Lens processing apparatus

Abstract

Provided is a wafer processing apparatus that forms a structure that enables high-precision processing by reducing changes in axial force by suppressing thermal expansion of fixing screws that fix a chuck and a chuck base. The wafer processing apparatus includes a constant-temperature cooling water source (23) that supplies constant-temperature cooling water to a chuck table (12) to maintain a chuck (15) at approximately constant temperature, and a ring-shaped cover (27) that is disposed so as to cover at least the entire outer peripheral side surface of the chuck (15), stores constant-temperature cooling water that is discharged from the outer peripheral side surface of the chuck table (12) between the ring-shaped cover (27) and the outer peripheral side surface of the chuck table (12), and supplies the constant-temperature cooling water to the fixing screw (17) side.

Description

Technical Field

[0001] This invention relates to a wafer processing apparatus, and more particularly to a wafer processing apparatus that can perform high-precision grinding and lapping of a wafer held in a circular plate shape by a rotating chuck stage. Background Technology

[0002] In the past, as a processing apparatus for grinding the surface of a semiconductor wafer (hereinafter referred to as "wafer") flat, there is a known apparatus that includes a chuck stage for attracting and holding the wafer in the shape of a disc, and a rotating processing wheel having a grinding wheel for grinding the wafer, wherein the surface of the wafer is ground by the grinding wheel.

[0003] In such grinding apparatuses, during grinding, the processing heat stored in the grinding wheel or the like is transferred to the chuck stage via the wafer. As a result, the thermal expansion of the chuck stage hinders the processing of the wafer, which is being machined with precision in the micrometer unit.

[0004] Therefore, chuck stages with cooling functions have been proposed in the past. These chuck stages have a disc-shaped chuck (attraction plate) for holding wafers and a cooling mechanism located on the back side of the chuck. Furthermore, techniques have been proposed to reduce the thermal expansion of the chuck by allowing temperature-adjusted water to flow through a flow path inside the chuck (see, for example, Patent Documents 1 and 2).

[0005] In addition, the following technology is proposed: a flow path is set on the chuck base that rotates integrally with the chuck, so that the temperature-regulated water flows through the flow path on the chuck base, thereby reducing the thermal expansion of the chuck (see Patent Document 3).

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: JP 2014-237200

[0009] Patent Document 2: JP 2018-27588

[0010] Patent Document 3: JP 2017-69429 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] However, while the technologies described in Patent Documents 1, 2, and 3 can reduce the thermal expansion of the chuck, the fastening components, such as the fixing screws that secure the chuck to the chuck base, are typically made of different materials. Therefore, heat is transferred from the chuck and chuck base to the fixing screw, and it takes time for the fixing screw to reach approximately the same temperature as the chuck and chuck base, during which time the fixing screw undergoes thermal expansion. This thermal expansion of the fixing screw causes a change in the axial force securing the chuck, resulting in a change in the shape of the chuck. Therefore, there is a problem of poor accuracy that can easily occur during the machining process from the first to the Nth machining operation.

[0013] Therefore, in order to provide a wafer processing apparatus, a technical problem has arisen that needs to be solved. The object of the present invention is to solve this problem by providing a wafer processing apparatus configured to perform high-precision processing by reducing axial force variation by suppressing the thermal expansion of the fixing screws that fix the chuck and the chuck base.

[0014] Technical solutions for solving the problem

[0015] The present invention is proposed to achieve the above-mentioned objectives. The invention described in technical solution 1 provides a wafer processing apparatus, which includes a chuck stage. The chuck stage is fixed between the chuck and the chuck base using a plurality of fixing screws. The chuck attracts and holds the wafer. The chuck base rotates integrally with the chuck. The wafer processing apparatus includes a constant temperature cooling water supply mechanism and an annular cover. The constant temperature cooling water supply mechanism supplies constant temperature cooling water to the chuck stage to keep the chuck at a substantially constant temperature. The annular cover is arranged in such a way that it at least covers the substantially entire outer peripheral side surface of the chuck. The constant temperature cooling water discharged from the outer peripheral side surface of the chuck stage is stored between the annular cover and the outer peripheral side surface of the chuck stage and supplied to the fixing screw side.

