Polishing device

Abstract

To provide a polishing device which can flatten a substrate with high accuracy, while reducing adjustment manhours.SOLUTION: A polishing device 1 includes a holding table for holding a substrate, and a polishing unit 20 for polishing the substrate held by the holding table, wherein the polishing unit 20 has a mounting part 43 having a mounting surface 431 where a polishing pad 512 is mounted, a spindle motor for rotating the mounting part 43, a constant velocity joint 41 for transmitting the rotation of the spindle motor to the mounting part, and a tilting mechanism 42 for making the polishing pad 512 follow the inclination of the substrate, and the tilting mechanism 42 includes a movable side spherical surface member 50 which is connected to the mounting part 43 and is tilted with tilting of the mounting part 43, and a fixed side spherical surface member 49 which tiltably supports the movable side spherical surface member 50.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a polishing apparatus. [Background technology]

[0002] 2. Description of the Related Art One example of a substrate processing apparatus for processing substrates such as semiconductor wafers is a chemical mechanical polishing (CMP) apparatus for performing polishing (see, for example, Patent Document 1).

[0003] In such a polishing apparatus, the substrate and polishing pad are brought into contact with each other while rotating relative to each other, and a slurry appropriate for the object to be processed is supplied to the contact area, producing a chemical and mechanical polishing action to polish the substrate surface.

[0004] Here, in order to polish the substrate flat, it is necessary to make the substrate and the polishing pad parallel to each other and to make the pressing pressure of the polishing pad uniform.

[0005] Therefore, conventional polishing apparatuses use leveling bolts or the like to adjust the parallelism between the substrate and the polishing pad, but this is a labor-intensive and complicated task even for an experienced operator, and this has been problematic.

[0006] In order to solve the above problems, various techniques have been proposed in which a swing mechanism (gimbal mechanism) is provided on the polishing pad side to automatically follow the substrate (see, for example, Patent Documents 2 and 3). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Special Publication No. 11-505181 [Patent Document 2] Patent No. 6721967 [Patent Document 3] JP 2012-91240 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, as described in Patent Document 2, in a method in which a drive pin is used to transmit the rotation of the drive shaft that drives the polishing pad to the polishing pad, the angular velocity of the drive shaft and the angular velocity of the polishing pad are not the same, so even if the motor is rotated at a constant rotation speed, the rotation speed of the polishing pad fluctuates, resulting in uneven polishing and making it difficult to planarize the substrate.

[0009] Furthermore, as described in Patent Documents 2 and 3, in the method of using a bellows to move the polishing pad parallel to the substrate, there is a problem in that a repulsive force is generated due to deformation of the bellows, causing unevenness in the pressing pressure within the pad surface, making it difficult to flatten the substrate.

[0010] An object of the present invention is to provide a polishing apparatus capable of planarizing a substrate with high precision while reducing the number of adjustment steps. [Means for solving the problem]

[0011] In order to solve the above-mentioned problems and achieve the object, the polishing apparatus of the present invention is a polishing apparatus that polishes a substrate using a polishing pad, and comprises a holding table that holds a substrate, and a polishing unit that polishes the substrate held on the holding table, the polishing unit having a mounting portion having a mounting surface for mounting a polishing pad, a rotational drive source for rotating the mounting portion, a constant velocity joint for transmitting the rotation of the rotational drive source to the mounting portion, and a tilting mechanism for causing the polishing pad to follow the inclination of the substrate, and the tilting mechanism comprises a spherical portion connected to the mounting portion and tilting together with the tilting of the mounting portion, and a spherical seat that supports the spherical portion so that it can be tilted.

[0012] In the polishing apparatus, the mounting part may be held horizontally by its own weight when the polishing pad mounted on the mounting part is not in contact with a substrate.

[0013] In the polishing apparatus, the spherical portion may be made of a material containing metal, and the spherical seat may be made of a material containing resin.

