Polishing apparatus and polishing method

Abstract

A polishing device is provided that is capable of polishing a substrate with desired polishing performance without causing defects such as scratches or contamination on the substrate. The polishing device comprises a polishing table (2) for supporting a polishing pad (3), a polishing head (1) for polishing a substrate (W) by pressing the substrate (W) onto the polishing surface of the polishing pad (3), a pad temperature measuring device (10) for measuring the temperature of the polishing surface, a pad temperature adjusting device (5) for adjusting the temperature of the polishing surface, and a control device (40) for controlling the operation of the pad temperature adjusting device (5) based on the temperature of the polishing surface measured by the pad temperature measuring device (10). The pad temperature control device (5) includes a pad heater (11) positioned above the polishing surface, and the pad heater (11) has a long portion (11a) extending approximately radially from the polishing pad (3), and a slit-shaped nozzle (11b) formed along the length of the long portion (11a) for spraying a heating fluid toward the polishing surface.

Description

Technology Field

[0001] The present invention relates to a polishing apparatus and a polishing method for polishing a substrate, such as a semiconductor wafer, by sliding contact with a polishing pad, and in particular, to a polishing apparatus and a polishing method for polishing a substrate while adjusting the surface temperature of the polishing pad. Background Technology

[0002] Chemical Mechanical Polishing (CMP) equipment is used in the process of polishing the surface of a substrate in the manufacture of semiconductor devices. The CMP equipment holds and supports the substrate with a polishing head to rotate the substrate, and also polishes the surface of the substrate by pressing the substrate against a polishing pad on a rotating polishing table. During polishing, a polishing liquid (slurry) is supplied to the polishing pad, and the surface of the substrate is flattened by the chemical action of the polishing liquid and the mechanical action of the abrasive grains contained in the polishing liquid.

[0003] The polishing rate of a substrate depends not only on the polishing load on the polishing pad of the substrate but also on the surface temperature of the polishing pad. This is because the chemical action of the polishing solution on the substrate depends on temperature. Therefore, in the manufacture of semiconductor devices, it is important to maintain the surface temperature of the polishing pad during substrate polishing at an optimal value in order to increase the polishing rate of the substrate and maintain it more consistently.

[0004] Therefore, a pad temperature control device for adjusting the surface temperature of a polishing pad has been used conventionally (see, for example, Patent Document 1 and Patent Document 2). The pad temperature control device has a pad contact member (or heat exchanger) that contacts the surface of the polishing pad and supplies a temperature-controlled heating liquid and a cooling liquid. By adjusting the flow rate of the heating liquid and the flow rate of the cooling liquid supplied to the pad contact member, the surface temperature of the polishing pad during substrate polishing can be maintained at a desired temperature.

[0005] However, since the pad contact member of the pad temperature control device inevitably comes into contact with the polishing liquid during substrate polishing, contaminants such as abrasive particles contained in the polishing liquid and wear dust from the polishing pad adhere to the pad contact member. If these contaminants detach from the pad contact member during substrate polishing, they can contaminate the substrate or cause defects such as scratches. Furthermore, there is a risk that the contaminants detached from the pad contact member may deteriorate the surface condition of the polishing pad, which could adversely affect polishing performance. Prior art literature

[0006] Patent Document 1: Japanese Published Patent No. 2012-176449 Patent Document 2: Japanese Published Patent No. 2017-148933 The problem to be solved

[0007] The present invention aims to provide a polishing apparatus and a polishing method capable of polishing a substrate with desired polishing performance without causing defects such as scratches or contamination on the substrate. means of solving the problem

[0008] In one aspect, a polishing device is provided that comprises a polishing table for supporting a polishing pad, a polishing head for polishing a substrate by pressing the substrate against the polishing surface of the polishing pad, a pad temperature measuring device for measuring the temperature of the polishing surface, a pad temperature adjusting device for adjusting the temperature of the polishing surface, and a control device for controlling the operation of the pad temperature adjusting device based on the temperature of the polishing surface measured by the pad temperature measuring device, wherein the pad temperature adjusting device includes a pad heater disposed above the polishing surface, and the pad heater has a long section extending approximately radially in the polishing pad and a slit-shaped nozzle formed along the length of the long section for spraying a heating fluid toward the polishing surface.

