Polishing head and polishing processing device

Abstract

Provided are a polishing head and a polishing treatment device whereby it is possible to address phenomena such as wrinkles and star marks, further improvement of a substrate surface such as SFQR is possible, and polishing treatment of large numbers of substrates can be performed stably with high quality.　A polishing head 100 has a membrane support ring 3, a membrane 4 that covers an opening on a lower end side of the membrane support ring 3 and holes a substrate W via a backing film adhered to a front surface side of the membrane 4, and a retainer ring 6 that includes the membrane support ring 3 therein and is formed in a shape that surrounds the outer periphery of the substrate W. A plurality of radial ribs 4a extending radially from the vicinity of the center of the membrane and an annular rib 4b formed with a small size relative to the size of an elastic body are formed on a back surface side of the membrane 4, and the radial ribs 4a are formed extending radially outward from the annular rib 4b. In a region on the back surface side of the elastic body that is surrounded by adjacent radial ribs 4a, the membrane support ring 3, and the annular rib 4b, there is arranged a rib restriction member 33 that is formed having a shape that adjoins side surfaces of the radial ribs 4a, the internal peripheral surface of the membrane support ring 3, and the external peripheral surface of the annular rib 4b.

Description

[Technical field]

[0001] The present invention relates to a polishing head and a polishing processing apparatus used in polishing a substrate such as a semiconductor wafer or a glass substrate. [Background technology]

[0002] In recent years, in the manufacturing process of semiconductor devices, with the increasing integration density of substrates such as semiconductor wafers and glass substrates (hereinafter referred to as wafers), the flattening technology of the substrate surface has become increasingly important. The most important flattening technology is chemical mechanical polishing (CMP). This chemical mechanical polishing is performed by using a polishing processing device (also called a polishing device) to supply a polishing liquid containing abrasive grains such as silica (SiO2) onto a polishing surface such as a polishing pad, while sliding the substrate against the polishing surface.

[0003] For example, the CMP apparatus disclosed in Patent Document 1 is such that even if the template wears and the template thickness gradually becomes thinner, the pressing force of the backing film pressing the edge of the wafer is prevented from becoming excessively high, and thus, even if the template thickness changes over time, the polishing rate at the edge of the wafer can be prevented from fluctuating significantly compared to the polishing rate in other areas of the wafer.

[0004] In addition, the polishing head disclosed in Patent Document 2 applies a pressing force corresponding to the amount of pressure fluid sealed in the multiple pressure chambers to the back side of the substrate from each pressure chamber, applying the desired pressing force across the entire surface of the substrate to be processed without discontinuities, and furthermore, by making the outer diameter of the backing film smaller than the outer diameter of the wafer, stress concentration at the wafer edge is prevented. This prevents uneven polishing, insufficient polishing, and overpolishing caused by uneven pressing force, significantly improving the current deterioration of ESFQR (Edge Site Front least square range), and realizing high-quality production technology. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-121650 A [Patent Document 2] JP 2014-018933 A Summary of the Invention [Problem to be solved by the invention]

[0006] In such polishing processing devices, if the relative speed and pressing force between the surface of the wafer to be polished (hereinafter referred to as the "polished surface") and the polishing pad are not uniform over the entire surface of the polished surface, polishing unevenness such as insufficient polishing or over-polishing will occur.

[0007] However, while measures to improve ESFQR have been developed so far that focus on static pressure distribution, research into the wrinkle and star mark phenomena caused by the rotational motion of the platen and head has been lacking. Clarifying and dealing with these two dynamic phenomena is considered an urgent issue.

[0008] The wrinkle phenomenon is a phenomenon shown in FIG. 16, in which the membrane is deformed and wrinkled due to the rotational force during polishing. The inventors of this application analyzed the frictional motion that transmits the rotational motion to the wafer through the membrane. As a result, they clarified the phenomenon of multiple wrinkles in the shape of an involute curve occurring from the center of the membrane (see Figure 17). Figure 17 shows the wrinkle pattern that occurred in the membrane transferred to an involute curve. They also clarified that the wrinkle pattern can take on a pattern similar to that of a typhoon spiral or can take on a spiral shape, depending on the number of wrinkles that occur.

[0009] Specifically, the wrinkle phenomenon occurs when the bulging part of the membrane separates from the wafer, causing a change (decrease) in the processing pressure (see area B in Figure 18). To reduce this phenomenon, it is necessary to prevent wrinkles from forming in the membrane. In other words, to prevent wrinkles, a mechanism is required that can prevent shear deformation within the membrane surface.

[0010] The star mark phenomenon is a phenomenon as shown in Fig. 19, which is caused by a gap between the outer diameter of the wafer and the inner diameter of the retainer. Figs. 20(a) and 20(b) are diagrams showing an example of Δθ analysis. When the wafer is subjected to rotational friction from the platen (pad), the outer diameter of the wafer comes into contact with the inner diameter of the retaining ring (see Figure 20(a)). At that contact point, a CCW=CW state is established with B as the fulcrum. The wafer moves to point A at the same rotation speed ωr as the retaining ring due to a phenomenon caused by the frictional force with the retaining ring (see Figure 20(b)).