[0014] In the polishing apparatus, the holding table may hold a polishing pad instead of a substrate, the mounting portion may mount the substrate instead of the polishing pad, and the tilting mechanism may cause the substrate to follow the polishing pad. Effect of the Invention

[0015] The present invention has an effect of making it possible to planarize a substrate with high precision while reducing the number of adjustment steps. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view showing an example of the configuration of a polishing apparatus according to the first embodiment. [Diagram 2] 2 is a cross-sectional view of a polishing unit of the polishing apparatus shown in FIG. [Diagram 3] 3 is a cross-sectional view showing the lower end portion of the spindle unit of the polishing unit shown in FIG. 2, etc. FIG. [Figure 4] FIG. 4 is a cross-sectional view showing a state in which the grinding wheel attached to the spindle unit shown in FIG. 3 is tilted. [Diagram 5] FIG. 5 is a perspective view showing an outer race of a constant velocity joint of the spindle unit shown in FIG. [Figure 6] FIG. 6 is a perspective view showing an inner race of a constant velocity joint of the spindle unit shown in FIG. [Figure 7] FIG. 7 is a perspective view showing a ball of a constant velocity joint of the spindle unit shown in FIG. [Figure 8] FIG. 8 is a perspective view showing a cage of a constant velocity joint of the spindle unit shown in FIG. [Figure 9] FIG. 9 is a perspective view illustrating a main part of a polishing apparatus according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The form (embodiment) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiment. Furthermore, the components described below include those that a person skilled in the art can easily imagine and those that are substantially the same. Furthermore, the configurations described below can be appropriately combined. Furthermore, various omissions, substitutions, or modifications of the configurations can be made without departing from the gist of the present invention.

[0018] [Embodiment 1] A polishing apparatus according to a first embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view showing an example of the configuration of the polishing apparatus according to the first embodiment. Fig. 2 is a cross-sectional view of a polishing unit of the polishing apparatus shown in Fig. 1.

[0019] (substrate) 1 according to the first embodiment is a processing apparatus for polishing a substrate 200. The substrate 200 to be processed by the polishing apparatus 1 shown in Fig. 1 is a wafer such as a disk-shaped semiconductor wafer or an optical device wafer, whose base material is silicon, sapphire, gallium, etc. The substrate 200 has devices formed in each region partitioned by planned division lines set in a lattice pattern on a surface 201 of the base material.

[0020] The device is, for example, an integrated circuit such as an IC (Integrated Circuit) or an LSI (Large Scale Integration), an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), an optical element such as an LED (Light-Emitting Diode), a MEMS (Micro Electro Mechanical Systems), or a semiconductor memory (semiconductor memory device).

[0021] In the first embodiment, a protective tape 210 of the same diameter is attached to a front surface 201 of a substrate 200, and a back surface 202 is polished by a polishing apparatus 1. After being polished, the substrate 200 is divided into individual devices along the planned division lines.

[0022] (polishing equipment) Next, the polishing apparatus 1 will be described. The polishing apparatus 1 is an apparatus that polishes the back surface 202 of the substrate 200. In the first embodiment, the polishing apparatus 1 is a so-called CMP (Chemical Mechanical Polishing) apparatus that polishes the back surface 202 of the substrate 200 while supplying a slurry, which is an abrasive liquid, to the back surface 202. As shown in FIG. 1, the polishing apparatus 1 includes an apparatus main body 2, a holding table 10, a polishing unit 20, a processing feed unit 30, and a control unit 100.

[0023] The holding table 10 has a holding surface 11 on which a surface 201 of a substrate 200 is placed via a protective tape 210, and suction-holds the substrate 200 placed on the holding surface 11. The holding surface 11 of the holding table 10 is disk-shaped and made of porous ceramics or the like, and is connected to a vacuum suction source (not shown) via a vacuum suction path (not shown).

[0024] The holding table 10 has a holding surface 11 sucked by a vacuum suction source, and sucks and holds the substrate 200 placed on the holding surface 11 via the protective tape 210. The holding table 10 is provided so as to be movable in the X-axis direction parallel to the horizontal direction by a holding table moving unit (not shown), and is rotated about an axis parallel to the vertical direction (Z-axis direction) by a rotation moving unit (not shown). The holding table 10 is moved in the X-axis direction by the holding table moving unit between a processing position below the polishing unit 20 and a carry-in / out position where the holding table 10 is retracted from the processing position below the polishing unit 20 and where the substrate 200 is carried in and out.

[0025] The polishing unit 20 polishes a rear surface 202 of the substrate 200 held on the holding table 10. The configuration of the polishing unit 20 will be described later.

