Retainer ring, substrate polishing device, and cleaning method of substrate processing device and retainer ring

Abstract

To provide a retainer ring that provides a preferable polishing rate.SOLUTION: A retainer ring is attached to a polishing head for pushing a substrate against a polishing pad. The retainer ring includes a ring body formed with a plurality of groove portions extending from an inner peripheral side to an outer peripheral side, in a bottom surface that contacts the polishing pad. A first surface forming an inner wall of the groove portions formed in the ring body and a second surface facing the first surface are formed substantially in parallel to each other. The first surface and the second surface are inclined toward a rotation direction of the retainer ring at the time of polishing of the substrate.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a retainer ring, a substrate polishing apparatus, a substrate processing apparatus, and a method for cleaning a retainer ring. [Background technology]

[0002] The polishing rate in a substrate polishing apparatus is a factor related to productivity, and a higher polishing rate is generally desirable. The retainer ring used in the substrate polishing apparatus is generally considered to be one factor that determines the polishing rate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-116656 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-155188 [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-129863 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a retainer ring, a substrate polishing apparatus, a substrate processing apparatus, and a method for cleaning a retainer ring, which are capable of achieving a good polishing rate. [Means for solving the problem]

[0005] [1] A retainer ring according to one aspect of the present invention comprises: A retainer ring attached to a polishing head for pressing a substrate against a polishing pad, a ring body having a bottom surface that contacts the polishing pad and has a plurality of grooves that extend from the inner periphery to the outer periphery; a first surface constituting an inner wall of the groove formed in the ring body and a second surface opposing the first surface are formed substantially parallel to each other; The first surface and the second surface are inclined toward the direction of rotation of the retainer ring when polishing the substrate.

[0006] [2] A retainer ring according to one aspect of the present invention is the retainer ring described in [1] above, the first surface and the second surface are located in the front and rear, respectively, in a rotation direction of the retainer ring during polishing of the substrate; In the depth direction of the groove, the length of the second surface is longer than the length of the first surface.

[0007] [3] A substrate polishing apparatus according to one aspect of the present invention includes the retainer ring according to [1] or [2] above.

[0008] [4] A substrate polishing apparatus according to one aspect of the present invention is the substrate polishing apparatus described in [3] above, The retainer ring further includes a cleaning mechanism having a cleaning nozzle that sprays cleaning liquid toward the groove at an angle that substantially matches the inclination angle of the inner wall of the groove of the retainer ring.

[0009] [5] A substrate polishing apparatus according to one aspect of the present invention is the substrate polishing apparatus according to the above [3] or [4]. In the location, Further, a cleaning mechanism for cleaning the retainer ring is provided. When the cleaning mechanism cleans the retainer ring, the retainer ring rotates in a direction opposite to the direction of rotation when polishing the substrate.

[0010] [6] A substrate processing apparatus according to one aspect of the present invention includes the substrate polishing apparatus according to any one of the above items [3] to [5].

[0011] [7] A retainer ring cleaning method according to one aspect of the present invention is the retainer ring cleaning method described in [1] or [2] above, placing the retainer ring on top of a cleaning mechanism; rotating the retainer ring in a direction opposite to a direction of rotation during polishing of the substrate; spraying a cleaning liquid from a cleaning nozzle of the cleaning mechanism unit toward the groove at an angle that substantially matches an inclination angle of the inner wall of the groove of the retainer ring; It has. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a retainer ring, a substrate polishing apparatus, a substrate processing apparatus, and a method for cleaning a retainer ring, which are capable of obtaining a good polishing rate. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram showing an example of a schematic configuration of a substrate polishing apparatus according to an embodiment of the present invention; [Figure 2] 1 is a perspective view of a substrate polishing apparatus according to an embodiment of the present invention. [Figure 3] 1 is a cross-sectional view showing an internal configuration of a substrate polishing apparatus according to an embodiment of the present invention. [Figure 4] FIG. 2 is a schematic diagram of a side surface of the retainer ring according to the embodiment. [Figure 5] FIG. 5 is an enlarged view of an area P shown in FIG. [Figure 6] 10A and 10B are diagrams illustrating the state of a polishing liquid in a groove formed in the retainer ring according to the embodiment. [Figure 7] 4 shows the shape of the bottom surface of the retainer ring according to the present embodiment. [Figure 8] 10A and 10B are diagrams showing other examples of the shape of the bottom surface of the retainer ring according to the embodiment. [Figure 9] FIG. 10 is a diagram showing the results of comparing the polishing rate of the retainer ring according to the present embodiment with that of a conventional example. [Figure 10] FIG. 2 is a diagram showing an example of a schematic configuration of a cleaning mechanism that cleans the retainer ring according to the embodiment. [Figure 11] FIG. 2 is a schematic side view of the cleaning mechanism unit according to the embodiment. [Figure 12]5A to 5C are diagrams showing a flow of a method for cleaning a retainer ring according to the present embodiment. [Figure 13] 10 is a side view of a groove formed in a retainer ring according to Comparative Example 1. FIG. [Figure 14] 10 is a side view of a groove formed in a retainer ring according to Comparative Example 2. FIG. [Figure 15] FIG. 10 is a side view of a groove formed in a retainer ring according to Comparative Example 3. [Figure 16] FIG. 10 is a side view of a groove formed in a retainer ring according to Comparative Example 4. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, each embodiment will be described with reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of well-known matters or redundant description of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art.