[0016] According to this structure, the chuck and chuck base are kept at a constant temperature by allowing constant-temperature cooling water to flow from the constant-temperature cooling water supply mechanism to the chuck table. Simultaneously, the constant-temperature cooling water supplied to the chuck table is discharged from the outer peripheral side of the chuck table, and this discharged constant-temperature cooling water is received by a gap formed between an annular cover and the chuck table. This annular cover is configured to cover approximately the entire outer peripheral side of the chuck table. Furthermore, when a predetermined amount of constant-temperature cooling water is stored in the gap and actively supplied to the fixing screw side, the time until the fixing screw reaches the same temperature as the chuck and chuck table can be shortened. Therefore, the thermal expansion change of the fixing screw during machining can be minimized. Thus, changes in the axial force of the fixing chuck can be suppressed, eliminating machining accuracy differences between the first and Nth machining operations on the wafer, enabling high-precision machining of the wafer.

[0017] The invention described in technical solution 2 provides a wafer processing apparatus, which relates to the structure described in technical solution 1, wherein the cover extends to approximately the same height as the head of the fixing screw, and is capable of storing the constant temperature cooling water to the position where the head of the fixing screw is immersed in the constant temperature cooling water.

[0018] With this structure, the cover extends to the height of the fixing screw, so the constant-temperature cooling water received in the gap between the annular cover and the chuck stage is stored at the position where the head of the fixing screw is immersed. Therefore, the constant-temperature cooling water received in the gap between the annular cover and the chuck stage passes through the head of the fixing screw and comes into direct contact with the fixing screw, allowing for active temperature regulation of the fixing screw.

[0019] The invention described in technical solution 3 provides a wafer processing apparatus, which relates to the structure described in technical solution 1 or 2, wherein the chuck has a slit that cuts from the outer peripheral side of the chuck to the inner peripheral side of the mounting hole where the fixing screw is installed.

[0020] According to this structure, the constant-temperature cooling water received in the gap between the annular cover and the chuck stage directly contacts the outer peripheral side of the fixing screw while passing through a slit, and is stored at the top of the fixing screw. Therefore, the constant-temperature cooling water received in the gap between the annular cover and the chuck stage directly contacts the fixing screw from the outer peripheral side through the slit and threaded into the threaded hole to the head, enabling active temperature regulation of the fixing screw.

[0021] The effects of the invention

[0022] According to the present invention, constant-temperature cooling water flows from the constant-temperature cooling water supply mechanism to the chuck table, maintaining the chuck at a constant temperature. Simultaneously, the constant-temperature cooling water supplied to the chuck table is discharged from the outer peripheral side of the chuck table. This discharged constant-temperature cooling water is caught in the gap between the chuck table and an annular cover that is provided in a manner that covers the entire outer peripheral side of the chuck table. The constant-temperature cooling water caught in this gap is then supplied to the fixing screw side, and active adjustments are made to ensure that the temperature of the fixing screw is approximately the same as that of the constant-temperature cooling water. Therefore, the time required for the fixing screw to reach the same temperature as the chuck and chuck table can be shortened. Furthermore, the thermal expansion changes of the fixing screw during machining can be minimized. As a result, changes in the axial force of the fixing chuck can be suppressed, and the shape of the chuck can be maintained approximately constant. Therefore, the accuracy difference between the machining of the first wafer and the machining of the Nth wafer can be eliminated, enabling high-precision machining of wafers. Attached Figure Description

[0023] Figure 1This diagram illustrates the main structural components of the rotating mechanism section of the wafer processing apparatus according to an embodiment of the present invention. Figure 1 (A) is a perspective view of the rotating mechanism. Figure 1 (B) is along Figure 1 A cross-sectional view along line A-A in (A);

[0024] Figure 2 A diagram illustrating the structure of the temperature control path formed in the chuck base of the aforementioned rotating mechanism.