[0026] The processing feed unit 30 moves the polishing unit 20 in the Z-axis direction to move the polishing unit 20 away from and toward the holding table 10 at the processing position. In the first embodiment, the processing feed unit 30 is provided on a standing wall 3 erected from one end of the device body 2 in the X-axis direction. As shown in Figs. 1 and 2, the processing feed unit 30 includes a well-known ball screw 31 rotatably provided around its axis, a well-known motor 32 for rotating the ball screw 31 around its axis, a nut 33 fixed to the polishing unit 20 screwed into the ball screw 31, and a well-known guide rail 34 for supporting the housing 21 of the polishing unit 20 movably in the Z-axis direction. In the present invention, the processing feed unit 30 may include an air cylinder or the like for moving the polishing unit 20 in the Z-axis direction.

[0027] The control unit 100 controls each of the above-mentioned constituent units constituting the polishing apparatus 1. In other words, the control unit 100 causes the polishing apparatus 1 to execute a processing operation on the substrate 200. The control unit 100 is a computer having an arithmetic processing device having a microprocessor such as a CPU (central processing unit), a storage device having a memory such as a ROM (read only memory) or a RAM (random access memory), and an input / output interface device.

[0028] The arithmetic processing device of the control unit 100 performs arithmetic processing in accordance with a computer program stored in the storage device, and outputs control signals for controlling the polishing apparatus 1 to the above-mentioned components of the polishing apparatus 1 via the input / output interface device. The control unit 100 is also connected to a display unit configured with a liquid crystal display device or the like for displaying the status and images of the processing operation, an input unit used by the operator to register processing content information, and an alarm unit for notifying the operator. The input unit is configured with at least one of a touch panel provided on the display unit and a keyboard, etc. The alarm unit notifies the operator by emitting at least one of sound, light, and a message on the touch panel.

[0029] Next, the grinding unit 20 will be described. FIG. 3 is a cross-sectional view showing the lower end portion of the spindle unit of the grinding unit shown in FIG. 2, etc. FIG. 4 is a cross-sectional view showing a state in which the grinding wheel attached to the spindle unit shown in FIG. 3 is tilted. FIG. 5 is a perspective view showing an outer race of the constant velocity joint of the spindle unit shown in FIG. 3. FIG. 6 is a perspective view showing an inner race of the constant velocity joint of the spindle unit shown in FIG. 3. FIG. 7 is a perspective view showing a ball of the constant velocity joint of the spindle unit shown in FIG. 3. FIG. 8 is a perspective view showing a cage of the constant velocity joint of the spindle unit shown in FIG. 3.

[0030] As shown in FIG. 2, the polishing unit 20 includes a housing 21 that is raised and lowered along the Z-axis direction by a processing feed unit 30, a spindle motor 22 that is a rotation drive source, and a spindle unit 23.

[0031] The housing 21 is made of a metal such as stainless steel or ceramics, and is fixed to a nut 33 of the processing feed unit 30. As shown in Fig. 2, the housing 21 includes a horizontal plate portion 24 that is flat along the horizontal direction, a vertical plate portion 25 that stands upright from the outer edge of the horizontal plate portion 24 and has a nut 33 fixed thereto, a cover portion 26 that is connected to the horizontal plate portion 24 and the vertical plate portion 25 and covers the periphery of the spindle motor 22, and a cylindrical rotation support portion 27. The horizontal plate portion 24 extends from the standing wall 3 in the X-axis direction, which is the direction in which the holding table is moved by the holding table moving unit.

[0032] The vertical plate portion 25 stands upright from the outer edge of the horizontal plate portion 24 closer to the standing wall 3. The cover portion 26 is connected to both ends of the horizontal plate portion 24 in the Y-axis direction that is parallel to the horizontal direction and perpendicular to the X-axis direction, and to both ends of the vertical plate portion 25 in the Y-axis direction.

[0033] The rotation support part 27 is provided at the end part of the horizontal plate part 24 away from the standing wall 3, and is formed in a cylindrical shape whose axis is parallel to the Z-axis direction. The rotation support part 27 accommodates therein a bearing 28 that supports the spindle unit 23 rotatably about an axis parallel to the Z-axis direction. The bearing 28 supports the spindle unit 23 with respect to the rotation support part 27 of the housing 21 rotatably about its axis.

[0034] The spindle motor 22 is fixed to the vertical plate portion 25 of the housing 21, and is disposed such that the axis of the output shaft 29 is parallel to the Z-axis direction.