[0011] However, at point A, the CCW force exceeds the CW frictional static force, and the relative rotation returns to point B. During this return to point B, a relative rotation ωws occurs in the wafer, and the wafer rotation is repeated as follows: retainer ring rotation: ωr ⇒ substrate relative rotation: ωws ⇒ retainer ring rotation: ωr (see Figure 21). This relative rotation causes the RR (Removal Rate) to be greater in the AOB region of the wafer than in adjacent regions of the same radius, forming a sector-shaped valley bottom shape with a deeper concave shape toward the periphery. The period of this relative rotational motion varies depending on the ratio of the platen diameter (Pd) to the wafer diameter (Sd). In general-purpose machines, Sd / Pd is around 0.4, and under these conditions the period for one rotation of the retaining ring is approximately 5. Therefore, a star-shaped (pentagonal) pattern is observed in the RR contour map with 5 periods (see Figure 19).

[0012] Thus, in order to further improve the SFQR of the wafer surface and perform high-quality, stable mass polishing, it is necessary to address not only the star mark phenomenon but also the wrinkle phenomenon.

[0013] The main objective of the present invention is to provide a polishing head and polishing processing apparatus that can deal with previously unexplained wrinkle and stark crystal phenomena, further improve the SFQR of the substrate surface, and perform high-quality, stable, large-scale polishing processing. [Means for solving the problem]

[0014] The present invention is a polishing processing apparatus having a polishing table having a polishing pad, and a polishing head that holds a substrate to be polished and brings the surface to be polished into sliding contact with the polishing pad, the polishing head comprising an annular body having an inner diameter that is sized to surround the outer periphery of the substrate to be polished, an elastic body that covers the lower end opening of the annular body and holds the substrate via a backing film attached to the surface side of the elastic body, a retainer ring that contains the annular body and is formed into a shape that surrounds the outer periphery of the substrate, and a retainer ring that is shaped to hold the annular body and the retainer ring together horizontally. and a driving means for rotating the elastic body, wherein a plurality of radial ribs extending radially from near the center and a circular rib formed with a size relatively smaller than the size of the elastic body are formed on the back side of the elastic body, the radial ribs are formed radially outward from the circular rib, and a rib restraining member formed in a shape that contacts the side of the radial rib, the inner surface of the circular body, and the outer surface of the circular rib is arranged in an area surrounded by adjacent radial ribs, the circular body, and the circular rib on the back side of the elastic body.

[0015] The present invention also relates to a polishing head that is provided in a polishing processing device having a horizontally rotating polishing pad, the polishing head comprising: an annular body having an inner diameter that is sized to surround the outer periphery of a substrate to be polished; an elastic body that covers the lower end opening of the annular body and holds the substrate via a backing film attached to its front surface; a retaining ring that contains the annular body and is formed in a shape that surrounds the outer periphery of the substrate; and a driving means for horizontally rotating the annular body and the retaining ring together, the rear side of the elastic body being formed with a plurality of radial ribs extending radially from near the center and a circular rib formed with a size relatively smaller than the size of the elastic body, the radial ribs being formed radially outward from this circular rib, and a rib restraining member formed in a shape that contacts the side of the radial rib, the inner peripheral surface of the annular body, and the outer peripheral surface of the circular rib is arranged in an area surrounded by adjacent radial ribs, the annular body, and the circular rib on the rear side of the elastic body. Effect of the Invention

[0016] According to the present invention, it is possible to provide a polishing head and polishing processing device that can deal with previously unexplained wrinkle and stark crystal phenomena, further improve the SFQR of the substrate surface, and perform high-quality, stable, large-scale polishing processing. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a diagram for explaining an example of a polishing head and its peripheral configuration included in the polishing processing device. [Diagram 2] FIG. 2 is a schematic vertical cross-sectional view for explaining an example of a polishing head and its peripheral configuration of the polishing processing device. [Diagram 3] FIG. 4 is a schematic perspective view for explaining an example of the configuration of a membrane and a membrane support ring. [Figure 4] FIG. 4 is a schematic cross-sectional view illustrating an example of a configuration of a membrane and a membrane support ring. [Diagram 5]FIG. 4 is a schematic perspective view illustrating an example of a configuration of a rib restraint member. [Figure 6] FIG. 13 is a schematic perspective view for explaining an example of a restraining and restricting mechanism that connects a plurality of rib restraining members arranged on the back side of the membrane. [Figure 7] FIG. 4 is a schematic perspective view for explaining an example of a rib configuration. [Figure 8] 13 is a plan view illustrating an example of a state in which a plurality of rib restraining members and a restraint restriction mechanism are disposed on the back side of the membrane. FIG. [Figure 9] FIG. 13 is a diagram for explaining another example of the configuration of the membrane. [Figure 10] FIG. 10 is a diagram for explaining another example of the membrane configuration different from that in FIG. 9 . [Figure 11] 1A is a schematic vertical cross-sectional view illustrating an example of an adjustment mechanism for a retainer ring, and FIG. 1B is a schematic top view illustrating an example of an adjustment mechanism for a retainer ring. [Figure 12] 12 is a schematic top view showing an example of a specific configuration of the retainer ring shown in FIG. 11. [Figure 13] 5(a) and 5(b) are schematic top views for explaining an example of a mechanism for adjusting the diameter size of a retaining ring 6. FIG. [Figure 14] 13A is a schematic perspective view illustrating an example of an adjustment mechanism for a retaining ring, different from that in FIG. 12; FIG. 13B is a schematic top view illustrating an example of an adjustment mechanism for a retaining ring, different from that in FIG. [Figure 15] 15A, 15B, 15C, and 15D are diagrams showing an example of a specific configuration of the retainer ring shown in FIG. 14. [Figure 16] 1A and 1B are diagrams for explaining the phenomenon of wrinkles. [Figure 17] FIG. 4 is a diagram showing an example of an involute curve. [Figure 18] FIG. 13 is a diagram showing an example of a membrane lifting phenomenon. [Figure 19] FIG. 2 is a diagram for explaining the phenomenon of stark cook generation. [Figure 20] 4(a) and (b) are diagrams showing an example of Δθ analysis. [Figure 21] FIG. 4 is a diagram showing an example of an angular velocity line. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The polishing processing apparatus of this embodiment polishes a substrate such as a semiconductor wafer or a glass substrate (hereinafter, also referred to as a wafer). In this specification, one surface of the substrate is referred to as a circular or approximately circular polished surface. Also, the surface of the polishing pad that contacts the polished surface of the wafer is referred to as a polishing surface.

