Substrate holding device, substrate processing apparatus, substrate processing method, and storage medium

Abstract

To provide a substrate holding device capable of eliminating a variation in a film thickness of a substrate.SOLUTION: A substrate holding device 10 comprises an offset mechanism 80 configured to offset a carrier 71 relative to a retainer ring 70.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a substrate holding device, a substrate processing device, a substrate processing method, and a recording medium. [Background technology]

[0002] In the manufacture of semiconductor devices, various types of films are formed on wafers, which are an example of substrates. After the film formation process, the wafer is polished to remove unnecessary parts of the film and surface irregularities. Chemical mechanical polishing (CMP) is a typical wafer polishing technique.

[0003] CMP is performed by supplying a slurry onto the polishing surface while sliding a wafer against the polishing surface. The film formed on the wafer is polished by the combined effect of the mechanical action of the abrasive grains contained in the slurry and the chemical action of the slurry's chemical components. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6585445 Summary of the Invention [Problem to be solved by the invention]

[0005] The process of forming a film on a wafer is carried out using various deposition techniques such as plating, chemical vapor deposition (CVD), and physical vapor deposition (PVD). In these deposition techniques, the film may not be formed uniformly over the entire surface of the wafer. For example, there may be variations in film thickness along the circumferential direction of the wafer.

[0006] However, it is difficult to eliminate such variations in the film thickness of the wafer (for example, variations in the film thickness along the circumferential direction) with conventional CMP technology. Therefore, if the film on the wafer is polished uniformly, there is a risk that variations in the film thickness will remain on the wafer.

[0007] SUMMARY OF THE PRESENT DISCLOSURE In view of the above, an object of the present invention is to provide a substrate holding device, a substrate processing apparatus, a substrate processing method, and a recording medium that are capable of eliminating variations in film thickness on a substrate. [Means for solving the problem]

[0008] In one aspect, a substrate holding device is provided, comprising: an elastic membrane forming at least one pressure chamber for pressing a substrate; a carrier connected to the elastic membrane; a retaining ring surrounding the carrier; and an offset mechanism for offsetting the carrier relative to the retaining ring.

[0009] In one embodiment, the substrate holding device includes a tilting structure for tilting the retaining ring. In one embodiment, the tilting structure includes a spherical bearing disposed in an accommodating recess of the carrier and mounted on a shaft portion of the retaining ring. In one embodiment, the tilting structure includes a ball joint connecting the retainer ring and the head shaft.

[0010] In one aspect, the offset mechanism includes a plurality of pressing actuators supported by the carrier, each of the plurality of pressing actuators applying a pressing force to the carrier. In one aspect, the offset mechanism includes a plurality of pressing actuators supported by the retaining ring for applying a pressing force to the carrier. In one embodiment, the substrate holding device includes a rotational torque transmission mechanism that transmits a rotational torque acting on the retainer ring to the carrier.

[0011] In one aspect, there is provided a substrate processing apparatus including the substrate holding device, a polishing table supporting a polishing pad having a polishing surface against which a substrate held by the substrate holding device is pressed, and a control device for controlling an operation of the substrate holding device, the control device determining an eccentricity direction and an eccentricity amount of the carrier based on a film thickness distribution of the substrate measured during polishing of the substrate, and operating the offset mechanism to offset the carrier based on the determined eccentricity direction and eccentricity amount.

[0012] In one embodiment, the control device determines whether the relative angle of the substrate with respect to the substrate holding device has changed when measuring the film thickness distribution of the substrate, and if the relative angle has changed, corrects the relative angle based on the amount of change in the relative angle to determine the eccentricity direction and amount of eccentricity of the carrier. In one embodiment, after starting polishing of the substrate, the control device determines whether a current film thickness distribution in the circumferential direction of the substrate is within a predetermined first target film thickness distribution range, and if the current film thickness distribution is within the first target film thickness distribution range, operates the offset mechanism to return the carrier to an initial position, and if the current film thickness distribution is not within the first target film thickness distribution range, checks whether the eccentricity direction and amount of eccentricity of the carrier correspond to the film thickness distribution of the substrate. In one embodiment, after starting polishing of the substrate, the control device determines whether a current film thickness distribution in the radial direction of the substrate is within a predetermined second target film thickness distribution range, and if the current film thickness distribution is within the second target film thickness distribution range, determines whether a current film thickness distribution in the circumferential direction of the substrate is within a predetermined first target film thickness distribution range, and if the current film thickness distribution is not within the second target film thickness distribution range, operates a pressure adjustment device to change the pressure of the fluid supplied to the pressure chamber.

[0013] In one aspect, there is provided a substrate processing method comprising: pressing a substrate held by a substrate holding device against a polishing surface of a polishing pad to polish the substrate; determining a direction and amount of eccentricity of a carrier connected to an elastic membrane that forms at least one pressure chamber for pressing the substrate based on a film thickness distribution of the substrate measured while polishing the substrate; and operating an offset mechanism that offsets the carrier based on the determined direction and amount of eccentricity, thereby offsetting the carrier.

[0014] In one embodiment, a determination is made as to whether or not the relative angle of the substrate with respect to the substrate holding device has changed when the film thickness distribution of the substrate is measured, and if the relative angle has changed, the relative angle is corrected based on the amount of change in the relative angle, and the eccentricity direction and amount of eccentricity of the carrier are determined. In one embodiment, after polishing of the substrate begins, it is determined whether a current film thickness distribution in the circumferential direction of the substrate is within a predetermined first target film thickness distribution range, and if the current film thickness distribution is within the first target film thickness distribution range, the offset mechanism is operated to return the carrier to an initial position, and if the current film thickness distribution is not within the first target film thickness distribution range, it is confirmed whether the eccentricity direction and amount of eccentricity of the carrier correspond to the film thickness distribution of the substrate. In one embodiment, after polishing of the substrate begins, it is determined whether a current film thickness distribution in the radial direction of the substrate is within a predetermined second target film thickness distribution range, and if the current film thickness distribution is within the second target film thickness distribution range, it is determined whether a current film thickness distribution in the circumferential direction of the substrate is within a predetermined first target film thickness distribution range, and if the current film thickness distribution is not within the second target film thickness distribution range, a pressure adjustment device is operated to change the pressure of the fluid supplied to the pressure chamber.

[0015] In one aspect, there is provided a non-transitory computer-readable recording medium having recorded thereon a program for causing a computer to execute the steps of: causing a substrate holding device to perform an operation of pressing a substrate against a polishing surface of a polishing pad to polish the substrate; determining, based on a film thickness distribution of the substrate measured while polishing the substrate, an eccentricity direction and an eccentricity amount of a carrier connected to an elastic membrane that forms at least one pressure chamber for pressing the substrate; and causing an offset mechanism to perform an operation of offsetting the carrier based on the determined eccentricity direction and eccentricity amount.