[0035] The spindle unit 23 comprises a cylindrical shaft portion 40 having a cylindrical appearance and an outer diameter that varies stepwise so that the lower end is larger in diameter than the upper end, a constant velocity joint 41 provided at the lower end of the shaft portion 40, a tilting mechanism 42, and a disk-shaped mounting portion 43 attached to the tilting mechanism 42.

[0036] The shaft portion 40 is made of a metal such as stainless steel or ceramics, and is formed into a cylindrical shape with its axis parallel to the Z-axis direction. The shaft portion 40 is attached to the inner periphery of a bearing 28 in a rotation support portion 27 of the housing 21, and is supported so that its axis is parallel to the Z-axis direction and is rotatable about its axis relative to the housing 21. A pulley 44 is fixed to the upper end of the shaft portion 40.

[0037] As shown in Figures 3 and 4, the constant velocity joint 41 comprises an outer race 45 fixed to the lower end of the shaft portion 40, an inner race 46 housed within the outer race 45, balls 47 housed between the outer race 45 and the inner race 46 so as to be able to roll freely, and a cage 48 that positions the balls 47 between the outer race 45 and the inner race 46.

[0038] The outer race 45 is made of a metal such as stainless steel or ceramics, is formed in a cylindrical shape coaxial with the shaft portion 40, and rotates integrally with the shaft portion 40 about the axis relative to the housing 21. The outer race 45 has inner and outer diameters larger than the outer diameter of the shaft portion. The outer race 45 is integrally formed at its lower end with an inner peripheral protrusion 451 that protrudes inwardly around the entire circumference.

[0039] As shown in Fig. 3, the inner peripheral protrusion 451 of the outer race 45 has an inner peripheral surface 452 formed into a spherical shape in a cross section parallel to the axis. In a cross section parallel to the axis, the inner peripheral surface 452 of the inner peripheral protrusion 451 of the outer race 45 is curved into a spherical shape that is concave toward the outer periphery of the outer race 45 and has a center of curvature located on the axis. Also, as shown in Fig. 5, the outer race 45 has a spherical groove 453 formed on the inner peripheral surface 452 of the inner peripheral protrusion 451.

[0040] The spherical grooves 453 extend linearly along the Z-axis direction, and are provided at intervals in the circumferential direction of the inner peripheral surface 452 of the inner peripheral protruding portion 451 of the outer race 45. In a cross section parallel to the axis, the spherical grooves 453 have a groove bottom 454 that is curved spherically. In a cross section parallel to the axis, the center of curvature of the groove bottom 454 is located on the axis, and forms part of a spherical surface that is concave from the inner peripheral surface 452.

[0041] The inner race 46 is made of a metal such as stainless steel or ceramics, and is formed into a thick ring shape housed inside the outer race 45, and is disposed coaxially with the shaft portion 40 and the outer race 45. As shown in FIG. 3, the inner race 46 has an outer peripheral surface 462 formed into a spherical shape in a cross section parallel to the axis. In a cross section parallel to the axis, the outer peripheral surface 462 of the inner race 46 is curved into a spherical shape that is convex toward the outer periphery of the inner race 46 and has a center of curvature located on the axis. In addition, as shown in FIG. 6, the inner race 46 has a spherical groove 463 formed in the outer peripheral surface 462.

[0042] The spherical grooves 463 extend linearly along the Z-axis direction, and are provided in plurality at intervals in the circumferential direction of the outer circumferential surface 462 of the inner race 46. In a cross section parallel to the axis, the spherical grooves 463 have a groove bottom 464 that is curved spherically. In a cross section parallel to the axis, the center of curvature of the groove bottom 464 is located on the axis, and forms part of a spherical surface that is concave from the outer circumferential surface 462. The spherical groove 463 of the inner race 46 faces the spherical groove 453 of the outer race 45.

[0043] Additionally, the outer diameter of the inner race 46 is smaller than the inner diameter of the outer race 45. Therefore, when the inner race 46 is housed within the outer race 45, an outer peripheral surface 462 faces an inner peripheral surface 452 of the outer race 45 with a gap therebetween.

