Polishing apparatus and polishing method

Abstract

To suppress dryness of a substrate when the substrate is released from a substrate holding member in a polishing device.SOLUTION: A polishing device includes: a polishing table supporting a polishing pad; a substrate holding member including a substrate holding surface and a pressure chamber formed of an elastic film, the pressure chamber having a plurality of areas concentrically arranged, the substrate holding member being configured to press the substrate against the polishing pad by a pressure in the pressure chamber; a pressure regulator that adjusts a pressure of gas supplied to the pressure chamber of the substrate holding member; and a release nozzle capable of jetting pressurized fluid. The pressure regulator is controlled to pressurize all areas of the pressure chamber to pressurize the entire elastic film, then, the pressure chamber is pressurized such that the pressure of one or a plurality of center side areas including an area at the center of the pressure chamber is higher than pressures of the other areas, to pressurize the center part, and the release nozzle is controlled to jet the pressurized fluid to a contact position of the elastic film and the substrate, so that the substrate is released from the elastic film.SELECTED DRAWING: Figure 9B

Description

[Technical Field]

[0001] The present invention relates to a polishing apparatus and a polishing method for polishing substrates such as semiconductor wafers. [Background technology]

[0002] In the manufacturing process of semiconductor devices, techniques for planarizing the surface of semiconductor devices are becoming increasingly important. The most important of these planarization techniques is chemical mechanical polishing (CMP). CMP involves supplying a polishing solution containing abrasive grains such as silica (SiO2) onto a polishing pad while sliding a substrate such as a wafer against the polishing surface.

[0003] A polishing apparatus for performing CMP includes a polishing table that supports a polishing pad having a polishing surface, and a substrate holding member called a top ring or the like for holding a substrate. When polishing a substrate using such a polishing apparatus, the substrate is held by the top ring and pressed against the polishing surface with a predetermined pressure. Furthermore, the polishing table and the top ring are moved relative to each other, causing the substrate to slide against the polishing surface, resulting in a flat, mirror-finished surface.

[0004] In such a polishing apparatus, if the relative pressure between the wafer and the polishing surface of the polishing pad during polishing is not uniform across the entire surface of the wafer, under-polishing or over-polishing will occur depending on the pressure applied to each part of the wafer. To equalize the pressure on the wafer, a pressure chamber formed from an elastic membrane is provided below the top ring, and a gas such as air is supplied to this pressure chamber, which presses the substrate against the polishing surface of the polishing pad via the membrane, thereby polishing the substrate.

[0005] After the polishing process is completed, the wafer on the polishing surface is vacuum-attached to the top ring, and the top ring is raised together with the wafer and then moved to a position above the transfer stage, where the wafer is released from the membrane. The wafer is released by supplying gas to the pressure chamber to inflate the membrane and spraying a release shower into the gap between the wafer and the membrane (Patent Document 1, Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2018-006549 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-185589 Summary of the Invention [Problem to be solved by the invention]

[0007] In the above-described wafer release process, when a fluid containing a gas such as nitrogen gas is sprayed between the membrane and the wafer as a release shower, the wafer surface may dry out instantaneously, causing defects on the wafer.

[0008] The present invention has been made in view of the above, and has as its object to prevent a substrate from drying out when the substrate is released from a substrate holding member in a polishing apparatus. [Means for solving the problem]

[0009] According to one aspect of the present invention, there is provided a polishing table for supporting a polishing pad, a substrate holding surface formed of an elastic film, and a pressure chamber, the pressure chamber including a plurality of areas concentrically arranged. a substrate holding member that presses the substrate against the polishing pad by the pressure in the pressure chamber; a pressure regulator that adjusts the pressure of the gas supplied to the pressure chamber of the substrate holding member; one or more release nozzles that can spray pressurized fluid; and a control device that executes a substrate release process that releases the substrate from the elastic membrane by controlling the pressure regulator to pressurize the entire area of ​​the pressure chamber, thereby pressurizing the entire elastic membrane, and then pressurizing the pressure chamber so that the pressure in one or more central areas including an area at the center of the pressure chamber is higher than the pressure in other areas, and controlling the one or more release nozzles to spray the pressurized fluid at a contact point between the elastic membrane and the substrate. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a plan view showing the overall configuration of a polishing apparatus according to an embodiment; [Figure 2] FIG. 2 is a schematic view showing the configuration of a polishing unit. [Figure 3] 2 is a schematic cross-sectional view of a top ring constituting a substrate holding member that holds a wafer, which is an object to be polished, and presses it against the polishing surface of a polishing table. FIG. [Figure 4] FIG. 2 is a schematic view showing a top ring and a substrate transfer device (pusher). [Figure 5] FIG. 2 is a schematic diagram showing a detailed structure of a pusher. [Figure 6] FIG. 10 is a fluid circuit diagram of pressurized fluid supplied to a release nozzle. [Figure 7] FIG. 10 is a plan view of the pusher showing the orientation of the release nozzle. [Figure 8A] FIG. 10 is an explanatory view illustrating the release of the substrate from the top ring. [Figure 8B] FIG. 10 is an explanatory view illustrating the release of the substrate from the top ring. [Figure 8C] FIG. 10 is an explanatory view illustrating the release of the substrate from the top ring. [Figure 8D]FIG. 10 is an explanatory view illustrating the release of the substrate from the top ring. [Figure 9A] 10 is a time chart of a substrate release process according to a comparative example. [Figure 9B] 4 is a time chart of a substrate release process according to the present embodiment. [Figure 10] 10 is a flowchart of a substrate release process according to the present embodiment. [Figure 11] 10 is a measurement example of the difference in wafer release time depending on the injection start timing of the pressurized fluid. [Figure 12] This is an example of measurement of the difference in wafer release time depending on the orientation of the release nozzle. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, this embodiment will be described with reference to the drawings. A substrate processing apparatus 100 according to this embodiment is, as an example, a polishing apparatus for polishing substrates. In this embodiment, a wafer is used as an example of the substrate, but the present invention can be applied to any substrate other than a wafer (such as a glass substrate or a printed wiring board).

[0012] Fig. 1 is a plan view showing the overall configuration of a substrate processing apparatus 100 according to one embodiment of the present invention. As shown in Fig. 1, the substrate processing apparatus 100 has a substantially rectangular housing 1, the interior of which is partitioned by partition walls 1a and 1b into a load / unload section 2, a polishing section 3, and a cleaning section 4. The load / unload section 2, the polishing section 3, and the cleaning section 4 are each assembled independently and evacuated independently. The substrate processing apparatus 100 also has a control device 5 that controls the substrate processing operation.

[0013] The load / unload section 2 has two or more (four in this embodiment) front load sections 20 on which wafer cassettes for stocking a large number of wafers (substrates) are placed. These front load sections 20 are arranged adjacent to the housing 1 and aligned along the width direction (direction perpendicular to the longitudinal direction) of the substrate processing apparatus 100. The front load sections 20 can be equipped with open cassettes, SMIF (Standard Manufacturing Interface) pods, or FOUPs (Front Opening Unified Pods). Here, , SMIF, and FOUP are airtight containers that can store wafer cassettes inside and maintain an environment independent from the outside space by covering them with a partition wall.

[0014] Furthermore, in the load / unload section 2, a traveling mechanism 21 is installed along the row of front load sections 20, and a transfer robot (loader) 22 is installed on this traveling mechanism 21, capable of moving in the direction of the wafer cassette arrangement. The transfer robot 22 can access the wafer cassettes loaded in the front load section 20 by moving on the traveling mechanism 21. The transfer robot 22 has two hands, one on top and one on bottom, and the upper hand is used to return processed wafers to the wafer cassette, and the lower hand is used to remove unprocessed wafers from the wafer cassette, so that the upper and lower hands can be used separately. Furthermore, the lower hand of the transfer robot 22 is configured to be able to rotate around its axis to flip the wafer over.

[0015] Because the loading / unloading section 2 is the area that needs to be kept the cleanest, the interior of the loading / unloading section 2 is always maintained at a higher pressure than the outside of the substrate processing apparatus 100, the polishing section 3, and the cleaning section 4. The polishing section 3 is the dirtiest area because it uses slurry as the polishing liquid. Therefore, a negative pressure is created inside the polishing section 3, and this pressure is maintained lower than the internal pressure of the cleaning section 4. The loading / unloading section 2 is provided with a filter fan unit (not shown) having a clean air filter such as a HEPA filter, ULPA filter, or chemical filter, and this filter fan unit always blows out clean air from which particles, toxic vapors, and toxic gases have been removed.

[0016] The polishing section 3 is an area where wafer polishing (planarization) is performed, and includes a first polishing unit 3A, a second polishing unit 3B, a third polishing unit 3C, and a fourth polishing unit 3D. The first polishing unit 3A, the second polishing unit 3B, the third polishing unit 3C, and the fourth polishing unit 3D are arranged along the longitudinal direction of the substrate processing apparatus 100, for example, as shown in FIG.

[0017] As shown in FIG. 1, the first polishing unit 3A includes a polishing table 30A on which a polishing pad 10 having a polishing surface is attached, a top ring (substrate holding member) 31A for holding a wafer and polishing the wafer while pressing it against the polishing pad 10 on the polishing table 30A, a polishing liquid supply nozzle 32A for supplying a polishing liquid or a dressing liquid (e.g., pure water such as DIW) to the polishing pad 10, a dresser 33A for dressing the polishing surface of the polishing pad 10, and an atomizer 34A for spraying a mixed fluid of a liquid (e.g., pure water such as DIW) and a gas (e.g., nitrogen gas) or a liquid (e.g., pure water such as DIW) in a mist onto the polishing surface.

[0018] Similarly, the second polishing unit 3B includes a polishing table 30B having a polishing pad 10 attached thereto, a top ring (substrate holding member) 31B, a polishing liquid supply nozzle 32B, a dresser 33B, and an atomizer 34B; the third polishing unit 3C includes a polishing table 30C having a polishing pad 10 attached thereto, a top ring (substrate holding member) 31C, a polishing liquid supply nozzle 32C, a dresser 33C, and an atomizer 34C; and the fourth polishing unit 3D includes a polishing table 30D having a polishing pad 10 attached thereto, a top ring (substrate holding member) 31D, a polishing liquid supply nozzle 32D, a dresser 33D, and an atomizer 34D.