[0016] In one aspect, the method has a computer execute a step of determining whether or not a relative angle of the substrate with respect to the substrate holding device has changed when measuring the film thickness distribution of the substrate, and if the relative angle has changed, correcting the relative angle based on the amount of change in the relative angle to determine the eccentricity direction and amount of eccentricity of the carrier. In one aspect, after starting polishing of the substrate, a computer is caused to execute the steps of: determining whether a current film thickness distribution in the circumferential direction of the substrate is within a predetermined first target film thickness distribution range; causing the offset mechanism to perform an operation of returning the carrier to an initial position if the current film thickness distribution is within the first target film thickness distribution range; and confirming whether the eccentricity direction and eccentricity amount of the carrier correspond to the film thickness distribution of the substrate if the current film thickness distribution is not within the first target film thickness distribution range. In one aspect, after polishing of the substrate begins, a computer is caused to execute the steps of determining whether a current film thickness distribution in the radial direction of the substrate is within a predetermined second target film thickness distribution range, and if the current film thickness distribution is within the second target film thickness distribution range, determining whether a current film thickness distribution in the circumferential direction of the substrate is within a predetermined first target film thickness distribution range, and if the current film thickness distribution is not within the second target film thickness distribution range, causing a pressure adjustment device to perform an operation of changing the pressure of the fluid supplied to the pressure chamber. Effect of the Invention

[0017] The substrate holding device can eliminate variations in the film thickness of the substrate by operating an offset mechanism that offsets the carrier connected to the elastic film. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 illustrates an embodiment of a substrate processing apparatus. [Diagram 2] Figure 2(a) is a horizontal cross-sectional view (cross-sectional view along line CC) of the polishing head, Figure 2(b) is a vertical cross-sectional view (cross-sectional view along line AA) of the polishing head, and Figure 2(c) is a vertical cross-sectional view (cross-sectional view along line BB) of the polishing head. [Diagram 3] 3(a) is a plan view showing a retainer ring and a spacer, FIG. 3(b) is a cross-sectional view taken along line XX in FIG. 3(a), and FIG. 3(c) is a cross-sectional view taken along line YY in FIG. 3(a). [Figure 4] 1 is a diagram showing an elastic membrane that forms a pressure chamber and a carrier connected to the elastic membrane; [Diagram 5] FIG. 4 is a diagram showing a rotational torque transmission mechanism. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. 8(a) is a diagram showing the carrier in a non-eccentric state, FIG. 8(b) is a diagram showing the carrier in an eccentric state, and FIG. 8(c) is a diagram showing the amount of eccentricity of the carrier. [Figure 9] 9(a) and 9(b) are diagrams showing the difference in pressing force acting on the peripheral edge of the wafer. [Figure 10] FIG. 10(a) is a diagram showing a uniform gap formed between the retaining ring and the carrier, and FIG. 10(b) is a diagram showing a non-uniform gap formed between the retaining ring and the carrier. [Figure 11] FIG. 1 illustrates an embodiment of a wafer polishing flow incorporating the operation of an offset mechanism. [Figure 12]13A and 13B are diagrams showing an example of information associated with a film thickness distribution of a wafer when determining an eccentricity direction and an eccentricity amount of a carrier. [Figure 13] FIG. 11 is a diagram showing another embodiment of a wafer polishing flow. [Figure 14] FIG. 11 is a diagram showing another embodiment of a wafer polishing flow. [Figure 15] FIG. 13 is a diagram showing a reference position of the angle in the circumferential direction of the wafer. [Figure 16] 16(a) to 16(c) are diagrams showing another embodiment of the offset mechanism. [Figure 17] FIG. 17(a) is a diagram showing the carrier in a non-eccentric state, FIG. 17(b) is a diagram showing the carrier in an eccentric state, and FIG. 17(c) is a diagram showing the amount of eccentricity of the carrier. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings described below, the same or corresponding components are denoted by the same reference numerals, and duplicated descriptions will be omitted. In the multiple embodiments described below, the configuration of one embodiment that is not particularly described is the same as the other embodiments, so duplicated descriptions will be omitted.

[0020] Fig. 1 is a diagram showing one embodiment of a substrate processing apparatus. As shown in Fig. 1, the substrate processing apparatus (more specifically, a polishing apparatus) 1 includes a substrate holding device (polishing head) 10 that holds and rotates a wafer W, which is an example of a substrate, a polishing table 2 that supports a polishing pad 5, and a polishing liquid supply nozzle 19 that supplies a polishing liquid (slurry) onto the polishing pad 5.

[0021] The polishing head 10 is configured to hold the wafer W on its lower surface by vacuum suction. The polishing head 10 and the polishing table 2 rotate in the same direction, and in this state, the polishing head 10 presses the wafer W against the polishing surface 5a of the polishing pad 5. A polishing liquid supply nozzle 19 supplies the polishing liquid onto the polishing pad 5. The wafer W comes into sliding contact with the polishing pad 5 in the presence of the polishing liquid, and is polished by a combined effect of the chemical action of the chemical components of the polishing liquid and the mechanical action of the abrasive grains contained in the polishing liquid.

[0022] The substrate processing apparatus 1 includes a head shaft 12 connected to a polishing head 10, a head arm 13 connected to the head shaft 12, and an arm shaft 14 supporting the head arm 13 so that it can swing freely.

[0023] The head shaft 12 is configured to move up and down relative to the head arm 13 by a vertical movement mechanism (not shown). The head arm 13 is configured to rotate about the arm shaft 14 by a rotation mechanism (not shown). The polishing head 10 holding the wafer W moves between a transfer position for the wafer W (a position outside the polishing table 2) and a position above the polishing table 2 by the rotation of the head arm 13.

[0024] The substrate processing apparatus 1 includes a head motor 15 that rotates the head shaft 12. The head motor 15 is built into the head arm 13. When the head motor 15 is driven, the polishing head 10 rotates together with the head shaft 12. The substrate processing apparatus 1 includes a rotation angle measuring device 50A connected to the head motor 15. The rotation angle measuring device 50A is configured to measure the rotation angle of the polishing head 10. An example of the rotation angle measuring device 50A is a rotary encoder.

[0025] The polishing table 2 is supported by a table shaft 3. The table shaft 3 is connected to a table motor 4. When the table motor 4 is driven, the polishing table 2 (and the polishing pad 5) rotates together with the table shaft 3. The substrate processing apparatus 1 includes a rotation angle measuring device 50B connected to the table motor 4. The rotation angle measuring device 50B is configured to measure the rotation angle of the polishing table 2. An example of the rotation angle measuring device 50B is a rotary encoder.

[0026] Figure 2(a) is a horizontal cross-sectional view (cross-sectional view along line CC) of the polishing head, Figure 2(b) is a vertical cross-sectional view (cross-sectional view along line AA) of the polishing head, and Figure 2(c) is a vertical cross-sectional view (cross-sectional view along line BB) of the polishing head.

[0027] 2(a) to 2(c), the polishing head 10 includes a head body 20. The head body 20 includes a circular housing (or flange) 21 connected to the head shaft 12, a spacer 75 attached to the lower surface of the housing 21, a carrier 71 disposed below the spacer 75, and a retainer ring 70 disposed on the side of the carrier 71.

[0028] Fig. 3(a) is a plan view showing the retainer ring and the spacer, Fig. 3(b) is a cross-sectional view taken along line XX in Fig. 3(a), and Fig. 3(c) is a cross-sectional view taken along line YY in Fig. 3(a). In Fig. 3(b) and Fig. 3(c), the housing 21 and the carrier 71 are omitted.

