JP7107688B2 - Polishing method and polishing apparatus - Google Patents

Description

The present invention relates to a polishing method and a polishing apparatus for polishing the surface or peripheral edge of a substrate such as a wafer with a polishing tool to obtain a desired polishing profile.

2. Description of the Related Art Conventionally, a polishing apparatus has been used to polish the peripheral edge of a substrate. FIG. 42 is a schematic diagram showing a conventional polishing apparatus. A substrate W such as a wafer is held by vacuum suction or the like on a stage surface 200a of a substrate stage 200, which is a substrate holding portion, and is rotated together with the substrate stage 200 about its axis. A polishing tape 205 , which is a polishing tool, is pressed against the peripheral edge of the substrate W by a pressing member 208 . The pressing member 208 is connected to an air cylinder 209 , and a force for pressing the polishing tape 205 against the substrate W is applied from the air cylinder 209 to the pressing member 208 . During polishing of the substrate W, pure water is supplied to the center of the substrate W, and the upper surface of the substrate W is covered with pure water. The polishing tape 205 polishes the peripheral edge of the substrate W in the presence of pure water to form a stepped depression 210 on the peripheral edge of the substrate W as shown in FIG.

JP 2014-150131 A JP 2013-172019 A

However, one or both of the substrate stage 200 and the pressing member 208 may be tilted due to problems such as assembly accuracy of the polishing apparatus. For example, as shown in FIG. 44, when the pressing member 208 is tilted, the polishing tape 205 is pressed obliquely against the peripheral edge of the substrate W. It will be formed in the department. Similarly, as shown in FIG. 45, when the axis of the substrate stage 200 is tilted, the polishing tape 205 is pressed obliquely against the peripheral edge of the substrate W, resulting in an obliquely polished surface. It is formed at the peripheral portion of the substrate W.

A similar problem may also occur in the polishing apparatus for polishing the surface (front side or back side) of the substrate shown in FIG. The polishing apparatus shown in FIG. 46 has a substrate holder 300 that holds and rotates the substrate W, and a polishing head 301 that polishes the surface (front side or back side) of the substrate W. As shown in FIG. A polishing head 301 holds a polishing tool 302 such as a polishing tape. The polishing head 301 has a pressing member 303 at its lower portion, and is configured to press the polishing tool 302 against the surface of the substrate W with the pressing member 303 . The polishing head 301 polishes the surface of the substrate W by pressing the polishing tool 302 against the surface of the substrate W rotated by the substrate holder 300 while rotating about its axis.

In the polishing apparatus shown in FIG. 46, if either the polishing head 301 or the substrate holder 300 is tilted with respect to the other, the polishing tool 302 cannot properly contact the surface of the substrate W, resulting in the desired polishing profile cannot be obtained.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a polishing method and a polishing apparatus capable of optimizing the relative angle between a substrate holder and a pressing member that presses a polishing tool against a substrate.

In one aspect of the present invention, at least three sensors measure the heights of at least three points on the substrate holding surface, calculate the inclination of the substrate holding surface based on the output signals of the sensors, and measure the height of the pressing member. The heights of at least three points on a plane parallel to the pressing surface are measured by the sensors, the inclination of the pressing surface is calculated based on the output signal of the sensor, and the relative relationship between the substrate holding surface and the pressing surface is calculated. After that, the substrate is held on the substrate holding surface, the inclination of the substrate holding surface or the pressing surface is adjusted so that the relative angle is within the allowable range, and then the substrate is held. In the polishing method, polishing of the substrate is started by pressing a polishing tool against the substrate with the pressing surface in a state in which the inclination of the surface or the pressing surface is adjusted.

In a preferred embodiment of the present invention, the inclination of the substrate holding surface or the pressing surface is adjusted so that the relative angle is within the allowable range, and the pressing surface presses the polishing tool against the substrate. The step of polishing the substrate is a step of pressing the polishing tool against the peripheral portion of the substrate with the pressing surface whose inclination is adjusted so that the relative angle is within the allowable range.
In a preferred aspect of the present invention, the step of holding the substrate on the substrate holding surface is a step of holding the substrate on the substrate holding surface whose inclination is adjusted so that the relative angle is within an allowable range. characterized by being
A preferred aspect of the present invention is characterized in that the at least three points on the substrate holding surface are at least three points on the outer peripheral portion of the substrate holding surface.

In a preferred aspect of the present invention, the step of measuring the heights of at least three points on the substrate holding surface includes using at least three sensors to measure the heights of at least three points in each of a plurality of regions within the substrate holding surface. and the step of calculating the inclination of the substrate holding surface includes calculating the inclination of each of the plurality of regions, calculating the average of the calculated inclinations of the plurality of regions, and calculating the calculated average is specified as the inclination of the substrate holding surface.
A preferred aspect of the present invention is characterized in that the step of measuring the heights of at least three points in each of the plurality of regions is performed while intermittently rotating the substrate holding surface.
A preferred aspect of the present invention is characterized in that the plurality of regions are arranged around the center of the substrate holding surface at equal intervals.
A preferred aspect of the present invention is characterized in that the inclination of the substrate holding surface and the inclination of the pressing surface are expressed as vectors on a three-dimensional coordinate system.

One aspect of the present invention includes a substrate holding portion having a substrate holding surface, a pressing member having a pressing surface for pressing a polishing tool against the substrate, heights of at least three points on the substrate holding surface, and the pressing surface. at least three sensors for measuring the heights of at least three points on a plane parallel to the substrate holding surface and the inclination of the pressing surface are calculated based on the output signals of the sensors; a processing unit that calculates the relative angle with the pressing surface; an inclination adjusting device that adjusts the inclination of the substrate holding surface or the pressing surface; and a state in which the inclination of the substrate holding surface or the pressing surface is adjusted and a pressing device for applying a pressing force to the pressing member to press the polishing tool against the substrate on the substrate holding surface , wherein the inclination of the substrate holding surface or the pressing surface of the pressing device is adjusted by the inclination adjusting device. After the polishing, the polishing tool is pressed against the substrate on the substrate holding surface to start polishing the substrate .

In a preferred aspect of the present invention, the tilt adjustment device includes a first tilt mechanism and a second tilt mechanism for adjusting the tilt of the pressing surface, and the pressing member includes the first tilt mechanism and the second tilt mechanism. characterized by being connected to
In a preferred aspect of the present invention, the first tilt mechanism and the second tilt mechanism each include a first support shaft and a second support shaft perpendicular to each other, and the pressing member includes the first support shaft and the It is characterized by being rotatable around the second support shaft.
A preferred aspect of the present invention is characterized in that the tilt adjusting device is a pressing member tilting actuator that tilts the pressing surface, and the pressing member tilting actuator includes at least two actuators.
A preferred aspect of the present invention is characterized in that the tilt adjusting device is a substrate holding surface tilting actuator that tilts the substrate holding surface, and the substrate holding surface tilting actuator includes at least two actuators.
A preferred aspect of the present invention is characterized in that the sensor is positioned above the outer peripheral portion of the substrate holding surface.
A preferred aspect of the present invention is characterized in that the sensor is a displacement sensor.
A preferred aspect of the present invention is characterized by further comprising a bracket to which the sensor is fixed.

According to the present invention, the inclination of the substrate holding surface or the pressing member can be adjusted based on the relative angle between the substrate holding surface and the pressing surface. The pressing member can press the polishing tool against the surface or peripheral edge of the substrate on the stage surface at an optimum angle. As a result, a desired polishing profile can be obtained.

1(a) and 1(b) are enlarged cross-sectional views showing the peripheral portion of the substrate. 1 is a plan view schematically showing an embodiment of a polishing apparatus; FIG. FIG. 3 is a side view of the polishing apparatus shown in FIG. 2 as seen from the direction of arrow A; FIG. 3 is a side view of the polishing apparatus shown in FIG. 2 as seen from the direction of arrow B; It is a perspective view which shows a sensor typically. It is a schematic diagram which shows the structure of a polishing head. FIG. 7 is a view of the base block and the first support shaft as viewed in the direction indicated by arrow C in FIG. 6; It is a front view which shows an air cylinder, a direct-acting guide, and a pressing member. It is a figure which shows the sensor and process part which are measuring the inclination of the stage surface of a substrate stage. FIG. 10 is a schematic diagram showing an embodiment of measuring the tilt of the stage surface in a plurality of areas within the stage surface. Fig. 3 shows three points in a reference plane measured by a sensor; FIG. 3 shows the coordinates of each of the three points on the reference plane before zero resetting of the sensor; FIG. 13 shows the coordinates of each of the three points on the reference plane after zero reset of the sensor; It is a figure explaining the process of creating three mutually orthogonal vectors from the coordinate of three points. FIG. 4 is a diagram for explaining the process of decomposing a normal vector into an X-oriented vector, a Y-oriented vector, and a Z-oriented vector; FIG. 10 is a diagram showing a sensor and a processing unit that measure the inclination of the pressing surface of the pressing member; 5 is a flowchart for explaining the flow of a process for matching the inclination of the pressing surface with the inclination of the stage surface; 5 is a flowchart for explaining the flow of a process for matching the inclination of the pressing surface with the inclination of the stage surface; FIG. 11 is a side view schematically showing another embodiment of a polishing apparatus; FIG. 10 is a diagram showing a state in which the polishing head has been moved until the upper surface of the protrusion is positioned below the three sensors; FIG. 11 is a side view schematically showing still another embodiment of a polishing apparatus; FIG. 22 is a diagram showing the arrangement of the actuators shown in FIG. 21; It is a figure which shows an example of a detailed structure of an actuator. FIG. 10 is a plan view showing a stage tilt actuator with two actuators and one ball joint; FIG. 22 is a plan view of the polishing apparatus shown in FIG. 21; FIG. 10 is a diagram showing a state in which the polishing head and reference plate have been moved until the reference surface of the reference plate is positioned below the sensor; 4 is a flowchart for explaining the flow of a process for matching the inclination of the stage surface with the inclination of the pressing surface; 4 is a flowchart for explaining the flow of a process for matching the inclination of the stage surface with the inclination of the pressing surface; FIG. 10 is a diagram showing an embodiment in which an actuator is connected to the polishing head instead of the substrate holder; FIG. 11 is a side view schematically showing still another embodiment of a polishing apparatus; 31 is a bottom view of the polishing head shown in FIG. 30; FIG. FIG. 4 is a plan view of the polishing head at the polishing position; FIG. 33 is a cross-sectional view showing the hydrostatic support stage shown in FIG. 32; 34(a) and 34(b) are diagrams for explaining the substrate holding surface of the substrate holding part. FIG. 4 is a diagram showing a state in which a dummy substrate is held by a substrate holding portion; FIG. 10 is a diagram showing a state in which the sensor measures the heights of three points on the lower surface of the dummy substrate; FIG. 4 is a diagram showing a state in which the sensor measures the height of the polishing surface (lower surface) of the polishing tool; It is a figure which shows the state where the sensor target jig|tool was attached to the bottom part of the polishing head. FIG. 39(a) is a diagram showing an example of a fastening mechanism for detachably attaching the sensor target jig to the polishing head, and FIG. 39(b) is a diagram showing another example of the fastening mechanism. It is a figure which shows the state when measuring the height of three points|pieces on the flat surface of a sensor target jig|tool with a sensor. FIG. 10 is a diagram showing an embodiment of a polishing apparatus provided with a substrate holding surface tilting actuator that tilts the entire substrate holding part; It is a schematic diagram which shows the conventional polishing apparatus. FIG. 4 is a cross-sectional view showing a stepped depression formed in the peripheral edge of a substrate; FIG. 10 is a diagram showing a state in which an inclined pressing member presses the polishing tape against the peripheral edge of the substrate; FIG. 10 is a diagram showing a state in which the pressing member presses the polishing tape against the peripheral edge of the tilted substrate; FIG. 3 is a schematic diagram showing another example of a conventional polishing apparatus;

1(a) and 1(b) are enlarged cross-sectional views showing the peripheral portion of the substrate. More specifically, FIG. 1(a) is a cross-sectional view of a so-called straight substrate, and FIG. 1(b) is a cross-sectional view of a so-called round substrate. Examples of substrates include wafers. The perimeter of the substrate is defined as the area including the bevel, top edge and bottom edge. In the substrate W of FIG. 1(a), the bevel portion is composed of an upper inclined portion (upper bevel portion) P, a lower inclined portion (lower bevel portion) Q, and side portions (apex) R. It is the outermost peripheral surface (indicated by symbol S). In the substrate W of FIG. 1(b), the bevel portion is a portion (indicated by symbol S) having a curved cross section, which constitutes the outermost peripheral surface of the substrate W. As shown in FIG. The top edge portion is an annular flat portion T1 located radially inward of the bevel portion S. As shown in FIG. The bottom edge portion is an annular flat portion T2 located on the opposite side of the top edge portion and radially inward of the bevel portion S. The top edge T1 may also include regions where devices are formed. In the following description, an embodiment of polishing the top edge portion T1 will be described, but the present invention can also be applied to polishing of the bottom edge portion T2 and polishing of the bevel portion S.