[0019] Next, a transfer mechanism for transferring wafers will be described. As shown in Fig. 1, a first linear transporter 6 is disposed adjacent to the first polishing unit 3A and the second polishing unit 3B. This first linear transporter 6 transfers wafers to the first polishing unit 3A and the second polishing unit 3B. This is a mechanism for transporting wafers between four transport positions (referred to as the first transport position TP1, second transport position TP2, third transport position TP3, and fourth transport position TP4, in order from the load / unload section side) along the direction in which unit 3B is arranged.

[0020] A second linear transporter 7 is disposed adjacent to the third polishing unit 3C and the fourth polishing unit 3D. The second linear transporter 7 is a mechanism for transporting wafers between three transfer positions (referred to as a fifth transfer position TP5, a sixth transfer position TP6, and a seventh transfer position TP7, in order from the load / unload section side) along the direction in which the third polishing unit 3C and the fourth polishing unit 3D are arranged.

[0021] Wafers are transported to the first polishing unit 3A and the second polishing unit 3B by the first linear transporter 6. The top ring 31A of the first polishing unit 3A moves between the polishing position and the second transfer position TP2 by the swing motion of the top ring head 110. Therefore, wafers are transferred to and from the top ring 31A at the second transfer position TP2. Similarly, the top ring 31B of the second polishing unit 3B moves between the polishing position and the third transfer position TP3, and wafers are transferred to and from the top ring 31B at the third transfer position TP3. The top ring 31C of the third polishing unit 3C moves between the polishing position and the sixth transfer position TP6, and wafers are transferred to and from the top ring 31C at the sixth transfer position TP6. The top ring 31D of the fourth polishing unit 3D moves between the polishing position and the seventh transfer position TP7, and wafers are transferred to and from the top ring 31D at the seventh transfer position TP7.

[0022] A lifter 11 for receiving a wafer from the transfer robot 22 is disposed at the first transfer position TP1. The wafer is transferred from the transfer robot 22 to the first linear transporter 6 via the lifter 11. A shutter (not shown) is provided on the partition wall 1a between the lifter 11 and the transfer robot 22. When transferring a wafer, the shutter is opened to transfer the wafer from the transfer robot 22 to the lifter 11. A swing transporter 12 is disposed between the first linear transporter 6, the second linear transporter 7, and the cleaning unit 4. The swing transporter 12 has a hand that can move between the fourth transfer position TP4 and the fifth transfer position TP5. The swing transporter 12 transfers the wafer from the first linear transporter 6 to the second linear transporter 7. The wafer is transferred by the second linear transporter 7 to the third polishing unit 3C and / or the fourth polishing unit 3D. The wafer polished in the polishing section 3 is transported to the cleaning section 4 via the swing transporter 12 , where it is cleaned and dried, and then handed over to the transfer robot 22 .

[0023] The above-described configuration of the polishing apparatus is an example, and other configurations may be adopted. Furthermore, the substrate processing apparatus 100 may be an apparatus other than a polishing apparatus.

[0024] [Polishing unit] Next, the polishing units will be described in more detail. The first polishing unit 3A, the second polishing unit 3B, the third polishing unit 3C, and the fourth polishing unit 3D have the same configuration, so the following description will focus on the first polishing unit 3A.

[0025] 2 is a schematic diagram showing the configuration of the first polishing unit 3A according to this embodiment. As shown in FIG. 2, the first polishing unit 3A includes a polishing table 30A and a top ring 31A that holds a substrate such as a wafer as an object to be polished and presses it against the polishing surface of the polishing table 30A.

[0026] The polishing table 30A is connected to a motor (not shown) disposed below it via a table shaft 30Aa, and is rotatable around the table shaft 30Aa. A polishing pad 10 is attached to the upper surface of the table 30A, and a polishing surface 10a of the polishing pad 10 forms a polishing surface for polishing the wafer W. A polishing liquid supply nozzle 102 is installed above the polishing table 30A, and this polishing liquid supply nozzle 102 supplies a polishing liquid Q onto the polishing pad 10 on the polishing table 30A.

[0027] The top ring 31A basically comprises a top ring body 202 that presses the wafer W against the polishing surface 10a, and a retainer ring 203 that holds the outer peripheral edge of the wafer W to prevent the wafer W from jumping out of the top ring.

[0028] The top ring 31A is connected to a top ring shaft 111, which is movable up and down relative to the top ring head 110 by a vertical movement mechanism 124. The vertical movement of the top ring shaft 111 raises and lowers the entire top ring 31A relative to the top ring head 110, thereby positioning it. A rotary joint 125 is attached to the upper end of the top ring shaft 111.

[0029] The up-and-down movement mechanism 124 that moves the top ring shaft 111 and the top ring 31A up and down includes a bridge 128 that rotatably supports the top ring shaft 111 via a bearing 126, a ball screw 132 attached to the bridge 128, a support base 129 supported by a support column 130, and a servo motor 138 provided on the support base 129. The support base 129 that supports the servo motor 138 is fixed to the top ring head 110 via the support column 130.

[0030] The ball screw 132 includes a screw shaft 132a connected to a servo motor 138 and a nut 132b onto which the screw shaft 132a is threaded. The top ring shaft 111 moves up and down integrally with the bridge 128. Therefore, when the servo motor 138 is driven, the bridge 128 moves up and down via the ball screw 132, which in turn moves the top ring shaft 111 and the top ring 31A up and down.

[0031] The top ring shaft 111 is connected to a rotating barrel 112 via a key (not shown). The rotating barrel 112 is provided with a timing pulley 113 on its outer periphery. A top ring rotary motor 114 is fixed to the top ring head 110, and the timing pulley 113 is connected to a timing pulley 116 attached to the top ring rotary motor 114 via a timing belt 115. Therefore, by driving the top ring rotary motor 114, the rotating barrel 112 and the top ring shaft 111 rotate together via the timing pulley 116, timing belt 115, and timing pulley 113, thereby rotating the top ring 31A. The top ring rotary motor 114 is provided with an encoder 140. The encoder 140 detects the rotational angle position of the top ring 31A and accumulates the number of rotations of the top ring 31A. A separate sensor may be provided to detect the "reference position (0 degrees)" of the rotational angle of the top ring 31A. The top ring head 110 is supported by a top ring head shaft 117 that is rotatably supported on a frame (not shown).

[0032] The control device 5 controls each device in the apparatus, including the top ring rotary motor 114, the servo motor 138, and the encoder 140. The storage unit 51 is connected to the control device 5 by wire or wirelessly, and the control device 5 can refer to the storage unit 51. The storage unit 51 stores programs for controlling substrate processing operations, various parameters, and the like. The storage unit 51 has volatile and / or non-volatile memory.

[0033] In the first polishing unit 3A configured as shown in FIG. 2, the top ring 31A has: A substrate such as a wafer W can be held on its lower surface. The top ring head 110 is rotatable about a top ring head shaft 117, and the top ring 31A holding the wafer W on its lower surface is moved from the wafer W receiving position to above the polishing table 30A by the rotation of the top ring head 110. The top ring 31A is then lowered to press the wafer W against the surface (polishing surface) 10a of the polishing pad 10. At this time, the top ring 31A and the polishing table 30A are rotated, and a polishing liquid is supplied onto the polishing pad 10 from a polishing liquid supply nozzle 32A provided above the polishing table 30A. In this manner, the wafer W is brought into sliding contact with the polishing surface 10a of the polishing pad 10, thereby polishing the surface of the wafer W.

[0034] [Top ring] Next, the top ring (substrate holding member) in the polishing apparatus of the present invention will be described. Fig. 3 is a schematic cross-sectional view of a top ring 31A constituting a substrate holding member or substrate holding device that holds a wafer W, which is an object to be polished, and presses it against the polishing surface on the polishing table. Fig. 3 shows only the main components that make up the top ring 31A.

[0035] As shown in FIG. 3, the top ring 31A basically comprises a top ring body (also referred to as a carrier) 202 that presses the wafer W against the polishing surface 101a, and a retainer ring 203 that directly presses the wafer W against the polishing surface 101a. The top ring body (carrier) 202 is a roughly disk-shaped member, and the retainer ring 203 is attached to the outer periphery of the top ring body 202. The top ring body 202 is made of a resin such as engineering plastic (e.g., PEEK). An elastic membrane 204 that contacts the backside of the wafer is attached to the bottom surface of the top ring body 202. The elastic membrane 204 is made of a rubber material with excellent strength and durability, such as ethylene propylene rubber (EPDM), polyurethane rubber, or silicone rubber.

[0036] The elastic membrane 204 has multiple concentric partition walls 204a, which define a pressure chamber consisting of multiple areas / chambers between the upper surface of the elastic membrane 204 and the lower surface of the top ring body 202. The pressure chamber includes a first area 205, which is a circular chamber, a second area 206, which is an annular chamber, a third area 207, which is an annular chamber, and a fourth area 208, which is an annular chamber. That is, the first area 205 is formed in the center or central part of the top ring body 202, and the second area 206, the third area 207, and the fourth area 208 are formed concentrically in this order from the center toward the periphery. Here, a case where four areas are formed in the elastic membrane 204 is described, but the number of areas may be three or less, or five or more (e.g., eight).

[0037] The elastic membrane 204 has a plurality of holes 204h in the second area 206 that penetrate the thickness direction of the elastic membrane for wafer adsorption. In this embodiment, the holes 204h are provided in the second area, but they may be provided in areas other than the second area. Note that instead of providing a plurality of holes in the elastic membrane 204 for wafer adsorption, the wafer may be adsorbed to the elastic membrane by the adhesive properties of the rubber material of the elastic membrane 204 and the expansion / contraction of the elastic membrane 204.

[0038] The top ring body 202 is provided with a flow path 211 communicating with the first area 205, a flow path 212 communicating with the second area 206, a flow path 213 communicating with the third area 207, and a flow path 214 communicating with the fourth area 208. The flow path 211 communicating with the first area 205, the flow path 213 communicating with the third area 207, and the flow path 214 communicating with the fourth area 208 are connected to flow paths 221, 223, and 224 via a rotary joint 225, respectively. The flow paths 221, 223, and 224 are connected to a pressure adjustment unit 230 via valves V1-1, V3-1, and V4-1 and pressure regulators R1, R3, and R4 (for example, electropneumatic regulators), respectively. The flow paths 221, 223, and 224 are provided with , are connected to a vacuum source 231 via valves V1-2, V3-2, and V4-2, respectively, and can be communicated with the atmosphere via valves V1-3, V3-3, and V4-3.