[0029] The retainer ring 70 includes a ring portion 70a that contacts the polishing surface 5a of the polishing pad 5, and a drive ring 70b fixed to the upper portion of the ring portion 70a. The ring portion 70a surrounds the peripheral portion of the wafer W and holds the wafer W so that the wafer W does not jump out of the polishing head 10 during polishing.

[0030] The drive ring 70b of the retainer ring 70 has a plurality of spokes 70d (six in the embodiment shown in FIG. 3) extending radially from a shaft portion 70c (described later) disposed at the center portion of the drive ring 70b. The spacer 75 has a plurality of radial grooves 75a in which the plurality of spokes 70d are housed.

[0031] A small gap is formed between the grooves 75a of the spacer 75 and the spokes 70d of the drive ring 70b. Therefore, the retaining ring 70 moves up and down and tilts relative to the spacer 75. When the housing 21 (and the head shaft 12) is rotated by the drive of the head motor 15, the rotational torque acting on the housing 21 is transmitted to the retaining ring 70 via the spacer 75.

[0032] Fig. 4 is a diagram showing an elastic membrane forming a pressure chamber and a carrier connected to the elastic membrane. As shown in Fig. 4, the polishing head 10 is provided with an elastic membrane 72 forming at least one (eight in this embodiment) pressure chamber 77a, 77b, 77c, 77d, 77e, 77f, 77g, 77h for pressing the wafer W. The elastic membrane 72 is made of a flexible rubber material having excellent strength and durability, such as ethylene propylene rubber (EPDM), polyurethane rubber, silicone rubber, etc.

[0033] The elastic membrane 72 has a plurality of (eight in this embodiment) annular peripheral walls 78a, 78b, 78c, 78d, 78e, 78f, 78g, and 78h. These peripheral walls 78a to 78h are concentrically disposed and connected to the carrier 71.

[0034] The lower surface of the carrier 71 and the peripheral walls 78a to 78h form pressure chambers 77a to 77h disposed below the carrier 71. The pressure chambers 77a to 77g have an annular shape, and the pressure chamber 77h has a circular shape. The pressure chambers 77a to 77h are disposed concentrically.

[0035] The elastic membrane 72 has a side wall 72a disposed on a side of the carrier 71. The side wall 72a is disposed concentrically with the peripheral walls 78a to 78h. One end of the side wall 72a is connected to the retainer ring 70, and the other end is connected to the carrier 71.

[0036] 4, the substrate processing apparatus 1 includes a fluid line 79a connected to each of the pressure chambers 77a to 77h. The fluid line 79a is connected to the pressure adjustment device 16 via a rotary joint (not shown). More specifically, the fluid line 79a passes through a through hole 74 (see FIGS. 3(a) and 3(c)) formed in the spacer 75 and communication holes formed in the housing 21 and the head shaft 12, and is connected to the pressure adjustment device 16.

[0037] The pressure adjusting device 16 is configured to adjust the pressure inside each of the pressure chambers 77a to 77h independently. An example of the pressure adjusting device 16 is an electropneumatic regulator. Although not shown, each of the pressure chambers 77a to 77h is configured to create a positive pressure or a negative pressure therein. Furthermore, the pressure chambers 77a to 77h can be opened to the atmosphere.

[0038] The polishing head 10 includes an annular rolling diaphragm 86 disposed between the housing 21 and the drive ring 70b (see FIGS. 2(b) and 2(c)). The substrate processing apparatus 1 includes a fluid line 79b connected to the rolling diaphragm 86. The fluid line 79b, like the fluid line 79a, is connected to the pressure regulator 16 via a rotary joint. The pressure regulator 16 is configured to independently regulate the pressure inside the rolling diaphragm 86.

[0039] 5 is a diagram showing a rotation torque transmission mechanism. As shown in FIG. 5 (and FIGS. 2(a) and 2(c)), the polishing head 10 is provided with a rotation torque transmission mechanism 85 that transmits the rotation torque acting on the retainer ring 70 to the carrier 71.

[0040] When the head motor 15 is driven, the retaining ring 70 rotates together with the housing 21. The rotational torque transmission mechanism 85 is configured to transmit the rotational torque acting on the retaining ring 70 to the carrier 71. The rotational torque transmission mechanism 85 includes a plurality of protrusions 85a extending from the drive ring 70b of the retaining ring 70 toward the carrier 71, and fitting portions 85b into which the plurality of protrusions 85a each fit loosely.

[0041] The multiple protrusions 85a are fixed to the inner circumferential surface of the drive ring 70b disposed radially outward of the carrier 71. The multiple fitting portions 85b are formed on the outer circumferential surface of the carrier 71 disposed radially inward of the drive ring 70b.

[0042] Since the fitting portion 85b has a size larger than the protrusion 85a, the protrusion 85a fits loosely into the fitting portion 85b. In the embodiment shown in Fig. 2(a), three protrusions 85a are arranged at equal intervals along the circumferential direction of the drive ring 70b, but the number of protrusions 85a is not limited to this embodiment.

[0043] As each protrusion 85 a fits into each fitting portion 85 b , the rotational torque transmission mechanism 85 transmits the rotational torque acting on the retaining ring 70 to the carrier 71 , and the carrier 71 rotates together with the retaining ring 70 .

[0044] The rotation torque transmission mechanism 85 not only transmits the rotation torque acting on the retaining ring 70 to the carrier 71, but also holds the carrier 71 to the retaining ring 70. Therefore, even if the polishing head 10 rises together with the head shaft 12 and gravity acts on the carrier 71, the carrier 71 will not fall off the retaining ring 70. In this way, the rotation torque transmission mechanism 85 applies a rotational force to the carrier 71 while preventing the carrier 71 from falling off the retaining ring 70.

[0045] Fig. 6 is a diagram showing the tilting structure. As shown in Fig. 6, the polishing head 10 is provided with a tilting structure 76 that tilts the retaining ring 70. The tilting structure 76 is disposed in an accommodating recess 71a formed in the center portion of the carrier 71.

[0046] The retainer ring 70 surrounding the carrier 71 has a shaft portion 70c extending from the lower surface of the drive ring 70b toward the accommodating recess 71a of the carrier 71. The shaft portion 70c is formed at the center of the drive ring 70b and extends along the central axis CL1 of the head shaft 12. The shaft portion 70c extends into the accommodating recess 71a.

[0047] 6, the tilting structure 76 includes a spherical bearing mounted on the shaft portion 70c of the retaining ring 70. The tilting structure 76 as a spherical bearing includes an annular inner ring 76a and an outer ring 76b that slidably supports the outer circumferential surface of the inner ring 76a.

[0048] The spacer 75 has an annular protrusion 73 extending toward the accommodating recess 71a. The annular protrusion 73 is disposed radially outward of the shaft portion 70c of the retainer ring 70, and the tilting structure 76 is disposed between the shaft portion 70c and the annular protrusion 73.