[0015] (Substrate processing equipment) FIG. 1 is a diagram showing an example of a schematic configuration of a substrate processing apparatus 100 according to this embodiment. As shown in FIG. 1, the substrate processing apparatus 100 has a substantially rectangular housing 2, the interior of which is partitioned by partition walls 2a and 2b into a load / unload section 6, a polishing section (substrate polishing apparatus) 1, and a cleaning section 8. The substrate processing apparatus 100 has an operation control section (control device) 10 that controls wafer processing operations.

[0016] The load / unload section 6 is equipped with load ports 12 on which wafer cassettes containing a large number of wafers are placed. A traveling mechanism 14 is installed in the load / unload section 6 along the row of load ports 12, and a transfer robot (loader) 16 that can move along the direction in which the wafer cassettes are arranged is installed on this traveling mechanism 14. The transfer robot 16 can access the wafer cassettes placed on the load ports 12 by moving on the traveling mechanism 14.

[0017] The polishing section (substrate polishing apparatus) 1 is an area where wafer polishing is performed and includes a first polishing unit 1A, a second polishing unit 1B, a third polishing unit 1C, and a fourth polishing unit 1D. The first polishing unit 1A includes a first polishing table 22A to which a polishing pad 20 having a polishing surface is attached, a first polishing head 24A for holding a wafer and polishing the wafer while pressing it against the polishing pad 20 on the first polishing table 22A, a first polishing liquid supply nozzle 26A for supplying a polishing liquid (e.g., slurry) or a dressing liquid (e.g., pure water) to the polishing pad 20, a first dressing unit 28A for dressing the polishing surface of the polishing pad 20, and a first atomizer 30A for spraying a mixed fluid of a liquid (e.g., pure water) and a gas (e.g., nitrogen gas) or a liquid (e.g., pure water) onto the polishing surface.

[0018] Similarly, the second polishing unit 1B comprises a second polishing table 22B having a polishing pad 20 attached thereto, a second polishing head 24B, a second polishing liquid supply nozzle 26B, a second dressing unit 28B, and a second atomizer 30B; the third polishing unit 1C comprises a third polishing table 22C having a polishing pad 20 attached thereto, a third polishing head 24C, a third polishing liquid supply nozzle 26C, a third dressing unit 28C, and a third atomizer 30C; and the fourth polishing unit 1D comprises a fourth polishing table 22D having a polishing pad 20 attached thereto, a fourth polishing head 24D, a fourth polishing liquid supply nozzle 26D, a fourth dressing unit 28D, and a fourth atomizer 30D.

[0019] A first linear transporter 40 is disposed adjacent to the first polishing unit 1A and the second polishing unit 1B. This first linear transporter 40 is a mechanism for transporting wafers between four transfer positions (first transfer position TP1, second transfer position TP2, third transfer position TP3, and fourth transfer position TP4). Furthermore, a second linear transporter 42 is disposed adjacent to the third polishing unit 1C and the fourth polishing unit 1D. This second linear transporter 42 is a mechanism for transporting wafers between three transfer positions (fifth transfer position TP5, sixth transfer position TP6, and seventh transfer position TP7).