2 is a plan view schematically showing an embodiment of the polishing apparatus, FIG. 3 is a side view of the polishing apparatus shown in FIG. 2 as seen from the direction of arrow A, and FIG. 4 is the polishing apparatus shown in FIG. is a side view when viewed from the direction of an arrow B. FIG. The polishing apparatus includes a substrate holder 1 that holds and rotates a substrate (eg, wafer) W. As shown in FIG. The substrate holder 1 has a substrate stage 2 capable of holding a substrate W, and a stage motor 3 rotating the substrate stage 2 about its axis L. As shown in FIG. The upper surface of the substrate stage 2 constitutes a stage surface 2a, which is a substrate holding surface for holding the substrate W. As shown in FIG. The substrate stage 2 is connected to a stage motor 3, and the stage surface 2a of the substrate stage 2 is rotated about the axis L of the substrate stage 2 by the stage motor 3. As shown in FIG. The substrate W to be polished is held on the stage surface 2 a of the substrate stage 2 by vacuum suction or the like, and rotated together with the substrate stage 2 by the stage motor 3 .

The polishing apparatus has a polishing head 10 having a pressing member 11 that presses the polishing tape 7 against the peripheral edge of the substrate W. As shown in FIG. The pressing member 11 is arranged above the substrate stage 2 and is arranged at a position shifted from the axis L of the substrate stage 2 . More specifically, the pressing member 11 is arranged above the peripheral portion of the substrate W held on the stage surface 2a.

The polishing tape 7 is a polishing tool for polishing the substrate W. FIG. One end of the polishing tape 7 is fixed to the unwinding reel 14 and the other end of the polishing tape 7 is fixed to the take-up reel 15 . Most of the polishing tape 7 is wound around both the supply reel 14 and the take-up reel 15 , and a portion of the polishing tape 7 extends between the supply reel 14 and the take-up reel 15 . The supply reel 14 and the take-up reel 15 are subjected to torque in opposite directions by reel motors 17 and 18, respectively, so that the abrasive tape 7 is tensioned.

A tape feeding device 20 is arranged between the supply reel 14 and the take-up reel 15 . The polishing tape 7 is sent from the take-up reel 14 to the take-up reel 15 at a constant speed by the tape feeder 20 . The polishing tape 7 extending between the supply reel 14 and the take-up reel 15 is supported by two guide rollers 21,22. These two guide rollers 21 , 22 are arranged between the supply reel 14 and the take-up reel 15 . A lower surface of the polishing tape 7 extending between the guide rollers 21 and 22 constitutes a polishing surface for polishing the substrate W. As shown in FIG. As a polishing tool, instead of the polishing tape 7, a fixed abrasive (that is, a whetstone) may be used.

The pressing member 11 is positioned between two guide rollers 21,22. The guide rollers 21 and 22 are arranged so that the polishing tape 7 between the guide rollers 21 and 22 extends in the tangential direction of the substrate W at the contact point between the peripheral edge portion of the substrate W and the polishing tape 7 .

Polishing of the substrate W is performed as follows. The substrate W is held on the substrate stage 2 so that the film (eg, device layer) formed on the surface faces upward, and the substrate W is rotated about its axis L together with the substrate stage 2 . Liquid (for example, pure water) is supplied to the center of the rotating substrate W from a liquid supply nozzle (not shown). In this state, the pressing member 11 of the polishing head 10 presses the polishing tape 7 onto the peripheral edge of the substrate W, more specifically, the top edge of the substrate W (see symbol T1 in FIGS. 1A and 1B). press against. The substrate W is polished by sliding contact between the rotating substrate W and the polishing tape 7 . The polishing tape 7 during polishing of the substrate W extends in the tangential direction of the substrate W at the contact point between the substrate W and the polishing tape 7, as shown in FIG.

The polishing apparatus includes three sensors 30 capable of measuring the height of the stage surface 2a of the substrate stage 2. FIG. In one embodiment, the height of the stage surface 2a is the distance from a reference point to the stage surface 2a. These sensors 30 are positioned above the outer peripheral portion of the stage surface 2a, which is the substrate holding surface, and are arranged so as to be able to measure the height of the outer peripheral portion of the stage surface 2a. This is for measuring the height of the region of the stage surface 2 a closest to the pressing member 11 .

The three sensors 30 are fixed to brackets 35 , and the brackets 35 are detachably fixed to fixed posts 36 . The fixed column 36 is a stationary member whose position and angle are fixed and fixed to the base surface 5 . A stage motor 3 is also fixed to the base surface 5 . The relative positions of the sensor 30 held by the bracket 35 and the substrate stage 2 are fixed. On the other hand, at least the pressing member 11 of the polishing head 10 is configured to be tiltable with respect to the sensor 30 and the substrate stage 2 .

The polishing apparatus further includes a processing section 40 that calculates the tilt of the stage surface 2a based on the output signal of the sensor 30. FIG. As shown in FIG. 2, the processing section 40 includes therein a storage device 40a and an arithmetic device 40b. The storage device 40a includes a hard disk drive (HDD), solid state drive (SSD), or the like. A CPU (Central Processing Unit) is used as the arithmetic unit 40b. A program is stored in advance in the storage device 40a, and the arithmetic device 40b operates according to the program. The sensor 30 is connected to the processing section 40 and the output signal of the sensor 30 is sent to the processing section 40 . The output signal of the sensor 30 is a signal indicating the height of the stage surface 2a.

As shown in FIG. 4, the polishing head 10 includes an air cylinder 25 as a pressing device that applies a pressing force to the pressing member 11, and a base block 39 to which the air cylinder 25 is fixed. In this embodiment, the air cylinder 25 is fixed to the base block 39 via a fixing member 42 attached to the base block 39 . The base block 39 is rotatably supported by the first support shaft 51 . The pressing member 11 is connected to the air cylinder 25 .

As shown in FIG. 2, the first support shaft 51 is connected to a polishing head moving device 41 that moves the polishing head 10 in a predetermined first direction D. As shown in FIG. The first direction D in this embodiment is the direction in which a straight line (imaginary line) connecting the axial center L of the substrate stage 2 and the pressing member 11 when the substrate stage 2 is viewed from above extends. A first direction D is perpendicular to the abrasive tape 7 extending between the guide rollers 21,22. The polishing head moving device 41 includes a linear motion guide 43 to which a first support shaft 51 is fixed, a ball screw mechanism 44 connected to the first support shaft 51, and a servomotor 45 connected to the ball screw mechanism 44. I have. The linear motion guide 43 and the ball screw mechanism 44 extend in the first direction D described above. The first support shaft 51 moves in the first direction D when the servomotor 45 drives the ball screw mechanism 44 . Since the air cylinder 25 and the base block 39 are connected to the first support shaft 51, when the servo motor 45 drives the ball screw mechanism 44, the polishing head 10 moves in the first direction D along with the first support shaft 51. That is, the substrate stage 2 moves toward and away from the stage surface 2 a of the substrate stage 2 and the sensor 30 .

As shown in FIG. 4, the linear motion guide 43 and the motor base 46 are fixed to the base plate 47. As shown in FIG. A servo motor 45 is fixed to a motor base 46 . The base plate 47 is fixed to the base surface 5 via installation blocks 48 .

FIG. 5 is a perspective view schematically showing the sensor 30. FIG. The sensors 30 are spaced from each other and arranged at the same height. In this embodiment, each sensor 30 is a contact displacement sensor having a probe that contacts the object to be measured. The arrangement of the three sensors 30 is not particularly limited as long as the sensors 30 are not arranged in a straight line. In one embodiment, more than four sensors 30 may be provided. In one embodiment, sensor 30 may be a non-contact displacement sensor.

FIG. 6 is a schematic diagram showing the configuration of the polishing head 10. As shown in FIG. As shown in FIG. 6, the polishing head 10 includes a pressing member 11 that presses the polishing tape 7 against the peripheral edge of the substrate W, a pressing member holder 28 that holds the pressing member 11 , and a pressing member holder 28 that presses the pressing member 11 . and an air cylinder 25 as a pressing device that applies force. In FIG. 6, the substrate W and polishing tape 7 are not shown. The pressing member 11 is fixed to the end of the pressing member holder 28 . As described above, the pressing member 11 is arranged at a position away from the axis L of the substrate stage 2 .

The pressing member 11 has a pressing surface 11a parallel to the stage surface 2a. The pressing surface 111a is a flat surface, and the pressing member 11 is configured to press the polishing tape 7 against the peripheral portion of the substrate W with the pressing surface 11a. The air cylinder 25 is connected to a linear motion guide 33 extending parallel to the axis L of the substrate stage 2 , and the air cylinder 25 is connected to the pressing member holder 28 and the pressing member 11 via the linear motion guide 33 . there is More specifically, the piston rod 27 of the air cylinder 25 is fixed to the movable portion 33a of the direct-acting guide 33, and the pressing member holder 28 is fixed to the movable portion 33a of the direct-acting guide 33. As shown in FIG. Therefore, the pressing member 11 and the pressing member holder 28 move together with the piston rod 27 . The movement directions of the piston rod 27, the pressing member holder 28, and the pressing member 11 are restricted by the linear motion guide 33 to the direction parallel to the axis L of the substrate stage 2, that is, the direction perpendicular to the stage surface 2a. be. In this embodiment, the axis L of the substrate stage 2 extends vertically.

As shown in FIG. 6, the polishing head 10 further comprises a base block 39. As shown in FIG. The air cylinder 25 and linear motion guide 33 are fixed to the base block 39 . In this embodiment, the air cylinder 25 is fixed to the base block 39 via a fixing member 42 attached to the base block 39 . The base block 39 is rotatably supported by the first support shaft 51 . A fixing plate 52 is fixed to the base block 39 by a plurality of (four in FIG. 6) first screws 55 .

FIG. 7 is a view of the base block 39 and the first support shaft 51 viewed from the direction indicated by arrow C in FIG. The first support shaft 51 has a cylindrical portion 51b and a flange portion 51c wider than the cylindrical portion 51b. The base block 39 is rotatably supported by the cylindrical portion 51b of the first support shaft 51. As shown in FIG. More specifically, the base block 39 is formed with a circular through hole 39a through which the cylindrical portion 51b of the first support shaft 51 passes. The outer peripheral surface of the cylindrical portion 51b of the first support shaft 51 is in contact with the through hole 39a of the base block 39, and the base block 39 is rotatably supported by the first support shaft 51. As shown in FIG.

A through hole (not shown) through which the first screw 55 passes is formed in the fixing plate 52 and the base block 39 . The first screw 55 extends through holes in the fixing plate 52 and the base block 39 and is screwed into a threaded hole (not shown) formed in the flange portion 51 c of the first support shaft 51 . The diameter of each through hole formed in the base block 39 is larger than the diameter of the first screw 55, and a certain amount of clearance exists between the first screw 55 and the through hole of the base block 39. Therefore, the base block 39 is rotatable about the first support shaft 51 within a certain range. When the first screw 55 is tightened, the base block 39 is sandwiched between the fixing plate 52 and the flange portion 51c of the first support shaft 51, thereby preventing the base block 39 from rotating.

