computer (or a CPU, MPU, etc.) in the substrate holding device 101, the substrate processing apparatus, etc. may read and execute the program. In this case, the program and the storage medium storing the program constitute the present invention. [Explanation of symbols]

[0089] 101 Substrate holding device 1 chuck 2 Convex part 3 Convex part (outer peripheral convex part) 4 Convex part (inner circumference convex part) 5 Bulkhead 6 Suction port

Claims

1. A chuck for suction-holding a substrate, a plurality of protrusions that come into contact with the rear surface of the substrate that is held by suction; an annular partition; a bottom portion on which the plurality of protrusions and the partition wall are disposed, the plurality of convex portions are constituted by a plurality of groups, each group including a first convex portion disposed outside the partition wall and a second convex portion disposed inside the partition wall and adjacent to the first convex portion with the partition wall interposed therebetween; When the height of the first convex portion included in each of the plurality of groups is ho and the height of the second convex portion included in each of the plurality of groups is hi, hi>ho Fulfilling a height of the partition wall is equal to or less than a height of the first convex portion included in each of the plurality of groups; A chuck characterized by:

2. 2. The chuck according to claim 1, wherein the first convex portion included in each of the plurality of groups is the convex portion arranged on the outermost side of the plurality of convex portions arranged on the bottom portion.

3. 3. The chuck according to claim 1, wherein the height of the partition wall is lower than the height of the first convex portions included in each of the plurality of groups.

4. When the cross-sectional area of ​​the first convex portions included in each of the plurality of groups is So and the cross-sectional area of ​​the second convex portions included in each of the plurality of groups is Si, Si>So 4. The chuck according to claim 1, wherein the following is satisfied:

5. 5. The chuck according to claim 1, wherein the partition wall is positioned closer to the first convex portions included in each of the plurality of groups than to the second convex portions included in each of the plurality of groups.

6. 6. The chuck according to claim 1, wherein the partition wall is composed of two adjacent partition walls.

7. 7. The chuck according to claim 6, wherein the outer partition of the double partition has a height lower than the second protrusions included in each of the plurality of groups.

8. 6. The chuck according to claim 1, further comprising a first suction port in the bottom portion for sucking the inner periphery of the partition wall.

9. 8. The chuck according to claim 6, further comprising a second suction port at the bottom for sucking the area between the double partition walls.

10. 10. The chuck according to claim 1, wherein the partition has a diameter smaller than that of the substrate.

11. 11. The chuck according to claim 1, further comprising a third protrusion that is different from the plurality of protrusions.

12. A chuck for suction-holding a substrate, a plurality of protrusions that come into contact with the rear surface of the substrate that is held by suction; an annular partition; a bottom portion on which the plurality of protrusions and the partition wall are disposed, the plurality of convex portions are constituted by a plurality of groups, each group including a first convex portion disposed outside the partition wall and a second convex portion disposed inside the partition wall and adjacent to the first convex portion with the partition wall interposed therebetween; When the height of the first convex portion included in each of the plurality of groups is ho and the height of the second convex portion included in each of the plurality of groups is hi, hi>ho Fulfilling When the cross-sectional area of ​​the first convex portions included in each of the plurality of groups is So and the cross-sectional area of ​​the second convex portions included in each of the plurality of groups is Si, Si>So fulfill, A chuck characterized by:

13. A chuck for suction-holding a substrate, a plurality of protrusions that come into contact with the rear surface of the substrate that is held by suction; an annular partition; a bottom portion on which the plurality of protrusions and the partition wall are disposed, the plurality of convex portions are constituted by a plurality of groups, each group including a first convex portion disposed outside the partition wall and a second convex portion disposed inside the partition wall and adjacent to the first convex portion with the partition wall interposed therebetween; When the height of the first convex portion included in each of the plurality of groups is ho and the height of the second convex portion included in each of the plurality of groups is hi, hi>ho Fulfilling The partition wall includes two adjacent partition walls, an outer partition wall of the double partition wall has a height lower than that of the second protrusions included in each of the plurality of groups; A chuck characterized by:

14. A substrate holding device comprising the chuck according to claim 1 , wherein the substrate is held by suction by using the chuck to suck an inner peripheral region of the partition wall.

15. 15. The substrate holding device according to claim 14, further comprising: a valve that opens and closes a flow path for suctioning the inner peripheral region of the partition; and a control unit that controls the valve.

16. When the height of the first convex portion included in each of the plurality of groups is ho, the height of the second convex portion included in each of the plurality of groups is hi, the Young's modulus of the substrate is E, the thickness of the substrate is h, the suction pressure on the substrate is Pv, and the distance between the first convex portion and the second convex portion included in each of the plurality of groups is L, 1944 ４ DR ３ 16. The substrate holding device according to claim 14, wherein the following is satisfied:

17. 17. A substrate processing apparatus comprising: a pattern forming unit that forms a pattern on the substrate held by suction by the substrate holding device according to claim 14.

18. a pattern forming step of forming a pattern on the substrate by processing the substrate using the substrate processing apparatus according to claim 17; a processing step of processing the substrate after the pattern is formed in the pattern forming step; manufacturing an article from the substrate processed in the processing step; A method for manufacturing an article, comprising:

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