[0009] In one sun, the pad temperature control device further comprises an up-and-down movement mechanism that moves the pad heater up and down relative to the polishing surface.

[0010] In one sun, the pad temperature adjustment device further comprises a rotation mechanism that rotates the pad heater in a horizontal direction relative to the polishing surface.

[0011] In one sun, the pad temperature control device further comprises a rotation mechanism that rotates the pad heater around its longitudinal axis.

[0012] In one sun, the pad temperature adjustment device further comprises a shutter mechanism for adjusting the opening degree of the nozzle.

[0013] In one case, the pad temperature measuring device is a measuring device capable of measuring a temperature profile along the radial direction of the polishing pad, and the shutter mechanism is composed of piezo elements arranged along the longitudinal direction of the nozzle of the pad heater.

[0014] In one sun, the control device adjusts the amount of expansion of each piezo element based on the temperature profile.

[0015] In one sun, the pad temperature control device further comprises a cooling mechanism that cools the polishing surface by spraying a cooling fluid onto the polishing surface.

[0016] In one aspect, the cooling mechanism includes a pad cooler positioned above the polishing surface, and the pad temperature control device further includes a rotation mechanism that rotates the pad cooler around its longitudinal axis.

[0017] In one aspect, the cooling mechanism comprises a pad cooler positioned above the polishing surface, and the pad cooler comprises an elongated portion extending approximately radially from the polishing pad and a plurality of nozzles arranged along the length of the elongated portion for spraying the cooling fluid toward the polishing surface, and the cooling mechanism further comprises a shutter mechanism for adjusting the opening degree of the plurality of nozzles of the pad cooler.

[0018] In one aspect, the cooling mechanism comprises a pad cooler positioned above the polishing surface, and the cooling mechanism further comprises a guide plate attached to the pad cooler and an actuator for rotating the guide plate.

[0019] In one sun, the pad temperature control device further comprises a suction mechanism positioned above the polishing surface and sucking in air above the polishing surface.

[0020] In one sun, the pad temperature control device further comprises a heater disposed within the pad heater.

[0021] In one sun, the polishing table is placed in a polishing chamber, and the pad temperature control device further comprises a polishing chamber suction device that sucks in air in the polishing chamber so that the pressure in the polishing chamber is maintained at a predetermined value.

[0022] In one sun, a cleaning device is further provided for cleaning the pad heater at an evacuation position on the side of the polishing pad.

[0023] In one sun, the heating fluid is superheated steam.

[0024] In one aspect, the control device executes a pad temperature control initiation operation when initiating control of the surface temperature of the polishing pad, and the pad temperature control initiation operation is an operation of supplying the heating fluid having a flow rate and / or temperature greater than the flow rate and / or temperature of the heating fluid calculated to reach the temperature of the polishing surface to the pad heater.

[0025] In one sun, the pad temperature control device further comprises a heating fluid supply line that supplies the heating fluid to the pad heater and a flow regulator disposed in the heating fluid supply line, and the control device increases the flow rate of the heating fluid using the flow regulator during the pad temperature control initiation operation.

[0026] In one day, the control device terminates the pad temperature control initiation operation when the temperature of the polishing surface of the polishing pad reaches the target temperature.

[0027] In one aspect, a polishing method is provided for polishing a substrate by pressing the substrate against the polishing surface while adjusting the temperature of the polishing surface of the polishing pad with a pad heater positioned above the polishing surface. When the temperature control of the polishing surface is initiated, a pad temperature control initiation operation is performed to bring the temperature of the polishing surface to a target temperature. During the polishing of the substrate, a heating fluid is sprayed from a slit-shaped nozzle formed in the elongated portion of the pad heater based on the temperature of the polishing surface measured by a pad temperature measuring device that measures the temperature of the polishing surface, thereby maintaining the temperature of the polishing surface at the target temperature. The pad temperature control initiation operation is an operation of supplying the heating fluid to the pad heater having a flow rate and / or temperature greater than the flow rate and / or temperature of the heating fluid calculated to bring the temperature of the polishing surface to a target temperature.