The first support shaft 51 has a polygonal portion 51a at its end. The polygonal portion 51a is connected to the end of the cylindrical portion 51b. As shown in FIG. 6, the fixed plate 52 is formed with a polygonal hole 52a through which the polygonal portion 51a of the first support shaft 51 passes. The polygonal hole 52 a is composed of a polygonal surface, and this polygonal surface is in contact with the outer surface of the polygonal portion 51 a of the first support shaft 51 . The polygonal portion 51a is fitted into the polygonal hole 52a, and the engagement between the polygonal portion 51a and the polygonal hole 52a prevents the fixed plate 52 from rotating relative to the first support shaft 51. It has become.

A notch 52b is formed in the fixed plate 52 . The notch 52b is located away from the axis of the first support shaft 51. As shown in FIG. An eccentric cam 57 is arranged in the notch 52b, and this eccentric cam 57 is rotatably attached to the base block 39. As shown in FIG.

The pressing member 11 is connected to the first support shaft 51 via the pressing member holder 28 , the linear motion guide 33 and the base block 39 . During polishing of the substrate W, the first screw 55 is kept tightened. Therefore, the posture of the polishing head 10 including the base block 39, the pressing member 11, the linear motion guide 33, and the air cylinder 25 is fixed. Loosening the first screw 55 allows the polishing head 10 to rotate about the axis of the first support shaft 51 . When the eccentric cam 57 is rotated with the first screw 55 loosened, the polishing head 10 rotates about the axis of the first support shaft 51 in the direction indicated by the arrow in FIG.

A rotation angle of the polishing head 10 depends on a rotation angle of the eccentric cam 57 . In other words, the inclination of the pressing surface 11 a of the pressing member 11 is adjusted by rotating the eccentric cam 57 . In this embodiment, the first support shaft 51, the fixed plate 52, the eccentric cam 57, and the first screw 55 enable the pressing member 11 to rotate about the first support shaft 51, thereby adjusting the inclination of the pressing surface 11a. A first tilt mechanism 60 for adjustment is configured.

As shown in FIG. 6 , a second support shaft 62 is fixed to the movable portion 33 a of the linear motion guide 33 . This second support shaft 62 extends in a direction perpendicular to the first support shaft 51 . The pressing member holder 28 holding the pressing member 11 is rotatably supported by the second support shaft 62 . The pressing member holder 28 is fixed to the movable portion 33 a of the linear motion guide 33 with a plurality of (two in this embodiment) second screws 64 . More specifically, the pressing member holder 28 is formed with a through hole (not shown) through which the second screw 64 passes. It is screwed into a threaded hole (not shown). The diameter of the through hole formed in the pressing member holder 28 is larger than the diameter of the second screw 64, and a certain amount of clearance exists between the second screw 64 and the through hole. Therefore, the pressing member holder 28 is rotatable about the second support shaft 62 within a certain range.

FIG. 8 is a front view showing the air cylinder 25, the linear motion guide 33, and the pressing member 11. FIG. The pressing member holder 28 and the pressing member 11 are rotatably supported by a second support shaft 62 , and the pressing member holder 28 is fixed to the movable portion 33 a of the linear motion guide 33 with a second screw 64 . As long as the second screw 64 is tightened, the pressing member holder 28 and the pressing member 11 are not allowed to rotate about the second support shaft 62 . In one embodiment, there may be one second screw 64 .

The pressing member 11 is connected to the second support shaft 62 via the pressing member holder 28 . During polishing of the substrate W, the second screw 64 is kept tightened. Therefore, the postures of the pressing member 11 and the pressing member holder 28 are fixed. Loosening the second screw 64 allows the pressing member 11 and the pressing member holder 28 to rotate about the second support shaft 62 in the direction indicated by the arrow. By manually tilting the pressing member 11 and the pressing member holder 28 with the second screw 64 loosened and then tightening the second screw 64, the inclination of the pressing surface 11a of the pressing member 11 can be adjusted. In this embodiment, the second support shaft 62 and the second screw 64 allow the pressing member 11 to rotate about the second support shaft 62 perpendicular to the first support shaft 51, thereby adjusting the inclination of the pressing surface 11a. A second tilt mechanism 69 for adjustment is configured.

The pressing surface 11 a of the pressing member 11 is desirably parallel to the stage surface 2 a of the substrate stage 2 . However, as described with reference to FIGS. 44 and 45, the pressing surface 11a of the pressing member 11 and/or the stage surface 2a of the substrate stage 2 may tilt due to the assembling accuracy of the polishing apparatus. Therefore, in this embodiment, the inclination of the pressing surface 11a of the pressing member 11 is adjusted by the first tilt mechanism 60 and the second tilting mechanism 69, which are tilt adjusting devices, so that the pressing surface 11a is parallel to the stage surface 2a. be done.

The three sensors 30 measure the heights of three points on the stage surface 2a required to calculate the tilt of the stage surface 2a. The positions of these three points correspond to the positions of the three sensors 30. FIG. In this embodiment, the three points are points on the outer peripheral portion of the stage surface 2a. FIG. 9 is a diagram showing the sensor 30 and the processing section 40 measuring the tilt of the stage surface 2a of the substrate stage 2. As shown in FIG. The three sensors 30 measure the heights of three points on the stage surface 2a and send three output signals respectively indicating the measured heights to the processing section 40 .

The processing unit 40 identifies the positions of the three points on the stage surface 2 a from the received three output signals and the relative positions of the three sensors 30 . The relative positions of the three sensors 30 are fixed and the relative position of each sensor 30 is known. The positions of the three points on the stage surface 2a can be expressed as coordinates on a three-dimensional coordinate system defined by mutually orthogonal X-, Y-, and Z-axes. A three-dimensional coordinate system defined by the X, Y, and Z axes is hereinafter referred to as an XYZ coordinate system.

FIG. 10 is a schematic diagram showing an embodiment in which tilts of the stage surface 2a are measured in a plurality of areas within the stage surface 2a. In this embodiment, the substrate stage 2 is intermittently rotated in increments of 45 degrees, and the tilt of the stage surface 2a is measured in eight regions R1 to R8 of the stage surface 2a. First, while the substrate stage 2 is stationary, the sensor 30 measures the heights of three points S1, S2, and S3 within the region R1, which is the reference plane, as shown in FIG. Three points S1, S2, and S3 within the region R1 are points uniquely determined by the positions of the three sensors 30. FIG. The positions of the three sensors 30 are not particularly limited as long as the corresponding three points S1, S2, S3 are not aligned. However, when the sensors 30 are arranged so that the surface area formed by the three sensors 30 is extremely large compared to the contact area of the pressing member 11, for example, the sensors 30 are arranged at intervals of 120 degrees on the outer peripheral edge of the substrate. If this is the case, there is a possibility that the inclination of the pressing surface 11a of the pressing member 11 cannot be accurately measured when polishing the peripheral edge of the substrate. Further, when three sensors 30 are provided near the center of the substrate, there is a possibility that the inclination of the pressing surface 11a of the pressing member 11 cannot be measured with high accuracy. Therefore, it is preferable to position all the three sensors 30 in the vicinity of the pressing surface 11a of the pressing member 11 in order to measure with higher accuracy.

The processing unit 40 defines the first straight line L1 connecting the points S2 and S3 as the Y-axis of the XYZ coordinate system. The three sensors 30 are installed such that the first straight line L1 is parallel to the axis of the first support shaft 51 (see FIG. 7) when viewed from above the substrate stage 2 . The processing unit 40 defines a second straight line L2 extending from the point S1 and intersecting the Y axis perpendicularly as the X axis of the XYZ coordinate system. When viewed from above the substrate stage 2, the second straight line L2 is parallel to the axis of the second support shaft 62 (see FIG. 6). An intersection point O between the X axis and the Y axis is the origin of the XYZ coordinate system. A straight line perpendicular to both the X and Y axes and passing through the origin O is defined as the Z axis of the XYZ coordinate system. In this manner, the XYZ coordinate system is determined from the positions of the three points S1, S2, and S3 within the region R1, which is the reference plane.

Next, a zero reset of the sensor 30 is performed. The zero reset of the sensor 30 is calibration of the sensor 30, and is an operation of resetting the height measurement values at three points on the reference plane (region R1) to zero. The respective coordinates of the three points S1, S2, S3 in the area R1 before zero resetting of the sensor 30 are as follows (see FIG. 12).
Coordinates of S1: (-d1, 0, α)
Coordinates of S2: (0, -d2, β)
Coordinates of S3: (0, d3, γ)
d1 (absolute value) is the distance from origin O to point S1, d2 (absolute value) is the distance from origin O to point S2, and d3 (absolute value) is the distance from origin O to point S3. . d1, d2, and d3 can be calculated from the relative positions of the three sensors 30. FIG. α, β, γ are the coordinates of the points S1, S2, S3 on the Z-axis, and are the measured values obtained from the sensor 30 on the reference plane R1 (that is, the output signal of the sensor 30).

Subsequently, the processing unit 40 performs zero reset of the sensor 30 . Specifically, the coordinates of the points S1, S2 and S3 on the Z axis (that is, the output signals of the three sensors 30) are reset to zero. _Let S1 _R1 , S2 _R1 and S3 _R1 be the coordinates of the three points S1, S2 and S3 in the region _R1 after the zero reset of the sensor 30 is performed _. (see FIG. 13).
S1 _R1 : (-d1, 0, 0)
S2 _R1 : (0, -d2, 0)
S3 _R1 : (0, d3, 0)

Next, the processing unit 40 obtains the normal vector of the region R1 indicating the inclination of the region R1 as follows. First, the processing unit 40 creates three mutually orthogonal vectors from the coordinates S1 _R1 , S2 _R1 and S3 _R1 of the three points (see FIG. 14).
Vector V1 _R1 =S2 _R1 -S1 _R1 = (d1, -d2, 0)
Vector V2 _R1 = S3 _R1 - S2 _R1 = (0, d3 + d2, 0)
Vector V3 _R1 =V1 _R1 ×V2 _R1 , (x represents the cross product)
Vector V1 _R1 is a vector from point S1 to point S2, and vector V2 _R1 is a vector from point S2 to point S3. Vector V3 _R1 is a vector that is orthogonal to both vector V1 _R1 and vector V2 _R1 . That is, vector V3 _R1 is the normal vector of region R1. In FIG. 14, the starting points of the three V1 _R1 , V2 _R1 and V3 _R1 are placed on the point S1, but other points may be used.

Next, as shown in FIG. 15, the processing unit 40 divides the normal vector V3 _R1 of the region R1 into an X directional vector V3 _{R1, X} on the X axis and a Y directional vector V3 _{R1, Y} on the Y axis. , Z-oriented vector V3 _R1,Z on the Z-axis. The normal vector V3 _R1 is the sum of the X directional vector V3 _R1,X , the Y directional vector V3 _{R1, Y} , and the Z directional vector V3 _{R1, Z} , and is expressed as follows.
Normal vector V3 _R1 =V3 _R1,X +V3 _R1,Y +V3 _R1,Z
An X-oriented vector is defined as a vector that forms a component projected onto the X-axis when a certain vector is decomposed into the X-axis, Y-axis, and Z-axis. Similarly, the Y-axis oriented vector is a vector that is a component projected onto the Y-axis when a certain vector is decomposed into the X-, Y-, and Z-axes. are defined as vectors forming components projected onto the Z-axis when resolved into the Z-axis.

In FIG. 15, the normal vector V3R1 of the region _R1 is tilted with respect to the Z-axis for the sake of explanation. The normal vector V3 _R1 is actually parallel to the Z axis. Therefore, the X, Y and Z components of the X directional vector V3 _R1,X and the Y directional vector V3 _R1,Y of region R1 are zero.

The substrate stage 2 is then rotated by 45 degrees and then comes to rest. Similarly, in the area R2, the sensor 30 measures the heights of three points on the stage surface 2a, and the processing section 40 calculates a normal vector representing the inclination of the area R2. By repeating such operations, the processing unit 40 generates eight normal vectors V3 _R1 , V3 _R2 , V3 _R3 , V3 _R4 , V3 _R5 , V3 _R6 , V3 _R7 , V3 _R8 representing the gradients of the eight regions R1 to R8, respectively. to create Each normal vector is represented on the XYZ coordinate system. The normal vectors consist of a set of X-oriented vectors on the X-axis, Y-oriented vectors on the Y-axis, and Z-oriented vectors on the Z-axis. More specifically, the normal vector is the sum of the X, Y, and Z orientation vectors.