[0019] The polishing processing device has a polishing table to which a polishing pad serving as a polishing member is attached, for horizontally rotating the polishing pad, and a polishing head for bringing the surface of the substrate to be polished into sliding contact with the polishing pad so as to face the polishing pad. The substrate is pressed against the polishing pad by the polishing head, and the surface to be polished is polished by rotating the polishing table and the polishing head while supplying a polishing liquid (slurry) to the polishing pad.

[0020] [Example of embodiment] FIG. 1 is a schematic diagram of a polishing processing apparatus S according to the present embodiment. The polishing processing apparatus S shown in FIG. 1 has a polishing table 51, and a polishing pad 50 is attached to the surface of the polishing table 51.

[0021] The polishing processing apparatus S further includes a polishing head 100 that holds a substrate (wafer) W and presses its surface to be polished against the polishing pad 50, a nozzle N for supplying a polishing liquid toward the polishing pad 50, a motor (not shown) for horizontally rotating the polishing table 51 and the polishing head 100, respectively, a polishing liquid supply mechanism (not shown) connected to the nozzle N, and a control unit 20 including a computer for controlling each driving unit including the motor.

[0022] The polishing pad 50 is disk-shaped, and its radius is larger than the maximum diameter of the polished surface of the wafer W. In this mechanism, the rotation speed and direction of the polishing pad 50 and the polishing head 100 can be changed to adjust the relative polishing speed within the surface of the wafer W. The polishing pad 50 itself has elasticity, and commercially available materials such as nonwoven fabric and urethane foam can be used.

[0023] The polishing head 100 has a holding mechanism that holds the wafer W so that its surface to be polished is in sliding contact with the polishing pad 50, and a pressing mechanism that applies pressure to the held wafer W from the back direction (back side) of its surface to be polished toward the polishing pad 50. Details of these mechanisms will be described later.

[0024] The control unit 20 mainly performs control of positioning the nozzle N, control of starting or stopping the supply of polishing liquid from the nozzle N, control of the supply amount per unit time of the polishing liquid jetted from the nozzle N, and control of starting and stopping the motor. The rotational force of the motor controlled by the control unit 20 is transmitted to the polishing table 51 via a drive unit (not shown). This causes the polishing table 51 to rotate horizontally or stop rotating. The rotational force (torque) of the motor is also transmitted via a drive unit (not shown, for example, a universal joint) to the polishing head 100. This causes the polishing head 100 to rotate horizontally or stop rotating.

[0025] The rotation direction of the polishing table 51 and the polishing head 100 are generally the same. This is because if they are rotated in opposite directions, the relative polishing speed within the wafer surface will be non-uniform, which may make it impossible to polish an even amount. By rotating the polishing table 51 and the polishing head 100 in the same direction and adjusting the rotation speeds of both, the polishing precision can be improved.

[0026] The rotational force of a single motor may be transmitted to the polishing table 51 and the polishing head 100 via gears having different gear ratios, or may be transmitted to each of the polishing table 51 and the polishing head 100 via separate motors. Both can be designed arbitrarily. The control procedure by the control unit 20 will be described later.

[0027] The polishing liquid is supplied from the nozzle N to the polishing pad 12 for a predetermined time under the control of the control unit 20 when the rotation speed of the polishing table 51 reaches a predetermined value. Next, the polishing head 100 provided in the polishing processing device S and its peripheral configuration will be described in detail.