[0025] Figure 3 for Figure 1 A partial enlarged view of the rotating mechanism shown. Figure 3 (A) is its 3D diagram. Figure 3 (B) is along Figure 3 A cross-sectional view along line B-B in (A);

[0026] Figure 4 To indicate Figure 3 A partially enlarged view of a modified example of the aforementioned rotating mechanism. Figure 4 (A) is its 3D diagram. Figure 4 (B) is along Figure 4 A cross-sectional view along line C-C in (A). Detailed Implementation

[0027] The present invention aims to provide a wafer machining apparatus with the following structure, which enables high-precision machining by reducing axial force variation by suppressing thermal expansion of the fixing screws that fix the chuck and chuck base. The wafer machining apparatus includes a chuck stage, which fixes the chuck and chuck base together with a plurality of fixing screws. The chuck attracts and holds the wafer. The chuck base rotates integrally with the chuck. The wafer machining apparatus has an annular cover, which is provided in such a way that it at least covers the substantially entire outer peripheral side surface of the chuck, so that the constant-temperature cooling water discharged from the outer peripheral side surface of the chuck stage is stored between the annular cover and the outer peripheral side surface of the chuck and supplied to the fixing screw side.

[0028] Example

[0029] Hereinafter, an embodiment of the present invention will be described in detail based on the accompanying drawings. Furthermore, in the following embodiments, when referring to the number, value, quantity, range, etc., of the constituent elements, they are not limited to that specific quantity, except where specifically stated or where they are clearly limited in principle to a particular quantity; they may be more than or less than that specific quantity.

[0030] Furthermore, when referring to the shape or positional relationship of constituent elements, unless specifically stated otherwise or considered to be obviously different in principle, it substantially includes cases where their shape is similar or analogous.

[0031] Furthermore, the accompanying drawings may exaggerate characteristic features by enlarging them for easier understanding, and the size ratios of the constituent elements may not be the same as actual dimensions. Additionally, in sectional views, some section lines of the constituent elements are sometimes omitted to facilitate understanding of their cross-sectional structure.

[0032] Furthermore, in the following description, the expressions indicating directions such as up / down and left / right are not absolute. They are appropriate when depicting the postures of the various parts of the wafer processing apparatus of the present invention, but should be interpreted differently if the postures change. Additionally, throughout the description of the embodiments, the same reference numerals are used to denote the same elements.

[0033] Hereinafter, we will take the application of the wafer processing apparatus according to the embodiments of the present invention to a grinding apparatus for processing the surface of a wafer into a flat surface as an example, referring to... Figures 1-3 The preferred embodiments will be described in detail.

[0034] Figure 1 This diagram is intended to roughly illustrate the main structural components of the rotating mechanism 10 in the wafer processing apparatus of the present invention. Figure 1 (A) is a perspective view of the rotating mechanism 10. Figure 1 (B) is along Figure 1 A cross-sectional view along line A-A in (A). The wafer processing apparatus has a rotating mechanism 10 mounted on the apparatus body 11. Furthermore, the entire wafer processing apparatus is controlled by a program within the control device 50 in a predetermined sequence.

[0035] The rotating mechanism 10 has a chuck table 12 that holds and rotates a wafer (not shown) horizontally. The chuck table 12 holds the wafer and is positioned below the grinding section (not shown), so that the wafer comes into contact with the rotating grinding wheel of the grinding section to perform grinding on the surface of the wafer.

[0036] The chuck table 12 includes a circular chuck base 14, a circular chuck 15, and a temperature control unit 16. The chuck base 14 is rotatably mounted via a rotary joint 13. The chuck 15 is rotatably mounted on the chuck base 14. The temperature control unit 16 is located between the chuck 15 and the chuck base 14 and is disposed on the chuck base 14. The chuck 15 and the chuck base 14 are fixed together by fixing screws 17, which serve as fastening components.