[0044] The balls 47 are made of metal such as stainless steel or ceramics, and are formed into a spherical shape as shown in Fig. 7. With the inner race 46 housed in the outer race 45, the balls 47 are housed in the mutually opposing spherical grooves 453, 463 of the outer race 45 and the inner race 46, and are free to roll on the groove bottoms 454, 464. By rolling on the groove bottoms 454, 464 of the spherical grooves 453, 463 as shown in Figs. 3 and 4, the balls 47 are free to change the orientation of the axis of the inner race 46 relative to the axis of the outer race 45.

[0045] The cage 48 is made of a metal such as stainless steel or ceramics, and is formed in a ring shape as shown in Fig. 8. The inner diameter of the cage 48 is larger than the outer diameter of the inner race 46 and smaller than the inner diameter of the outer race 45. A receiving hole 481 that receives the ball 47 penetrates the cage 48. The cage 48 is disposed between the outer race 45 and the inner race 46, and holds the ball 47 between the outer race 45 and the inner race 46 by receiving the ball 47 in the receiving hole 481.

[0046] Because balls 47 are housed in spherical grooves 453, 463, when outer race 45 rotates about its axis, inner race 46 also rotates about its axis integrally with outer race 45. Furthermore, in constant velocity joint 41, the center of rotation that changes the orientation of the axis of inner race 46 relative to the axis of outer race 45 coincides with the center of curvature of inner circumferential surface 452 of inner circumferential protruding portion 451 of outer race 45 and the center of curvature of outer circumferential surface 462 of inner race 46.

[0047] In the present invention, it is preferable that constant velocity joint 41 has three or more spherical grooves 453, 463, balls 47, and accommodating holes 481 arranged at equal intervals in the circumferential direction. However, constant velocity joint 41 is not limited to having three or more spherical grooves 453, 463, balls 47, and accommodating holes 481 arranged at equal intervals in the circumferential direction, as long as rotation can be transmitted.

[0048] As shown in Figs. 3 and 4, the tilt mechanism 42 includes a fixed-side spherical member 49 that is a spherical seat and a movable-side spherical member 50 that is a spherical portion. In the first embodiment, a pair of fixed-side spherical members 49 are provided, each of which is made of a hard resin. That is, the fixed-side spherical members 49 are made of resin. Each of the fixed-side spherical members 49 is formed in a ring shape and is fixed to the shaft portion 40 side and the side away from the shaft portion 40 of the inner peripheral protrusion 451 of the outer race 45. The inner peripheral surface 491 of the fixed-side spherical member 49 is formed in a spherical shape with the same center of curvature as the inner peripheral surface 452 of the inner peripheral protrusion 451 of the outer race 45.

[0049] In the first embodiment, a pair of movable-side spherical members 50 are provided, and each is made of a metal such as stainless steel. That is, the movable-side spherical member 50 is made of a material containing metal. The movable-side spherical members 50 are each formed in a ring shape and fixed to the shaft portion 40 side and the side away from the shaft portion 40 of the inner race 46. The outer peripheral surface 501 of the movable-side spherical member 50 is formed in a spherical shape with the same center of curvature as the inner peripheral surface 491 of the fixed-side spherical member 49 and the inner peripheral surface 452 of the inner peripheral protrusion 451 of the outer race 45. In addition, the outer peripheral surface 501 of the movable-side spherical member 50 slides on the inner peripheral surface 491 of the fixed-side spherical member 49.

[0050] Thus, in the first embodiment, the tilting mechanism 42 constitutes a so-called sliding bearing in which the inner peripheral surface 491 of the fixed-side spherical member 49 and the outer peripheral surface 501 of the movable-side spherical member 50 slide against each other, but in the present invention, balls or rollers may be provided between the inner peripheral surface 491 of the fixed-side spherical member 49 and the outer peripheral surface 501 of the movable-side spherical member 50 as rolling elements for rolling therebetween. Also, in the present invention, the material of both the fixed-side spherical member 49 and the movable-side spherical member 50 is not limited to resin or metal, and both may be made of resin, both may be made of metal, both may be made of ceramics, or the like.

[0051] The mounting part 43 is formed in a ring shape and has a mounting surface 431 on the underside for mounting the polishing wheel 51. The polishing wheel 51 mounted on the mounting part 43 includes a ring-shaped wheel base 511 mounted on the mounting surface 431, and a ring-shaped polishing pad 512 provided on the underside of the wheel base 511 coaxially with the wheel base 511. By mounting the wheel base 511 of the polishing wheel 51 on the mounting surface 431, the polishing pad 512 is mounted on the mounting surface 431 via the wheel base 511. The polishing pad 512 polishes the back surface 202 of the substrate 200.