[0028] [Polishing head and its peripheral components] 2 is a schematic vertical cross-sectional view for explaining an example of the polishing head 100 and its peripheral configuration included in the polishing processing device S. An example of the configuration of the polishing head 100 will be explained with reference to FIG. In addition, the polishing head 100 holds the wafer W so that its polished surface is in sliding contact with the polishing pad 50 at a pressure controlled by the polishing processing device S in order to further improve the GBIR (Global backside ideal range) of the wafer surface, and applies pressure to the held wafer W from the back direction (back side) of its polished surface toward the polishing pad 50.

[0029] [Polishing head configuration] 2 has a holding mechanism that brings the wafer W to be polished into sliding contact with the polishing pad 50 while a polishing pressure (processing pressure) is applied to the wafer W. The polishing head 100 also has a pressing mechanism for applying the polishing pressure (processing pressure) (P1) and pressing the retainer ring 6 toward the polishing pad 50 (P2).

[0030] In this manner, the polishing head 100 of the polishing processing device S is configured to supply a pressure fluid (e.g., compressed air) to the pressure chamber via an air pipe connected to a fluid supply mechanism (not shown) or to recover the supplied pressure fluid. In other words, the polishing head 100 is configured to adjust the amount of pressure fluid supplied to the pressure chamber to generate a processing pressure to be applied to the wafer W.

[0031] The retainer ring 6 according to this embodiment prevents the wafer W from jumping out toward the outer periphery due to the rotational force of the polishing head 100 and the polishing table 51. The retainer ring 6 also affects the contact pressure between the edge of the wafer and the polishing pad 50.

[0032] The polishing head 100 has a main head housing 1, a sub head housing 2, a membrane support ring 3, a membrane 4, a backing film 5, a retainer ring 6 (four retainer members 6a), and a rotary frame .

[0033] Here, the polishing head 100 is configured so that a driving force (for example, a rotational force (torque) of a motor serving as a starting means) is transmitted via each component connected to the head housing 1. Specifically, the retaining ring 6 is connected to the membrane support ring 3 via a drive pin 8. This allows the various components of the polishing head 100 to rotate horizontally as a unit or to stop rotating. The start and stop of rotation, the amount of rotation per unit time, etc. are controlled by the control unit 20 based on preset contents.

[0034] The membrane support ring 3 is an annular body formed in an annular shape using, for example, a SUS material. The membrane 4 covers the opening at the lower end side of the membrane support ring 3 (annular body 3), and holds the wafer W via a backing film 5 attached to its front surface side. The membrane 4 is a cylindrical elastic body (cylindrical elastic body) formed in a generally cylindrical (pot-shaped) shape with an inner diameter that allows it to be fitted onto the outer circumferential surface of the membrane support ring 3. The membrane 4 is also made of a rubber material having excellent strength and durability, such as ethylene propylene rubber (EPDM) or silicone rubber. Here, an example of the configuration of the membrane 4 and the membrane support ring 3 that function as a holding mechanism for holding the wafer W, and the details of the surrounding configuration will be described.

[0035] FIG. 3 is a schematic perspective view for explaining an example of the configuration of the membrane 4 and the membrane support ring 3. As shown in FIG. FIG. 4 is a schematic cross-sectional view for explaining an example of the configuration of the membrane 4 and the membrane support ring 3. As shown in FIG. FIG. 5 is a schematic perspective view for explaining an example of the configuration of the rib restraint member 33. As shown in FIG. FIG. 6 is a schematic perspective view for explaining an example of a restraining and restricting mechanism 31 (32) that connects a plurality of rib restraining members 33 arranged on the back surface side of the membrane 4. As shown in FIG. FIG. 7 is a schematic perspective view for explaining an example of a rib configuration. FIG. 8 is a plan view for explaining an example of a state in which a plurality of rib restraining members 33 and a restraint restriction mechanism 31 (32) are disposed on the back surface side of the membrane 4. As shown in FIG. An example of a rib configuration according to the present invention will be described in detail below with reference to Figs.

[0036] As shown in Figures 3 and 4, the polishing head 100 has a membrane support ring 3 (annular body 3) having an inner diameter large enough to surround the outer periphery of the substrate W to be polished, and a membrane 4 that covers the opening at the lower end of the annular body and holds the substrate W via a backing film attached to its surface side.

[0037] 7, the back surface of the membrane 4 is formed with a plurality of radial ribs 4a extending radially from the vicinity of the center, and a circular rib 4b formed with a size relatively smaller than the size of the membrane 4. The radial ribs 4a are formed radially outward from the circular rib 4b. 5, 4 and 8, a rib restraint member 33 is disposed in each of the regions surrounded by adjacent radial ribs 4a, membrane support ring 3 (annular body 3), and annular rib 4b. The rib restraint member 33 is formed in a shape that contacts the side surface of the radial rib 4a, the inner peripheral surface of the membrane support ring 3 (annular body 3), and the outer peripheral surface of the annular rib 4b.

[0038] 3, five rib restraint members 33 are arranged, but the number is not limited to this. For example, four or six rib restraint members 33 may be arranged. In this case, a number of radial ribs 4a corresponding to the number of rib restraint members 33 to be used (arranged) are formed on the back surface of the membrane 4. The number of rib restraint members 33 can also be determined according to the number of radial ribs 4a to be formed on the back surface of the membrane 4.