The processing unit 40 calculates the average of the eight normal vectors (that is, the eight X directional vectors, the eight Y directional vectors, and the eight Z directional vectors), and calculates the average of the calculated normal vectors on the stage surface. 2a is designated as a normal vector indicating the inclination of the processing unit 40 and stored in the storage device 40a. In order to accurately determine the inclination of the stage surface 2a, a plurality of regions (eg, regions R1 to R8) within the stage surface 2a are located on the outer periphery of the stage surface 2a and are aligned with the axis L of the substrate stage 2, that is, It is preferable that they are distributed at regular intervals around the center of the stage surface 2a.

In the embodiment described above, the tilt of the stage surface 2a is measured in a plurality of regions R1 to R8 within the stage surface 2a in order to obtain a more accurate tilt of the stage surface 2a. That is, while intermittently rotating the substrate stage 2 about its axis L, the sensor 30 and the processing unit 40 measure the inclination of the stage surface 2a in a plurality of areas within the stage surface 2a. The processing unit 40 calculates the average of the inclinations obtained in each area (that is, the average of normal vectors), and designates this average as the normal vector representing the inclination of the entire stage surface 2a. In one embodiment, the tilt of the stage surface 2a may be obtained in only one region within the stage surface 2a. For example, the processing unit 40 may use the normal vector V3 _R1 in the region R1 described above as the inclination of the stage surface 2a.

After the inclination of the stage surface 2a is determined, the inclination of the pressing surface 11a of the pressing member 11 is measured. FIG. 16 is a diagram showing the sensor 30 and the processing section 40 measuring the inclination of the pressing surface 11a of the pressing member 11. As shown in FIG. As shown in FIG. 16, a target plate 71 is attached to the pressing surface 11a, which is the lower surface of the pressing member 11, before measurement. The target plate 71 is detachably fixed to the pressing surface 11a of the pressing member 11 by fasteners (not shown) such as screws. The target plate 71 is made of a metal such as stainless steel or a hard material such as ceramic. The target plate 71 has a flat upper surface 71 a having an area larger than the pressing surface 11 a , and the sensor 30 is positioned above the target plate 71 . Since the upper surface 71a of the target plate 71 is in contact with the pressing surface 11a of the pressing member 11, the upper surface 71a of the target plate 71 is parallel to the pressing surface 11a. That is, the inclination of the upper surface 71a of the target plate 71 is the same as the inclination of the pressing surface 11a.

The three sensors 30 measure the heights of three points on the target plate 71 required to calculate the inclination of the pressing surface 11a. The positions of these three points correspond to the positions of the three sensors 30. FIG. As shown in FIG. 16, the three sensors 30 measure the heights of three points on the upper surface 71a of the target plate 71 and send three output signals respectively indicating the measured heights to the processing section 40. The processing unit 40 calculates the inclination of the pressing surface 11 a based on the output signal of the sensor 30 . That is, the processing unit 40 identifies the positions of three points on the target plate 71 from the received three output signals and the relative positions of the three sensors 30, and calculates the normal vector of the plane containing the three points. . This normal vector is a vector representing the inclination of the target plate 71, that is, the inclination of the pressing surface 11a. After the inclination of the pressing surface 11 a is calculated, the target plate 71 remains attached to the pressing member 11 .

The processing unit 40 is configured to calculate the relative angle between the stage surface 2a and the pressing surface 11a based on the inclination of the stage surface 2a and the inclination of the pressing surface 11a. In the following description, the normal vector indicating the inclination of the stage surface 2a will be referred to as the first normal vector, and the normal vector indicating the inclination of the pressing surface 11a will be referred to as the second normal vector. The first normal vector and the second normal vector are vectors on the three-dimensional XYZ coordinate system defined by the X, Y, and Z axes described above. Like the first normal vector, the second normal vector consists of a set of X directional vectors on the X axis, Y directional vectors on the Y axis, and Z directional vectors on the Z axis. That is, the second normal vector is the sum of the X, Y, and Z orientation vectors.

The processing unit 40 calculates the relative angle between the pressing surface 11a and the stage surface 2a based on the first normal vector and the second normal vector. A relative angle is composed of an X-axis angle and a Y-axis angle. More specifically, the processing unit 40 calculates the relative angle between the stage surface 2a and the pressing surface 11a, that is, the angle formed by the first normal vector and the second normal vector, and calculates the calculated angle is resolved into X-axis and Y-axis angles. The X-axis angle is the angle in the direction of rotation about the X-axis of the XYZ coordinate system, and the Y-axis angle is the angle in the direction of rotation about the Y-axis of the XYZ coordinate system. The X-axis angle and the Y-axis angle correspond to correction angles of the pressing member 11 required to make the pressing surface 11a parallel to the stage surface 2a.

The inclination of the pressing surface 11a is adjusted based on the calculated X-axis angle and Y-axis angle. Specifically, by loosening the first screw 55 and rotating the eccentric cam 57, the entire polishing head 10 including the pressing member 11 is rotated about the first support shaft 51 by the Y-axis angle. While rotating the polishing head 10 around the first support shaft 51 , the sensor 30 continuously measures the heights of three points on the target plate 71 . Since the sensor 30 is fixed to the bracket 35, the attitude of the sensor 30 does not change even when the polishing head 10 is tilted. Since the target plate 71 is fixed to the pressing surface 11 a of the polishing head 10 , the output signal of the sensor 30 changes as the polishing head 10 is rotated around the first support shaft 51 . A change in the output signal of the sensor 30 corresponds to a change in the inclination of the pressing surface 11a. While the polishing head 10 is rotating around the first support shaft 51, the processing section 40 continuously calculates the Y-axis angle. The worker rotates the polishing head 10 around the first support shaft 51 until the Y-axis angle becomes zero. After that, the first screw 55 is tightened.

Next, the second screw 64 is loosened, and the pressing member holder 28 and the pressing member 11 are rotated around the second support shaft 62 . While the pressing member holder 28 and the pressing member 11 are rotated around the second support shaft 62, the sensor 30 continuously measures the heights of three points on the target plate 71, and the processing unit 40 determines the X-axis angle. Calculate continuously. The worker rotates the pressing member 11 around the second support shaft 62 until the X-axis angle becomes zero. After that, the second screw 64 is tightened. The fact that the relative angle between the stage surface 2a and the pressing surface 11a is substantially 0, that is, both the X-axis angle and the Y-axis angle are substantially 0, means that the pressing surface 11a is substantially aligned with the stage surface 2a. means that they are substantially parallel to each other. Note that "substantially 0" means that the relative angle (absolute value) between the stage surface 2a and the pressing surface 11a is within the allowable range (same below). This allowable range is a predetermined angle range, for example, 0 to 2 degrees. In this manner, the inclination of the pressing surface 11a of the pressing member 11 can be adjusted. The adjusted pressing surface 11a is substantially parallel to the stage surface 2a. In one embodiment, the pressing member 11 may first be rotated about the second support shaft 62 and then the polishing head 10 may be rotated about the first support shaft 51 .

After the inclination of the pressing surface 11 a is adjusted, the target plate 71 is removed from the pressing member 11 . Additionally, sensor 30 and bracket 35 are removed from the polishing apparatus. The substrate W to be polished is held on the stage surface 2 a with its center aligned with the axis L of the substrate stage 2 . The substrate W is rotated around the axis L of the substrate stage 2 by the stage motor 3 . While supplying a liquid (for example, pure water) to the center of the substrate W, the polishing head 10 presses the polishing tape 7 against the peripheral portion of the substrate W with the pressing surface 11a of the pressing member 11 to polish the peripheral portion. According to this embodiment, since the stage surface 2a of the substrate stage 2 and the pressing surface 11a of the pressing member 11 are parallel to each other, the polishing tape 7 is applied to the top edge portion of the substrate W (FIGS. 1A and 1B). (see symbol T1 in b)).

The flow of the process for matching the inclination of the pressing surface 11a with the inclination of the stage surface 2a will be described below with reference to the flow charts of FIGS. 17 and 18. FIG. In step 1, the three sensors 30 measure the heights of three points within the region R1 of the stage surface 2a, which is the reference surface, and the processing unit 40 measures the heights of the three points and the three sensors 30 as described above. determine the XYZ coordinate system based on the relative positions of In step 2, the processing unit 40 resets the sensor 30 to zero. In step 3, the processing section 40 calculates the inclination of the region R1 from the positions (coordinates) of the three points within the region R1.

In step 4, the three sensors 30 measure the heights of three points within another area (for example, area R2) within the stage surface 2a. At step 5, the processing section 40 calculates the inclination of the other area from the positions (coordinates) of the three points in the other area. In step 6, steps 4 and 5 are repeated until the slopes of all the predefined regions R1 to R8 are calculated. In step 7, the processing section 40 calculates the average of the inclinations of the plurality of regions R1 to R8, designates the average of the inclinations as the inclination of the stage surface 2a, and stores it in the storage device 40a of the processing section 40. FIG.

As shown in FIG. 18 , in step 8, the target plate 71 is attached to the pressing surface 11 a of the pressing member 11 . In step 9 , sensor 30 measures the height of three points on target plate 71 . At step 10 , the processing section 40 calculates the inclination of the pressing surface 11 a based on the positions (coordinates) of the three points on the target plate 71 . At step 11, the processing unit 40 calculates the relative angles (that is, the X-axis angle and the Y-axis angle) between the stage surface 2a and the pressing surface 11a from the inclination of the stage surface 2a and the inclination of the pressing surface 11a.

In step 12 , the inclination of the pressing surface 11 a of the pressing member 11 is adjusted while the sensor 30 measures the heights of three points on the target plate 71 . The processing unit 40 calculates in real time the relative angle (that is, the X-axis angle and the Y-axis angle) between the stage surface 2a and the pressing surface 11a based on the output signal of the sensor 30, and calculates the calculated X-axis angle. and Y-axis angle can be displayed on a display (not shown). The operator rotates the polishing head 10 including the pressing member 11 around the first support shaft 51 until the Y-axis angle becomes substantially zero. Similarly, the operator rotates the pressing member holder 28 and the pressing member 11 around the second support shaft 62 until the X-axis angle becomes substantially zero (step 13).

In step 14, the target plate 71 is removed from the pressing surface 11a, and the bracket 35 is removed from the fixing column 36 together with the sensor 30. As shown in FIG. In step 15 , the substrate W to be polished is placed on the stage surface 2 a with its center aligned with the axis L of the substrate stage 2 . In step 16 , the substrate W is held on the stage surface 2 a by vacuum suction or the like, and the stage surface 2 a and the substrate W are rotated around the axis L of the substrate stage 2 . A liquid such as pure water is supplied to the center of the rotating substrate W. As shown in FIG. In step 17, with the pressing surface 11a parallel to the stage surface 2a, the pressing member 11 presses the polishing tape 7 against the peripheral edge portion (the top edge portion in this embodiment) of the substrate W, and the polishing tape 7 is pressed against the liquid. Polish the periphery with

According to this embodiment, the substrate W is polished by the polishing tape 7 while the stage surface 2a and the pressing surface 11a are parallel to each other. As a result, a stepped depression 210 as shown in FIG. 43 can be formed in the peripheral portion of the substrate W.

FIG. 19 is a side view schematically showing another embodiment of the polishing apparatus. The configuration and operation of this embodiment that are not specifically described are the same as the configuration and operation of the embodiment shown in FIGS. 1 to 18, so redundant description thereof will be omitted. As shown in FIG. 19 , the pressing member 11 has a projecting portion 72 projecting toward the axis L of the substrate stage 2 and the sensor 30 . The protruding portion 72 has an upper surface 72 a parallel to the pressing surface 11 a of the pressing member 11 . Therefore, the inclination of the upper surface 72a of the projecting portion 72 is the same as the inclination of the pressing surface 11a. The upper surface 72 a has an area larger than the area of the triangle formed by the three sensors 30 .