[0020] A lifter 44 for receiving a wafer from the transfer robot 16 is disposed adjacent to the first transfer position TP1. The wafer is delivered from the transfer robot 16 to the first linear transporter 40 via this lifter 44. A shutter (not shown) is provided on the partition wall 2a between the lifter 44 and the transfer robot 16, and the shutter is opened when the wafer is to be transferred so that the wafer can be delivered from the transfer robot 16 to the lifter 44.

[0021] The wafer is transferred to the lifter 44 by the transfer robot 16, and then transferred from the lifter 44 to the first linear transporter 40, and then transferred to the polishing units 1A and 1B by the first linear transporter 40. The polishing head 24A of the first polishing unit 1A moves between a position above the first polishing table 22A and the second transfer position TP2 by the swinging motion of the head arm 31. Therefore, the transfer of the wafer to the polishing head 24A is performed at the second transfer position TP2. This is done at position TP2.

[0022] Similarly, the polishing head 24B of the second polishing unit 1B moves between a position above the polishing table 22B and a third transfer position TP3, and the transfer of a wafer to the polishing head 24B is performed at the third transfer position TP3. The polishing head 24C of the third polishing unit 1C moves between a position above the polishing table 22C and a sixth transfer position TP6, and the transfer of a wafer to the polishing head 24C is performed at the sixth transfer position TP6. The polishing head 24D of the fourth polishing unit 1D moves between a position above the polishing table 22D and a seventh transfer position TP7, and the transfer of a wafer to the polishing head 24D is performed at the seventh transfer position TP7.

[0023] A swing transporter 46 is disposed between the first linear transporter 40, the second linear transporter 42, and the cleaning unit 8. Wafers are transferred from the first linear transporter 40 to the second linear transporter 42 by the swing transporter 46. The wafers are transported by the second linear transporter 42 to the third polishing unit 1C and / or the fourth polishing unit 1D.

[0024] A wafer temporary placement table 48 mounted on a frame (not shown) is disposed to the side of the swing transporter 46. As shown in FIG. 3, this temporary placement table 48 is disposed adjacent to the first linear transporter 40 and is located between the first linear transporter 40 and the cleaning unit 8. The swing transporter 46 transports wafers between the fourth transfer position TP4, the fifth transfer position TP5, and the temporary placement table 48.

[0025] The wafer placed on the temporary table 48 is transferred to the cleaning unit 8 by a first transfer robot 50 of the cleaning unit 8. The cleaning unit 8 includes a primary cleaning unit 52 and a secondary cleaning unit 54 that clean the polished wafer with a cleaning solution, and a drying unit 56 that dries the cleaned wafer. The first transfer robot 50 operates to transfer the wafer from the temporary table 48 to the primary cleaning unit 52 and then from the primary cleaning unit 52 to the secondary cleaning unit 54. A second transfer robot 58 is disposed between the secondary cleaning unit 54 and the drying unit 56. The second transfer robot 58 operates to transfer the wafer from the secondary cleaning unit 54 to the drying unit 56.

[0026] The dried wafer is removed from the drying unit 56 by the transfer robot 16 and returned to the wafer cassette. In this manner, in the substrate processing apparatus 100, the wafer undergoes a series of processes including polishing, cleaning, and drying.

[0027] (Substrate polishing equipment) Next, a description will be given of the substrate polishing apparatus 1 according to this embodiment. The first polishing unit 1A, the second polishing unit 1B, the third polishing unit 1C, and the fourth polishing unit 1D of the substrate polishing apparatus 1 have the same configuration. Therefore, the first polishing unit 1A will be described below.

[0028] Fig. 2 is a perspective view showing the first polishing unit 1A. As shown in Fig. 2, the first polishing unit 1A includes a polishing table 22A that supports the polishing pad 20, a polishing head 24A that presses the wafer W against the polishing pad 20, and a polishing liquid supply nozzle 26A that supplies a polishing liquid (slurry) to the polishing pad 20. In Fig. 2, the first dressing unit 28A and the first atomizer 30A are not shown.