[0039] On the other hand, flow path 212 communicating with second area 206 is connected to flow path 222 via rotary joint 225. Flow path 222 is then connected to pressure adjustment unit 230 via air-water separation tank 235, valve V2-1, and pressure regulator R2 (e.g., an electropneumatic regulator). Flow path 222 is also connected to vacuum source 131 via air-water separation tank 235 and valve V2-2, and can communicate with the atmosphere via valve V2-3. Pressure regulators R1 to R4 are connected to control device 5, which controls pressure regulators R1 to R4 to vary the pressure of the gas supplied to each area within membrane 204.

[0040] In this way, by varying the pressure in each chamber within the membrane 204 and controlling the expansion of the membrane 204, it is possible to peel (release) the wafer W adsorbed to the membrane 204. For example, the expansion of the membrane 204 can be controlled by varying the pressure of the gas supplied into the membrane 204 in accordance with the adhesion force of the wafer W to the membrane 204, and the time required for the wafer W to be peeled from the membrane 204 (hereinafter also referred to as the wafer release time) can be stabilized. For example, by varying the pressure within the membrane 204, it is possible to change the pressure to an appropriate level according to the wafer W, thereby reducing stress on the wafer W.

[0041] A retainer ring pressurizing chamber 209 made of an elastic membrane is also formed directly above the retainer ring 203. The retainer ring pressurizing chamber 209 is connected to a flow path 226 via a flow path 215 and a rotary joint 225 formed in the top ring body (carrier) 202. The flow path 226 is then connected to a pressure adjustment unit 230 via a valve V5-1 and a pressure regulator R5 (electro-pneumatic regulator). The flow path 226 is also connected to a vacuum source 231 via a valve V5-2 and is communicable with the atmosphere via a valve V5-3. While the retainer ring pressurizing chamber 209 is used as the retainer ring pressing mechanism in this embodiment, the retainer ring pressing mechanism may alternatively be a fluid actuator using air, water, oil, or the like; an electric actuator using a ball screw, or an elastic member such as a spring or a bag.

[0042] Pressure regulators R1, R2, R3, R4, and R5 each have a pressure adjustment function that adjusts the pressure of the pressurized fluid supplied from pressure adjustment unit 230 to first area 205, second area 206, third area 207, fourth area 208, and retainer ring pressurization chamber 209. Pressure regulators R1, R2, R3, R4, and R5 and valves V1-1 to V1-3, V2-1 to V2-3, V3-1 to V3-3, V4-1 to V4-3, and V5-1 to V5-3 are connected to control device 5 (see FIGS. 1 and 2), which controls their operation. In addition, pressure sensors P1, P2, P3, P4, and P5 and flow rate sensors F1, F2, F3, F4, and F5 are installed in flow paths 221, 222, 223, 224, and 226, respectively.

[0043] 3, as described above, the first area 205 is formed in the central portion or center of the top ring body 202, and the second area 206, third area 207, and fourth area 208 are formed concentrically from the center toward the periphery. The pressure of the fluid supplied to the first area 205, second area 206, third area 207, fourth area 208, and retaining ring pressurizing chamber 209 can be independently adjusted by the pressure adjusting unit 230 and pressure regulators R1, R2, R3, R4, and R5. With this structure, the pressure with which the wafer W is pressed against the polishing pad 10 can be adjusted for each area of ​​the wafer W, and the pressure with which the retaining ring 203 presses the polishing pad 10 can be adjusted. It can be adjusted.

[0044] Next, a series of polishing steps performed by the substrate processing apparatus 100 configured as shown in FIGS. 1 to 3 will be described. The top ring 31A receives the wafer W from the first linear transporter 6 and holds it by vacuum suction. The elastic membrane 204 has multiple holes 204h for vacuum suction of the wafer W, and these holes 204h are connected to the vacuum source 131. The top ring 31A, holding the wafer W by vacuum suction, descends to a preset polishing position for the top ring. At this polishing position, the retainer ring 203 contacts the surface (polishing surface) 10a of the polishing pad 10. However, because the top ring 31A holds the wafer W by vacuum suction, there is a slight gap (e.g., about 1 mm) between the lower surface (polished surface) of the wafer W and the surface (polishing surface) 10a of the polishing pad 10 before polishing. At this time, both the polishing table 30A and the top ring 31A are rotated. In this state, the elastic membrane 204 on the back side of the wafer is inflated, the underside of the wafer (surface to be polished) is brought into contact with the surface (polishing surface) of the polishing pad 10, and the polishing table 30A and the top ring 31A are moved relative to each other, thereby polishing the wafer until the surface (polishing surface) of the wafer W reaches a predetermined state (for example, a predetermined film thickness).

[0045] After the wafer processing process on the polishing pad 10 is completed, the membrane 204 is contracted, and the wafer W is vacuum-sucked to the top ring 31A. The top ring 31A is then raised and moved to the substrate transfer device (e.g., pusher) 150 of the first linear transporter (substrate transfer unit) 6. After the movement, gas (e.g., nitrogen) is supplied to each area within the membrane 204 to expand the membrane 204 to a predetermined extent, reducing the contact area with the wafer W, and pressurized fluid is blown between the membrane 204 and the wafer W. This peels the wafer W from the membrane 204. This removal of the wafer W from the membrane 204 is also referred to as wafer release. Wafer release will be described in detail below.

[0046] The predetermined degree to which the membrane 204 is inflated is the degree to which the wafer W is positioned so that pressurized fluid can be ejected from a release nozzle, which will be described later, onto the rear surface of the wafer W. In one example, the membrane 204 is inflated so that the height of the rear surface of the wafer W is approximately the same as the height of the release nozzle 153 or slightly lower than the height of the release nozzle 153. In this way, the pressurized fluid ejected from the release nozzle 153 enters between the membrane and the wafer, hits the membrane (and / or the rear surface of the wafer), and is then supplied to the contact point between the membrane and the wafer.

[0047] [Pusher] FIG. 4 is a schematic diagram showing the top ring 31A and the pusher 150. It is a schematic diagram showing the pusher raised to transfer the wafer W from the top ring 31A to the pusher 150. As shown in FIG. 3, the pusher 150 includes a top ring guide 151 that can be fitted to the outer circumferential surface of the top ring 31A to perform centering between the top ring 31A and the pusher 150, a push stage 152 that supports the wafer when transferring the wafer between the top ring 31A and the pusher 150, an air cylinder (not shown) for vertically moving the push stage 152, and another air cylinder (not shown) for vertically moving the push stage 152 and the top ring guide 151. One or more (e.g., three) seating sensors 154 are provided on the push stage 152 to detect the release of the wafer W by detecting that the wafer W released from the membrane 204 has been placed on the push stage 152. The seating sensors 154 are, for example, contact sensors. The number of seating sensors may be 2 or less, or 4 or more. In this embodiment, an example is given in which wafer release is detected by seating sensor 154, but wafer release may also be detected by monitoring the pressure in the pressure chamber of membrane 204.

[0048] The operation of transferring the wafer W from the top ring 31A to the pusher 150 will be described below. After the wafer processing process on the polishing pad 10 is completed, the top ring 31A adsorbs the wafer W. The adsorption of the wafer W is performed by connecting the holes 204h of the membrane 204 to the vacuum source 131. In this way, the top ring 31A has a membrane 204 with holes 204h formed on its surface, and adsorbs the wafer W onto the surface of the membrane 204 by sucking the wafer W through the holes 204h.

[0049] After the wafer W is attracted to the top ring 31A, the top ring 31A is raised and moved to the pusher 150 to release the wafer W. After the wafer W is moved to the pusher 150, a cleaning operation may be performed by rotating the top ring 31A while supplying pure water or a chemical solution to the wafer W attracted to and held by the top ring 31A.

[0050] Then, the push stage 152 of the pusher 150 and the top ring guide 151 rise, and the top ring guide 151 engages with the outer peripheral surface of the top ring 31A, aligning the top ring 31A and the pusher 150. At this time, the top ring guide 151 pushes up the retainer ring 203, but at the same time, the retainer ring pressurization chamber 209 is evacuated to allow the retainer ring 203 to rise quickly. When the pusher has finished lifting, the bottom surface of the retainer ring 203 is pressed against the top surface of the top ring guide 151 and is raised above the bottom surface of the membrane 204, exposing the gap between the wafer and the membrane. In the example shown in FIG. 4, the bottom surface of the retainer ring 203 is located a predetermined height (e.g., 1 mm) above the bottom surface of the membrane. Then, the vacuum suction of the wafer W by the top ring 31A is stopped, and the wafer is released (processed). It should be noted that the desired positional relationship may be achieved by lowering the top ring instead of raising the pusher.

[0051] FIG. 5 is a schematic diagram showing the detailed structure of the pusher 150. As shown in FIG. 5, the pusher 150 includes a top ring guide 151, a push stage 152, and two release nozzles (substrate peeling promoters) 153 formed in the top ring guide 151 and capable of spraying pressurized fluid F. The pressurized fluid F may be pressurized gas (e.g., pressurized nitrogen) alone, pressurized liquid (e.g., pressurized water) alone, or a mixture of pressurized gas (e.g., pressurized nitrogen) and liquid (e.g., pure water). The release nozzles 153 are connected to the control device 5 via a control line or the like and are controlled by the control device 5. The pusher 150 further includes a position detection unit 154 that detects the position of the wafer W adsorbed to the membrane 204. In this embodiment, as an example, the position detection unit 154 detects the height of the backside of the wafer W adsorbed to the membrane 204. The position detection unit 154 has, for example, an imaging unit that captures an image of the inside of the top ring guide 151, and detects the height of the rear surface of the wafer W from the captured image. The position detection unit 154 may be omitted.

[0052] A plurality of release nozzles 153 are provided at predetermined intervals in the circumferential direction of the top ring guide 151, and spray the pressurized fluid F radially inward of the top ring guide 151 and toward the center of the top ring guide 151. This allows a release shower of the pressurized fluid F to be sprayed between the wafer W and the membrane 204, thereby performing wafer release to detach the wafer W from the membrane 204.