[0028] In one sun, the process of maintaining the temperature of the polishing surface at the target temperature is performed by at least one of the following: adjusting the temperature and / or flow rate of the heating fluid; adjusting the vertical movement of the pad heater relative to the polishing surface; adjusting the horizontal rotational movement of the pad heater relative to the polishing surface; and adjusting the rotational movement of the pad heater around its longitudinal axis.

[0029] In one sun, the flow rate of the heating fluid is adjusted by a shutter that can adjust the opening degree of the nozzle of the pad heater.

[0030] In one sun, the pad temperature measuring device is a measuring device capable of measuring a temperature profile along the radial direction of the polishing pad, and the shutter is composed of piezo elements arranged along the longitudinal direction of the nozzle of the pad heater, and the adjustment of the flow rate of the heating fluid is performed by adjusting the expansion amount of each piezo element based on the temperature profile.

[0031] In one sun, the process of maintaining the temperature of the polishing surface at the target temperature is carried out by the pad heater and a cooling mechanism that cools the polishing surface by spraying a cooling fluid onto the polishing surface.

[0032] In one aspect, the cooling mechanism comprises a pad cooler positioned above the polishing surface, and the pad cooler comprises a long section extending approximately radially from the polishing pad and a plurality of nozzles arranged along the length of the long section for spraying the cooling fluid toward the polishing surface, and the process of maintaining the temperature of the polishing surface at the target temperature is further performed by adding at least one of the following: adjusting the rotational movement of the pad cooler around its longitudinal axis, adjusting the degree of opening of the plurality of nozzles of the pad cooler by a shutter, and adjusting the rotational movement of a guide plate attached to the pad cooler.

[0033] In one sun, the pad temperature control initiation operation is an operation of increasing the flow rate of the heating fluid using a flow regulator placed in the heating fluid supply line that supplies the heating fluid to the pad heater.

[0034] In one sun, when the temperature of the polishing surface of the polishing pad reaches the target temperature, the pad temperature control initiation operation is terminated. Effects of the invention

[0035] According to the present invention, the pad temperature control device adjusts the temperature of the polishing surface of the polishing pad to a predetermined target temperature in a non-contact manner with the polishing surface of the polishing pad, so the pad temperature control device does not have components to which dirt, such as abrasive particles contained in the polishing liquid and wear powder of the polishing pad, adheres. As a result, defects such as scratches and contamination caused by dirt detached from the pad temperature control device are prevented from occurring on the substrate. Furthermore, since the surface condition of the polishing pad does not change due to dirt detached from the pad temperature control device, the substrate can be polished at a desired polishing rate that is achieved when the temperature of the polishing surface of the polishing pad is maintained at a predetermined target temperature. Brief explanation of the drawing