[0039] As described above, on the back side of the membrane 4, a plurality of radial ribs 4a are formed extending radially from near the center of the back side of the membrane 4 (see FIG. 7). In addition, annular ribs 4b are formed with a size relatively smaller than the size of the membrane 4. As shown in FIG. 7, the radial ribs 4a are formed radially outward from the annular rib 4b. The radial ribs 4a and the annular rib 4b are formed integrally with the membrane 4, for example, using the same material. In addition, the heights and widths of the radial ribs 4a and the annular rib 4b may be the same, or may be set arbitrarily.

[0040] 5, the rib restraint member 33 is formed in a shape that contacts the side surface of the radial rib 4a, the inner peripheral surface of the membrane support ring 3 (annular body 3), and the outer peripheral surface of the annular rib 4b in the region surrounded by adjacent radial ribs 4a, membrane support ring 3 (annular body 3), and annular rib 4b. The rib restraint member 33 is a frame formed in a substantially sector shape using, for example, a resin material. The rib restraining member 33 also has grooves 33a and 33b. The grooves 33a and 33b are grooves in which a rod-shaped body 32 of a restraint restriction mechanism, which will be described later, is placed.

[0041] 5 and 8, the radial rib 4a of the membrane 4 is sandwiched between a pair of adjacent rib restraint members 33 arranged on the back surface side of the membrane 4. Therefore, the rib restraint members 33 are formed to a size that allows them to be inscribed in the membrane support ring 3 (annular body 3) and that allows a space to be formed corresponding to the width size A of the radial rib 4a as shown in FIG.

[0042] In this way, each radial rib 4a is sandwiched between a pair of adjacent rib restraining members 33, thereby making it possible to prevent deformation of the radial rib 4a in the rotational direction caused by the rotational force during the polishing process. In other words, the rib restraining members 33 restrain the radial rib 4a to prevent deformation due to the rotational force, thereby restricting its movement. In addition, the rib restraining member 33 makes it possible to prevent deformation of the annular rib 4b in the rotational direction caused by the rotational force during the polishing process. In other words, the rib restraining member 33 restrains the annular rib 4b and regulates its movement so as to prevent deformation due to the rotational force.

[0043] In this way, the rib restraint member 33 restrains the radial rib 4a and the annular rib 4b so that they do not "move" due to the rotational force during the polishing process, thereby preventing the membrane 4 from being deformed and wrinkled due to the rotational force during the polishing process. In other words, by preventing the radial rib 4a, which is an elastic body, from being deformed in the rotational direction and preventing wrinkles from being generated on the surface of the membrane 4 in the region between adjacent radial ribs 4a, the occurrence of wrinkles on the entire surface of the membrane 4 can be effectively suppressed. In this way, the polishing head 100 according to this embodiment can effectively prevent the membrane 4 from being deformed and wrinkled due to the rotational force during the polishing process.

[0044] Furthermore, even when the rib restraining member 33 is disposed in this manner, the radial rib 4a and the annular rib 4b are not restrained in the vertical direction and can move freely. Therefore, the polishing pressure (processing pressure) can be applied (P1) to the lower surface sides of the radial rib 4a and the annular rib 4b.

[0045] In the conventional mechanism, the rotation phase of the outer periphery of the membrane was synchronized with the membrane ring, but the rotation phase of the center was delayed, resulting in an inlute curve wrinkle phenomenon. In contrast, in the polishing head 100 according to this embodiment, the rib restraining member 33 restrains the radial rib 4a in the direction of the rotation angle θ and the annular rib 4b in the direction of the radius r. Therefore, the outer periphery and the center of the membrane 4 rotate synchronously, and no shear deformation occurs, which prevents the occurrence of wrinkles.

[0046] Note that Figures 3, 4, etc. show an example in which a rib restraint member 33 formed in a shape that contacts the outer peripheral surface of the annular rib 4b, the radial rib 4a adjacent to the annular rib 4b, and the inner peripheral surfaces of the radial rib 4a and the membrane support ring 3 is arranged in the area surrounded by the membrane support ring 3 and the membrane support ring 3, but the present invention is not limited to this configuration.

[0047] For example, if multiple radial ribs 4a extending radially from near the center are formed on the back side of the membrane 4, the rib restraint member 33 may be formed in a shape that contacts the radial ribs 4a and the inner surface of the membrane support ring 3 in the area surrounded by adjacent radial ribs 4a and the membrane support ring 3.

[0048] 6, 3 and 4, the polishing head 100 has a restraint restriction mechanism 31 (32) that connects the membrane support ring 3 and the rib restraint member 33. Specifically, for example, the membrane support ring 3 has a plurality of grooves 3a formed on its inner peripheral surface, and the restraint restriction mechanism 31 (32) can be configured as a disk body 31 formed to a size that fits within the inner peripheral region of the annular rib 4b, and a rod-shaped body 32 extending outward from the disk body 31 and formed so that its ends engage with the grooves 3a.