[0049] The outer ring 76b is fixed to the inner peripheral surface of the annular projection 73 and slidably supports the inner ring 76a. Therefore, the inner ring 76a can tilt in all directions (360 degrees) relative to the outer ring 76b. The shaft portion 70c is inserted into the inner ring 76a. Therefore, the retaining ring 70 including the shaft portion 70c can move only vertically relative to the inner ring 76a, while the horizontal movement of the retaining ring 70 is restricted by the tilting structure 76. With this configuration, the retaining ring 70 is configured to be vertically movable and tiltable independently of the head body 20.

[0050] Fig. 7 is a plan view of the offset mechanism. As shown in Fig. 6 and Fig. 7, the polishing head 10 includes an offset mechanism 80 that offsets the carrier 71 with respect to the retaining ring 70. In this embodiment, the offset mechanism 80 is disposed in the accommodating recess 71a of the carrier 71. The offset mechanism 80 includes a plurality of pressing actuators 81 that are disposed at equal intervals along the circumferential direction of the retaining ring 70.

[0051] The pressing actuators 81 have the same structure. The pressing actuators 81 are configured to apply a pressing force to the spokes 70d in a direction parallel to the extension direction of the spokes 70d (i.e., a direction perpendicular to the central axis CL1).

[0052] A ball screw mechanism including a motor and a ball screw, or an air cylinder, can be given as an example of the pressing actuator 81. In one embodiment, the pressing actuator 81 may be a combination of a ball screw mechanism and an air cylinder.

[0053] The multiple pressing actuators 81 are disposed at equal intervals along the circumferential direction of the annular protrusion 73. In this embodiment, three pressing actuators 81 are disposed, but the number of pressing actuators 81 is not limited to this embodiment.

[0054] The pressing actuator 81 includes a pressing member 81a that applies a pressing force to the head main body 20 (more specifically, the annular protrusion 73 of the spacer 75), and a holding member 81b that holds the pressing member 81a. The holding member 81b is embedded in the inner circumferential surface of the accommodation recess 71a of the carrier 71. The pressing member 81a extends from the holding member 81b toward the annular protrusion 73, and is configured to be freely expandable and contractible.

[0055] Each pressing actuator 81 expands or contracts a pressing member 81a by being driven. When the pressing member 81a expands, a pressing force is applied to the annular protrusion 73. The spacer 75 including the annular protrusion 73 is fixed to the head shaft 12 via the housing 21. Therefore, the pressing force applied to the annular protrusion 73 acts on the carrier 71 to which the pressing actuator 81 is attached.

[0056] Since the protrusion 85a of the rotation torque transmission mechanism 85 is loosely fitted into the fitting portion 85b, the carrier 71 is movable relative to the retaining ring 70. Therefore, each pressing actuator 81 applies the pressing force applied to the annular protrusion 73 to the carrier 71. In other words, each pressing actuator 81 indirectly applies the pressing force to the carrier 71.

[0057] Fig. 8(a) is a diagram showing the carrier in a non-eccentric state, Fig. 8(b) is a diagram showing the carrier in an eccentric state, and Fig. 8(c) is a diagram showing the amount of eccentricity of the carrier. Carrier 71 moves relative to retaining ring 70 depending on the magnitude of the pressing force applied to annular protrusion 73 and the pressing direction against annular protrusion 73.

[0058] 8(a), the central axis CL1 of the retaining ring 70 (i.e., the head main body 20) and the central axis CL2 of the carrier 71 coincide with each other. In this manner, the position where the central axes CL1 and CL2 coincide with each other is the initial position of the carrier 71. In other words, the initial position of the carrier 71 is the position when the displacement amounts of all the pressing actuators 81 are at their initial values.

[0059] By operating each pressing actuator 81, the carrier 71 (i.e., the central axis CL2) becomes eccentric with respect to the central axis CL1 of the retaining ring 70. The eccentric direction and amount of eccentricity of the carrier 71 depend on the pressing direction and magnitude of the pressing force of each pressing actuator 81. In Fig. 8(b) and Fig. 8(c), of the three pressing actuators 81, one pressing actuator 81 is expanded and the other two pressing actuators 81 are contracted, so that the central axis CL2 of the carrier 71 is displaced from the central axis CL1 by an eccentricity amount (displacement amount) d.

[0060] 9(a) and 9(b) are diagrams showing the difference in pressing force acting on the peripheral portion of the wafer. As shown in FIG. 9(a), when a sufficient gap is formed between the carrier 71 and the retaining ring 70 (i.e., when the gap is large), the elastic film 72 forming the pressure chamber 77a does not contact the ring portion 70a of the retaining ring 70.

[0061] 9(a), the carrier 71 is disposed at an initial position, and a uniform gap is formed between the retainer ring 70 and the elastic membrane 72 in the circumferential direction of the wafer W. In this case, the expansion force of the elastic membrane 72 is dispersed into a force acting on the side wall 72a side and a force acting on the wafer W side. Therefore, the pressing force of the elastic membrane 72 against the polishing surface 5a of the wafer W is small, and as a result, the polishing rate at the peripheral portion of the wafer W is almost the same as (or slightly smaller than) the polishing rate on the inner side of the peripheral portion of the wafer W.

[0062] 9(b), when there is not a sufficient gap between the carrier 71 and the retaining ring 70 (i.e., when the gap is small), the elastic membrane 72 that forms the pressure chamber 77a comes into contact with the ring portion 70a of the retaining ring 70. The region where the elastic membrane 72 comes into contact with the ring portion 70a is called a contact region 72b.

[0063] In this case, the expansion force of the elastic film 72 acts largely on the wafer W side. Therefore, the pressing force of the elastic film 72 against the polishing surface 5a of the wafer W is large, and as a result, the polishing rate at the peripheral portion of the wafer W is greater than the polishing rate on the inner side of the peripheral portion of the wafer W.

[0064] The offset mechanism 80 is configured to offset (displace or move) the carrier 71 to form a non-uniform gap between the retainer ring 70 and the elastic film 72 in the circumferential direction of the wafer W. Therefore, even if there is variation in the film thickness along the circumferential direction of the wafer W, the offset mechanism 80 can control the polishing rate for each of a plurality of regions on the peripheral portion of the wafer W by offsetting the carrier 71, thereby polishing the wafer W non-uniformly in the circumferential direction of the wafer W. In this way, the offset mechanism 80 can eliminate the variation in the film thickness on the peripheral portion of the wafer W.

[0065] In one embodiment, the elastic membrane 72 may have a slippery coating material SR1 applied to its surface so that the elastic membrane 72 moves smoothly over the wafer W when the offset mechanism 80 offsets the carrier 71 (see FIGS. 9(a) and 9(b)). The coating material SR1 faces the back surface of the wafer W. One example of the coating material SR1 is a polytetrafluoroethylene (PTFE) coating.

[0066] The carrier 71 has a surface facing the spacer 75. In one embodiment, the carrier 71 may have a coating material SR2 having good slipperiness applied to the surface facing the spacer 75 (see FIG. 6). One example of the coating material SR2 is a polytetrafluoroethylene (PTFE) coating.