[0036] FIG. 1 is a schematic diagram showing a polishing device according to one embodiment. FIG. 2 is a schematic diagram showing a heating fluid supply system and a cooling fluid supply system according to one embodiment. FIG. 3(a) is a schematic diagram showing a pad heater according to one embodiment, FIG. 3(b) is a cross-sectional view of the pad heater shown in FIG. 3(a), and FIG. 3(c) is a plan view showing an example of the arrangement of the pad heater with respect to a polishing pad (3). FIG. 4(a) is a schematic diagram of a pad cooler according to one embodiment, and FIG. 4(b) is a cross-sectional view of the pad cooler shown in FIG. 4(a). FIG. 5(a) is a schematic diagram of a suction nozzle according to one embodiment, and FIG. 5(b) is a cross-sectional view of the suction nozzle shown in FIG. 5(a). FIG. 6(a) is a drawing showing an example in which the long section of a pad heater and the long section of a pad cooler are formed integrally, and FIG. 6(b) is a schematic diagram showing an example in which a common long section is installed that performs the functions of both the long section of a pad heater and the long section of a pad cooler. Figure 7 is a schematic diagram showing an example of an up-and-down movement mechanism. FIG. 8(a) is a schematic diagram showing an example of a rotating mechanism, and FIG. 8(b) is a plan view showing a pad heater rotated by the rotating mechanism. FIG. 9(a) is a schematic diagram showing an example of a rotating mechanism that rotates a pad heater around its longitudinal axis, FIG. 9(b) is a cross-sectional view showing the pad heater shown in FIG. 9(a) when rotated upward, and FIG. 9(c) is a cross-sectional view showing the pad heater shown in FIG. 9(a) when rotated downward. FIG. 10 is a cross-sectional view schematically showing a pad heater according to another embodiment. FIG. 11 (a) is a perspective view of a shutter mechanism according to another embodiment viewed from the bottom side, and FIG. 11 (b) is a schematic diagram showing an example of the operation of the shutter mechanism shown in FIG. 11 (a). Figure 12 is a graph showing an example of a target temperature profile of a polishing pad and a temperature profile obtained by a pad temperature measuring device. FIG. 13 is a cross-sectional view schematically showing a pad heater according to another embodiment. FIG. 14 is a schematic diagram showing a polishing device equipped with a pad temperature control device according to another embodiment. FIG. 15 (a) is a schematic diagram showing a pad cooler of a cooling mechanism according to another embodiment, and FIG. 15 (b) is a cross-sectional view of the pad cooler shown in FIG. 15 (a). FIG. 16 is a cross-sectional view schematically showing a pad cooler of a cooling mechanism according to another embodiment. FIG. 17 is a schematic diagram showing a pad cooler of a cooling mechanism according to another embodiment. Figure 18 is a graph illustrating an example of a pad temperature control initiation operation. FIG. 19 is a schematic diagram showing a polishing device equipped with a pad temperature control device according to another embodiment. FIG. 20 is a schematic diagram showing a heating fluid supply system and a cooling fluid supply system according to another embodiment. FIG. 21 is a schematic diagram showing a heating fluid supply system according to another embodiment. FIG. 22 is a schematic diagram showing a combination of a cooling fluid supply system and a suction mechanism according to another embodiment. FIG. 23 is a schematic diagram showing a combination of a heating fluid supply system, a cooling fluid supply system, and a suction mechanism according to another embodiment. Specific details for implementing the invention

[0037] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0038] FIG. 1 is a schematic diagram showing a polishing device according to one embodiment. The polishing device shown in FIG. 1 comprises a polishing head (1) that holds and supports and rotates a wafer (W), which is an example of a substrate; a polishing table (2) that supports a polishing pad (3); a polishing liquid supply nozzle (4) that supplies a polishing liquid (e.g., slurry) to the surface of the polishing pad (3); a pad temperature measuring device (10) that measures the temperature of the surface of the polishing pad (3); and a pad temperature adjusting device (5) that adjusts the surface temperature of the polishing pad (3). The surface (upper surface) of the polishing pad (3) forms a polishing surface for polishing the wafer (W).

[0039] Additionally, the polishing device has a control device (40) that controls the operation of a pad temperature adjustment device (5) based on the temperature of the polishing surface of the polishing pad (3) measured by a pad temperature measuring device (10) (hereinafter referred to as the pad surface temperature). In this embodiment, the control device (40) is configured to control the operation of the entire polishing device including the pad temperature adjustment device (5).

[0040] The polishing head (1) is movable in the vertical direction and is also rotatable around its axis in the direction indicated by the arrow. The wafer (W) is held and supported on the lower surface of the polishing head (1) by vacuum suction, etc. A motor (not shown) is connected to the polishing table (2) and is rotatable in the direction indicated by the arrow. As shown in FIG. 1, the polishing head (1) and the polishing table (2) rotate in the same direction. A polishing pad (3) is attached to the upper surface of the polishing table (2).

[0041] Polishing of the wafer (W) is performed as follows. The wafer (W) to be polished is held and supported by the polishing head (1) and is also rotated by the polishing head (1). Meanwhile, the polishing pad (3) is rotated together with the polishing table (2). In this state, polishing liquid is supplied from the polishing liquid supply nozzle (4) to the surface of the polishing pad (3), and the surface of the wafer (W) is pressed against the surface of the polishing pad (3) (i.e., the polishing surface) by the polishing head (1). The surface of the wafer (W) is polished by sliding contact with the polishing pad (3) in the presence of the polishing liquid. The surface of the wafer (W) is flattened by the chemical action of the polishing liquid and the mechanical action of the abrasive particles contained in the polishing liquid.