[0053] [Fluid supply to release nozzle] 6 is a fluid circuit diagram of the pressurized fluid F supplied to the release nozzle 153. The release nozzle 153 is connected to a flow path 331, which branches into a flow path 311 and a flow path 321, and is connected to a liquid supply source 312 via the flow path 311, and to a gas supply source 322 via the flow path 321. The liquid supply source 312 may be, for example, pure water such as DIW, or other semi-solid liquid. The gas supply source 322 may be a supply source that supplies a liquid that does not affect the semiconductor process. The gas supply source 322 may be a supply source that supplies, for example, an inert gas such as nitrogen gas, or other gas that does not affect the semiconductor process. Here, a configuration that can supply a liquid and / or a gas as the pressurized fluid F is described, but a configuration that supplies only a liquid or a piping configuration that supplies only a gas may also be used.

[0054] The liquid supply source 312 supplies liquid at a predetermined pressure or adjusted to the predetermined pressure. A valve 313 and a flow meter 314 are provided in a flow path 311 connected to the liquid supply source 312. The valve 313 may be a gate valve or a flow control valve controlled by the control device 5. The flow meter 314 may be, for example, a Karman type or a differential pressure type. The liquid supply source 312 is configured to supply liquid adjusted to the predetermined pressure to the valve 313. The liquid supply source 312 may include, for example, a factory utility line or a flow path connected to the factory utility line, and / or a pressure regulator, a flow control valve, etc. (not shown) connected to the factory utility line. The valve 313 may also be directly connected to the factory utility line, etc. By opening the valve 313, liquid at the predetermined pressure can be supplied from the liquid supply source 312 to the flow path 331 via the flow path 311.

[0055] The gas supply source 322 supplies gas at a predetermined pressure or adjusted to a predetermined pressure. A valve 323 and a check valve 324 are provided in a flow path 321 connected to the gas supply source 322. The valve 323 may be a gate valve or a flow control valve controlled by the control device 5. The gas supply source 322 is configured to supply gas adjusted to a predetermined pressure to the valve 323. The gas supply source 322 may include, for example, a factory utility line or a flow path connected to the factory utility line, and / or a pressure regulator, a flow control valve, etc. (not shown) connected to the factory utility line. The valve 323 may also be directly connected to the factory utility line, etc. By opening the valve 323, gas at a predetermined pressure can be supplied from the gas supply source 322 to the flow path 331 via the flow path 321.

[0056] According to the above configuration, by closing valve 323 and opening only valve 313, only liquid can be ejected from release nozzle 153 as pressurized fluid F. Furthermore, according to the above configuration, by closing valve 313 and opening only valve 323, only gas can be ejected from release nozzle 153 as pressurized fluid F. Furthermore, according to the above configuration, both liquid and gas can be ejected from release nozzle 153 as pressurized fluid F.

[0057] In one example, first, only valve 313 is opened to fill flow path 331 with a liquid (e.g., DIW), and then only valve 323 is opened to spray the liquid (e.g., DIW) filled in flow path 331 from release nozzle 153 using gas (e.g., nitrogen gas) from gas supply source 322. In this case, pressurized fluid F is a mixed fluid of liquid (e.g., DIW) and gas (e.g., nitrogen gas). The pressure of the gas (e.g., nitrogen gas) supplied from gas supply source 322 can be set higher than the pressure of the liquid (e.g., DIW) supplied from liquid supply source 312. For example, the pressure of the liquid (e.g., DIW) can be set to 0.2 MPa, and the pressure of the gas (e.g., nitrogen gas) can be set to 0.4 MPa. If there is a pressure difference between the liquid and the gas, it is not preferable to open valves 313 and 323 simultaneously for reasons described below. Therefore, as described above, only the liquid is first filled into the flow path 331, and then the supply of the liquid is stopped and gas is supplied to the flow path 331, so that the liquid is pushed out and sprayed by the gas. At this time, by adjusting the start time of spraying the pressurized fluid based on the start time of membrane expansion so that the liquid filled in the flow path does not run out before the wafer is released and only the gas is sprayed onto the wafer, drying of the wafer can be effectively suppressed.

[0058] Conventionally, valves 323 and 313 connected to gas supply source 322 and liquid supply source 312, respectively, which have different pressures, are simultaneously opened to spray a mixture of gas and liquid from the release nozzle. However, in this case, a pressure difference occurs at the junction of the gas and liquid pipes (the junction of flow paths 311 and 321), which can block the liquid with the gas and result in only gas being sprayed from the release nozzle. This can result in the wafer drying out depending on the wafer release time. Therefore, in this embodiment, the liquid is first filled into flow path 331, and then the supply of liquid is stopped and gas is supplied to flow path 331. This suppresses or prevents only gas from being sprayed from the release nozzle, thereby preventing the wafer from drying out. Furthermore, by starting the spray of pressurized fluid a predetermined delay time after the membrane expansion starts, it is possible to prevent the liquid filled into the flow path from being exhausted before the wafer is released, resulting in only gas being sprayed onto the wafer, thereby effectively preventing the wafer from drying out.

[0059] [Release nozzle direction] FIG. 7 is a plan view of the pusher showing the orientation of the release nozzle. Line D0 indicates the jetting direction of the release nozzle according to the comparative example. Line D1 indicates the jetting direction of the release nozzle 153 according to this embodiment. As shown in the figure, the jetting direction D0 of the release nozzle according to the comparative example prevents the pressurized fluid from concentrating at the center of the wafer to prevent wafer hovering. Hovering is a phenomenon in which, when gas or pressurized fluid containing gas is concentrated at the center of the wafer, the wafer W does not seat on the push stage 152 even after it is released from the membrane 204, and remains floating. This hovering is thought to be caused by the time it takes for the pressurized fluid to be jetted onto the wafer during the wafer release operation. On the other hand, in this embodiment, as described below, the wafer can be released with a shorter pressurized fluid jetting time by using two-stage pressurization of the membrane (full pressurization + center pressurization) and / or adjusting the start timing of pressurized fluid jetting. Therefore, hovering during wafer release can be prevented even when the pressurized fluid containing gas or pressurized fluid containing gas is directed toward the center of the wafer. In this embodiment, by directing the jetting direction of the release nozzle 153 toward the center of the wafer W, the pressurized fluid can be sprayed more efficiently onto the contact point between the membrane and the wafer, further reducing the wafer release time (the time required to release the wafer). Note that when only liquid is sprayed as the pressurized fluid, the hovering problem does not occur, and therefore, by directing the jetting direction of the release nozzle 153 toward the center of the wafer W, the wafer release time can be reduced.

[0060] [Wafer release principle] 8A to 8D are explanatory diagrams illustrating the release of a wafer from a top ring. Note that in these figures, the push stage 152 and seating sensor 154 are omitted to avoid complicating the drawings.

[0061] As described above, after the wafer processing process on the polishing pad 10 is completed, the top ring 31A holding the wafer W by suction is moved to the pusher 150, and the retainer ring 203 of the top ring 31A is engaged with the top ring guide 151 of the pusher 150 (FIG. 8A).

[0062] Thereafter, the vacuum suction of the wafer W by the top ring 31A is stopped, and gas is supplied to all areas 205-208 of the membrane 204 to pressurize it, thereby expanding the entire membrane 204 (total pressurization step, FIG. 8B). Pressurizing / expanding the entire membrane means uniformly expanding the entire membrane so that the entire membrane has approximately the same height. In other words, the total pressurization step can also be referred to as the total expansion step. At this time, the height of the contact point between the membrane 204 and the wafer W is adjusted to approximately match the height of the release nozzle 253 (approximately the same height as or slightly lower than the release nozzle 253). Since the membrane 204 expands more easily toward the center and less easily toward the periphery, for example, to uniformly expand the entire membrane, the pressure in each area is adjusted so that the pressure in the most central area 1 is lowest and the pressure increases sequentially toward the periphery. After pressurizing the entire membrane, all areas 205 to 208 of the membrane 204 are temporarily connected to the atmosphere, and the pressure in all areas 205 to 208 is reset.

[0063] Next, gas is supplied to each area 205-208 of the membrane 204 to pressurize / expand the center of the membrane 204 (center pressurization step, FIG. 8C). This causes the contact area (adhesion area) between the membrane 204 and the wafer W to shrink toward the center of the wafer W. At this time, the height of the contact area between the membrane 204 and the wafer W remains roughly the same as in the entire pressurization step and roughly coincides with the height of the release nozzle 253. In one example, the pressure in the first area 205, which is closest to the center, is set to at least four times the pressure in the first area 205 during the entire pressurization step, and the pressure in the other areas 206 to 208 is reduced compared to the pressure in the entire pressurization step. This allows the center pressurization step to be performed, in which the pressure in the first area 205 is made higher than the pressure in the other areas 206-208, thereby expanding the first area 205 more than the other areas. In other words, the center pressurization step can also be referred to as the center expansion step. In addition, when the membrane has a large number of pressure chamber areas, multiple areas, including the central first area, may be pressurized at a higher pressure than the other areas. Here, the first area 205 is defined as the area (the center of the membrane) pressurized at a higher pressure than the other areas in the central pressurization step. However, if the center of the membrane 204 is defined based on the radius of the membrane 204, the area within a range from the center (center point) of the membrane 204 to a radial length of 50% or less of the radius can be pressurized as the central membrane. More preferably, the area within a range from the center of the membrane 204 to a radial length between 40% and 50% of the radius can be pressurized as the central membrane. For example, in FIG. 3, of the four areas 205, 206, 207, and 208, the first area 205 and the second area 206 can be defined as the central membrane and pressurized at a higher pressure than the other areas.

[0064] As mentioned above, the membrane tends to expand more easily toward the center, so if each area is pressurized with the same pressure, the area toward the center of the membrane will expand to slightly protrude. However, the central pressurization step of this embodiment differs from this in that the pressure in the area toward the center of the membrane is made higher than in the other areas, actively protruding the center of the membrane. This sufficiently reduces the contact area between the membrane and the wafer and facilitates wafer release.