Before the three sensors 30 measure the height of the stage surface 2 a of the substrate stage 2 , the polishing head 10 including the projecting portion 72 is moved away from the substrate stage 2 by the polishing head moving device 41 . While the three sensors 30 are measuring the height of the stage surface 2 a of the substrate stage 2 , the polishing head 10 including the protrusion 72 remains separated from the stage surface 2 a of the substrate stage 2 . After the measurement of the height of the stage surface 2a is completed, the polishing head 10 is moved by the polishing head moving device 41 until the upper surface 72a of the projecting portion 72 is positioned below the three sensors 30 as shown in FIG. It is moved toward the substrate stage 2 . The three sensors 30 measure the heights of three points on the upper surface 72a of the protrusion 72 parallel to the pressing surface 11a, and send three output signals respectively indicating the measured heights to the processing unit 40. FIG. The processing unit 40 calculates the inclination of the pressing surface 11 a based on the relative position of the sensor 30 and the output signal of the sensor 30 . In this embodiment, the target plate 71 described above is unnecessary.

FIG. 21 is a side view schematically showing still another embodiment of the polishing apparatus. In FIG. 21, illustration of the polishing tape 7 is omitted. The configuration and operation of this embodiment that are not specifically described are the same as the configuration and operation of the embodiment shown in FIGS. 1 to 16, so redundant description thereof will be omitted. In this embodiment, by tilting the substrate stage 2 instead of the polishing head 10, the relative angle between the stage surface 2a and the pressing surface 11a is substantially zero. are substantially parallel to each other. In this embodiment, the first tilt mechanism 60 and the second tilt mechanism 69 may be omitted.

As shown in FIG. 21, three actuators 80 for tilting the entire substrate stage 2 and stage motor 3 are connected to the stage motor 3 . These three actuators 80 constitute a substrate holding surface tilting actuator 81 that tilts the entire substrate stage 2 including the stage surface 2a that is the substrate holding surface. The substrate holding surface tilting actuator 81 is an inclination adjusting device that adjusts the inclination of the stage surface 2a. FIG. 22 is a diagram showing the arrangement of the actuator 80 shown in FIG. 21. As shown in FIG. As shown in FIG. 22, these three actuators 80 are arranged around the axis L of the substrate stage 2 at equal intervals. Each stage motor 3 can be composed of a combination of a ball screw mechanism and a servomotor. Each actuator 80 is configured to move the stage motor 3 up and down. Therefore, the three actuators 80 can tilt the substrate stage 2 in desired directions and at desired angles.

FIG. 23 is a diagram showing an example of the detailed configuration of the actuator 80. As shown in FIG. The three actuators 80 are connected to the stage motor 3 via the support member 76 . The stage motor 3 is fixed to the support member 76 . Three actuators 80 are tiltably connected to the support member 76 . Each actuator 80 is composed of a combination of a ball screw mechanism 84 and a servomotor 85 .

The three actuators 80 are connected to an operation control section 86, and the operations of these actuators 80 are controlled by the operation control section 86. FIG. The processing section 40 described above is connected to the motion control section 86 , and information on the relative angle between the stage surface 2 a and the pressing surface 11 a calculated by the processing section 40 is sent to the motion control section 86 . The motion control unit 86 operates the three actuators 80 to adjust the tilt of the substrate stage 2 until the calculated relative angle becomes substantially zero.

While the sensor 30 measures the height of three points on the stage surface (substrate holding surface) 2a of the substrate stage 2, the three actuators 80 operate to detect the relative angle between the stage surface 2a and the pressing surface 11a. is substantially zero, the tilt of the substrate stage 2 is adjusted.

In one embodiment, four or more actuators 80 may be arranged around the axis L of the substrate stage 2 . Further, in one embodiment, two actuators 80 and one ball joint 82 may be arranged around the axis L of the substrate stage 2, as shown in FIG. The ball joint 82 is a device capable of tilting an object to be supported in all directions while supporting a load. In the example shown in FIG. 24, two actuators 80 and one ball joint 82 constitute a substrate holding surface tilting actuator 81 that tilts the entire substrate stage 2 including the stage surface 2a that is the substrate holding surface.

25 is a plan view of the polishing apparatus shown in FIG. 21. FIG. A reference plate 92 is fixed to the first support shaft 51 via a connecting arm 90 . More specifically, one end of the connecting arm 90 is fixed to the first support shaft 51 and the other end of the connecting arm 90 is fixed to the reference plate 92 . The reference plate 92 is positioned outside the stage surface 2a. The reference plate 92 has a flat upper surface which constitutes the reference surface 92a used for calibration of the sensor 30, which is the zero reset of the sensor 30 described above. In this embodiment, the reference plane 92a is a horizontal plane.

The polishing apparatus includes a polishing head moving device 41 (hereinafter referred to as first polishing head moving device 41) that moves the polishing head 10 and the reference plate 92 in the first direction D, and also moves the polishing head 10 and the reference plate 92 in the first direction D. A second polishing head moving device 95 for moving in a second direction F perpendicular to the first direction D is further provided. In this embodiment, the second polishing head moving device 95 is composed of a combination of a ball screw mechanism and a servomotor, but may have other configurations.

The reel motors 17 , 18 , the tape feeding device 20 (see FIG. 3), and the guide rollers 21 , 22 are held by a frame 97 which is fixed to the base plate 47 . The first polishing head moving device 41 is also fixed to the base plate 47 . The base plate 47 is connected to a second polishing head moving device 95 and moved in the second direction F by the second polishing head moving device 95 . Therefore, the polishing head 10, the reference plate 92, the supply reel 14, the take-up reel 15, the reel motors 17, 18, the tape feeder 20, and the guide rollers 21, 22 connected to the common base plate 47 are integrally It is moved in the second direction F by the second polishing head moving device 95 .

When the sensor 30 is zero reset, the second polishing head moving device 95 moves the polishing head 10 and the reference plate until the reference surface 92a of the reference plate 92 is positioned below the three sensors 30, as shown in FIG. 92, the feed reel 14, the take-up reel 15, the reel motors 17, 18, the tape feeding device 20, and the guide rollers 21, 22 are moved. The sensor 30 measures the heights of three points on the reference plane 92a and sends the height measurements to the processing unit 40 . The processing unit 40 resets the height measurement values of the three points on the reference plane 92a to zero. After the zero reset of the sensor 30 is completed, as shown in FIG. 25, the second polishing head moving device 95 is moved until the reference plate 92 is positioned outside the stage surface 2a and the polishing head 10 returns to the original polishing position. moves the polishing head 10, the reference plate 92, the supply reel 14, the take-up reel 15, the reel motors 17, 18, the tape feeding device 20, and the guide rollers 21, 22.

The flow of the process for matching the inclination of the stage surface 2a with the inclination of the pressing surface 11a will be described below with reference to the flow charts of FIGS. 27 and 28. FIG. In step 1 , the second polishing head moving device 95 moves the polishing head 10 and the reference plate 92 until the reference surface 92 a of the reference plate 92 is positioned below the three sensors 30 . In step 2, the three sensors 30 measure the heights of three points within the reference surface 92a of the reference plate 92, and the processing unit 40 determines the relative positions of the three points and the three sensors 30 as described above. Based on this, the XYZ coordinate system is determined. In step 3, the processing unit 40 resets the sensor 30 to zero. In step 4, the second polishing head moving device 95 moves the polishing head 10 and the reference plate 92 until the reference plate 92 is positioned outside the stage surface 2a.

In step 5, the three sensors 30 measure the height of three points within the area within the stage surface 2a (see R1 in FIG. 10, for example). At step 6, the processing section 40 calculates the inclination of the area from the positions (coordinates) of the three points in the area. In step 7, steps 5 and 6 are repeated until the slopes of all the predefined regions R1 to R8 (see FIG. 10) are calculated. In step 8, the processing section 40 calculates the average of the inclinations of the plurality of regions R1 to R8, designates the average of the inclinations as the inclination of the stage surface 2a, and stores it in the storage device 40a of the processing section 40. FIG.

As shown in FIG. 28 , in step 9 , the target plate 71 is attached to the pressing surface 11 a of the pressing member 11 . At step 10 , sensor 30 measures the height of three points on target plate 71 . At step 11 , the processing section 40 calculates the inclination of the pressing surface 11 a based on the positions (coordinates) of the three points on the target plate 71 . At step 12 , the target plate 71 is removed from the pressing member 11 . At step 13, the processing unit 40 calculates the relative angle between the stage surface 2a and the pressing surface 11a from the inclination of the stage surface 2a and the inclination of the pressing surface 11a.

In step 14, while the sensor 30 measures the heights of three points on the stage surface 2a, the three actuators 80 are operated so that the relative angle between the stage surface 2a and the pressing surface 11a is substantially zero. The inclination of the stage surface 2a is adjusted so that In step 15 the bracket 35 is removed from the fixed post 36 together with the sensor 30 . In step 16 , the substrate W to be polished is placed on the stage surface 2 a with its center aligned with the axis L of the substrate stage 2 . In step 17 , the substrate W is held on the stage surface 2 a by vacuum suction or the like, and the stage surface 2 a and the substrate W are rotated about the axis L of the substrate stage 2 . A liquid such as pure water is supplied to the center of the rotating substrate W. As shown in FIG. In step 18, with the pressing surface 11a parallel to the stage surface 2a, the pressing member 11 presses the polishing tape 7 against the peripheral edge portion (the top edge portion in this embodiment) of the substrate W, and the polishing tape 7 is pressed against the liquid. Polish the periphery with

The protruding portion 72 having the upper surface 72a parallel to the pressing surface 11a shown in FIG. 19 can also be applied to the embodiment shown in FIG.

FIG. 29 is a diagram showing an embodiment in which an actuator 80 is connected to the polishing head 10 instead of the substrate holder 1. As shown in FIG. The configuration of this embodiment, which is not particularly described, is the same as the configuration shown in FIG. 19, so redundant description thereof will be omitted. Three actuators 80 for tilting the entire polishing head 10 are connected to the installation block 48 via the support member 76 . The installation block 48 is fixed to the support member 76 . Three actuators 80 are tiltably connected to the support member 76 . The arrangement of the actuators 80 is the same as the arrangement shown in FIG. 22, and the configuration of each actuator 80 is the same as the configuration shown in FIG. In this embodiment, the first tilt mechanism 60 and the second tilt mechanism 69 may be omitted.

The three actuators 80 are connected to an operation control section 86, and the operations of these actuators 80 are controlled by the operation control section 86. FIG. The processing section 40 described above is connected to the motion control section 86 , and information on the relative angle between the stage surface 2 a and the pressing surface 11 a calculated by the processing section 40 is sent to the motion control section 86 . The motion control unit 86 operates the three actuators 80 to adjust the inclination of the pressing member 11 until the calculated relative angle becomes substantially zero.

While the sensor 30 measures the heights of three points on the upper surface 72a of the protruding portion 72, the three actuators 80 are operated so that the relative angle between the stage surface 2a and the pressing surface 11a becomes substantially zero. The inclination of the pressing surface 11a of the pressing member 11 is adjusted so that In this embodiment, the three actuators 80 constitute a pressing member tilting actuator 87 that tilts the entire polishing head 10 including the pressing member 11 . The pressing member tilting actuator 87 constitutes an inclination adjusting device that adjusts the inclination of the pressing surface 11 a of the pressing member 11 . Similar to the embodiment shown in FIG. 24 , the pressing member tilting actuator 87 may comprise two actuators 80 and one ball joint 82 .

The pressing member tilting actuator 87 shown in FIG. 29 may be applied to the embodiments described with reference to FIGS.

FIG. 30 is a side view schematically showing still another embodiment of the polishing apparatus; The polishing apparatus of this embodiment is an apparatus for polishing the surface (front side or back side) of a substrate such as a wafer. A substrate holder 111 and a polishing head 150 for polishing the first surface A1 of the substrate W held by the substrate holder 111 are provided. The polishing head 150 is arranged above the substrate W held by the substrate holding part 111 .

In one embodiment, the first side A1 of the substrate W is the backside or non-device side of the substrate W on which devices are not formed or are not to be formed. The opposite side, the second side A2 of the substrate W, is the front side, or device side, of the substrate W on which the devices are or are to be formed. In one embodiment, the first side A1 of the substrate W is the front side of the substrate W (the device side) and the second side A2 of the substrate W is the back side of the substrate W (the non-device side). An example of the back side, which is the non-device side, is the silicon side. In this embodiment, the substrate W is horizontally held by the substrate holding part 111 with the first surface A1 facing upward. The first surface A1 is a surface to be polished by a polishing device.