[0067] Fig. 10(a) is a diagram showing a uniform gap formed between the retaining ring and the carrier, and Fig. 10(b) is a diagram showing a non-uniform gap formed between the retaining ring and the carrier. In Fig. 10(a) and Fig. 10(b), the film thickness is large in the region AR at the peripheral portion of the wafer W. In Fig. 10(a), when the carrier 71 is not offset (decentered or moved) by the offset mechanism 80, the gap between the retaining ring 70 and the carrier 71 is uniform (i.e., gap A = gap B).

[0068] As described with reference to Fig. 9(b), the offset mechanism 80 can increase the polishing rate of a specific region in the circumferential direction of the wafer W by offsetting the carrier 71. As shown in Fig. 10(b), the region AR of the wafer W corresponds to the position where the polishing head angle is 0 degrees. Note that the region indicated by the thick black dotted line in Fig. 10(b) represents the contact region 72b of the elastic membrane 72 with the retainer ring 70.

[0069] Therefore, when the film thickness in the region AR is large, the offset mechanism 80 offsets (decenters or moves) the carrier 71 to a position where the polishing head angle is 0 degrees (i.e., gap A>gap B). The polishing rate of the wafer W depends on the amount of eccentricity of the carrier 71. Therefore, the amount of eccentricity of the carrier 71 is determined appropriately according to the film thickness in the region AR. As a result, the polishing rate in the region AR becomes higher than the polishing rates in other regions, and the region AR is actively polished. In this way, the film thickness in the region AR can be reduced.

[0070] The offset mechanism 80 is configured to offset the carrier 71 based on the measured film thickness of the wafer W during polishing of the wafer W. More specifically, as shown in Fig. 1, the substrate processing apparatus 1 includes a film thickness sensor 30 that detects a film thickness signal that changes according to the film thickness of the wafer W, and a control device 60 that measures the film thickness of the wafer W based on the film thickness signal detected by the film thickness sensor 30.

[0071] The film thickness sensor 30 is disposed inside the polishing table 2. Every time the polishing table 2 rotates once, the film thickness sensor 30 detects (generates) film thickness signals in a plurality of regions including the central portion of the wafer W. An example of the film thickness sensor 30 is an optical sensor or an eddy current sensor.

[0072] The control device 60 is electrically connected to components (e.g., the film thickness sensor 30, the rotation angle measuring devices 50A and 50B, etc.) of the substrate processing apparatus 1. The control device 60 acquires information such as a film thickness signal detected by the film thickness sensor 30, a rotation angle of the polishing head 10 measured by the rotation angle measuring device 50A, and a rotation angle of the polishing table 2 measured by the rotation angle measuring device 50B.

[0073] The control device 60 is configured to control the operations of the substrate processing apparatus 1 (e.g., the operations of the polishing head 10, the polishing table 2, and the polishing liquid supply nozzle 19) including the operation of the offset mechanism 80. In this embodiment, the control device 60 is formed of a computer.

[0074] As shown in FIG. 1, the control device 60 includes a memory unit 60D in which programs, data, etc. are stored, a measurement unit 60C that measures the film thickness of the wafer W based on a film thickness signal obtained from the film thickness sensor 30, a calculation unit 60B such as a CPU (central processing unit) or GPU (graphic processing unit) that performs calculations according to the programs stored in the memory unit 60D, and a control unit 60A that controls the operation of the substrate processing device 1 based on the results calculated by the calculation unit 60B.

[0075] Fig. 11 is a diagram showing one embodiment of a wafer polishing flow incorporating the operation of the offset mechanism. The control device 60 is configured to execute each step described with reference to Fig. 11. When polishing of the wafer W is started, the film thickness sensor 30 rotates together with the polishing table 2 and detects a film thickness signal while crossing the surface of the wafer W. The film thickness signal is an index value that directly or indirectly indicates the film thickness, and changes as the film thickness of the wafer W decreases.

[0076] 11, the measurement unit 60C measures the film thickness distribution on the wafer W based on the film thickness signals detected by the film thickness sensor 30.

[0077] The memory unit 60D stores the film thickness distribution of the wafer W measured by the measurement unit 60C. Thereafter, the calculation unit 60B determines the eccentricity direction and amount of eccentricity of the carrier 71 based on the film thickness distribution of the wafer W measured during polishing of the wafer W, and calculates the displacement amounts of the three pressing actuators 81 based on the determined eccentricity direction and amount of eccentricity (step S102).

[0078] 12 is a diagram showing an example of information associated with the film thickness distribution of the wafer when determining the eccentricity direction and amount of eccentricity of the carrier. The calculation unit 60B determines the eccentricity direction and amount of eccentricity of the carrier 71 by associating the information on the film thickness distribution of the wafer W with the following information (1) to (5): (1) Distance R1 of the central axis CL1 of the polishing head 10 from the rotation center CL3 of the polishing table 2 (2) The rotation angle RA1 of the position where the central axis CL1 of the polishing head 10 is disposed on the polishing table 2 (3) Rotation angle RA1 of the position where the film thickness sensor 30 is disposed on the polishing table 2 (4) Rotation angle RA2 of the polishing head 10 (5) Distance R2 of the film thickness sensor 30 from the center of rotation CL3 When the polishing head 10 is swung during polishing of the wafer W, the calculation unit 60B may associate information on the swing angle of the polishing head 10 with information on the film thickness distribution of the wafer W.

[0079] Rotation angle RA1 indicates the rotation angle of the polishing table 2 measured based on a rotation angle measuring device 50B (see Figure 1) connected to the table motor 4, and rotation angle RA2 indicates the rotation angle of the polishing head 10 measured based on a rotation angle measuring device 50A (see Figure 1) connected to the head motor 15.

[0080] When the rotation angle of the initial position of the film thickness sensor 30 (approximately 190 degrees in the embodiment shown in FIG. 12) is represented as RA1', the rotation angle RA1' represents the deviation in the rotation phase between the starting point of the rotation phase of the rotation angle measuring device 50B (i.e., zero degrees) and the position of the film thickness sensor 30. During polishing of the wafer W, the current rotation angle of the film thickness sensor 30 changes with the rotation of the polishing table 2. Therefore, the rotation angle RA1 when measuring the current rotation angle of the film thickness sensor 30 is calculated as the rotation angle obtained by adding the rotation angle RA1' of the initial position of the film thickness sensor 30.

[0081] When the rotation angle of the initial position of the polishing head 10 (approximately 260 degrees in the embodiment shown in FIG. 12) is expressed as RA1'', the rotation angle RA1'' represents the rotation phase shift between the starting point of the rotation phase of the rotation angle measuring device 50B (i.e., zero degrees) and the position of the polishing head 10. During polishing of the wafer W, the rotation angle of the polishing head 10 does not change with the rotation of the polishing table 2. Therefore, the rotation angle RA1 when measuring the current rotation angle of the polishing head 10 corresponds to the rotation angle RA1''.

[0082] The above-mentioned information (1) to (5) is stored in the storage unit 60D. These are examples of information associated with the film thickness distribution of the wafer W, and it is not necessary that all of the information (1) to (5) be associated with the film thickness distribution of the wafer W. At least one of the information (1) to (5) may be associated with the film thickness distribution of the wafer W.