[0065] Furthermore, at least during the central pressurization step, pressurized fluid F is sprayed from the release nozzle 153 toward the membrane-wafer contact point (FIG. 8C). This releases the wafer W from the membrane 204 (FIG. 8D). The wafer W released from the membrane 204 falls onto the push stage 152 and is detected by one or more seating sensors 154 (see FIGS. 4 and 5) on the push stage 152. The seating sensors 154 detect the wafer W, thereby detecting its release. For example, as shown in FIGS. 4 and 5, when three seating sensors 154 are provided, wafer release may be detected when all of the seating sensors 154 detect the wafer. Note that in FIGS. 8A to 8D, spraying of pressurized fluid is initiated during the central pressurization step (FIG. 8C). However, as will be described later, spraying of pressurized fluid may be initiated during the entire pressurization step, a predetermined delay time after the start of the entire pressurization step (FIG. 8B).

[0066] If wafer release cannot be detected in one central pressurizing step, the central pressurizing step may be repeated until wafer release is detected, with a reset step for resetting the pressure in the entire area of ​​the membrane 204 in between. If wafer release is not detected during a predetermined number of (one or more) central pressurizing steps, all areas of the membrane 204 are reset, and the control cycle (FIGS. 8A to 8C) is started again from the entire pressurizing step. When the number of times the control cycle is repeated reaches a predetermined upper limit, an alarm may be issued and the wafer release process may be terminated (error process).

[0067] [Wafer release control cycle] 9A is a time chart showing one control cycle of a wafer release process sequence according to a comparative example. FIG. 9B is a time chart showing one control cycle of a wafer release process sequence according to this embodiment. In this specification, the injection start time of pressurized fluid F is defined as the injection start time (= injection delay time) of pressurized fluid F relative to the start of expansion of membrane 204 (start of release process, t=0 in FIGS. 9A and 9B).

[0068] In the comparative example (Figure 9A), the direction of the release nozzle 153 was set to the direction D1 in Figure 7, DIW and nitrogen gas were supplied as the pressurized fluid F (the DIW and nitrogen gas valves were opened simultaneously), the start time of the injection of the pressurized fluid F was set to 0.5 seconds, and the membrane 204 was expanded only by the entire pressurization step.

[0069] 7, only DIW was supplied as the pressurized fluid F, the injection start time of the pressurized fluid F was set to 0.5 seconds, and the membrane 204 was expanded in the entire pressurization step (All) and the center pressurization step (Cent.). Note that the reduction in wafer release time is considered to be mainly due to the two-stage pressurization (entire pressurization + center pressurization). Therefore, in this embodiment (FIG. 9B), when a mixed fluid of DIW and nitrogen gas is injected as the pressurized fluid F, and when only nitrogen gas is injected as the pressurized fluid F, it is expected that the same results will be obtained as when only DIW is injected as the pressurized fluid F.

[0070] 9A, one control cycle of the wafer release process sequence according to the comparative example includes an all-pressurization step (All) of the membrane 204 and a release shower step (SW) of spraying pressurized fluid F (DIW, nitrogen gas). This control cycle is repeated until wafer release is detected. When wafer release is detected, the wafer release process is terminated, the entire area of ​​the membrane 204 is released to atmospheric pressure for resetting, and spraying of pressurized fluid F (DIW, nitrogen gas) is stopped (t=5.1 seconds in the figure).

[0071] In the example of FIG. 9A, expansion of the membrane 204 (total pressurization step) begins at time t = 0 (OFF to ON in the membrane curve in the figure), and spraying of pressurized fluid F from the release nozzle 153 begins at spraying start time t = td = 0.5 seconds (OFF to ON in the DIW and N2 curves in the figure). When the seating sensor 154 detects wafer release (OFF to ON in the wafer detection sensor curve in the figure), pressurization of the membrane 204 ends (ON to OFF in the membrane curve in the figure), the entire area of ​​the membrane 204 is released to atmospheric pressure (reset), and spraying of pressurized fluid F stops (ON to OFF in the DIW and N2 curves in the figure). In the example of FIG. 9A, wafer release is detected during the first control cycle, and the wafer release time is approximately 5.1 seconds. The wafer release time indicates the time required for wafer release and is defined as the time from when pressurization of the membrane 204 begins to when wafer release is detected.

[0072] 9B, one control cycle of the wafer release process sequence according to this embodiment includes an all-pressurizing step (All) of the membrane 204, a predetermined number (one or more) of center-pressurizing steps (Cent.) of the membrane 204, and a release shower step (SW) of spraying pressurized fluid F (DIW). This control cycle is repeated until wafer release is detected. When wafer release is detected, the wafer release process is terminated, the entire area of ​​the membrane 204 is opened to atmospheric pressure and reset (reset), and spraying of pressurized fluid F (DIW) is stopped (t=1.7 seconds in the figure).

[0073] In the example of FIG. 9B, the entire membrane 204 pressurization step (All) starts at time t = 0 (in the figure, the membrane curve changes from OFF to ON), and the release nozzle 153 starts spraying pressurized fluid F at spray start time t = td = 0.5 seconds (in the figure, the DIW curve changes from OFF to ON). After the entire membrane 204 pressurization step (All) is completed, a reset step (reset) is performed in which the entire membrane 204 is opened to the atmosphere and the pressure in the entire membrane 204 is reset to atmospheric pressure. Then, the center pressurization step (Cent.) of the membrane 204 starts. At this time, while the center (first area 205) of the membrane 204 is pressurized, the release nozzle 153 sprays pressurized fluid F onto the contact point between the membrane and the wafer, releasing the wafer W from the membrane 204 (in the figure, the wafer detection sensor curve changes from OFF to ON). The release of the wafer is detected by the seating sensor 154. When the seating sensor 154 detects the wafer release, the center pressurization step (Cent.) of the membrane 204 is terminated (in the figure, the membrane curve (solid line) changes from ON to OFF), the entire area of ​​the membrane 204 is released to atmospheric pressure, and the spray of the pressurized fluid F is stopped (in the figure, the DIW curve (solid line) changes from ON to OFF). In the example of FIG. 9B, wafer release is detected during the first control cycle, and the wafer release time is approximately 1.7 seconds. Note that in the figure, the dashed portions of the DIW curve and the membrane curve indicate the control when wafer release is not detected.

[0074] [Wafer release flow chart] FIG. 10 is a flowchart of the wafer release process according to this embodiment. In step S10, after the polishing operation is completed, the top ring 31A holding the wafer moves to the transfer position (above the pusher 150).

[0075] In step S20, the pusher 150 is raised to engage with the top ring 31A, completing preparations for starting the wafer release process.

[0076] In step S30, one control cycle of the wafer release process sequence described above with reference to Fig. 9B is started and executed, namely, the entire membrane 204 pressurization step and the central portion pressurization step are executed a predetermined number of times, and a release shower step is executed in which pressurized fluid F is sprayed onto the contact point between the membrane and the wafer, as shown in Fig. 9B.

[0077] In step S40, it is determined at predetermined time intervals whether the wafer has been released. The wafer is released, for example, depending on whether all of the seating sensors 154 have detected the wafer. If the wafer has been released, the spraying of the pressurized fluid F is stopped (step S50), and the pressure on the membrane 204 is stopped to reset the entire area of ​​the membrane 204 to atmospheric pressure, thereby completing the wafer release process (step S60). Thereafter, the pusher 150 descends to separate from the top ring 31A and moves to the cleaning position (a position for transferring the wafer to the cleaning unit 4) (step S70).

[0078] If the release of the wafer is not detected in step S40, the process proceeds to step S80. In step S80, it is determined whether one control cycle of the wafer release processing sequence has ended. If it is determined in step S80 that one control cycle has not ended, the process returns to step S30 and continues the currently ongoing one control cycle. On the other hand, if it is determined in step S80 that one control cycle has ended, the process proceeds to step S90.

[0079] In step S90, it is determined whether the number of repetitions of one control cycle has reached the upper limit. If it is determined that the number of repetitions of one control cycle has not reached the upper limit, the process proceeds to step S110. In step S110, an all-area free setting (corresponding to the reset step in FIG. 9B) is performed, in which all areas of membrane 204 are exposed to atmospheric pressure. Thereafter, the process proceeds to step S30, in which the next control cycle is started and executed.

[0080] If it is determined in step S90 that the number of repetitions of one control cycle has reached the upper limit, an alarm is issued and error processing is performed (step S100).

[0081] [Difference in wafer release time depending on release shower injection start time] Figure 11 shows an example of measurements that measured the difference in wafer release time depending on the start timing of pressurized fluid injection. The values ​​(0.0, 0.2, 0.5) at the top of the figure represent the start timing of the release shower (pressurized fluid) injection, and correspond to the delay time from the start of the full pressurization step of the membrane 204 to the start timing of pressurized fluid F injection. In this example, ten measurements were performed (N = 10). MAX indicates the maximum value of all ten measurements, MIN indicates the minimum value of all ten measurements, and RANGE indicates the difference between MAX and MIN, i.e., the range of variation in the measurements. AVERAGE indicates the average value of all ten measurements. For each measurement, the membrane was pressurized in two stages (full pressurization and center pressurization) as shown in Figure 9B. The release nozzle was oriented as shown in Figure 7. The pressurized fluid injection start timing (delay time) td1 was changed to 0.0, 0.2, and 0.5 seconds, and the wafer release time was measured. In both cases, the pressurized fluid F was a mixed fluid of DIW and nitrogen gas (DIW was pushed out and sprayed by nitrogen gas).

[0082] 11, it can be seen that the average wafer release time is shortest when the release shower injection start timing (delay time) is 0.0 seconds, but the variation (RANGE) of the measurement values ​​is the largest and the stability (reproducibility) of the wafer release process is low. Therefore, in consideration of the stability of the wafer release time, a delay time of 0.5 seconds is adopted in this embodiment.

[0083] Furthermore, when the pressurized fluid F is sprayed by pushing out the liquid with gas, if the delay time is 0.0 seconds, the DIW filled in the flow path will be exhausted from the release nozzle before the wafer is released, leaving only nitrogen gas to be sprayed onto the wafer, which may dry out the wafer. On the other hand, if a delay time of 0.5 seconds is used, the momentum of the DIW pushed out by the nitrogen gas can be used effectively and efficiently to release the wafer, allowing the wafer to be released within the DIW spray period. Furthermore, because wafer release can be completed within the DIW spray period, drying of the wafer can be suppressed, thereby suppressing the occurrence of defects.