[0052] In the first embodiment, the mounting portion 43 has the wheel base 511 of the polishing wheel 51, that is, the polishing pad 512, mounted on the mounting surface 431 by wax, a backing material (adhesive), vacuum suction, or the like.

[0053] In addition, in embodiment 1, the mounting portion 43 includes a ring-shaped pad mounting member 432 having a mounting surface 431, and a ring-shaped mounting member 433 fixed to the pad mounting member 432 and fixed and connected to one of the movable side spherical members 50.

[0054] In the spindle unit 23 having the above-described configuration, the shaft portion 40, the constant velocity joint 41, the tilt mechanism 42, the mounting portion 43 and the grinding wheel 51 are coaxially arranged.

[0055] In the spindle unit 23, a ring-shaped timing belt 52 is stretched between a pulley 35 fixed to the output shaft 29 of the spindle motor 22 and a pulley 44 fixed to the upper end of the shaft portion 40. For this reason, in the spindle unit 23, the spindle motor 22 rotates the output shaft 29 about its axis, causing the timing belt 52 to circulate around the pulleys 35, 44, thereby rotating the shaft portion 40, the constant velocity joint 41, the mounting portion 43, and the grinding wheel 51 about its axis. In this way, the spindle motor 22 rotates the mounting portion 43, i.e., the grinding pad 512, about an axis parallel to the Z-axis direction.

[0056] Furthermore, the outer race 45 and the inner race 46 of the constant velocity joint 41 rotate integrally around the axis, and since the inner race 46 is fixed to the mounting part 43 via one of the movable spherical members 50, the outer race 45 and the inner race 46 of the constant velocity joint 41 rotate integrally with the mounting part 43, i.e., the polishing pad 512. For this reason, the constant velocity joint 41 transmits the rotation of the spindle motor 22, which is the rotation drive source, to the mounting part 43, i.e., the polishing pad 512, to rotate the mounting part 43, i.e., the polishing pad 512.

[0057] Moreover, one side of the movable-side spherical member 50 of the tilting mechanism 42 is connected to the mounting part 43, and the outer circumferential surface 501 slides on the inner circumferential surface 491 of the fixed-side spherical member 49, so that the movable-side spherical member 50 tilts together with the mounting part 43. Since the outer circumferential surface 501 of the movable-side spherical member 50 slides on the inner circumferential surface 491 of the fixed-side spherical member 49, the fixed-side spherical member 49 of the tilting mechanism 42 supports the movable-side spherical member 50 in a tiltable manner. Note that tilting refers to the tilting of the axis of the movable-side spherical member 50 etc. with respect to the axis of the fixed-side spherical member 49 etc.

[0058] In addition, in the spindle unit 23, the inner diameter of the lower end of the outer race 45 is larger than the outer diameter of one of the fixed-side spherical members 49, a gap 53 is formed between the lower end of the outer race 45 and one of the fixed-side spherical members 49, and an annular intrusion portion 434 is formed in a ring shape thinner than the width of the gap 53 and is integrally formed with the mounting member 433 of the mounting part 43 and disposed within the gap 53. In this manner, in the spindle unit 23, the gap 53 and the annular intrusion portion 434 disposed within the gap 53 constitute a labyrinth seal that prevents the lubricating oil in the spindle unit 23 from leaking out to the outside and prevents grinding fluid such as slurry from entering from the outside.

[0059] In the spindle unit 23 having the above-mentioned configuration, the inner race 46 of the constant velocity joint 41, the movable spherical member 50, the mounting part 43, and the polishing wheel 51 rotate relative to the outer race 45 around the center of curvature of the inner peripheral surface 491 and the outer peripheral surface 501, and as shown in Fig. 4, the axis of the mounting part 43 etc. tilts relative to the axis of the outer race 45. For this reason, when the substrate 200 held on the holding table 10 tilts, the spindle unit 23 tilts the mounting part 43 to make the polishing pad 512 follow the tilt of the substrate 200. Incidentally, making the polishing pad 512 follow the tilt of the substrate 200 means tilting the mounting part 43 relative to the outer race 45 so that the lower surface of the polishing pad 512 comes into close contact with the back surface 202 of the substrate 200.