[0029] The polishing table 22A is connected to a table motor 25 disposed below the table shaft 23, and the table motor 25 rotates the polishing table 22A in the direction indicated by the arrow. The polishing pad 20 is attached to the upper surface of the polishing table 22A. The polishing head 24A is fixed to the lower end of a shaft 27. The polishing head 24A is configured to hold the wafer W on its lower surface by vacuum suction. The shaft 27 is connected to a rotation mechanism (described later) installed in the head arm 31, and the polishing head 24A is rotated via the shaft 27 by this rotation mechanism.

[0030] The surface of the wafer W is polished as follows: The polishing head 24A and the polishing table 22A are rotated in the directions indicated by the arrows, and a polishing liquid (slurry) is supplied onto the polishing pad 20 from the polishing liquid supply nozzle 26A. In this state, the polishing head 24A presses the wafer W against the polishing surface 20a of the polishing pad 20. The surface of the wafer W is polished by the mechanical action of the abrasive grains contained in the polishing liquid and the chemical action of the chemical components contained in the polishing liquid.

[0031] The wafer W polished by the first polishing unit 1A shown in Figure 2 is moved to the second transfer position TP2 (see Figure 1) by the swing operation of the head arm 31. The second transfer position TP2 functions as a wafer transfer position, where the wafer W is released. A pusher is provided at the second transfer position (wafer transfer position) TP2, and the polished wafer W is transferred to the transfer stage of the first linear transporter 40 by the up and down movement of the pusher.

[0032] Fig. 3 is a cross-sectional view of the first polishing unit 1A (substrate polishing apparatus 1). As shown in Fig. 3, the polishing head 24A includes a polishing head main body 18 that presses the wafer W against the polishing surface 20a, and a retainer ring 19 that supports the outer periphery of the wafer W to prevent the wafer W from jumping out of the polishing head 24A. The shape of the retainer ring 19 will be described later.

[0033] The polishing head 24A is connected to a shaft 27, and a rotary joint 35 is attached to the upper end of the shaft 27. The shaft 27 is configured to move up and down relative to the head arm 31 by a vertical movement mechanism 37, so that the entire polishing head 24A can be raised and lowered relative to the head arm 31 to position it.

[0034] The up-and-down movement mechanism 37 that moves the shaft 27 and polishing head 24A up and down includes a bridge 38 that rotatably supports the shaft 27 via a bearing 36, a ball screw 71 attached to the bridge 38, a support base 39 supported by a support column 70, and a servo motor 78 provided on the support base 39. The support base 39 that supports the servo motor 78 is fixed to the head arm 31 via the support column 70.

[0035] The ball screw 71 includes a screw shaft 71a connected to a servo motor 78 and a nut 71b onto which the screw shaft 71a is threaded. The shaft 27 moves up and down integrally with the bridge 38. Therefore, when the servo motor 78 is driven, the bridge 38 moves up and down via the ball screw 71, which in turn moves the shaft 27 and the polishing head 24A up and down.

[0036] Next, the rotation mechanism of the shaft 27 will be described. The shaft 27 is connected to a rotary cylinder 72 via a key (not shown). This rotary cylinder 72 is provided with a timing pulley 73 on its outer periphery. A head motor 76 is fixed to the head arm 31, and the timing pulley 73 is connected to a timing pulley 75 provided on the head motor 76 via a timing belt 74. By rotating the head motor 76, the rotary cylinder 72 and the shaft 27 rotate together via the timing pulley 75, timing belt 74, and timing pulley 73, and the polishing head 24A rotates. The head arm 31 is supported by an arm shaft 77 rotatably supported on a frame (not shown). The head motor 76, servo motor 78, and other devices within the apparatus control the substrate processing. The operation is controlled by an operation control section (control device) 10 (see FIG. 1) of the processing device 100 .

[0037] (retainer ring) Next, the retainer ring 19 according to this embodiment will be described.