The substrate holding part 111 is fixed to the upper surface of the base plate 112 . The substrate holding unit 111 includes a plurality of chucks 114 that grip the peripheral edge of the substrate W, and an annular hollow motor (chuck motor) 116 that rotates the substrate W via the chucks 114 . The chuck 114 is fixed to a hollow motor 116 and rotated about the axis CP of the substrate holder 111 by the hollow motor 116 . The substrate W is horizontally held by the chuck 114 . The plurality of chucks 114 are arranged around the axis CP of the substrate holder 111 and positioned at the same distance from the axis CP of the substrate holder 111 . When the substrate W is held by the multiple chucks 114 , the center point of the substrate W is on the axis CP of the substrate holder 111 .

All the chucks 114 holding the substrate W are integrally rotated about the axis CP of the substrate holder 111 , that is, the axis of the substrate W, by the hollow motor 116 . In one embodiment, the substrate holder 111 may include a plurality of rollers that can rotate about their own axes instead of the chuck 114 . According to the substrate holding part 111 having a plurality of rollers, the periphery of the substrate is held by the rollers, and the substrate is rotated around its own axis by each roller rotating around its own axis. .

A rinse liquid supply nozzle 118 that supplies a rinse liquid (for example, pure water) to the first surface A1 of the substrate W is arranged above the substrate W held by the substrate holder 111 . The rinse liquid supply nozzle 118 is connected to a rinse liquid supply source (not shown). The rinse liquid supply nozzle 118 is arranged facing the center of the substrate W. As shown in FIG. The rinse liquid is supplied to the center of the substrate W from the rinse liquid supply nozzle 118, and the rinse liquid spreads over the first surface A1 of the substrate W due to centrifugal force.

A polishing head 150 is connected to the head shaft 120 . The head shaft 120 is connected to a head rotation mechanism 122 that rotates the polishing head 150 about its axis HP. Further, the head shaft 120 is connected with an air cylinder 125 as a load applying device that applies a downward load to the polishing head 150 . The polishing head 150 includes a plurality of pressing members 155 for pressing the plurality of polishing tools 130 against the first surface A1 of the substrate W. As shown in FIG. The polishing head 150 has a housing 126 in which the pressing member 155 is housed. A plurality of polishing tools 130 are held by the polishing head 150 , and the rear sides of the polishing tools 130 are in contact with the pressing surface 155 a of the pressing member 155 . Although only two polishing tools 130 and two pressing members 155 are depicted in FIG. 30, three polishing tools 130 and three pressing members 155 are provided in this embodiment.

31 is a bottom view of the polishing head 150 shown in FIG. 30. FIG. The lower surface of the polishing tool 130 constitutes a polishing surface 130a for polishing the substrate W. As shown in FIG. The polishing surface 130 a extends in the radial direction of the polishing head 150 . The polishing tools 130 are arranged at regular intervals around the axis HP of the polishing head 150 .

Returning to FIG. 30 , the polishing tool 130 protrudes downward from the polishing head 150 . When the polishing head 150 rotates about its axis HP, the three polishing tools 130 likewise rotate about its axis HP. The polishing head 150 polishes the first surface A1 of the substrate W by bringing the polishing surface 130a of the polishing tool 130 into sliding contact with the first surface A1 of the substrate W while rotating about the axis HP. In one embodiment, the polishing head 150 may hold two polishing tools 130, or four or more polishing tools 130. FIG. Further, in one embodiment, polishing head 150 may hold only one polishing tool 130 .

In this embodiment, the polishing tool 130 is composed of a polishing tape having a polishing layer containing abrasive grains formed on one side thereof. Both ends of the polishing tape are held by two reels (not shown), and the lower surface (polishing surface 130a) of the polishing tape extending between the two reels is pressed against the first surface A1 of the substrate W by the pressing surface 155a of the pressing member 155. pressed against. In one embodiment, the abrasive tool 130 may be a sponge, nonwoven, foamed polyurethane, or fixed abrasive.

Three sensors 30 are arranged inside the substrate holding part 111 . Since the configuration and arrangement of the sensor 30 are the same as those of the sensor 30 described in the above-described embodiment, redundant description thereof will be omitted. The sensor 30 is provided to measure the height of the polishing surface 130a of the polishing tool 130 and the height of the substrate holding surface of the substrate holding part 111, as will be described later.

Three sensors 30 are fixed to bracket 133 . Bracket 133 is fixed to sensor lifting device 135 , and sensor lifting device 135 is fixed to base plate 112 . The three sensors 30 are connected to a sensor lifting device 135 via brackets 133 . The sensor lifting device 135 is configured to integrally lift and lower the three sensors 30 and the bracket 133 . The sensor lifting device 135 is composed of, for example, an air cylinder. FIG. 30 shows the sensor 30 and bracket 133 in the lowered position. The sensor 30 is electrically connected to the processing section 40 and the output signal of the sensor 30 is sent to the processing section 40 . The processing unit 40 includes therein a storage device 40a and an arithmetic device 40b. The detailed configuration and operation of the processing unit 40 are the same as those in the above-described embodiment, so redundant description thereof will be omitted.

The head rotation mechanism 122 and the air cylinder 125 are fixed to a horizontally extending swivel arm 140 . Head shaft 120 and polishing head 150 are rotatably supported at one end of swivel arm 140 . The other end of the swivel arm 140 is fixed to an arm support shaft 141 . The arm support shaft 141 extends vertically, and the lower portion of the arm support shaft 141 is connected to an arm rotation mechanism 143 . The arm rotation mechanism 143 is composed of a motor, a deceleration mechanism, and the like, and is configured to be able to rotate the arm support shaft 141 about its axis SP by a predetermined angle. When the arm rotation mechanism 143 rotates the arm support shaft 141 , the polishing head 150 and swivel arm 140 swivel about the arm support shaft 141 . More specifically, the polishing head 150 moves between a polishing position (described later) for polishing the substrate W, a position above the sensor 30 , and a retracted position outside the substrate holder 111 . 30 shows the state where the polishing head 150 is positioned above the sensor 30. FIG.

The polishing head 150 has a size smaller than the size of the substrate W. As shown in FIG. The axis HP of the polishing head 150 is shifted from the axis CP of the substrate holder 111 . Therefore, the polishing head 150 is eccentric with respect to the substrate W held by the substrate holding part 111 . The polishing head 150 is on the axis CP of the substrate holder 111 .

As shown in FIG. 30, the polishing apparatus includes a pressing member tilting actuator 87 that tilts the entire polishing head 150 including the pressing member 155 . The pressing member tilting actuator 87 has three actuators 80 , and each actuator 80 is composed of a combination of a ball screw mechanism 84 and a servomotor 85 . The three actuators 80 are connected to an operation control section 86, and the operations of these actuators 80 are controlled by the operation control section 86. FIG. The processing unit 40 described above is connected to the operation control unit 86, and the information on the relative angle between the substrate holding surface of the substrate holding unit 111 and the pressing surface 155a of the pressing member 155 calculated by the processing unit 40 is It is sent to the control unit 86 . The motion control unit 86 operates the three actuators 80 to adjust the inclination of the pressing member 155 until the calculated relative angle becomes substantially zero.

As in the embodiment shown in FIG. 22, the three actuators 80 are arranged around the axis SP of the arm support shaft 141. As shown in FIG. In one embodiment, four or more actuators 80 may be arranged around the axis SP of the arm support shaft 141 . Further, in one embodiment, similar to the embodiment shown in FIG. 24, the pressing member tilting actuator 87 includes two actuators 80 and one ball joint 82 arranged around the axis SP of the arm support shaft 141. may

In this embodiment, the pressing member tilting actuator 87 is connected to the polishing head 150 via the head shaft 120 , swivel arm 140 , arm support shaft 141 , arm rotation mechanism 143 and support member 76 . The arm rotation mechanism 143 is fixed to the support member 76 . Three actuators 80 are tiltably connected to the support member 76 .

The relative position between the sensor 30 held by the bracket 133 and the substrate holding portion 111 is fixed. On the other hand, the pressing member 155 of the polishing head 150 is configured to be tiltable with respect to the sensor 30 and the substrate holding section 111 .

FIG. 32 is a plan view of the polishing head 150 at the polishing position. A static pressure support stage 170 is arranged below the polishing head 150 at the polishing position. Similar to the sensor 30 , the static pressure support stage 170 is arranged inside the substrate holder 111 and adjacent to the sensor 30 . The static pressure support stage 170 is arranged below the substrate W held by the substrate holder 111 .

33 is a sectional view showing the hydrostatic support stage 170 shown in FIG. 32. FIG. The polishing head 150 is in the polishing position, and the hydrostatic support stage 170 is positioned below the polishing head 150 . The hydrostatic support stage 170 is configured to bring a fluid into contact with the second surface A2 (the surface opposite to the first surface A1) of the substrate W held by the chuck 114 so as to support the substrate W with the fluid. It is configured. The hydrostatic support stage 170 has a substrate support surface 170a close to the second surface A2 of the substrate W held by the chuck 114. As shown in FIG. The substrate support surface 170a in this embodiment is circular, but may have a square or other shape.

The hydrostatic support stage 170 further includes a plurality of fluid outlets 172 formed in the substrate support surface 170a and a plurality of fluid supply channels 174 connected to the plurality of fluid outlets 172, respectively. The fluid supply path 174 is connected to a fluid supply source (not shown). The flow rate of fluid passing through each fluid supply path 174 is adjusted by a flow control valve (not shown). In this embodiment, three fluid outlets 172 are provided. In one embodiment, the plurality of fluid outlets 172 may be a plurality of openings evenly distributed across the substrate support surface 170a.

As shown in FIG. 33 , the static pressure support stage 170 is connected to a stage elevating mechanism 175 . The stage lifting mechanism 175 is fixed to the upper surface of the base plate 112 . A stage lifting mechanism 175 lifts the static pressure support stage 170 until its substrate support surface (upper surface) 170a reaches a position close to the lower surface of the substrate W (second surface A2). The static pressure support stage 170 is arranged below the substrate W held by the substrate holding part 111, and the substrate support surface 170a is slightly separated from the second surface A2 of the substrate W. As shown in FIG.

Fluid (for example, liquid such as pure water) is supplied to the plurality of fluid outlets 172 through the fluid supply path 174, and the space between the substrate supporting surface 170a and the second surface A2 of the substrate W is filled with the fluid. . The substrate W is supported by fluid present between the substrate support surface 170a and the substrate W second surface A2. The substrate W and the hydrostatic support stage 170 are kept out of contact. In one embodiment, the clearance between the substrate W and the hydrostatic support stage 170 is between 50 μm and 500 μm.

The hydrostatic support stage 170 can support the second surface A2 of the substrate W in a non-contact manner via fluid. Therefore, when devices are formed on the second surface A2 of the substrate W, the hydrostatic support stage 170 can support the substrate W without destroying the devices. As the fluid used for the static pressure support stage 170, a liquid such as pure water, which is an incompressible fluid, or a gas, which is a compressible fluid such as air or nitrogen, may be used. When pure water is used, a pure water supply line installed in the factory where the polishing apparatus is installed can be used as the fluid supply source connected to the fluid supply path 174 .

The lower surface of the polishing head 150 and the substrate support surface 170a of the hydrostatic support stage 170 are arranged concentrically. Furthermore, the lower surface of the polishing head 150 and the substrate support surface 170a of the hydrostatic support stage 170 are arranged symmetrically with respect to the substrate W. As shown in FIG. That is, the lower surface of the polishing head 150 and the substrate support surface 170a of the static pressure support stage 170 are arranged so as to sandwich the substrate W, and the load applied to the substrate W from the polishing head 150 is the static pressure from directly below the polishing head 150. It is supported by support stage 170 . Therefore, the polishing head 150 can apply a large load to the first surface A1 of the substrate W. FIG.