[0060] Furthermore, the center of gravity of the combination of the inner race 46 of the constant velocity joint 41, the movable spherical member 50, the mounting part 43, and the polishing wheel 51 of the spindle unit 23 is located below the center of curvature of the inner circumferential surface 491 and the outer circumferential surface 501. For this reason, the spindle unit 23 is held horizontally by its own weight when the mounting part 43 and the polishing pad 512 mounted on the mounting part 43 are not in contact with the substrate 200, i.e., when no force is acting on the polishing pad 512.

[0061] In the spindle unit 23 configured as described above, the inner race 46 of the constant velocity joint 41, the movable spherical member 50, the mounting portion 43 and the polishing wheel 51 rotate relative to the outer race 45 around the center of curvature of the inner circumferential surface 491 and the outer circumferential surface 501, so that even if the polishing pad 512 tilts, the rotation speed of the outer race 45 etc. matches the rotation speed of the polishing pad 512.

[0062] In addition, in the spindle unit 23, a supply tube 54 for supplying slurry to the underside of the polishing pad 512 is passed through the mounting member 433 of the mounting part 43, the movable-side spherical member 50, and the inner periphery of the inner race 46. In the present invention, the method of supplying slurry in the spindle unit 23 is not limited to supplying by the supply tube 54.

[0063] The polishing unit 20 polishes the back surface 202 of the substrate 200 by rotating the polishing pad 512 around its axis using the spindle motor 22 while supplying slurry from the supply tube 54, and by moving the polishing pad 512 closer to the holding table 10 at the processing position at a predetermined feed speed using the processing feed unit 30.

[0064] Next, a processing operation of the polishing apparatus 1 according to the first embodiment will be described. First, the polishing apparatus 1 receives and registers processing conditions input by an operator via an input unit or the like via the control unit 100, and the substrate 200 is placed on the holding surface 11 of the holding table 10 at the loading / unloading position via the protective tape 210. When the control unit 100 receives an instruction to start the processing operation from the operator, the polishing apparatus 1 starts the processing operation.

[0065] In a processing operation, in the polishing apparatus 1, the control unit 100 sucks and holds the substrate 200 on the holding surface 11 of the holding table 10. In the polishing apparatus 1, the control unit 100 controls the spindle motor 22 to rotate the polishing pad 512 about its axis.

[0066] In the processing operation, in the polishing apparatus 1, the control unit 100 controls the holding table moving unit to move the holding table 10 toward the processing position, and the substrate 200 held by the holding table 10 is positioned below the polishing unit 20. Then, in the polishing apparatus 1, the control unit 100 controls the rotation moving unit to rotate the holding table 10 about its axis while supplying slurry, and feed the polishing unit 20 by the processing feed unit 30 while rotating the polishing pad 512 about its axis by the spindle motor 22, so that the polishing pad 512 is pressed against the back surface 202 of the substrate 200 while rotating, thereby polishing the back surface 202 of the substrate 200.

[0067] When polishing of the back surface 202 of the substrate 200 is completed, the control unit 100 of the polishing apparatus 1 stops the supply of slurry, stops the rotation of the holding table 10 about its axis, and moves the polishing unit 20 away from the substrate 200 by the processing feed unit 30, and then moves the holding table 10 toward the load / unload position by the holding table moving unit. Then, when the holding table 10 is positioned at the load / unload position, the control unit 100 of the polishing apparatus 1 stops the movement of the holding table 10 by the holding table moving unit, and stops suction holding of the substrate 200 on the holding table 10.

[0068] As described above, the polishing apparatus 1 of embodiment 1 is equipped with a tilting mechanism 42 that causes the polishing pad 512 to follow the inclination of the substrate 200, so that the substrate 200 and the polishing pad 512 can be positioned parallel to each other by tilting the mounting portion 43 without using leveling bolts or the like.

[0069] Furthermore, in the polishing apparatus 1 of embodiment 1, the center of rotation that changes the orientation of the axis of the inner race 46 of the constant velocity joint 41 relative to the axis of the outer race 45 coincides with the center of curvature of the inner surface 452 of the inner circumferential protrusion 451 of the outer race 45 and the center of curvature of the outer surface 462 of the inner race 46. Therefore, even if the polishing pad 512 tilts, the rotation speed of the outer race 45 etc. and the rotation speed of the polishing pad 512 match, thereby suppressing fluctuations in the rotation speed of the polishing pad 512 and suppressing uneven polishing.