[0083] After step S102, the control unit 60A receives a command from the calculation unit 60B and operates at least one of the three pressing actuators 81 to offset the carrier 71 (see step S103). In this manner, the offset mechanism 80 forms a non-uniform gap between the retainer ring 70 and the elastic film 72 in the circumferential direction of the wafer W.

[0084] Thereafter, the wafer W is polished for a predetermined time (see step S104), and the measurement unit 60C again measures the film thickness distribution on the wafer W based on the multiple film thickness signals detected by the film thickness sensor 30 (see step S105).

[0085] The calculation unit 60B determines whether the current average film thickness over the entire wafer W (i.e., in the circumferential and radial directions) is equal to or less than a predetermined target value based on the film thickness distribution of the wafer W measured in step S105 (see step S106). If the current average film thickness is equal to or less than the target value (see "YES" in step S106), the calculation unit 60B determines the polishing end point of the wafer W and ends polishing of the wafer W.

[0086] On the other hand, if the current average film thickness is not equal to or less than the target value (see "NO" in step S106), the calculation unit 60B determines whether the current film thickness distribution in the circumferential direction of the wafer W is within the range of a predetermined target film thickness distribution (first target film thickness distribution) (see step S107).

[0087] If the current film thickness distribution is within the range of the first target film thickness distribution (see "YES" in step S107), the control unit 60A returns the displacement amounts of all the pressing actuators 81 to their initial values ​​(i.e., initial positions) (see step S108). More specifically, the control unit 60A operates all the pressing actuators 81 so that the central axis CL1 of the retaining ring 70 and the central axis CL2 of the carrier 71 coincide with each other.

[0088] In this manner, the polishing head 10 forms a uniform gap between the retaining ring 70 and the elastic membrane 72 in the circumferential direction of the wafer W, thereby uniformly polishing the wafer W. After step S108, the control device 60 executes the same step as step S104.

[0089] If the current film thickness distribution is not within the range of the first target film thickness distribution (see "NO" in step S107), the calculation unit 60B executes an operation of checking (see step S109) whether the eccentricity direction and the eccentricity amount of the carrier 71 match (correspond) to the film thickness distribution of the wafer W. If the eccentricity direction and the eccentricity amount of the carrier 71 match (correspond) to the film thickness distribution of the wafer W (see "YES" in step S109), the control device 60 executes the same step as step S104.

[0090] On the other hand, if the eccentricity direction and amount of eccentricity of the carrier 71 do not match the film thickness distribution of the wafer W (see "NO" in step S109), the control device 60 executes the same step as step S102. More specifically, the calculation unit 60B again determines the eccentricity direction and amount of eccentricity of the carrier 71, and calculates the displacement amounts of the three pressing actuators 81 based on the determined eccentricity direction and amount of eccentricity.

[0091] In the flowchart shown in FIG. 11, the calculation unit 60B determines whether the current film thickness distribution in the circumferential direction of the wafer W is within the range of a first target film thickness distribution (see step S107), but in one embodiment, the calculation unit 60B may determine whether the current film thickness distribution in the radial direction of the wafer W is within the range of a predetermined target film thickness distribution (second target film thickness distribution).

[0092] Fig. 13 is a diagram showing another embodiment of the flow of polishing a wafer. As shown in Fig. 13, the control device 60 executes steps S201 to S206 corresponding to steps S101 to S106 in Fig. 11. After step S206, the calculation unit 60B determines whether the current film thickness distribution in the radial direction of the wafer W is within the range of the second target film thickness distribution (see step S207).

[0093] If the current film thickness distribution is within the range of the second target film thickness distribution (see "YES" in step S207), the calculation unit 60B executes step S210, which corresponds to step S107. Thereafter, the control device 60 executes step S211, which corresponds to step S108, or step S212, which corresponds to step S109, based on the result of step S210.

[0094] If the current film thickness distribution is not within the range of the second target film thickness distribution (see "NO" in step S207), the calculation unit 60B calculates the pressure change amount of the fluid supplied to each pressure chamber 77a-77h (see step S208). More specifically, the calculation unit 60B determines a pressure chamber corresponding to a specific film thickness so that the current film thickness distribution in the radial direction of the wafer W is within the range of the second target film thickness distribution, and calculates the pressure change amount of the fluid supplied to the determined pressure chamber.

[0095] After step S208, the calculation unit 60B issues a command to the control unit 60A based on the determined pressure change amount. In response to the command from the calculation unit 60B, the control unit 60A changes the output value of the pressure adjustment device 16 (more specifically, each electropneumatic regulator) and operates the pressure adjustment device 16 (see step S209). Thereafter, the calculation unit 60B executes step S210, which corresponds to step S107.

[0096] Fig. 14 is a diagram showing another embodiment of the wafer polishing flow. Fig. 15 is a diagram showing a reference position of the circumferential angle of the wafer. During polishing of the wafer W, the wafer W may be displaced in the rotation direction of the polishing head 10 due to the frictional force acting between the wafer W and the polishing pad 5.

[0097] If the wafer W is shifted in the rotation direction of the polishing head 10, the film thickness distribution of the wafer W will not match the displacement amount of the pressing actuator 81 calculated by the calculation unit 60B. As a result, the control unit 60A may not be able to accurately eliminate the variation in film thickness of the wafer W.

[0098] Therefore, the substrate processing apparatus 1 is provided with a reference position detection device 40 that detects a reference position of the circumferential angle of the wafer W during polishing of the wafer W (see FIG. 1). In this embodiment, the reference position of the circumferential angle of the wafer W is the position of a notch Nt formed on the peripheral edge of the wafer W (see FIG. 15).

[0099] 1, the reference position detection device 40 is disposed adjacent to the polishing head 10. An example of the reference position detection device 40 is a fiberscope. The reference position detection device 40 constantly monitors the position of the notch Nt of the wafer W while the wafer W is being polished.

[0100] The control device 60 (more specifically, the calculation unit 60B) is electrically connected to the reference position detection device 40 and is configured to obtain the position of the notch Nt of the wafer W from the reference position detection device 40 during polishing.

[0101] The control device 60 calculates the relative angle of the position of the notch Nt with respect to the polishing head 10 based on a first signal (first data) regarding the rotation angle of the polishing head 10 obtained from the rotation angle measuring device 50A and a second signal (second data) regarding the position of the notch Nt obtained from the reference position detection device 40.

[0102] Based on the rotation angle of the polishing head 10 acquired from the rotation angle measuring device 50A, the control device 60 determines the relative angle between the position of the notch Nt and the polishing head 10 before polishing of the wafer W starts. After polishing of the wafer W starts, the measuring unit 60C measures the film thickness distribution on the wafer W based on the multiple film thickness signals detected by the film thickness sensor 30 (see step S301).

[0103] At this time, the control device 60 (more specifically, the calculation unit 60B) starts polishing the wafer W, and identifies the position of the notch Nt based on the data acquired from the reference position detection device 40 during polishing of the wafer W.