Next, the operation of the polishing apparatus will be explained. A substrate W to be polished is transferred to the substrate holder 111 by a transfer robot (not shown). The substrate W is gripped by the chuck 114 of the substrate holding part 111 with the first surface A1 facing upward, and further rotated about the axis of the substrate W by the hollow motor 116 . A fluid (for example, a liquid such as pure water) is supplied to a plurality of fluid discharge ports 172 through a fluid supply path 174, and flows between the substrate support surface 170a of the hydrostatic support stage 170 and the second surface A2 of the substrate W. The space is filled with fluid. The substrate W is supported by a fluid flowing between the substrate support surface 170a and the substrate W second surface A2.

The rinse liquid supply nozzle 118 supplies the rinse liquid to the center of the substrate W, and the rinse liquid spreads over the first surface A1 of the substrate W due to centrifugal force. The head rotation mechanism 122 rotates the polishing head 150 around its axis HP. The air cylinder 125 moves the rotating polishing head 150 toward the first surface A1 of the substrate W, and the pressing surface 155a of the pressing member 155 presses the polishing surface 130a of the polishing tool 130 against the first surface of the substrate W. Press against A1. While the rinse liquid is present on the first surface A1 of the substrate W, the polishing tool 130 is brought into sliding contact with the first surface A1 of the substrate W to polish the first surface A1.

As in the previous embodiment, before polishing the substrate W, the pressing member tilting actuator 87 presses the pressing surface 155a of the pressing member 155 so that it is parallel to the substrate holding surface of the substrate holding part 111. The inclination of the surface 155a is adjusted. More specifically, the sensor 30 measures the heights of three points on the substrate holding surface of the substrate holding part 111 and the heights of three points on the pressing surface 155a of the pressing member 155, and the processing part 40 The inclination of the substrate holding surface of the substrate holding part 111 and the inclination of the pressing surface 155a of the pressing member 155 are calculated, and based on the inclination of the substrate holding surface of the substrate holding part 111 and the inclination of the pressing surface 155a of the pressing member 155, A relative angle between the substrate holding surface of the substrate holding part 111 and the pressing surface 155a is calculated. The processing unit 40 transmits the calculated relative angle to the motion control unit 86 . Then, the operation control unit 86 issues a command to the pressing member tilting actuator 87 to operate the pressing member tilting actuator 87 so that the relative angle becomes substantially 0, thereby tilting the polishing head 150 including the pressing member 155. to adjust.

Here, the substrate holding surface of the substrate holding part 111 will be described with reference to FIGS. 34(a) and 34(b). The substrate W is held on the substrate holding surface of the substrate holding part 111 . The substrate holding surface of the substrate holding portion 111 is a plane formed by a plurality of substrate contact points of the substrate holding portion 111 that determine the inclination (orientation) of the substrate W when held by the substrate holding portion 111 . In the embodiment shown in FIG. 34( a ), the tilt of the substrate W is determined by substrate contact points 114 a of multiple chucks 114 . Therefore, as shown in FIG. 34B, the substrate holding surface of the substrate holding part 111 is a plane (imaginary plane) including the plurality of substrate contact points 114 a of the plurality of chucks 114 . In the above-described embodiments shown in FIGS. 2 to 4, the substrate holding surface of the substrate holding part 1 is the stage surface 2a of the substrate stage 2. As shown in FIG.

The heights of three points on the substrate holding surface are measured by the sensor 30 as follows. As shown in FIG. 35, the arm rotation mechanism 143 moves the polishing head 150 to the retracted position outside the substrate holder 111 . Next, a plurality of chucks 114 hold a dummy substrate 160 imitating the substrate W to be polished. The dummy substrate 160 is a dummy structure having an outer edge of the same shape and size as the substrate W, and has a flat surface 160a. Cutouts such as notches or orientation flats may not be formed in the dummy substrate 160 . The dummy substrate 160 may be made of metal or hard resin, or may be another substrate having the same shape and size as the substrate W to be polished.

A peripheral edge of the dummy substrate 160 is supported by a plurality of substrate contact points 114 a of a plurality of chucks 114 . The lower surface of the dummy substrate 160 is a planar surface 160a that conforms to a substrate holding surface that includes a plurality of substrate contact points 114a.

As shown in FIG. 36, the sensor lifting device 135 lifts the three sensors 30 to predetermined measurement positions. The three sensors 30 measure the heights of three points on the flat surface 160a of the dummy substrate 160, that is, the substrate holding surface. The positions of these three points correspond to the positions of the three sensors 30. FIG. The three sensors 30 send three output signals to the processing unit 40, each indicative of the measured height. The processing unit 40 identifies the positions of the three points on the substrate holding surface from the received three output signals and the relative positions of the three sensors 30 . The processing unit 40 calculates the inclination of the substrate holding surface based on the positions (coordinates) of the three points on the substrate holding surface. The calculated inclination of the substrate holding surface is stored in the storage device 40 a of the processing section 40 . After measuring the heights of the three points on the substrate holding surface, the dummy substrate 160 is removed from the substrate holding portion 111 .

The inclination of the substrate holding surface is calculated in the same manner as the measurement of the inclination of the stage surface 2a in the above-described embodiment. The processing unit 40 may perform a zero reset of the three sensors 30 . That is, the height measurements at three points on the flat surface 160a (ie, substrate holding surface) of the dummy substrate 160 obtained by the three sensors 30 may be reset to zero.

The heights of the three points on the substrate holding surface may be measured at multiple regions within the flat surface 160a of the dummy substrate 160, as in the previously described embodiment. Specifically, while the dummy substrate 160 is intermittently rotated by the substrate holding part 111, the heights of three points on the substrate holding surface are measured in a plurality of regions within the flat surface 160a of the dummy substrate 160, and these The inclinations of the flat surface 160a of the dummy substrate 160 in a plurality of areas are calculated, the average of the calculated inclinations of the plurality of areas is calculated, and the calculated average is determined as the inclination of the substrate holding surface. The plurality of regions in the flat surface 160a of the dummy substrate 160 are preferably arranged around the center of the flat surface 160a (that is, the center of the substrate holding surface) at equal intervals.

Next, the sensor 30 measures the height of the polishing surface (lower surface) 130 a of the polishing tool 130 . FIG. 37 shows a state in which the sensor 30 measures the height of the polishing surface (lower surface) 130a of the polishing tool 130. FIG. The arm rotation mechanism 143 moves the polishing head 150 to a position above the three sensors 30 . Next, the sensor 30 is lifted to a predetermined measurement position by the sensor lifting device 135, and the three sensors 30 measure the heights of three points on the polishing surfaces 130a of the three polishing tools 130, respectively. Since the back side of the polishing tool 130 is supported by the pressing surface 155 a of the pressing member 155 , the polishing surface 130 a of the polishing tool 130 is parallel to the pressing surface 155 a of the pressing member 155 . The three sensors 30 respectively measure the heights of three points on the polishing surface 130a of the three polishing tools 130 and send three output signals respectively indicating the measured heights to the processing section 40. FIG.

The processing unit 40 calculates the inclinations of the polishing surfaces 130a of the three polishing tools 130 from the received three output signals and the relative positions of the three sensors 30, as in the above-described embodiment. The inclinations of the polishing surfaces 130 a of the three polishing tools 130 correspond to the inclinations of the pressing surfaces 155 a of the three pressing members 155 .

Next, based on the inclination of the substrate holding surface of the substrate holding part 111 and the inclination of the polishing surface 130a of the polishing tool 130 (that is, the inclination of the pressing surface 155a of the pressing member 155), the processing part 40 adjusts the substrate holding part 111. A relative angle between the substrate holding surface and the pressing surface 155a of the pressing member 155 is calculated. The processing unit 40 transmits the calculated relative angle to the motion control unit 86 . Then, the operation control unit 86 issues a command to the pressing member tilting actuator 87 to operate the pressing member tilting actuator 87 so that the relative angle becomes substantially 0, thereby tilting the polishing head 150 including the pressing member 155. to adjust. A polishing surface 130 a of the polishing tool 130 held by the tilt-adjusted polishing head 150 is substantially parallel to the substrate holding surface of the substrate holding part 111 .

Next, the arm rotation mechanism 143 moves the polishing head 150 to the retracted position outside the substrate holder 111 again. The substrate W is gripped by the chuck 114 of the substrate holding unit 111 and rotated around the axis of the substrate W by the hollow motor 116 . The arm rotation mechanism 143 moves the polishing head 150 to a polishing position above the hydrostatic support stage 170 . A fluid (for example, a liquid such as pure water) is supplied to a plurality of fluid discharge ports 172 through a fluid supply path 174, and flows between the substrate support surface 170a of the hydrostatic support stage 170 and the second surface A2 of the substrate W. The space is filled with fluid. The substrate W is supported by a fluid flowing between the substrate support surface 170a and the substrate W second surface A2.

The rinse liquid supply nozzle 118 supplies the rinse liquid to the center of the substrate W, and the rinse liquid spreads over the first surface A1 of the substrate W due to centrifugal force. The head rotation mechanism 122 rotates the polishing head 150 around its axis HP. The air cylinder 125 moves the rotating polishing head 150 toward the first surface A1 of the substrate W, and the pressing surface 155a of the pressing member 155 presses the polishing surface 130a of the polishing tool 130 against the first surface of the substrate W. Press against A1. While the rinse liquid is present on the first surface A1 of the substrate W, the polishing tool 130 is brought into sliding contact with the first surface A1 of the substrate W to polish the first surface A1.

According to this embodiment, the polishing surface 130 a of the polishing tool 130 is substantially parallel to the substrate holding surface of the substrate holding part 111 . Therefore, the polishing surface 130a of the polishing tool 130 is brought into sliding contact with the first surface A1 of the substrate W while being substantially parallel to the first surface A1 of the substrate W. As shown in FIG.

The inclination of the polishing surface 130 a of the polishing tool 130 corresponds to the inclination of the pressing surface 155 a of the pressing member 155 . Therefore, it is possible to calculate the inclination of the pressing surface 155a of the pressing member 155 from the heights of three points on the polishing surface 130a of the polishing tool 130 as described above. In one embodiment, as shown in FIG. 38, a sensor target jig 180 is attached to the bottom of the polishing head 150, and instead of the height of the three points on the polishing surface 130a of the polishing tool 130, the sensor target jig 180 The inclination of the pressing surface 155a of the pressing member 155 may be calculated from the heights of three points on the flat surface 180a.

A sensor target jig 180 shown in FIG. 38 is detachably attached to the bottom of the polishing head 150 . The lower surface of the sensor target jig 180 constitutes a flat surface 180 a that is parallel to the pressing surface 155 a of the pressing member 155 . The sensor target jig 180 has a bottom wall 181 covering the entirety of the polishing tools 130 a of the three polishing tools 130 and a peripheral wall 182 connected to the edge of the bottom wall 181 . A peripheral wall 182 extends upward from the bottom wall 181 and surrounds the sides of the polishing head 150 . The inner surface of the peripheral wall 182 has substantially the same shape and size as the side surface of the polishing head 150 , and the side surface of the polishing head 150 fits into the inner surface of the peripheral wall 182 . A lower surface of the bottom wall 181 is a flat surface 180 a parallel to the pressing surface 155 a of the pressing member 155 . The sensor target jig 180 can be made of metal, hard resin, or the like.

FIG. 39(a) is a diagram showing an example of a fastening mechanism for detachably attaching the sensor target jig 180 to the polishing head 150, and FIG. 39(b) is a diagram showing another example of the fastening mechanism. be. In the example shown in FIG. 39( a ), a through hole 182 a is formed in the peripheral wall 182 of the sensor target jig 180 . A screw hole 184 is formed in the side surface of the polishing head 150 . The screw 185 is screwed into the threaded hole 184 of the polishing head 150 through the through hole 182 a of the sensor target jig 180 , thereby fixing the sensor target jig 180 to the polishing head 150 . The sensor target fixture 180 can be removed from the polishing head 150 by removing the screw 185 from the polishing head 150 . In the example shown in FIG. 39( a ), the fastening mechanism for detachably attaching the sensor target jig 180 to the polishing head 150 is composed of through holes 182 a , screws 185 and threaded holes 184 .