[0070] Furthermore, in the polishing apparatus 1 of embodiment 1, the tilting mechanism 42 has the spherical inner surface 491 of the fixed side spherical member 49 and the spherical outer surface 501 of the movable side spherical member 50 sliding against each other to cause the polishing pad 512 to follow the tilt of the substrate 200, thereby suppressing the generation of tilting repulsive forces and the like when tilting the polishing pad 512, and thereby suppressing the occurrence of uneven pressing pressure within the polishing pad 512.

[0071] As a result, the polishing apparatus 1 according to the first embodiment has the effect of being able to planarize the substrate 200 with high precision while reducing the number of adjustment steps.

[0072] [Embodiment 2] A polishing apparatus according to a second embodiment of the present invention will be described with reference to the drawings. Fig. 9 is a perspective view showing a schematic view of a main part of the polishing apparatus according to the second embodiment. In Fig. 9, the same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof will be omitted.

[0073] 9, the polishing apparatus 1-2 according to the second embodiment includes a holding table 10 holding a polishing pad 512 on the holding surface 11 instead of the substrate 200, a mounting section 43 mounting the front surface 201 side of the substrate 200 on the mounting surface 431 via a protective tape 210 instead of the polishing pad 512, a polishing unit 20 attached to the tip of a swing arm 60 via a processing feed unit 30, and a slurry supply unit 70 for supplying a slurry to the polishing pad 512. The polishing apparatus 1-2 according to the second embodiment polishes the rear surface 202 of the substrate 200 by causing the swing arm 60 to abut against the polishing pad 512, supplying slurry from the slurry supply unit 70 to the polishing pad 512, and swinging the swing arm 60 around the base end while rotating the mounting section 43 and the holding table 10 around the axis. In the polishing apparatus 1-2 of the first embodiment, the tilting mechanism 42 causes the substrate 200 to follow the tilt of the polishing pad 512 during polishing.

[0074] The polishing apparatus 1-2 of embodiment 2 is equipped with a tilting mechanism 42 and a constant velocity joint 41, as in embodiment 1, so that the substrate 200 and the polishing pad 512 can be positioned parallel to each other without using leveling bolts or the like, thereby suppressing uneven polishing and preventing bias in the pressing pressure within the polishing pad 512.

[0075] As a result, similarly to the first embodiment, the polishing apparatus 1-2 according to the second embodiment has the effect of being able to planarize the substrate 200 with high precision while reducing the number of adjustment steps.

[0076] The present invention is not limited to the above embodiment. In other words, various modifications can be made without departing from the gist of the present invention. For example, in the present invention, the polishing apparatus 1 may polish the substrate 200 while supplying a polishing liquid other than the slurry, or may polish the substrate 200 without supplying a polishing liquid. [Explanation of symbols]

[0077] 1,1-2 Polishing equipment 10 Holding table 20 Polishing unit 22 Spindle motor (rotation drive source) 41 Constant velocity joint 42 Tilt mechanism 43 Mounting part 49 Fixed side spherical member (spherical seat) 50 Movable side spherical member (spherical part) 200 boards 431 Mounting surface 512 Polishing Pad

Claims

1. A polishing apparatus for polishing a substrate using a polishing pad, comprising: A holding table for holding the substrate; a polishing unit that polishes the substrate held on the holding table, The polishing unit comprises: a mounting portion having a mounting surface for mounting a polishing pad; A rotary drive source for rotating the mounting portion; a constant velocity joint for transmitting rotation of the rotary drive source to the mounting portion; a tilting mechanism for causing the polishing pad to follow the tilt of the substrate; The tilt mechanism includes: A spherical portion connected to the mounting portion and tilting with the mounting portion; and a spherical seat that supports the spherical portion so that the spherical portion can tilt.

2. 2. The polishing apparatus according to claim 1, wherein the mounting portion is held horizontally by its own weight when the polishing pad mounted on the mounting portion is not in contact with the substrate.

3. The spherical portion is configured to include a metal, 3. The polishing apparatus according to claim 1, wherein the spherical seat is made of a material containing a resin.

4. The holding table holds a polishing pad instead of a substrate, The mounting portion mounts a substrate instead of a polishing pad, 3. The polishing apparatus according to claim 1, wherein the tilting mechanism causes the substrate to follow the polishing pad.

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