[0104] The calculation unit 60B checks whether the positional relationship between the circumferential direction of the wafer W and the circumferential direction of the polishing head 10 at the time of measuring the film thickness distribution of the wafer W (i.e., the current relative angle) has changed compared to the relative angle before starting polishing of the wafer W (see step S302). If the current relative angle has not changed (see "NO" in step S303), the control device 60 executes steps S305 to S312, which correspond to steps S102 to S109.

[0105] On the other hand, if the current relative angle has changed (see “YES” in step S303), the calculation unit 60B calculates the amount of change in the current relative angle, and corrects the film thickness distribution on the wafer W based on the calculated amount of change in the relative angle (see step S304).

[0106] More specifically, the calculation unit 60B corrects the relative angle to synchronize the positional relationship of the film thickness distribution of the wafer W with the eccentricity direction and amount of eccentricity of the pressing actuator 81. Thereafter, the control device 60 executes steps S305 to S312. According to this embodiment, even if the wafer W is shifted in the rotation direction of the polishing head 10, the control unit 60A can eliminate the variation in the film thickness of the wafer W.

[0107] The control device 60 executes each of the above-mentioned steps according to instructions included in the program stored in the storage unit 60D. The program for causing the control device 60 to execute each of the above-mentioned steps is recorded in a computer-readable recording medium, which is a non-transitory tangible object, and is provided to the control device 60 via the recording medium. Alternatively, the program may be input to the control device 60 via a communication network such as the Internet or a local area network.

[0108] Figures 16(a) to 16(c) are diagrams showing another embodiment of the offset mechanism. In the embodiment shown in Figures 16(a) to 16(c), configurations that are not particularly described are the same as those in the above-mentioned embodiment, and therefore redundant description will be omitted.

[0109] Figure 16(a) is a horizontal cross-sectional view (cross-sectional view along line CC) of the polishing head, Figure 16(b) is a vertical cross-sectional view (cross-sectional view along line AA) of the polishing head, and Figure 16(c) is a vertical cross-sectional view (cross-sectional view along line BB) of the polishing head.

[0110] 16(a) to 16(c), the head body 20 does not include a spacer 75, and the drive ring 70b and the housing 21 are integrally configured. In other words, the drive ring 70b and the housing 21 are the same structure.

[0111] The head shaft 12 is connected to the drive ring 70b (i.e., the housing 21) via a tilting structure 96. In this embodiment, the tilting structure 96 is a ball joint. The drive ring 70b (i.e., the housing 21) is tiltable with respect to the head shaft 12 by the tilting structure 96.

[0112] The carrier 71 is disposed below the drive ring 70b. In this embodiment, the carrier 71 may have a coating material SR2 applied to the surface facing the drive ring 70b (see FIG. 6). Similarly, the elastic film 72 may have a coating material SR1 with good slipperiness applied to its surface (see FIGS. 9(a) and 9(b)).

[0113] 16(a) to 16(c), the polishing head 10 may include an offset mechanism 90 instead of the offset mechanism 80. The offset mechanism 90 includes a plurality of pressing actuators 91 that directly apply a pressing force to the carrier 71.

[0114] The pressing actuators 91 have the same structure. Each pressing actuator 91 is configured to apply a pressing force to the carrier 71 in a direction perpendicular to the central axis line CL1. An example of the pressing actuator 91 is a ball screw mechanism including a motor and a ball screw, or an air cylinder. In one embodiment, the pressing actuator 91 may be a combination of a ball screw mechanism and an air cylinder.

[0115] The multiple pressing actuators 91 are arranged at equal intervals along the circumferential direction of the retaining ring 70 and are supported by the retaining ring 70. More specifically, the retaining ring 70 has multiple housing insertion portions 95 arranged at equal intervals along the circumferential direction thereof.

[0116] Each of the pressing actuators 91 is housed in each of the housing insertion portions 95. In this embodiment, three pressing actuators 91 are arranged, but the number of pressing actuators 91 is not limited to this embodiment.

[0117] The pressing actuator 91 includes a pressing member 91a that applies a pressing force to the carrier 71, and a holding member 91b that holds the pressing member 91a. The housing insertion portion 95 has an insertion hole 95a that extends in the radial direction of the retainer ring 70, and a recessed portion 95b connected to the insertion hole 95a. The pressing member 91a is inserted into the insertion hole 95a, and the holding member 91b is placed in the recessed portion 95b.

[0118] The pressing member 91a extends from the holding member 91b toward the carrier 71 and is configured to be freely expandable and contractible. Each pressing actuator 91 expands or contracts the pressing member 91a by being driven. When the pressing member 91a expands, it applies a pressing force to the carrier 71.

[0119] Fig. 17(a) is a diagram showing the carrier in a non-eccentric state, Fig. 17(b) is a diagram showing the carrier in an eccentric state, and Fig. 17(c) is a diagram showing the amount of eccentricity of the carrier. Carrier 71 moves relative to retaining ring 70 according to the magnitude and pressing direction of the pressing force applied by pressing actuator 91.

[0120] 17(a), the central axis CL1 of the retaining ring 70 (i.e., the head main body 20) and the central axis CL2 of the carrier 71 are aligned with each other. On the other hand, by operating each pressing actuator 91, the central axis CL2 of the carrier 71 becomes eccentric with respect to the central axis CL1 of the retaining ring 70.

[0121] The eccentric direction and amount of eccentricity of the carrier 71 depend on the pressing direction and the magnitude of the pressing force of each pressing actuator 91. In Figures 17(b) and 17(c), of the three pressing actuators 91, two pressing actuators 91 are expanded and one pressing actuator 91 is contracted, so that the central axis CL2 of the carrier 71 is displaced from the central axis CL1 by an eccentricity amount (displacement amount) d.

[0122] In this embodiment as well, the offset mechanism 90 is configured to offset (displace or move) the carrier 71 to form a non-uniform gap between the retainer ring 70 and the elastic film 72 in the circumferential direction of the wafer W. Therefore, even if the film thickness varies along the circumferential direction of the wafer, the offset mechanism 90 can eliminate the film thickness variation at the peripheral portion of the wafer W.

[0123] In one embodiment, the embodiment shown in Figures 1 to 15 may be combined with the embodiment shown in Figure 16. More specifically, the polishing head 10 may include a combination of an offset mechanism 80 and an offset mechanism 90.

[0124] The above-described embodiments have been described for the purpose of enabling a person having ordinary skill in the art to practice the present invention. Various modifications of the above-described embodiments are naturally possible for a person skilled in the art, and the technical idea of ​​the present invention can be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but is to be interpreted in the broadest scope according to the technical idea defined by the claims. [Explanation of symbols]

[0125] 1. Substrate Processing Equipment 2 Polishing table 3 Table Axis 4 Table Motor 5 Polishing Pads 5a Polished surface 10 Polishing head (substrate holding device) 12 Head shaft 13 Head Arm 14 Arm shaft 15 Head Motor 16 Pressure Regulating Device 20 Head body 21 Housing 30 Film Thickness Sensor 40 Reference position detection device 50A Rotation Angle Measuring Instrument 50B Rotation Angle Measuring Instrument 60 Control device 60A Control Unit 60B calculation section 60C measurement section 60D storage section 70 Retainer ring 70a Ring section 70b Drive Ring 70c shaft 70d spokes 71 Career 71a Recessed portion 72 Elastic Membrane 72a side wall 72b Contact area 73 Annular protrusion 74 Through Hole 75 Spacer 75a groove 76 Tilt structure 76a Inner circle 76b Outer ring 77a~77h Pressure chamber 78a~78h Peripheral wall 79a Fluid Line 79b Fluid Line 80 Offset mechanism 81 Pressing actuator 81a Pressing member 81b Holding member 85 Rotational torque transmission mechanism 85a protrusion 85b Fitting part 86 Rolling Diaphragm 90 Offset mechanism 91 Pressing actuator 91a Pressing member 91b Holding member 95 Storage Insertion Part 95a Insertion hole 95b Recess 96 Tilt structure

Claims

1. an elastic membrane that forms at least one pressure chamber for pressing the substrate; a carrier coupled to the elastic membrane; a retainer ring surrounding the carrier; an offset mechanism for offsetting the carrier with respect to the retaining ring.