In the example shown in FIG. 39( b ), a magnet 187 is fixed to the bottom surface of the polishing head 150 and a magnet 188 is also fixed to the top surface of the bottom wall 181 of the sensor target jig 180 . When the sides of the polishing head 150 are fitted to the inner surface of the peripheral wall 182 of the sensor target jig 180, the magnets 187 on the polishing head 150 attract the magnets 188 on the sensor target jig 180, thereby causing the sensor target jig 180 to move. are fixed to the polishing head 150 . In the example shown in FIG. 39(b), the fastening mechanism for detachably attaching the sensor target jig 180 to the polishing head 150 consists of a magnet 187 fixed to the polishing head 150 and a magnet 187 fixed to the sensor target jig 180. Consists of a magnet 188 . If the sensor target jig 180 is made of a magnetic material, the magnet 188 fixed to the sensor target jig 180 may be omitted. In this case, the fastening mechanism consists of a magnet 187 fixed to the polishing head 150 .

The fastening mechanism is not limited to the examples shown in FIGS. 39(a) and 39(b). For example, the fastening mechanism may consist of a latch, such as a snap lock. Either magnet 187 or magnet 188 shown in FIG. 39(b) may be replaced with a magnetic material.

FIG. 40 is a diagram showing a state in which the sensor 30 measures the heights of three points on the flat surface 180a of the sensor target jig 180. FIG. The sensor lifting device 135 lifts the three sensors 30 to predetermined measurement positions. The three sensors 30 measure the height of three points on the flat surface 180a of the sensor target jig 180. FIG. The positions of these three points correspond to the positions of the three sensors 30. FIG. The three sensors 30 send three output signals to the processing unit 40, each indicative of the measured height.

The processing unit 40 identifies the positions of three points on the flat surface 180a of the sensor target jig 180 from the received three output signals and the relative positions of the three sensors 30 . The processing unit 40 calculates the inclination of the flat surface 180 a of the sensor target jig 180 based on the positions (coordinates) of the three points on the flat surface 180 a of the sensor target jig 180 . The inclination of the flat surface 180 a of the sensor target jig 180 corresponds to the pressing surface 155 a of the pressing member 155 . The calculated inclination of the flat surface 180 a of the sensor target jig 180 , that is, the inclination of the pressing surface 155 a of the pressing member 155 is stored in the storage device 40 a of the processing unit 40 . After measuring the heights of the three points on the flat surface 180 a of the sensor target jig 180 , the sensor target jig 180 is removed from the polishing head 150 .

In the embodiment described with reference to FIGS. 30 to 40, a pressing member tilting actuator 87 is provided to tilt the entire polishing head 150 including the pressing member 155 . In one embodiment, as shown in FIG. 41, instead of the pressing member tilting actuator 87, a substrate holding surface tilting actuator 81 that tilts the entire substrate holding part 111 may be provided. The structure of the substrate holding surface tilting actuator 81 is the same as that of the substrate holding surface tilting actuator 81 described with reference to FIGS. 22 to 24, so redundant description thereof is omitted. The three actuators 80 of the substrate holding surface tilting actuator 81 are connected to the base plate 112 so as to be tiltable. The three actuators 80 are arranged around the axis CP of the substrate holder 111 .

The sensor lifting device 135 supporting the sensor 30 is not fixed to the base plate 112 and is not in contact with the substrate holder 111 . In this embodiment, the sensor lifting device 135 is fixed to a mounting base 190 extending through a hole formed in the base plate 112 , and the mounting base 190 is fixed to a mounting surface 191 . The entire substrate holding part 111 is tilted independently of the sensor 30 and the sensor lifting device 135 . That is, the entire substrate holding part 111 can be tilted by the substrate holding surface tilting actuator 81, while the postures of the sensor 30 and the sensor lifting device 135 remain unchanged.

Before polishing the substrate W, the inclination of the substrate holding part 111 is adjusted by the substrate holding surface tilting actuator 81 so that the substrate holding surface of the substrate holding part 111 is parallel to the pressing surface 155 a of the pressing member 155 . More specifically, the sensor 30 measures the height of the substrate holding surface of the substrate holding part 111 and the height of the pressing surface 155a of the pressing member 155, and the processing part 40 measures the substrate holding surface of the substrate holding part 111. and the inclination of the pressing surface 155a of the pressing member 155 are calculated. and the pressing surface 155a. The processing unit 40 transmits the calculated relative angle to the motion control unit 86 . Then, the motion control unit 86 issues a command to the substrate holding surface tilting actuator 81 to operate the substrate holding surface tilting actuator 81 so that the relative angle becomes substantially zero, thereby adjusting the inclination of the substrate holding unit 111. do. The substrate holding surface of the substrate holding part 111 whose inclination is adjusted is parallel to the polishing surface 130 a of the polishing tool 130 held by the polishing head 150 .

In the embodiments described so far, the polishing head 150 is arranged above the substrate holding surface of the substrate holding part 111, and the sensor 30 is arranged below the substrate holding surface of the substrate holding part 111. is not limited to the embodiment of In one embodiment, the sensor 30 may be positioned above the substrate holding surface of the substrate holder 111 and the polishing head 150 may be positioned below the substrate holding surface of the substrate holder 111 .

The present invention can of course be applied not only to a polishing apparatus for polishing the top edge of a circular substrate, but also to a polishing apparatus for polishing the top edge of a rectangular substrate. In addition, the term "substrate" as used herein includes not only semiconductor substrates, glass substrates, and printed circuit boards, but also magnetic recording media, magnetic recording sensors, mirrors, optical elements and micromechanical elements, or partially fabricated integrated circuits. Including circuit. The substrate may also have, for example, a layer containing nickel or cobalt on its surface.

The above-described embodiments are described for the purpose of enabling a person having ordinary knowledge in the technical field to which the present invention belongs to implement the present invention. Various modifications of the above embodiments can be made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Accordingly, the present invention is not limited to the described embodiments, but is to be construed in its broadest scope in accordance with the technical spirit defined by the claims.

REFERENCE SIGNS LIST 1 substrate holder 2 substrate stage 2a stage surface 3 stage motor 7 polishing tape 10 polishing head 11 pressing member 11a pressing surface 14 unwinding reel 15 take-up reels 17, 18 reel motor 20 tape feeding devices 21, 22 guide roller 25 air cylinder 27 Piston rod 28 Pressing member holder 30 Sensor 33 Linear guide 35 Bracket 39 Base block 40 Processing unit 41 Polishing head moving device 42 Fixed member 43 Linear guide 44 Ball screw mechanism 45 Servo motor 46 Motor base 47 Base plate 48 Installation block 51 1 Support shaft 51a Polygon portion 52 Fixed plate 52a Polygon hole 52b Notch 55 First screw 57 Eccentric cam 60 First tilt mechanism 62 Second support shaft 64 Second screw 69 Second tilt mechanism 71 Target plate 72 Protruding portion 72a Upper surface 76 of projecting portion Support member 80 Actuator 81 Substrate holding surface tilting actuator 82 Ball joint 84 Ball screw mechanism 85 Servo motor 86 Motion control unit 87 Pressing member tilting actuator 90 Connecting arm 92 Reference plate 92a Reference surface 95 Second polishing head moving device 97 Frame 98 Reel moving mechanism 111 Substrate holder 112 Base plate 114 Chuck 116 Hollow motor (chuck motor)
118 rinse liquid supply nozzle 120 head shaft 122 head rotation mechanism 125 air cylinder 130 polishing tool 130a polishing surface 126 housing 133 bracket 135 sensor lifting device 140 swing arm 141 arm support shaft 143 arm rotation mechanism 150 polishing head 155 pressing member 155a pressing surface 160 Dummy substrate 160a Flat surface 170 Static pressure support stage 170a Substrate support surface 172 Fluid outlet 174 Fluid supply path 175 Stage lifting mechanism 180 Sensor target jig 180a Flat surface 181 Bottom wall 182 Peripheral wall 182a Through hole 184 Screw hole 185 Screw 187 Magnet 188 Magnet 190 Installation table 191 Installation surface

Claims (16)

measuring the height of at least three points on the substrate holding surface with at least three sensors;
calculating the inclination of the substrate holding surface based on the output signal of the sensor;
measuring heights of at least three points on a plane parallel to the pressing surface of the pressing member with the sensors;
calculating the inclination of the pressing surface based on the output signal of the sensor;
calculating the relative angle between the substrate holding surface and the pressing surface;
holding a substrate on the substrate holding surface;
adjusting the inclination of the substrate holding surface or the pressing surface so that the relative angle is within an allowable range;
A polishing method, wherein polishing of the substrate is started by pressing a polishing tool against the substrate with the pressing surface in a state in which the inclination of the substrate holding surface or the pressing surface is adjusted. polishing the substrate by pressing a polishing tool against the substrate with the pressing surface in a state in which the inclination of the substrate holding surface or the pressing surface is adjusted so that the relative angle is within an allowable range; 2. The polishing method according to claim 1, wherein the pressing surface is tilted so that the relative angle is within an allowable range, and the polishing tool is pressed against the peripheral edge of the substrate. The step of holding the substrate on the substrate holding surface is a step of holding the substrate on the substrate holding surface whose inclination is adjusted so that the relative angle is within an allowable range. Item 1. The polishing method according to item 1. 2. The polishing method according to claim 1, wherein the at least three points on the substrate holding surface are at least three points on the outer peripheral portion of the substrate holding surface. The step of measuring the heights of at least three points on the substrate holding surface is a step of measuring the heights of at least three points in each of a plurality of regions within the substrate holding surface with at least three sensors,
In the step of calculating the inclination of the substrate holding surface, the inclination of each of the plurality of regions is calculated, the average of the calculated inclinations of the plurality of regions is calculated, and the calculated average is used as the substrate holding surface. 2. The polishing method according to claim 1, wherein the step of designating the inclination of . 6. The polishing method according to claim 5, wherein the step of measuring heights of at least three points in each of said plurality of areas is performed while intermittently rotating said substrate holding surface. 6. The polishing method according to claim 5, wherein the plurality of regions are arranged around the center of the substrate holding surface at regular intervals. 8. The polishing method according to claim 1, wherein the tilt of said substrate holding surface and the tilt of said pressing surface are expressed as vectors on a three-dimensional coordinate system. a substrate holding part having a substrate holding surface;
a pressing member having a pressing surface for pressing the polishing tool against the substrate;
at least three sensors that measure the heights of at least three points on the substrate holding surface and the heights of at least three points on a plane parallel to the pressing surface;
a processing unit that calculates the inclination of the substrate holding surface and the inclination of the pressing surface based on the output signal of the sensor, and calculates the relative angle between the substrate holding surface and the pressing surface;
an inclination adjusting device that adjusts the inclination of the substrate holding surface or the pressing surface ;
a pressing device that presses the polishing tool against the substrate on the substrate holding surface by applying a pressing force to the pressing member in a state where the inclination of the substrate holding surface or the pressing surface is adjusted ;
The pressing device presses the polishing tool against the substrate on the substrate holding surface to start polishing the substrate after the inclination of the substrate holding surface or the pressing surface is adjusted by the inclination adjusting device. polishing equipment. The tilt adjustment device includes a first tilt mechanism and a second tilt mechanism for adjusting the tilt of the pressing surface, and the pressing member is connected to the first tilt mechanism and the second tilt mechanism. 10. A polishing apparatus according to claim 9. The first tilting mechanism and the second tilting mechanism respectively include a first support shaft and a second support shaft perpendicular to each other, and the pressing member is tilted about the first support shaft and the second support shaft. 11. The polishing apparatus according to claim 10, which is rotatable. 10. The polishing apparatus according to claim 9, wherein the tilt adjusting device is a pressing member tilting actuator that tilts the pressing surface, and the pressing member tilting actuator includes at least two actuators. 10. A polishing apparatus according to claim 9, wherein said tilt adjusting device is a substrate holding surface tilting actuator for tilting said substrate holding surface, and said substrate holding surface tilting actuator comprises at least two actuators. . 10. A polishing apparatus according to claim 9, wherein said sensor is positioned above the outer peripheral portion of said substrate holding surface. 10. A polishing apparatus according to claim 9, wherein said sensor is a displacement sensor. 10. A polishing apparatus according to claim 9, further comprising a bracket to which said sensor is fixed.

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