[0084] [Difference in wafer release time depending on release nozzle orientation] FIG. 12 shows a measurement example that measured the difference in wafer release time depending on the orientation of the release nozzle. In FIG. 12, Nozzle D1 is an example in which the release nozzle orientation shown by line D1 in FIG. 7 is adopted as the present embodiment. Nozzle D0 is an example in which the release nozzle orientation shown by line D0 in FIG. 7 is adopted as a comparative example. The only difference between the two is the orientation of the release nozzle; other conditions are the same. That is, for both Nozzle D1 and Nozzle D0, the membrane was pressurized in two stages (full pressurization and central pressurization) as shown in FIG. 9B, the pressurized fluid injection start time td1 = 0.5 seconds, and the pressurized fluid F was a mixture of DIW and nitrogen gas (DIW was pushed out and injected by nitrogen gas). As with the measurement example of FIG. 11, a total of 10 measurements (N = 10) were performed in this measurement example, and the meanings of MAX, MIN, RANGE, and AVERAGE are the same as those in FIG. 11.

[0085] The measurement results shown in Figure 12 show that by setting the release nozzle orientation to D1 (the orientation in which the release shower / pressurized fluid is directed toward the center of the wafer), the wafer release time can be significantly reduced and the variation in wafer release time can also be suppressed compared to when the orientation is D0 (the orientation in which the release shower / pressurized fluid is not concentrated at the center of the wafer).

[0086] According to the embodiment described above, the center of the membrane is pressurized to reduce the area of ​​contact between the membrane and the wafer, and then the pressurized fluid is sprayed onto the contact point between the membrane and the wafer, thereby shortening the wafer release time. Because the wafer release time can be shortened, it is possible to prevent the wafer surface from drying out due to the pressurized fluid, which can cause defects.

[0087] Furthermore, since the entire membrane is pressurized before the central portion of the membrane is pressurized, the stress applied to the wafer can be reduced.

[0088] In the above embodiment, when only a liquid (e.g., DIW) is sprayed as the pressurized fluid, drying of the wafer surface and the occurrence of defects can be effectively suppressed / prevented. Note that when only a liquid (e.g., DIW) is sprayed as the pressurized fluid, there is a concern that the pressure of the pressurized fluid will be low and the wafer release time will be long. However, by combining the above-described full pressurization and central pressurization of the membrane, the membrane can be quickly expanded. Furthermore, by spraying the liquid while reducing the contact area between the membrane and the wafer, the wafer release time can be shortened. Therefore, by spraying only a liquid as the pressurized fluid, drying of the wafer surface can be effectively suppressed / prevented while avoiding the problem of increased wafer release time.

[0089] In the above embodiment, when the flow path of the release nozzle is filled with liquid (e.g., DIW) and the liquid is pushed out and sprayed from the release nozzle using gas (e.g., nitrogen gas), there is a risk that the liquid will run out before the wafer is released, resulting in only the gas being sprayed. However, by starting spraying from the release nozzle (spraying of liquid using gas) after an appropriate delay time from when the membrane starts to expand, the wafer can be released while the liquid is being sprayed, before the filled liquid runs out. This prevents the wafer from drying out and suppresses the occurrence of defects.

[0090] Furthermore, by combining the above-mentioned full pressurization and central pressurization of the membrane, and by setting a delay time for the pressurized fluid injection, the wafer release time can be shortened with good reproducibility, so that even when only gas is injected as the pressurized fluid, the wafer surface can be prevented from drying out and causing defects.

[0091] According to the above embodiment, the release nozzle is oriented toward the center of the wafer, so that the pressurized fluid can be concentrated at the contact point between the membrane and the wafer, further shortening the wafer release time.

[0092] According to the above embodiment, by setting the ejection start timing / delay time of the release shower (pressurized fluid) to appropriate values, it is possible to shorten the wafer release time while avoiding a decrease in the stability / reproducibility of the wafer release process.

[0093] According to the above embodiment, the release nozzle is switchably connected to a liquid supply source and a gas supply source, so that liquid only, gas only, or liquid + gas can be sprayed as pressurized fluid depending on the user's request.

[0094] (Other embodiments) (1) In the above embodiment, the substrate transfer device is a pusher. However, the substrate transfer device may be a retainer ring station, which is an annular member that engages with the top ring. The retainer ring station has a shape that roughly corresponds to the annular portion of the top ring guide 151 of the pusher 150 shown in FIG. 5. As in the case of the top ring guide 151 of the pusher 150, the release shower nozzle 153 can be provided on the inner peripheral surface of the retainer ring station. When the retainer ring station is used, the wafer can be received by a transfer stage or hand of the transporter.

[0095] (2) The wafer release processing method according to the above embodiment is not limited to wafers and polishing apparatuses, but can be applied to any substrate processing apparatus having a mechanism for holding any substrate on the surface of a membrane.

[0096] At least the following aspects can be understood from the above-described embodiment. [1] According to one embodiment, there is provided a polishing apparatus comprising: a polishing table for supporting a polishing pad; a substrate holding member having a substrate holding surface and a pressure chamber made of an elastic membrane, the pressure chamber having a plurality of concentrically arranged areas, and pressing the substrate against the polishing pad by the pressure in the pressure chamber; a pressure regulator for adjusting the pressure of gas supplied to the pressure chamber of the substrate holding member; one or more release nozzles capable of spraying pressurized fluid; and a control device that performs a substrate release process to release the substrate from the elastic membrane by controlling the pressure regulator to pressurize all areas of the pressure chamber to pressurize the entire elastic membrane, and then pressurizing the pressure chamber so that the pressure in one or more central areas including an area at the center of the pressure chamber is higher than the pressure in other areas, and controlling the one or more release nozzles to spray the pressurized fluid at a contact point between the elastic membrane and the substrate. The substrate holding member holds a substrate on the substrate holding surface. The injection of the pressurized fluid can start when the pressurization of the entire elastic membrane starts or during the pressurization. The "one or more central areas including the area at the center of the pressure chamber" can be one or more areas (including the area at the center of the pressure chamber) within a radial distance from the center of the pressure chamber (elastic membrane, substrate holding surface) that is 50% or less of the radius of the pressure chamber. More preferably, it can be one or more areas (including the area at the center of the pressure chamber) within a radial distance from the center of the pressure chamber that is between 40% and 50% of the radius of the pressure chamber. For example, if the pressure chamber (elastic membrane, substrate holding surface) has a radius of r, one or more areas within a circular area having a radius of 0.5r or less (or, for example, 0.45r or less) from the center are pressurized as the center of the pressure chamber (elastic membrane, substrate holding surface). The one or more areas to be pressurized can be continuous or discrete.

[0097] According to this embodiment, the center of the elastic membrane is pressurized to reduce the contact area between the elastic membrane and the substrate, and then the pressurized fluid is sprayed onto the contact area between the elastic membrane and the substrate, thereby shortening the substrate release time. Because the substrate release time can be shortened, it is possible to prevent the substrate surface from drying out due to the pressurized fluid, which can cause defects. Furthermore, because the entire elastic membrane expands evenly before the center of the elastic membrane expands, it is possible to reduce stress on the substrate.

[0098] According to this embodiment, by pressurizing the central area of ​​the membrane (pressure chamber), which is easy to expand, to a higher pressure than the outer area, which is difficult to expand, the center of the membrane is actively protruded, and the area of ​​contact between the membrane and the wafer can be effectively reduced. Furthermore, when there are many areas, by pressurizing multiple areas, including the central area, more than the other areas, the degree of protrusion of the center of the membrane can be adjusted and stress on the wafer can be reduced.

[0099] [2] According to one embodiment, the method further includes a detection device that detects release of the substrate from the elastic film, and the control device is configured to perform a central portion pressurizing step of pressurizing the central portion of the elastic film a predetermined number of times after performing a whole pressurizing step of pressurizing the entire elastic film. The substrate release process is terminated when the detection device detects the release of the substrate from the elastic membrane. The detection device can be configured to detect the substrate release by monitoring, for example, a contact sensor such as a seating sensor or pressure within the membrane.

[0100] According to this embodiment, if the substrate is not released after one central pressure step, the substrate can be released by resetting the pressure of the elastic membrane (opening the pressure chamber of the elastic membrane to the atmosphere) and then repeating the process of performing the central pressure step.

[0101] [3] According to one embodiment, the control device is configured to repeat one control cycle, which is the execution of the central pressure step a predetermined number of times after the entire pressure step, until a predetermined upper limit number of times is reached, and terminates the substrate release process when the detection device detects the release of the substrate from the elastic film.

[0102] According to this aspect, if the substrate is not released in one control cycle, the substrate can be released by repeating the control cycle.

[0103] [4] According to one embodiment, the control device controls the release nozzle to start spraying the pressurized fluid after a predetermined delay time after the start of pressurization of the entire elastic membrane and while the entire elastic membrane is being pressurized.

[0104] According to this aspect, by starting the injection of pressurized fluid with an appropriate delay time after starting the pressurization of the elastic membrane, it is possible to suppress variations in substrate release time and improve the stability (reproducibility) of the substrate release process. Furthermore, when filling the flow path of the release nozzle with liquid and forcing the liquid out of the release nozzle with gas, the injection from the release nozzle (injection of liquid by gas) starts an appropriate delay time after the membrane starts expanding. Therefore, the liquid filled in the nozzle does not run out before the wafer is released, preventing only gas from being injected, and the wafer can be released during the liquid injection period. This prevents the wafer from drying out and the occurrence of defects.

[0105] [5] According to one embodiment, the control device pressurizes the pressure chamber so that the pressure in the area at the center of the pressure chamber is higher than the pressure in other areas, thereby pressurizing the center of the elastic membrane.

[0106] According to this configuration, only a single area at the center of the pressure chamber is pressurized to a higher pressure than the other areas, which effectively reduces the contact area between the elastic membrane and the substrate, thereby further shortening the substrate release time.

[0107] [6] According to one embodiment, the one or more central areas including the area at the center of the pressure chamber are one or more areas included in a range from the center of the pressure chamber to a radial length of 50% or less of the radius of the pressure chamber.

[0108] According to this embodiment, it is possible to effectively balance the reduction in the contact area between the elastic film and the substrate and the suppression of stress on the substrate.

[0109] [7] According to one embodiment, the one or more central areas including the area at the center of the pressure chamber are one or more areas that are within a range from the center of the pressure chamber to a radial length that is between 40% and 50% of the radius of the pressure chamber.