[0049] In this way, the disk body 31 and the rod-like body 32 function as a restraining and restricting means that connects the membrane support ring 3 and the rib restraining member 33. Therefore, it becomes possible to deal with the wrinkle phenomenon by the membrane 4, the membrane support ring 3 and their surroundings, and it is possible to further improve the SFQR, etc. of the substrate surface.

[0050] FIG. 9 is a diagram for explaining another example of the configuration of the membrane 4 described above. 9, a plurality of annular ribs 40a are formed on the back surface side of the membrane 40, each of which is formed to be relatively smaller than the size of the membrane 40. In addition, annular rib restraining members R1 (R1 to R8) are arranged to cover a part or the whole of the inner peripheral surface and the outer peripheral surface of each of the annular ribs 40a.

[0051] The annular rib restraining member R1 (R1 to R8) makes it possible to prevent deformation of the annular rib 40a caused by the rotational force during the polishing process. In other words, the annular rib restraining member R1 (R1 to R8) restrains the annular rib 40a and restricts its movement so as to prevent deformation due to the rotational force. By preventing the elastic annular rib 40a from being deformed by rotational force and preventing wrinkles from occurring on the surface of the membrane 4 in the areas between adjacent annular ribs 40a, the occurrence of wrinkles on the entire surface of the membrane 4 can be effectively suppressed.

[0052] Even with the membrane 40 having such a configuration, it is possible to deal with the wrinkle phenomenon and further improve the SFQR and the like of the substrate surface. Furthermore, even when the annular rib restraint member R1 (R1 to R8) is arranged, the annular rib 40a can move freely in the vertical direction, and polishing pressure (processing pressure) can also be applied (P1) to the underside of the annular rib 40a.

[0053] FIG. 10 is a diagram for explaining another example of the configuration of the membrane 40 described above. 10, a plurality of annular ribs 40a are formed on the back surface of the membrane 40, each of which is formed to a size relatively smaller than the size of the membrane 40. In addition, annular rib restraining members R10 (R10 to R13) are formed to the same size as the back surface region of the membrane 40 sandwiched between adjacent annular ribs 40a, and have holes formed on the surface thereof, and are disposed in each of the back surface regions.

[0054] The annular rib restraining member R1 (R1 to R8) makes it possible to prevent deformation of the annular rib 40a caused by the rotational force during the polishing process. In other words, the annular rib restraining member R1 (R1 to R8) restrains the annular rib 40a and restricts its movement so as to prevent deformation due to the rotational force. By preventing the elastic annular rib 40a from being deformed by rotational force and preventing wrinkles from occurring on the surface of the membrane 4 in the areas between adjacent annular ribs 40a, the occurrence of wrinkles on the entire surface of the membrane 4 can be effectively suppressed.

[0055] Even with the membrane 40 having such a configuration, it is possible to deal with the wrinkle phenomenon and further improve the SFQR and the like of the substrate surface. Even when the annular rib restraining member R10 (R10 to R13) is provided, the annular rib 40a can move freely in the vertical direction, and polishing pressure (processing pressure) can be applied (P1) to the underside of the annular rib 40a. In addition, holes are formed in the annular rib restraining member R10 (R10 to R13), so that it is easy to attach and detach it from the membrane 40.

[0056] 2 is a thin film stretched over the outer bottom surface (outer surface) of the membrane 4. For example, a porous material such as nonwoven fabric can be used as the material. The backing film 5 holds the surface to be polished of the wafer W in a sliding contact with the polishing pad 50, facing the polishing pad 50. In this way, the membrane 4 and the backing film 5 function as a holding mechanism for holding the wafer W.

[0057] The inventors of this application have discovered through their analysis that the star mark phenomenon occurs when there is a gap between the substrate and the retainer ring. Therefore, as a countermeasure, it is necessary to make the gap smaller. However, it has become clear that a small gap makes it difficult to attach and detach the substrate, and therefore the retainer ring needs to have an opening and closing function. As an example of the opening and closing function of the retaining ring, an adjustment mechanism that makes it possible to change the diameter size of the retaining ring will be described below.

[0058] Figure 11 is a schematic diagram for explaining an example of an adjustment mechanism for a retainer ring, where Figure 11(a) is a schematic diagram of a vertical cross section, and Figure 11(b) is a schematic diagram as seen from above. FIG. 12 is a schematic top view for explaining an example of a specific configuration of the retainer ring shown in FIG. Fig. 13 is a schematic top view for explaining an example of a mechanism for adjusting the diameter of the retainer ring 6. Fig. 13(a) shows the retainer ring in a closed state, and Fig. 13(b) shows the retainer ring in an open state. Specifically, the state in which the retainer member 6a is moved outward to change the diameter of the retainer ring 6 (Fig. 13(b)) is the open state, and the state in which the retainer ring 6 has returned to its original diameter size is the closed state (Fig. 13(a)).

[0059] The retainer ring 6 is formed into a shape surrounding the outer periphery of the wafer W. The retainer ring 6 not only regulates the wafer W from jumping out toward the outer periphery due to the rotational force of the polishing head 100 and the polishing table 51, but also participates in controlling the contact pressure between the edge of the wafer and the polishing pad 50.