[0038] Fig. 4 is a schematic diagram of a side surface of a retainer ring 19 according to this embodiment. As shown in Fig. 4, the retainer ring 19 has a ring main body 19A, and a plurality of grooves 19b are formed in a bottom surface 19a of the ring main body 19A (the surface that comes into contact with the polishing surface 20a of the polishing pad 20). The plurality of grooves 19b are formed so that their inner walls are inclined relative to the polishing surface 20a of the polishing pad 20 in the rotation direction A of the retainer ring 19 during polishing of the substrate (wafer W).

[0039] Fig. 5 is an enlarged view of region P shown in Fig. 4. As shown in Fig. 5, the inner wall of groove 19b has a first surface and a second surface opposing the first surface. First surface 19b1 and second surface 19b2 are located in front and behind, respectively, in rotation direction A of retainer ring 19 during polishing of the substrate (wafer W).

[0040] The first surface 19b1 and the second surface 19b2 are formed substantially parallel to each other. Therefore, even if the bottom surface 19a of the retainer ring 19 (ring main body 19A) wears (decreases in the thickness direction) due to sliding contact with the polishing pad 20, the width D (see FIG. 5) of the opening of the groove portion 19b does not change. In other words, even if the bottom surface 19a of the retainer ring 19 wears, the contact area of ​​the retainer ring 19 with the polishing pad 20 does not change. Therefore, the pressure pressing on the polishing pad 20 can be kept constant.

[0041] Furthermore, first surface 19b1 and second surface 19b2 are formed so as to be inclined toward a rotation direction A of retainer ring 19 during polishing of a substrate (wafer W). Specifically, the inclination angle θ1 of first surface 19b1 and second surface 19b2 is 90 degrees or more, and more preferably an obtuse angle of 100 to 135 degrees.

[0042] 6 is a diagram showing the state of the polishing liquid (slurry) S drawn into the grooves 19b during polishing of a substrate (wafer W). When polishing a substrate (wafer W), the polishing liquid S supplied to the polishing pad 20 is drawn into the grooves 19b. The polishing liquid S drawn into the grooves 19b then rises upward (in the Y direction in FIG. 6) as the retainer ring 19 rotates. In contrast, in the retainer ring 19 of this embodiment, the inner wall (second surface 19b2) of the grooves 19b is inclined toward the rotation direction A of the retainer ring 19 during polishing of the substrate (wafer W). This presses the polishing liquid S downward diagonally forward in the rotation direction A (in the X direction in FIG. 6), preventing the polishing liquid S from escaping upward inside the grooves 19b. Therefore, when polishing a substrate (wafer W), a flow of polishing liquid S is generated from inside groove portion 19b of retainer ring 19 toward polishing surface 20a of polishing pad 20, and polishing liquid S can be spread over a wider area on polishing surface 20a. As a result, the proportion of polishing liquid that contributes to polishing can be increased.

[0043] Furthermore, since the inner wall (second surface 19b2) of groove portion 19b is inclined toward the rotation direction A of retainer ring 19 when polishing the substrate (wafer W), the area of ​​second surface 19b2 of the inner wall of groove portion 19b is larger than when it is not inclined, and therefore more polishing liquid S can be taken into groove portion 19b.

[0044] FIG. 7 is a diagram showing the shape of the groove 19b as viewed from the bottom surface 19a side of the retainer ring 19 (ring main body 19A) (only a part of the arc on the circumference is shown). As shown in FIG. 7, the retainer ring 19 has the groove 19b extending from the inner periphery side to the outer periphery side, and the groove 19b extends from the bottom surface 19a side to the outer periphery side. Groove portions 19b have a radial shape when viewed from the side. Groove portions 19b have such a shape that polishing liquid S can be taken into the interior of groove portions 19b.

[0045] 8 is a diagram showing another example of the shape of groove 19b as viewed from the bottom surface 19a of retainer ring 19 (ring main body 19A). As shown in FIG. 8, groove 19b may be formed so that it is inclined when retainer ring 19 is viewed from the bottom surface 19a. By shaping groove 19b in this way, the area of ​​the inner wall (second surface 19b2) can be increased, allowing more polishing liquid S to be taken into groove 19b.