[0110] According to this embodiment, the contact area between the elastic film and the substrate is reduced, and stress on the substrate is suppressed. This allows for more effective balancing.

[0111] [8] According to one embodiment, the ejection direction of the one or more release nozzles is directed toward the center of the substrate.

[0112] According to this embodiment, the pressurized fluid can be concentrated at the contact point between the elastic membrane and the substrate, which has been contracted to the center of the elastic membrane / substrate by central pressure application, thereby further shortening the substrate release time.

[0113] [9] According to one embodiment, the pressurized fluid sprayed from the release nozzle is a liquid, such as pure water (DIW) or other liquid that does not affect the semiconductor manufacturing process.

[0114] According to this aspect, by using a liquid as the pressurized fluid to be applied to the contact point between the elastic film and the substrate, it is possible to more effectively prevent the substrate surface from drying and defects caused by drying.

[0115]

[10] According to one embodiment, the pressurized fluid sprayed from the release nozzle is a gas, which may be, for example, an inert gas such as nitrogen gas or any other gas that does not affect the semiconductor manufacturing process.

[0116] By applying pressure to the center of the elastic film and applying pressurized fluid, the substrate release time can be shortened, so even if gas is used as the pressurized fluid, drying of the substrate surface and defects caused by drying can be suppressed.

[0117]

[11] According to one embodiment, the pressurized fluid ejected from the release nozzle is a liquid and a gas.

[0118] By applying pressure to the center of the elastic film and applying pressurized fluid, the substrate release time can be shortened, so drying of the substrate surface and defects caused by drying can be suppressed even when liquid or gas is used as the pressurized fluid.

[0119]

[12] According to one embodiment, the release nozzle is connected to a liquid supply source and a gas supply source, and is capable of injecting liquid and / or gas as the pressurized fluid.

[0120] According to this aspect, the user can select a liquid, a gas, or a mixture of a liquid and a gas as the pressurized fluid according to his or her desire.

[0121]

[13] According to one embodiment, there is provided a method for polishing a substrate using a substrate holding member having a substrate holding surface and a pressure chamber formed by an elastic membrane, the pressure chamber having a plurality of areas concentrically arranged, the method comprising: pressing the substrate against a polishing pad by pressure in the pressure chamber, and polishing the substrate while moving the substrate and the polishing pad relative to each other; holding the polished substrate on the substrate holding surface of the substrate holding member; and releasing the substrate from the elastic membrane when transferring the substrate from the substrate holding member to a substrate transfer device, wherein the transferring step comprises: an overall pressurizing step of pressurizing the entire elastic membrane by pressurizing the entire area of ​​the pressure chamber; a central pressurizing step of pressurizing the center of the elastic membrane by pressurizing the pressure chamber so that the pressure in one or more areas including an area at the center of the pressure chamber is higher than the pressure in other areas; and a step of injecting the pressurized fluid onto a contact point between the elastic membrane and the substrate while pressurizing at least the central part of the elastic membrane.

[0122] According to this embodiment, the same effects as those described above in relation to [1] are achieved.

[0123]

[14] According to one embodiment, there is provided a non-volatile storage medium storing a program for causing a computer to execute a control method for a polishing apparatus that polishes a substrate using a substrate holding member having a substrate holding surface and a pressure chamber formed by an elastic membrane, the pressure chamber having a plurality of areas concentrically arranged, the method including: pressing the substrate against a polishing pad by pressure in the pressure chamber, and polishing the substrate while moving the substrate and the polishing pad relative to each other; holding the polished substrate on the substrate holding surface of the substrate holding member; and releasing the substrate from the elastic membrane when transferring the substrate from the substrate holding member to a substrate transfer device, the releasing step including: an entire pressurizing step of pressurizing the entire elastic membrane by applying pressure to all areas of the pressure chamber; a central pressurizing step of pressurizing the center of the elastic membrane by applying pressure to the pressure chamber so that the pressure in one or more areas including an area at the center of the pressure chamber is higher than the pressure in other areas; and spraying the pressurized fluid onto a contact point between the elastic membrane and the substrate while pressurizing at least the central part of the elastic membrane. A non-volatile storage medium is provided that stores the program.

[0124] According to this embodiment, the same effects as those described above in relation to [1] are achieved.

[0125] According to one aspect, there is provided a substrate processing apparatus comprising: a substrate holding member having a substrate holding surface and a pressure chamber formed by an elastic membrane, the pressure chamber having a plurality of concentrically arranged areas; a pressure regulator for adjusting the pressure of gas supplied to the pressure chamber of the substrate holding member; one or more release nozzles capable of injecting pressurized fluid; and a control device for performing a substrate release process to release the substrate from the elastic membrane by controlling the pressure regulator to pressurize all areas of the pressure chamber to pressurize the entire elastic membrane, and then pressurizing the pressure chamber so that the pressure in one or more central areas including an area at the center of the pressure chamber is higher than the pressure in other areas, and controlling the one or more release nozzles to inject the pressurized fluid at a contact point between the elastic membrane and the substrate. The present invention can also include the features described above in [2] to

[12] .

[0126] According to one aspect, a method for processing a substrate using a substrate holding member having a substrate holding surface and a pressure chamber formed of an elastic membrane, the pressure chamber having a plurality of areas concentrically arranged, the method comprising the steps of: holding the processed substrate on the substrate holding surface of the substrate holding member; a step of releasing the substrate from the elastic membrane when transferring the substrate from the substrate holding member to a substrate transfer device, the transferring step including: an entire pressurizing step of pressurizing the entire elastic membrane by pressurizing the entire area of ​​the pressure chamber, a central pressurizing step of pressurizing the center of the elastic membrane by pressurizing the pressure chamber so that the pressure in one or more central areas including an area at the center of the pressure chamber is higher than the pressure in other areas, and a step of injecting the pressurized fluid onto a contact point between the elastic membrane and the substrate while pressurizing at least the central area of ​​the elastic membrane. The method can also include the features described above in [2] to

[12] .

[0127] Although the embodiments of the present invention have been described above, the above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and the present invention naturally includes equivalents thereof. Furthermore, any combination of the embodiments and modifications is possible within the scope of solving at least part of the above-described problems or achieving at least part of the effects, and any combination or omission of the components described in the claims and specification is possible. [Explanation of symbols]

[0128] 1. Housing 2 Load / Unload Section 3 Polishing section 3A,3B,3C,3D polishing unit 4 Cleaning section 5. Control device 6. First Linear Transporter 7. Second Linear Transporter 10 Polishing Pads 10a Polished surface 11 Lifter 12 Swing Transporter 20 Front Load Section 21 Running mechanism 22 Transport robot 30A, 30B, 30C, 30D Polishing Table 31A, 31B, 31C, 31D Top ring (substrate holder) 32A, 32B, 32C, 32D Polishing liquid supply nozzle 33A, 33B, 33C, 33D Dresser 34A, 34B, 34C, 34D atomizer 30Aa Table axis 51 Storage section 100 Substrate processing apparatus 102 Polishing liquid supply nozzle 111 Top ring shaft 112 Rotating Cylinder 113 Timing pulley 114 Top ring rotation motor 115 Timing belt 116 Timing pulley 117 Top ring head shaft 124 Vertical movement mechanism 125 rotary joint 126 Bearings 128 Bridge 129 Support stand 130 Post 131,231 Vacuum source 132 Ball screw 132a Screw shaft 132b Nut 138 Servo motor 140 Encoder 150 Substrate transfer device (pusher) 151 Top ring guide 152 Push Stage 153 Release nozzle 154 Seat sensor 202 Top ring body 203 Retainer ring 204 Elastic membrane 204a Bulkhead 205 Area 1 206 Area 2 207 Third Area 208 Area 4 209 Retainer ring pressure chamber 211, 212, 213, 214, 215, 221, 223, 224, 226 flow channels 225 rotary joint 230 Pressure adjustment unit 235 Air-water separation tank 311, 321, 331 channels 313, 323 valves 314 Flow meter 324 Check valve 312 Liquid Source 322 Gas Supply Source

Claims

1. a polishing table for supporting the polishing pad; a substrate holding member having a substrate holding surface and a pressure chamber formed of an elastic membrane, the pressure chamber having a plurality of areas arranged concentrically, and pressing the substrate against the polishing pad by pressure within the pressure chamber; a pressure regulator that adjusts the pressure of the gas supplied to the pressure chamber of the substrate holding member; one or more release nozzles capable of injecting pressurized fluid; a control device that controls the pressure regulator to pressurize all areas of the pressure chamber so that the entire area is at approximately the same height and at approximately the same height as the one or more release nozzles, thereby pressurizing the entire elastic membrane, and then pressurizing the pressure chamber so that the pressure in one or more central areas including an area at the center of the pressure chamber is higher than the pressure in other areas, thereby pressurizing the center of the elastic membrane, and controlling the one or more release nozzles to spray the pressurized fluid onto a contact point between the elastic membrane and the substrate, thereby executing a substrate release process that releases the substrate from the elastic membrane; A polishing apparatus comprising:

2. a polishing table for supporting the polishing pad; a substrate holding member having a substrate holding surface and a pressure chamber formed of an elastic membrane, the pressure chamber having a plurality of areas arranged concentrically, and pressing the substrate against the polishing pad by pressure within the pressure chamber; a pressure regulator that adjusts the pressure of the gas supplied to the pressure chamber of the substrate holding member; one or more release nozzles capable of injecting pressurized fluid; The pressure regulator is controlled to pressurize the entire area of ​​the pressure chamber to pressurize the entire elastic membrane, and then the pressure chamber is pressurized so that the pressure in one or more central areas including the area at the center of the pressure chamber becomes higher than the pressure in the other areas to pressurize the center of the elastic membrane, and the one or more release nozzles are controlled to inject the pressurized fluid at a contact point between the elastic membrane and the substrate, thereby releasing the substrate from the elastic membrane. a control device that executes a substrate release process to release the substrate from the Equipped with a detection device for detecting release of the substrate from the elastic membrane; The control device is configured to perform a total pressurization step of pressurizing the entire elastic membrane, and then a central pressurization step of pressurizing the center of the elastic membrane a predetermined number of times, and to terminate the substrate release process when the detection device detects the release of the substrate from the elastic membrane.