[0037] The chuck 15 includes an attraction plate 18 formed in the shape of a circular plate and a chuck side support 19. The chuck side support 19 surrounds the outer peripheral side and the bottom surface of the attraction plate 18 and is integrated with the attraction plate 18. The attraction plate 18 is composed of a porous material holding member, the upper surface of which forms an adsorption surface 18A for attracting and holding the circular crystal. Moreover, in this embodiment, the chuck side support 19 of the chuck 15 is formed of alumina, and the chuck base 14 and the fixing screw 17 are both formed of stainless steel (SUS).

[0038] On the chuck-side bracket 19, a plurality of mounting holes 20 (eight in this embodiment) are provided at approximately equal intervals along the circumferential direction on the outer periphery of the suction plate 18, extending vertically. On the chuck base 14 side, a number of threaded holes 33 are formed corresponding to the mounting holes 20 of the chuck-side bracket 19. The chuck-side bracket 19 is then overlapped on the chuck base 14 with the mounting holes 20 aligned with the threaded holes 33. When fixing screws 17 are threaded into the threaded holes 33 through the mounting holes 20 from the upper side of the chuck-side bracket 19, the chuck 15 and the chuck base 14 are concentrically and integrally fixed with respect to the center O of the chuck platform 12. Furthermore, a countersinking hole 20A is provided above the mounting hole 20. A portion of the countersinking hole 20A opens on the outer peripheral surface of the chuck-side bracket 19, exposing the side of the fixing screw 17 to the outer peripheral surface of the chuck-side bracket 19.

[0039] The temperature control unit 16 is disposed on the upper part of the chuck base 14 opposite to the chuck 15. The temperature control unit 16 is formed as a groove with a U-shaped cross-section, and the water passage 21 above the groove is covered and blocked by the lower part (interface) of the chuck 15.

[0040] like Figure 3 As shown, the waterway 21 is composed of multiple concentric ring-shaped waterway sections 21A, 21B, 21C, and 21D (in this embodiment, these four are 21A, 21B, 21C, and 21D) and a connecting waterway section 21E that sequentially connects these ring-shaped waterway sections 21A, 21B, 21C, and 21D to each other.

[0041] Furthermore, a through hole serving as a water supply port 21F is provided in the annular water passage section 21A located at the center of the chuck base 14, and a drain port 21G is provided in the annular water passage section 21D located at the outermost periphery of the chuck base 14. The water supply port 21F is connected to the thermostatic cooler water source 23 via a water supply pipe 22 disposed within the rotary joint 13. On the other hand, the drain port 21G is open at the outer periphery of the chuck base 14. A chuck pipe 24 is provided at the center of the chuck base 14. One end of this chuck pipe 24 is connected to the lower end of the suction plate 18.

[0042] The constant temperature cooling water source 23 supplies constant temperature cooling water to the water circuit 21 at a temperature of approximately 30°C, which can adjust the overall temperature of the chuck 15 to approximately 30°C. On the other hand, the vacuum source 25 applies an attractive force by drawing a vacuum on the suction plate 18 through the chuck piping 24, which can adsorb the wafer W and hold it on the adsorption surface 18A of the suction plate 18.

[0043] Additionally, a ring-shaped base side bracket 26 is installed on the outer peripheral surface of the chuck base 14. The top of the base side bracket 26 is slightly lower than the top of the chuck base 14, and is positioned at a height that does not block the front of the drain outlet 21G of the water passage 21. On the other hand, a labyrinth groove 26A is formed all around the bottom of the base side bracket 26, cutting inward from the bottom to the top. A portion of a labyrinth cover 30 is disposed in the labyrinth groove 26A, which seals the treated water that is about to enter the device body 11 and protects the power unit 29, which includes the motor 29A, power transmission belt 29B, pulley 29C, pulley 29D, and rotary joint 13.