[0046] (Comparative Example) FIG. 13 is an enlarged view of groove 191b of retainer ring 191 (ring main body 191A) according to Comparative Example 1. As shown in FIG. 13, retainer ring 191 according to Comparative Example 1 is formed so that the width of groove 191b decreases upward (in the depth direction) from bottom surface 191a. Therefore, when bottom surface 191a of retainer ring 191 wears (decreases in the thickness direction) due to sliding contact with polishing pad 20, width D1 of the opening of groove 191b changes (becomes smaller). In other words, when bottom surface 191a of retainer ring 191 wears, the contact area of ​​retainer ring 191 with polishing pad 20 changes. Therefore, the pressure pressing on polishing pad 20 cannot be kept constant.

[0047] FIG. 14 is an enlarged view of groove 192b of retainer ring 192 (ring main body 192A) according to Comparative Example 2. As shown in FIG. 14, retainer ring 192 according to Comparative Example 2 is formed so that the width of groove 192b decreases upward (in the depth direction) from bottom surface 192a. Therefore, when bottom surface 192a of retainer ring 192 wears (decreases in the thickness direction) due to sliding contact with polishing pad 20, width D2 of the opening of groove 192b changes (becomes smaller). In other words, when bottom surface 192a of retainer ring 192 wears, the contact area of ​​retainer ring 192 with polishing pad 20 changes. Therefore, the pressure pressing on polishing pad 20 cannot be kept constant.

[0048] FIG. 15 is an enlarged view of groove 193b of retainer ring 193 (ring main body 193A) according to Comparative Example 3. As shown in FIG. 15, retainer ring 193 according to Comparative Example 3 is formed so that the width of groove 193b increases upward (in the depth direction) from bottom surface 193a. Therefore, when bottom surface 193a of retainer ring 193 wears (decreases in the thickness direction) due to sliding contact with polishing pad 20, width D3 of the opening of groove 193b changes (increases). In other words, when bottom surface 193a of retainer ring 193 wears, the contact area of ​​retainer ring 193 with polishing pad 20 changes. Therefore, the pressure pressing on polishing pad 20 cannot be kept constant.

[0049] 16 is an enlarged view of groove 194b of retainer ring 194 (ring main body 194A) according to Comparative Example 4. In retainer ring 194 of this comparative example, the inner walls of groove 194b are generally parallel to each other. Therefore, even if bottom surface 194a of retainer ring 194 wears (decreases in the thickness direction) due to sliding contact with polishing pad 20, width D4 of the opening of groove 194b does not change, and the contact area of ​​retainer ring 194 with polishing pad 20 does not change. However, because the inner walls of groove 194b are vertical (90 degrees), polishing liquid S taken into groove 194b during polishing of a substrate (wafer W) floats up inside groove 194b (in the Y1 direction in FIG. 16). Therefore, it is not possible to create a flow of the polishing liquid S from inside the groove portion 194b of the retainer ring 194 toward the polishing surface 20a of the polishing pad 20, and the polishing liquid S cannot be spread over a wider area on the polishing surface 20a.

[0050] (Comparison of polishing rate with comparative example) FIG. 9 shows the results of comparing the polishing rate when the retainer ring 19 according to this embodiment is used and when the retainer ring 194 of Comparative Example 4 (see FIG. 16) is used. As shown in FIG. 9, when the retainer ring 19 according to this embodiment is used, the polishing rate is improved by about 10% compared to Comparative Example 4. Therefore, by using the retainer ring 19 according to this embodiment, it is possible to significantly improve the polishing rate. When the polishing pad during polishing is observed when the retainer ring 19 according to this embodiment is used and when the retainer ring 194 of Comparative Example 4 (see FIG. 16) is used, it can be confirmed that the polishing liquid S is spread over a wider area on the polishing pad when the retainer ring 19 according to this embodiment is used. From this, it can be inferred that the amount of polishing liquid S contributing to polishing is increasing.

[0051] As such, the retainer ring 19 of this embodiment is used in a polishing head 24 for pressing a substrate against a polishing pad, and is a retainer ring 19 for supporting the outer periphery of a substrate W held by the polishing head 24, and is provided with a ring body 19A having a bottom surface 19a that abuts the polishing pad 20 and has multiple grooves extending from the inner periphery to the outer periphery, and a first surface 19b1 that forms the inner wall of the grooves 19b formed in the ring body 19A and a second surface 19b2 that faces the first surface 19b1 are formed approximately parallel, and the first surface 19b1 and the second surface 19b2 are inclined toward the rotation direction A of the retainer ring when the substrate W is polished.