[0060] Specifically, the polishing head 100 is configured such that there is a gap between the edge of the wafer W and the inner wall of the inner circumference of the retainer ring 6 during polishing. Also, the retainer ring 6 can functionally press the surface of the polishing pad 50, "holding down the pad," with high precision. In this way, the retainer ring 6 functions as one of the pressing mechanisms of the polishing head 100.

[0061] 11, 12, and 13, the retainer ring 6 is made up of four retainer members 6a formed in a fan shape. The retainer ring 6 also has, as one of its peripheral components, an adjustment mechanism that moves each of the retainer members 6a outward with respect to the diameter center of the retainer ring 6 to change the diameter size of the retainer ring 6. The adjustment mechanism includes, for example, a rotary frame 7, a rotational motion gear 10, an adjustment guide 12, an arcuate portion 61 formed on the retainer member 6a (see FIGS. 2 and 12), and a motor M, as shown in FIGS.

[0062] The rotary frame 7 is configured to rotate horizontally together with the membrane support ring 3 and the retainer ring 6. As shown in Fig. 12, the peripheral surface of the rotary frame 7 is configured as a gear, and is configured to be rotatable within a predetermined range via a rotation gear 10 and a motor M. The rotation gear 10 and the motor M function as a rotation means for rotating the rotary frame 7.

[0063] Each of the retainer members 6a has an arc portion 61 formed with a curvature different from the curvature of the retainer member 6a with respect to the diametric center of the retainer ring 6. The rotary frame 7 has an adjustment guide 12 composed of a pair of rollers (e.g., bearings) that clamp each of the arc portions 61. In this manner, the adjustment guide 12 functions as a clamping means that clamps each of the arc portions 61. The adjustment mechanism functions as an adjustment means for changing the diameter size of the retainer ring 6 by controlling the motor M to rotate the rotary frame 7 within a predetermined range and move the retainer member 6a outward.

[0064] This makes it possible to adjust the "gap" that occurs during polishing between the edge of the wafer W and the inner wall of the inner circumference of the retainer ring 6. In this way, the retainer ring 6 and its surroundings can deal with the phenomenon of star marks, and the SFQR of the substrate surface can be further improved.

[0065] In the polishing head 100 of the polishing processing device S, an airbag P2 is disposed between the head housing 2 and the retainer ring 6, as shown in FIG. The polishing head 100 of the polishing processing device S is configured to supply a pressurized fluid (e.g., compressed air) to the air bag P2 through an air pipe connected to a fluid supply mechanism (not shown) or to recover the supplied pressurized fluid. In other words, the polishing head 100 is configured to adjust the amount of pressurized fluid supplied to the air bag P2 to generate pressure P2 that presses the surface of the polishing pad 50 by the retainer ring 6.

[0066] The airbag P2 is formed in a ring shape, and is inflated by sealing a pressurized fluid in the airbag P2, thereby allowing the retainer ring 6 to press the polishing pad 50 with a pressure P2 that corresponds to the amount of the sealed pressurized fluid. These components function as a pressure adjusting means for adjusting the amount of pressurized fluid supplied to the air bag P2 via the control unit 20, thereby adjusting the pressure P2 applied by the retaining ring 6 to the polishing pad 50. In other words, the pressure adjusting means is intended to optimize the stress at the edge of the wafer.

[0067] The polishing head 100 of this embodiment and the polishing processing device S having the same are capable of dealing with wrinkle phenomena, stark crystallography, etc., and can further improve the SFQR, etc. of the substrate surface, thereby enabling stable, high-quality polishing processing for large quantities.

[0068] [Variations] Fig. 14 is a schematic diagram for explaining an example of an adjustment mechanism for a retaining ring, which is different from that in Fig. 12. Fig. 14(a) is a schematic perspective view, and Fig. 14(b) is a schematic top view. Fig. 15 is a diagram showing an example of a specific configuration of the retaining ring shown in Fig. 14. The same components as those already explained are given the same reference numerals and the explanation thereof will be omitted.

[0069] Figures 15(a) and (c) show the retainer ring in a closed state, and Figures 15(b) and (d) show the retainer ring in an open state. Specifically, the state in which the retainer member 6a is moved outward to change the diameter of the retainer ring (Figures 15(b) and (d)) is the open state, and the state in which the retainer ring returns to its original diameter size is the closed state (Figures 15(a) and (c)).

[0070] 14 and 15, the retainer ring is made up of four fan-shaped retainer members 6a. The peripheral configuration of the retainer ring also includes an adjustment mechanism that moves each of the retainer members 6a outward from the center of the diameter of the retainer ring to change the diameter of the retainer ring.

[0071] The adjustment mechanism, for example, as shown in Figures 14 and 15, is configured to include a guide plate 22 formed in a ring shape, a guide hole 22a formed in the guide plate 22, a guide pin 21 formed in the retainer member 6a, and a motor (not shown) that rotates the annular frame 22. The guide hole 22a is formed with a curvature different from that of the retainer member 6a with respect to the diametric center of the retainer ring. The retainer members 6a of the retainer ring are connected to each other via spherical connecting members 20 on their opposing side surfaces. In this manner, the adjustment mechanism functions as an adjustment means for changing the diameter size of the retainer ring 6.