[0044] Furthermore, a generally annular cover 27 covering the outer peripheral side of the chuck 15 is provided on the chuck-side support 19. The cover 27 is formed of the same alumina as the chuck-side support 19, and the inner diameter of the main body 27A is larger than the outer diameter of the chuck 15. Moreover, a gap is formed between the chuck-side support 19 and the chuck 15, and a constant temperature cooling water storage chamber 28 is formed in this gap to store the constant temperature cooling water discharged from the drain port 21G. In addition, a fixed flange portion 27B bent outward is provided on the lower end side of the main body 27A, and a gap adjustment flange portion 27C bent inward toward the outer peripheral side of the chuck 15 is provided on the upper end side. In addition, a drain port 27D is provided on the fixed flange portion 27B, which extends from the outer periphery of the fixed flange portion 27B to the inner periphery. The drain port 27D is formed as a groove with a recessed cross-section that is generally U-shaped.

[0045] Regarding the cover 27, the fixing flange 27B is made to make approximately tight contact with the base side bracket 26, and is fixed to the base side bracket 26 by fixing screws 32. Additionally, as... Figure 3As shown in (B), the height H of the cover 27 when it is fixed to the base side bracket 26 is approximately equal to the height of the head 17A of the fixing screw 17 that mounts the chuck 15 to the chuck base 14. That is, the cover 27 extends to approximately the same height as the head 17A of the fixing screw 17. Furthermore, a gap δ1 is provided throughout the entire circumference between the inner circumferential surface of the main body 27A and the outer circumferential surface of the chuck base 14 in a manner that does not block the drain outlet 21G of the water passage 21. In addition, a predetermined gap δ2 is also provided between the inner circumferential surface of the gap adjustment flange 27C of the cover 27 and the outer circumferential surface of the chuck 15. The gap δ2 between the inner peripheral surface of the gap adjusting flange 27C and the outer peripheral surface of the chuck 15 has the function of allowing the constant temperature cooling water stored in the constant temperature cooling water storage chamber 28 to easily flow into the side of the head 17A of the fixing screw 17 when it rises, and also allows the constant temperature cooling water that overflows from the constant temperature cooling water storage chamber 28 but is not completely discharged from the outlet 27D to escape to the outside of the cover 27 through the gap δ2.

[0046] The power unit 29 transmits the rotation of the motor 29A, which is rotated under the control of the control device 50, to the chuck table 12 via the power transmission belt 29B mounted between the pulley 29D provided on the output shaft of the motor 29A and the pulley 29C provided on the rotating part of the rotary joint 13, and causes the chuck table 12 to rotate at a constant speed according to a specified speed.

[0047] Next, the operation of the machining apparatus configured in this manner will be explained. First, before grinding, constant-temperature cooling water at approximately 30°C flows from the constant-temperature cooling water source 23 through the water supply pipe 22 toward the constant-temperature control unit 16. This constant-temperature cooling water enters the water passage 21 from the water supply port 21F and then flows out from the drain port 21G into the constant-temperature cooling water storage chamber 28. The discharge rate of this constant-temperature cooling water is adjusted by the control device 50 to be slightly more than the amount discharged from the drain port 27D of the cover 27. Furthermore, the chuck base 14 and the chuck 15 of the chuck table 12 are adjusted to a temperature close to approximately 30°C, the same as the constant-temperature cooling water.

[0048] Furthermore, the constant-temperature cooling water discharged from the drain outlet 21G is stored in the constant-temperature cooling water storage chamber 28, and rises within the chamber over time. The height of the cover 27 extends to approximately the same height as the head 17A of the fixing screw 17, so the constant-temperature cooling water discharged into the storage chamber 28 rises to approximately the top of the head 17A of the fixing screw 17. Furthermore, as the constant-temperature water rises to the side of the head 17A of the fixing screw 17, the side of the head 17A of the fixing screw 17 gradually becomes immersed in the constant-temperature water. Thus, utilizing the heat of the constant-temperature cooling water, the fixing screw 17 is also adjusted to a temperature approximately the same as the constant-temperature cooling water. That is, the entire chuck table 12 is adjusted to a temperature approximately the same as the temperature of the constant-temperature cooling water (30°C).