3. 3. The polishing apparatus according to claim 2, The control device is configured to repeat one control cycle, which consists of performing the entire pressure step followed by the central pressure step a predetermined number of times, until a predetermined upper limit number of times is reached, and to terminate the substrate release process when the detection device detects the release of the substrate from the elastic film.

4. a polishing table for supporting the polishing pad; a substrate holding member having a substrate holding surface and a pressure chamber formed of an elastic membrane, the pressure chamber having a plurality of areas arranged concentrically, and pressing the substrate against the polishing pad by pressure within the pressure chamber; a pressure regulator that adjusts the pressure of the gas supplied to the pressure chamber of the substrate holding member; one or more release nozzles capable of injecting pressurized fluid; a control device that executes a substrate release process in which the pressure regulator is controlled to pressurize all areas of the pressure chamber to pressurize the entire elastic membrane, and then the pressure chamber is pressurized so that the pressure in one or more central areas including an area at the center of the pressure chamber becomes higher than the pressure in other areas, thereby pressurizing the center of the elastic membrane, and the one or more release nozzles are controlled to spray the pressurized fluid onto a contact point between the elastic membrane and the substrate, thereby releasing the substrate from the elastic membrane; Equipped with A polishing apparatus, wherein the one or more central areas including the area at the center of the pressure chamber are one or more areas included in a range from the center of the pressure chamber to a radial length of 50% or less of the radius of the pressure chamber.

5. 5. The polishing apparatus according to claim 4, A polishing apparatus, wherein the one or more central areas including the area at the center of the pressure chamber are one or more areas included in a range from the center of the pressure chamber to a radial length between 40% and 50% of the radius of the pressure chamber.

6. 5. The polishing apparatus according to claim 1, The control device controls the release nozzle to start spraying the pressurized fluid after a predetermined delay time has passed after the start of pressurizing the entire elastic membrane, while the entire elastic membrane is being pressurized.

7. 5. The polishing apparatus according to claim 1, The control device pressurizes the pressure chamber so that the pressure in the area at the center of the pressure chamber is higher than the pressure in other areas, thereby pressurizing the center of the elastic membrane.

8. 5. The polishing apparatus according to claim 1, A polishing apparatus, wherein the spray direction of the one or more release nozzles is directed toward the center of the substrate.

9. 5. The polishing apparatus according to claim 1, The pressurized fluid ejected from the release nozzle is a liquid.

10. 5. The polishing apparatus according to claim 1, A polishing apparatus, wherein the pressurized fluid ejected from the release nozzle is a gas.

11. 5. The polishing apparatus according to claim 1, A polishing apparatus, wherein the pressurized fluid ejected from the release nozzle is a liquid and a gas.

12. 5. The polishing apparatus according to claim 1, The release nozzle is connected to a liquid supply source and a gas supply source and is capable of injecting liquid and / or gas as the pressurized fluid.

13. 1. A method for polishing a substrate using a substrate holding member having a substrate holding surface and a pressure chamber formed of an elastic film, the pressure chamber having a plurality of areas concentrically arranged, the method comprising: pressing the substrate against a polishing pad by the pressure in the pressure chamber, and polishing the substrate while moving the substrate and the polishing pad relative to each other; holding the polished substrate on the substrate holding surface of the substrate holding member; releasing the substrate from the elastic film when transferring the substrate from the substrate holding member to a substrate transfer device; Including, The releasing step includes: an entire pressurizing step of pressurizing the entire area of ​​the pressure chamber so that the entire area is at approximately the same height, which is approximately the same height as one or more release nozzles capable of ejecting pressurized fluid, thereby pressurizing the entire elastic membrane; a central pressurizing step of pressurizing the pressure chamber so that the pressure in one or more central areas including an area at the center of the pressure chamber is higher than the pressure in other areas, thereby pressurizing the central area of ​​the elastic membrane; and injecting the pressurized fluid from the one or more release nozzles onto a contact point between the elastic membrane and the substrate while pressurizing at least the center portion of the elastic membrane. Polishing method.

14. A non-volatile storage medium storing a program for causing a computer to execute a control method for a polishing apparatus that polishes a substrate using a substrate holding member having a substrate holding surface and a pressure chamber formed of an elastic film, the pressure chamber having a plurality of areas concentrically arranged, the program comprising: pressing the substrate against a polishing pad by the pressure in the pressure chamber, and polishing the substrate while moving the substrate and the polishing pad relative to each other; holding the polished substrate on the substrate holding surface of the substrate holding member; releasing the substrate from the elastic film when transferring the substrate from the substrate holding member to a substrate transfer device; Including, The releasing step includes: an entire pressurizing step of pressurizing the entire area of ​​the pressure chamber so that the entire area is at approximately the same height, which is approximately the same height as one or more release nozzles capable of ejecting pressurized fluid, thereby pressurizing the entire elastic membrane; a central pressurizing step of pressurizing the pressure chamber so that the pressure in one or more central areas including an area at the center of the pressure chamber is higher than the pressure in other areas, thereby pressurizing the central area of ​​the elastic membrane; spraying the pressurized fluid from the one or more release nozzles onto a contact point between the elastic membrane and the substrate while pressurizing at least the center of the elastic membrane; A non-volatile storage medium that stores a program that causes a computer to execute the program.

15. 1. A method for polishing a substrate using a substrate holding member having a substrate holding surface and a pressure chamber formed of an elastic film, the pressure chamber having a plurality of areas concentrically arranged, the method comprising: pressing the substrate against a polishing pad by the pressure in the pressure chamber, and polishing the substrate while moving the substrate and the polishing pad relative to each other; holding the polished substrate on the substrate holding surface of the substrate holding member; releasing the substrate from the elastic film when transferring the substrate from the substrate holding member to a substrate transfer device; Including, The releasing step includes: a whole pressurizing step of pressurizing the whole area of ​​the pressure chamber to pressurize the whole elastic membrane; a central pressurizing step of pressurizing the pressure chamber so that the pressure in one or more central areas including an area at the center of the pressure chamber is higher than the pressure in other areas, thereby pressurizing the central area of ​​the elastic membrane; While pressurizing at least the center portion of the elastic film, injecting the pressurized fluid from one or more release nozzles capable of injecting the pressurized fluid onto a contact point between the elastic film and the substrate; and performing a central portion pressurizing step of pressing the central portion of the elastic film a predetermined number of times after performing an entirety pressurizing step of pressing the entire elastic film, and terminating the releasing step when release of the substrate from the elastic film is detected. Polishing method.

16. A non-volatile storage medium storing a program for causing a computer to execute a control method for a polishing apparatus that polishes a substrate using a substrate holding member having a substrate holding surface and a pressure chamber formed of an elastic film, the pressure chamber having a plurality of areas concentrically arranged, the program comprising: pressing the substrate against a polishing pad by the pressure in the pressure chamber, and polishing the substrate while moving the substrate and the polishing pad relative to each other; holding the polished substrate on the substrate holding surface of the substrate holding member; releasing the substrate from the elastic film when transferring the substrate from the substrate holding member to a substrate transfer device; Including, The releasing step includes: a whole pressurizing step of pressurizing the whole area of ​​the pressure chamber to pressurize the whole elastic membrane; a central pressurizing step of pressurizing the pressure chamber so that the pressure in one or more central areas including an area at the center of the pressure chamber is higher than the pressure in other areas, thereby pressurizing the central area of ​​the elastic membrane; While pressurizing at least the center portion of the elastic film, injecting the pressurized fluid from one or more release nozzles capable of injecting the pressurized fluid onto a contact point between the elastic film and the substrate; a step of performing a whole pressurizing step of pressurizing the whole elastic film, and then performing a center pressurizing step of pressurizing the center of the elastic film a predetermined number of times, and terminating the releasing step when release of the substrate from the elastic film is detected; A non-volatile storage medium that stores a program that causes a computer to execute the program.

17. 1. A method for polishing a substrate using a substrate holding member having a substrate holding surface and a pressure chamber formed of an elastic film, the pressure chamber having a plurality of areas concentrically arranged, the method comprising: pressing the substrate against a polishing pad by the pressure in the pressure chamber, and polishing the substrate while moving the substrate and the polishing pad relative to each other; holding the polished substrate on the substrate holding surface of the substrate holding member; releasing the substrate from the elastic film when transferring the substrate from the substrate holding member to a substrate transfer device; Including, The releasing step includes: a whole pressurizing step of pressurizing the whole area of ​​the pressure chamber to pressurize the whole elastic membrane; a central pressurizing step of pressurizing the center of the elastic membrane by pressurizing the pressure chamber so that the pressure in one or more central areas including the area at the center of the pressure chamber becomes higher than the pressure in other areas, wherein the one or more central areas including the area at the center of the pressure chamber are one or more areas included in a range from the center of the pressure chamber to a radial length of 50% or less of the radius of the pressure chamber; and spraying pressurized fluid from one or more release nozzles capable of spraying pressurized fluid onto a contact point between the elastic membrane and the substrate while pressurizing at least the center portion of the elastic membrane. Polishing method.

18. A non-volatile storage medium storing a program for causing a computer to execute a control method for a polishing apparatus that polishes a substrate using a substrate holding member having a substrate holding surface and a pressure chamber formed of an elastic film, the pressure chamber having a plurality of areas concentrically arranged, the program comprising: pressing the substrate against a polishing pad by the pressure in the pressure chamber, and polishing the substrate while moving the substrate and the polishing pad relative to each other; holding the polished substrate on the substrate holding surface of the substrate holding member; releasing the substrate from the elastic film when transferring the substrate from the substrate holding member to a substrate transfer device; Including, The releasing step includes: a whole pressurizing step of pressurizing the whole area of ​​the pressure chamber to pressurize the whole elastic membrane; a central pressurizing step of pressurizing the center of the elastic membrane by pressurizing the pressure chamber so that the pressure in one or more central areas including the area at the center of the pressure chamber becomes higher than the pressure in other areas, wherein the one or more central areas including the area at the center of the pressure chamber are one or more areas included in a range from the center of the pressure chamber to a radial length of 50% or less of the radius of the pressure chamber; While pressurizing at least the center portion of the elastic film, injecting the pressurized fluid from one or more release nozzles capable of injecting the pressurized fluid onto a contact point between the elastic film and the substrate; A non-volatile storage medium that stores a program that causes a computer to execute the program.

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