[0052] With this configuration, the retainer ring 19 of this embodiment can achieve a good polishing rate.

[0053] (cleaning mechanism) Next, a description will be given of the cleaning mechanism for cleaning the groove of the retainer ring according to this embodiment. The cleaning mechanism also cleans the gap between the retainer ring 19 and the membrane, but a description thereof will be omitted.

[0054] As an example, the following description will be based on the positional relationship between the first polishing unit 1A and the second transfer position (wafer transfer position) TP2, but the positional relationship between the second polishing unit 1B and the third transfer position TP3, the relationship between the third polishing unit 1C and the sixth transfer position TP6, and the positional relationship between the fourth polishing unit 1D and the seventh transfer position TP7 are similar.

[0055] As shown in Fig. 10, the polishing head 24A moves between a position above the first polishing table 22A and a second transfer position (wafer transfer position) TP2 by swinging the head arm 31. A pusher (not shown) is disposed at the second transfer position (wafer transfer position) TP2. Fig. 10 shows the traveling rails 47 of the first linear transporter 40, and the transfer stage 49 moves along the traveling rails 47. A state in which a wafer W is placed on the transfer stage 49 is shown.

[0056] Further, at the second transfer position (wafer transfer position) TP2, a cleaning mechanism 60 for cleaning the retainer ring 19 of the polishing head 24A is disposed, and the cleaning mechanism 60 is provided with a plurality of comb-shaped cleaning units 61 (in the illustrated example, it is composed of three cleaning units 61). Each cleaning unit 61 is capable of reciprocating as shown by the arrow between a radially outer position (retracted position) and a radially inner position (cleaning position).

[0057] 11 is a diagram showing how the cleaning mechanism 60 according to this embodiment cleans the inside of the groove of the retainer ring 19 (ring main body 19A) when it has moved to the cleaning position. In FIG. 11, the polishing head 24A holding the wafer W is located at the second transfer position (wafer transfer position) TP2. For ease of explanation, only the retainer ring 19 (ring main body 19A) is shown for the polishing head 24A, and only the cleaning nozzle 61n provided on the cleaning unit 61 is shown for the cleaning mechanism.

[0058] As shown in FIG. 11, the cleaning mechanism 60 rotates the polishing head 24A in a direction (rotation direction B) opposite to the rotation direction A used when polishing the wafer W, and sprays cleaning liquid from the cleaning nozzle 61n toward the groove portion 19b of the retainer ring 19 (ring main body 19A).

[0059] Here, the reason why the rotation direction of the polishing head 24A during cleaning is reversed from that during polishing will be explained. If the rotation direction of the polishing head 24A during cleaning were the same as that during polishing (rotation direction A in FIG. 4), the cleaning liquid would be knocked downward by the inner wall (second surface 19b2) of the groove 19b, making it difficult to clean the depths of the groove 19b. On the other hand, by rotating the polishing head 24A during cleaning in the opposite direction from that during polishing (rotation direction B), the cleaning liquid is not knocked downward by the inner wall (second surface 19b2) of the groove 19b. Rather, the inner wall (second surface 19b2) of the groove 19b scoops up the cleaning liquid, allowing more cleaning liquid to enter the groove 19b, thereby improving the cleaning effect. For this reason, in this embodiment, the rotation direction of the polishing head 24A during cleaning of the retainer ring 19 by the cleaning mechanism 60 is reversed from that during polishing.

[0060] Furthermore, the spray angle θ2 of the cleaning liquid sprayed from the cleaning nozzle 61n (the angle with respect to a plane parallel to the bottom surface 19a of the retainer ring 19) may be set to approximately match the inclination angle θ1 of the inner wall of the groove of the retainer ring 19. This allows more cleaning liquid to enter the inside of the groove of the retainer ring 19, thereby improving the cleaning effect.

[0061] (How to clean the retainer ring) Next, a method for cleaning the retainer ring 19 using the cleaning mechanism 60 will be described.

[0062] FIG. 12 is a flowchart showing the steps of the method for cleaning the retainer ring 19 by the cleaning mechanism 60.