[0049] Furthermore, when the entire chuck stage 12, including the chuck base 14, chuck 15, and fixing screws 17, is adjusted to a temperature approximately equal to that of the constant-temperature cooling water, the wafer W is placed on the adsorption surface 18A of the suction plate 18 in the chuck 15. Then, under the control of the control device 50, when the vacuum source 25 applies negative pressure to the adsorption surface 18A, the wafer W is adsorbed and held on the adsorption surface 18A. Then, under the control of the control device 50, the motor 29A is driven to rotate, and the driving force of the motor 29A causes the chuck stage 12 to rotate. In addition, the grinding unit (not shown in the figure) is simultaneously driven to perform grinding on the surface of the wafer.

[0050] Furthermore, during the grinding process, approximately 30°C constant-temperature cooling water flows from the constant-temperature cooling water source 23 towards the constant-temperature control unit 16 through the water supply pipe 22 in the chuck base 14, maintaining the chuck base 14 and chuck 15 at a constant temperature. The constant-temperature cooling water discharged from the drain port 21G and stored in the constant-temperature cooling water storage chamber 28 impregnates the side of the head 17A of the fixing screw 17, using the heat of this constant-temperature cooling water to adjust the fixing screw 17 to approximately the same temperature as the constant-temperature cooling water. Thus, during the grinding process, the entire chuck table 12, namely the chuck base 14, chuck 15, and fixing screw 17, is maintained at approximately the same temperature as the constant-temperature cooling water.

[0051] Therefore, in the machining apparatus of this embodiment, constant-temperature cooling water flows from the constant-temperature cooling water source 23, which serves as a constant-temperature cooling water supply mechanism, to the chuck table 12, thereby maintaining the chuck 15 and the suction plate 18 at approximately a constant temperature. Furthermore, the constant-temperature cooling water supplied to the chuck table 12 is discharged from its outer peripheral side. The discharged constant-temperature cooling water is received by the gap between the annular cover 27, which covers the entire outer peripheral side of the chuck table 12, and the constant-temperature cooling water storage chamber 28. The temperature of the fixing screw 17 is actively adjusted using the constant-temperature cooling water stored in the storage chamber 28. This shortens the time it takes for the fixing screw 17 to reach the same temperature as the chuck 15 and the chuck table 12, and minimizes thermal expansion changes of the fixing screw 17 during machining. Consequently, changes in the axial force of the fixing chuck 15 can be suppressed, and the shape of the chuck 15 can be maintained at approximately a constant value. This eliminates the machining accuracy difference between the first and Nth machining operations on the wafer, enabling high-precision machining of the wafer. Furthermore, the remaining constant-temperature cooling water in the gap between the annular cover 27 and the chuck table 12 can be discharged outside the chuck table 12 through the outlet 27D provided in the cover 27 and the gap δ1 provided between the cover 27 and the chuck 15.

[0052] Figure 4 To indicate Figure 3A partially enlarged view of a modified example of the rotating mechanism 10 shown. Figure 4 (A) is its 3D diagram. Figure 4 (B) is along Figure 4 A cross-sectional view along line C-C in (A). Furthermore, in Figure 4 In the modified example shown, a slit 31 is provided in the chuck 15. This slit 31 is cut out at the location of the mounting hole 20 on the chuck 15 side, through which the fixing screws 17 for fixing the chuck 15 and the chuck base 14 pass, so that it connects from the outer peripheral side of the chuck 15 to the inner peripheral side of the mounting hole 20, and opens within the mounting hole 20. Furthermore, Figure 4 Other structures and Figures 1 to 3 The structures are the same, therefore, for... Figures 1 to 3 The same structural components are marked with the same reference numerals and their descriptions are omitted; only the parts with different constructions are described. It should be noted that the opening width of the slit 31 is smaller than the thread diameter of the fixing screw 17, assuming that the fixing screw 17 will not come out of the slit 31.