[0072] This makes it possible to adjust the "gap" that occurs between the edge of the wafer W and the inner wall of the retainer ring during polishing. In this way, it becomes possible to deal with the phenomenon of star marks occurring by the retainer ring and its surroundings, and further improve the SFQR of the substrate surface.

[0073] The above-described embodiments are intended to more specifically explain the present invention, and the scope of the present invention is not limited to these examples. [Explanation of symbols]

[0074] 1 (2)...head housing, 3...membrane support ring (annular body), 3a...groove portion, 4...membrane (elastic body), 4a...radial rib, 4b...annular rib, 5...backing film, 6...retainer ring, 6a...retainer member, 7...rotary frame, 10...rotating motion gear, 12...adjustment guide, 20...control unit, 31...disk body, 32...rod-shaped body, 33...rib restraint member, 40a...annular rib, 50...polishing pad, 51...polishing table, 61...arc portion, 100...polishing head, S...polishing processing device, N...nozzle, R1 to R13...annular rib restraint member, W...wafer.

Claims

1. A polishing processing apparatus including a polishing table having a polishing pad, and a polishing head that holds a substrate to be polished and brings the surface to be polished into sliding contact with the polishing pad, The polishing head includes: an annular body having an inner diameter that is large enough to surround the outer periphery of the substrate to be polished; an elastic body that covers an opening at a lower end of the annular body and holds the substrate via a backing film attached to the surface side of the elastic body; a retainer ring that contains the annular body and is formed in a shape that surrounds the outer periphery of the substrate; a driving means for rotating the annular body and the retaining ring horizontally together, A plurality of radial ribs extending radially from the vicinity of the center of the elastic body and a circular rib formed to be relatively smaller than the size of the elastic body are formed on the back surface side of the elastic body, and the radial ribs are formed radially outward from the circular rib, a rib restraining member formed in a shape contacting a side surface of the radial rib, an inner peripheral surface of the annular body, and an outer peripheral surface of the annular rib is disposed in an area surrounded by adjacent radial ribs, the annular body, and the annular rib on the back surface side of the elastic body, Polishing processing equipment.

2. The present invention is characterized in that the annular body and the rib restraining member are connected to each other by a restraining restriction means. The polishing processing device according to claim 1 .

3. The annular body has a plurality of grooves formed on its inner circumferential surface, the restraint and restriction means comprises a disk body formed to a size that fits within the inner peripheral region of the annular rib, and a rod-shaped body extending outward from the disk body and formed so that ends of the rod-shaped body engage with each of the grooves, The polishing processing device according to claim 2 .

4. A plurality of annular ribs are formed on the back surface of the elastic body, each of which is formed to have a size relatively smaller than the size of the elastic body; An annular rib restraining member is provided to cover a part or the whole of the inner peripheral surface and the outer peripheral surface of each of the annular ribs. The polishing processing device according to claim 1 .

5. A plurality of annular ribs are formed on the back surface of the elastic body, each of which is formed to have a size relatively smaller than the size of the elastic body; The present invention is characterized in that an annular rib restraining member is formed to have the same size as a back side region of the elastic body sandwiched between adjacent annular ribs and has holes formed on a surface thereof, and is disposed in each of the back side regions. The polishing processing device according to claim 1 .

6. The retainer ring is characterized in that it is made up of a plurality of retainer members formed in a sector shape, and has an adjustment means for changing the diameter size of the retainer ring by moving each of the retainer members outward based on the diameter center of the retainer ring. The polishing processing apparatus according to claim 1 .

7. a rotary frame that rotates horizontally integrally with the annular body and the retainer ring; each of the retainer members has an arc portion formed with a curvature different from a curvature of the retainer member with respect to a diametric center of the retainer ring; the rotary frame has clamping means for clamping each of the arcuate portions, the adjusting means controls a rotating means that rotates the rotary frame within a predetermined range, thereby moving the retainer member outward and changing the diameter size of the retainer ring. The polishing processing device according to claim 6 .

8. Each of the retainer members is connected to the annular body via a drive pin. The polishing processing device according to claim 6 .

9. A polishing head provided in a polishing processing device having a horizontally rotating polishing pad, an annular body having an inner diameter that is large enough to surround the outer periphery of the substrate to be polished; an elastic body that covers an opening at a lower end of the annular body and holds the substrate via a backing film attached to the surface side of the elastic body; a retainer ring that contains the annular body and is formed in a shape that surrounds the outer periphery of the substrate; a driving means for rotating the annular body and the retaining ring horizontally together, A plurality of radial ribs extending radially from the vicinity of the center of the elastic body and a circular rib formed to be relatively smaller than the size of the elastic body are formed on the back surface side of the elastic body, and the radial ribs are formed radially outward from the circular rib, a rib restraining member formed in a shape contacting a side surface of the radial rib, an inner peripheral surface of the annular body, and an outer peripheral surface of the annular rib is disposed in an area surrounded by adjacent radial ribs, the annular body, and the annular rib on the back surface side of the elastic body, Polishing head.

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