[0063] 12, first, the retaining ring 19 is placed above the cleaning mechanism 60 (step S1). Specifically, the polishing head 24 having the retaining ring 19 is placed above the cleaning mechanism 60 by swinging the head arm 31 (see FIG. 10). For example, when cleaning the retaining ring 19 of the polishing head 24A, the polishing head 24A is moved from a position above the first polishing table 22A to the second transfer position (wafer transfer position) TP2 by swinging the head arm 31, thereby placing the polishing head 24A above the cleaning mechanism 60.

[0064] Next, the retainer ring is rotated in the direction opposite to the direction of rotation during polishing of the substrate (rotation direction B shown in FIG. 11) (step S2). Specifically, the head motor 76 (see FIG. 3) is rotated in the direction opposite to the direction during polishing, thereby rotating the polishing head 24A.

[0065] Then, the cleaning liquid is sprayed from the cleaning nozzle 61n of the cleaning mechanism 60 toward the groove at an angle that substantially matches the inclination angle of the inner wall of the groove of the retainer ring 19 (ring body 19A) (step S3).

[0066] Thus, the method for cleaning the retainer ring 19 according to this embodiment includes step S1 of placing the retainer ring 19 on top of the cleaning mechanism unit 60, step S2 of rotating the retainer ring 19 in a direction opposite to the rotation direction during polishing of the substrate (wafer W), and step S3 of spraying a cleaning liquid from the cleaning nozzle of the cleaning mechanism unit 60 toward the groove at an angle θ2 that is approximately equal to the inclination angle θ1 of the inner wall of the groove of the retainer ring 19.

[0067] This configuration makes it possible to efficiently clean the inside of the groove formed on the bottom surface 19a of the retainer ring 19.

[0068] 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 would naturally be possible for a person skilled in the art, and the technical concept of the present invention may also be applied to other embodiments. The present invention is not limited to the described embodiments, but is to be interpreted in the broadest scope in accordance with the technical concept defined by the claims. [Explanation of symbols]

[0069] 100 Substrate processing apparatus 1 Substrate polishing equipment 24 Polishing Head 18 Polishing head body 19 Retainer ring 19A Ring body 19a bottom 19b Groove 19b1 1st side (inner wall) 19b2 ​​2nd side (inner wall) 60 Cleaning mechanism 61 Cleaning unit 61n Cleaning nozzle

Claims

1. A retainer ring attached to a polishing head for pressing a substrate against a polishing pad, a ring body having a bottom surface that contacts the polishing pad and has a plurality of grooves that extend from the inner periphery to the outer periphery; a first surface constituting an inner wall of the groove formed in the ring body and a second surface opposing the first surface are formed substantially parallel to each other, the first surface and the second surface are inclined toward a rotation direction of the retainer ring during polishing of the substrate; Retainer ring.

2. the first surface and the second surface are located in the front and rear, respectively, in a rotation direction of the retainer ring during polishing of the substrate; In the depth direction of the groove, the length of the second surface is longer than the length of the first surface. The retainer ring of claim 1 .

3. A substrate polishing apparatus comprising the retainer ring according to claim 1 or 2.

4. a cleaning mechanism having a cleaning nozzle that sprays a cleaning liquid toward the groove at an angle that substantially matches the inclination angle of the inner wall of the groove of the retainer ring; 4. The substrate polishing apparatus according to claim 3.

5. Further, a cleaning mechanism for cleaning the retainer ring is provided. When the cleaning mechanism cleans the retainer ring, the retainer ring rotates in a direction opposite to the direction of rotation when polishing the substrate.

4. The substrate polishing apparatus according to claim 3.

6. A substrate processing apparatus comprising the substrate polishing apparatus according to claim 3.

7. 2. The method for cleaning a retainer ring according to claim 1, placing the retainer ring on top of a cleaning mechanism; rotating the retainer ring in a direction opposite to a direction of rotation during polishing of the substrate; spraying a cleaning liquid from a cleaning nozzle of the cleaning mechanism unit toward the groove at an angle that substantially matches an inclination angle of the inner wall of the groove of the retainer ring; A method for cleaning a retainer ring, comprising:

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