[0053] exist Figure 4 In the structure of the rotating mechanism 10 shown, constant-temperature cooling water is supplied from the constant-temperature cooling water source 23 to the constant-temperature control unit 16 to adjust the temperature of the chuck 15 and the chuck base 14. Then, constant-temperature cooling water, discharged from the drain port 21G of the chuck base 14 and stored in the constant-temperature cooling water storage chamber 28, enters the mounting hole 20 through the slit 31, further immersing the outer peripheral surface of the fixing screw 17. As a result, the fixing screw 17 is also thermally adjusted to approximately the same temperature as the constant-temperature cooling water. In this case, the area of ​​the fixing screw 17 immersed in the constant-temperature cooling water is greater than... Figure 3 The configuration shown is more complex, thus shortening the time until the temperature of the fixing screw 17 is approximately equal to that of the constant-temperature cooling water. Therefore, it further accelerates the process of bringing the chuck base 14, chuck 15, and fixing screw 17 of the chuck stage 12 to approximately 30°C, the same temperature as the constant-temperature cooling water.

[0054] It should be noted that various modifications can be made to this invention as long as they do not depart from its spirit, and this invention naturally includes such modified solutions.

[0055] Explanation of the labels:

[0056] The designation 10 indicates the rotating mechanism section;

[0057] The designation 11 indicates the main body of the device;

[0058] The number 12 indicates the chuck stage;

[0059] The number 14 indicates the chuck base;

[0060] The number 15 indicates the chuck;

[0061] The designation 16 indicates the temperature control unit;

[0062] The number 17 indicates a fixing screw;

[0063] The designation 17A indicates the head;

[0064] The designation 18 indicates an attraction plate;

[0065] The designation 18A indicates the adsorption surface;

[0066] The number 20 indicates a mounting hole;

[0067] The designation 20A indicates a countersunk hole;

[0068] Number 21 indicates waterway;

[0069] The designation 21F indicates the water supply outlet;

[0070] The designation 21G indicates a drain outlet;

[0071] The designation 22 indicates water supply piping;

[0072] The designation 23 indicates a constant temperature cooling water source (constant temperature cooling water supply mechanism);

[0073] The designation 24 indicates piping for the chuck;

[0074] The designation 25 indicates a vacuum source;

[0075] The designation 26 indicates the base-side support;

[0076] The designation 26A indicates a groove;

[0077] The designation 27 indicates a cover;

[0078] The designation 27D indicates the discharge outlet;

[0079] The designation 28 indicates a constant temperature cooling water storage chamber;

[0080] The designation 31 indicates a slit;

[0081] The designation 33 indicates a threaded hole;

[0082] The designation 50 indicates a control device;

[0083] The symbol W represents a wafer;

[0084] The symbols δ1 and δ2 represent gaps.

Claims

1. A wafer processing apparatus, comprising a chuck stage, wherein the chuck stage is used to fix a chuck and a chuck base together using a plurality of fixing screws, wherein, The chuck attracts and holds the wafer, and the chuck base rotates integrally with the chuck. The wafer processing apparatus is characterized by comprising: A constant-temperature cooling water supply mechanism that supplies constant-temperature cooling water to the chuck table to maintain the chuck at a substantially constant temperature; and An annular cover, configured to at least cover substantially the entire outer peripheral side of the chuck, stores the constant-temperature cooling water discharged from the outer peripheral side of the chuck table between the cover and the outer peripheral side of the chuck table, and supplies it to the fixing screw side. The chuck has a slit that extends from the outer peripheral side of the chuck to the inner peripheral side of the mounting hole where the fixing screw is installed.

2. The wafer processing apparatus according to claim 1, characterized in that, The cover extends to approximately the same height as the head of the fixing screw, and is able to store the constant temperature cooling water at the position where the head of the fixing screw is immersed in the constant temperature cooling water.

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