2. The substrate-holding device of claim 1 , further comprising a tilting structure for tilting the retaining ring.

3. The substrate support device according to claim 2 , wherein the tilt structure comprises a spherical bearing disposed in a receiving recess of the carrier and mounted on a shaft portion of the retaining ring.

4. The substrate support apparatus of claim 2 , wherein the tilt structure comprises a ball joint connecting the retainer ring and a head shaft.

5. the offset mechanism includes a plurality of pressing actuators supported by the carrier, The substrate holding device according to claim 1 , wherein each of the plurality of pressing actuators applies a pressing force to the carrier.

6. 2. The substrate holding device according to claim 1, wherein the offset mechanism includes a plurality of pressing actuators supported by the retainer ring for applying a pressing force to the carrier.

7. The substrate holding device according to claim 1 , further comprising a rotational torque transmission mechanism for transmitting a rotational torque acting on the retainer ring to the carrier.

8. A substrate holding device according to claim 1 ; a polishing table supporting a polishing pad having a polishing surface against which the substrate held by the substrate holding device is pressed; A control device for controlling an operation of the substrate holding device, The control device includes: determining a direction and an amount of eccentricity of the carrier based on a film thickness distribution of the substrate measured during polishing of the substrate; The substrate processing apparatus operates the offset mechanism based on the determined eccentricity direction and eccentricity amount to offset the carrier.

9. The control device includes: determining whether or not a relative angle of the substrate with respect to the substrate holding device has changed when measuring a film thickness distribution of the substrate; The substrate processing apparatus according to claim 8 , wherein, when the relative angle has changed, the relative angle is corrected based on an amount of change in the relative angle, and an eccentricity direction and an eccentricity amount of the carrier are determined.

10. The control device includes: After starting polishing of the substrate, determining whether a current film thickness distribution in a circumferential direction of the substrate is within a predetermined first target film thickness distribution range; if the current film thickness distribution is within the range of the first target film thickness distribution, operating the offset mechanism to return the carrier to an initial position; The substrate processing apparatus of claim 8 , further comprising: a step of confirming whether a direction and amount of eccentricity of the carrier correspond to a film thickness distribution of the substrate when the current film thickness distribution is not within a range of the first target film thickness distribution.

11. The control device includes: After starting polishing the substrate, determining whether a current film thickness distribution in a radial direction of the substrate is within a predetermined second target film thickness distribution range; If the current film thickness distribution is within the range of the second target film thickness distribution, determining whether the current film thickness distribution in the circumferential direction of the substrate is within the range of a predetermined first target film thickness distribution; The substrate processing apparatus of claim 8 , further comprising: a pressure adjusting device that operates to change a pressure of the fluid supplied to the pressure chamber when the current film thickness distribution is not within a range of the second target film thickness distribution.

12. The substrate held by the substrate holding device is pressed against the polishing surface of the polishing pad to polish the substrate; determining an eccentricity direction and an eccentricity amount of a carrier connected to an elastic film that forms at least one pressure chamber for pressing the substrate, based on a film thickness distribution of the substrate measured during polishing of the substrate; The substrate processing method further comprises: operating an offset mechanism for offsetting the carrier based on the determined eccentricity direction and eccentricity amount, thereby offsetting the carrier.

13. determining whether or not a relative angle of the substrate with respect to the substrate holding device has changed when measuring a film thickness distribution of the substrate; The substrate processing method according to claim 12 , further comprising the steps of: when the relative angle has changed, correcting the relative angle based on an amount of change in the relative angle, and determining a direction and an amount of eccentricity of the carrier.

14. After starting polishing of the substrate, determining whether a current film thickness distribution in a circumferential direction of the substrate is within a predetermined first target film thickness distribution range; if the current film thickness distribution is within the range of the first target film thickness distribution, operating the offset mechanism to return the carrier to an initial position; The substrate processing method according to claim 12 , further comprising the step of: confirming whether a direction and amount of eccentricity of the carrier correspond to a film thickness distribution of the substrate when the current film thickness distribution is not within a range of the first target film thickness distribution.

15. After starting polishing the substrate, determining whether a current film thickness distribution in a radial direction of the substrate is within a predetermined second target film thickness distribution range; If the current film thickness distribution is within the range of the second target film thickness distribution, determining whether the current film thickness distribution in the circumferential direction of the substrate is within the range of a predetermined first target film thickness distribution; 13. The substrate processing method according to claim 12, further comprising the step of: operating a pressure adjusting device to change a pressure of the fluid supplied to the pressure chamber when the current film thickness distribution is not within a range of the second target film thickness distribution.

16. causing a substrate holding device to perform an operation of pressing a substrate against a polishing surface of a polishing pad to polish the substrate; determining an eccentricity direction and an eccentricity amount of a carrier connected to an elastic film that forms at least one pressure chamber for pressing the substrate, based on a film thickness distribution of the substrate measured during polishing of the substrate; and causing an offset mechanism to perform an operation of offsetting the carrier based on the determined eccentricity direction and eccentricity amount.

17. determining whether a relative angle of the substrate with respect to the substrate holding device has changed when measuring a film thickness distribution of the substrate; and if the relative angle has changed, correcting the relative angle based on an amount of change in the relative angle to determine a direction and amount of eccentricity of the carrier.

18. After starting polishing of the substrate, determining whether a current film thickness distribution in a circumferential direction of the substrate is within a predetermined range of a first target film thickness distribution; causing the offset mechanism to execute an operation of returning the carrier to an initial position when the current film thickness distribution is within the range of the first target film thickness distribution; and if the current film thickness distribution is not within the range of the first target film thickness distribution, confirming whether a direction and amount of eccentricity of the carrier correspond to a film thickness distribution of the substrate.

19. determining whether or not a current film thickness distribution in a radial direction of the substrate is within a range of a predetermined second target film thickness distribution after starting polishing of the substrate; determining whether the current film thickness distribution in the circumferential direction of the substrate is within a range of a first target film thickness distribution when the current film thickness distribution is within the range of the second target film thickness distribution; and when the current film thickness distribution is not within the range of the second target film thickness distribution, causing a pressure adjusting device to perform an operation of changing the pressure of the fluid supplied to the pressure chamber.

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