[0042] The pad temperature control device (5) has a heating mechanism (9) that heats the polishing surface of the polishing pad (3), and the heating mechanism (9) is equipped with at least a pad heater (11) positioned above the polishing pad (3) and a heating fluid supply system (30) that supplies a heating fluid to the pad heater (11). By spraying the heating fluid supplied to the pad heater (11) via the heating fluid supply system (30) onto the polishing surface of the polishing pad (3), the polishing surface can be heated to a predetermined target temperature and maintained at the target temperature.

[0043] Additionally, the pad temperature control device (5) shown in FIG. 1 has a cooling mechanism (50) for cooling the polishing surface of the polishing pad (3) by spraying fluid onto the polishing surface of the polishing pad (3), and a suction mechanism (60) positioned above the polishing surface of the polishing pad (3).

[0044] The cooling mechanism (50) has at least a pad cooler (51) positioned above the polishing pad (3) and a cooling fluid supply system (52) that supplies cooling fluid to the pad cooler (51). The suction mechanism (60) has at least a suction nozzle (61) positioned above the polishing pad (3), a vacuum source (vacuum device) (63), and a suction line (62) connecting the vacuum source (63) to the suction nozzle (61). Examples of the vacuum source (63) include a suction pump, a suction fan, and an ejector. The suction mechanism (60) may have a flow regulator (64) positioned in the suction line (62). The flow regulator (64) is, for example, a damper.

[0045] The pad temperature measuring device (10) measures the pad surface temperature non-contactually and sends the measured value to the control device (40). The pad temperature measuring device (10) may be an infrared radiation thermometer or a thermocouple thermometer that measures the surface temperature of the polishing pad (3), or it may be a temperature distribution measuring device that obtains the temperature distribution (temperature profile) of the polishing pad (3) along the diameter direction of the polishing pad (3). Examples of a temperature distribution measuring device include thermography, a thermopile, and an infrared camera. When the pad temperature measuring device (10) is a temperature distribution measuring device, the pad temperature measuring device (10) is configured to measure the distribution of the surface temperature of the polishing pad (3) in an area extending in the radial direction of the polishing pad (3), which includes the center and outer periphery of the polishing pad (3). In this specification, the temperature distribution (temperature profile) represents the relationship between the pad surface temperature and the radial position on the wafer (W).

[0046] The control device (40) controls the operation of the pad temperature adjustment device (5) based on the measured pad surface temperature so that the pad surface temperature is maintained at a preset target temperature. Below, an example is described in which the heating fluid supplied from the heating fluid supply system (30) to the pad heater (11) is superheated steam. However, the heating fluid is not limited to this example. The heating fluid may be a high-temperature gas (e.g., high-temperature air, nitrogen, or argon) or heating steam. Also, superheated steam refers to high-temperature steam obtained by further heating saturated steam.

[0047] Additionally, examples are described below in which the cooling fluid is a gas at room temperature (e.g., an inert gas such as nitrogen or argon). However, the cooling fluid is not limited to this example. The cooling fluid may be a gas cooled to a set temperature lower than room temperature, or a gas heated at room temperature to a set temperature lower than the target temperature of the polishing pad (3). It is preferable that the cooling fluid be an inert gas to account for the effect on the polishing liquid. However, the cooling fluid may be a gas different from an inert gas such as air.

[0048] FIG. 2 is a schematic diagram showing a heating fluid supply system and a cooling fluid supply system according to one embodiment.

[0049] The heating fluid supply system (30) shown in FIG. 2 is equipped with a superheated steam generator (31), a superheated steam supply line (32) extending from the superheated steam generator (31) to a pad heater (11), a water supply line (33) supplying water to the superheated steam generator (31), and a gas supply line (34) supplying ambient temperature gas to the superheated steam generator (31). The gas supply line (34) branches off from a gas main line (70) extending from a gas source (not shown) and extends to the superheated steam generator (31).

[0050] The superheated steam generator (31) mixes water supplied from the water supply line (33) with ambient temperature gas supplied from the gas supply line (34) to generate superheated steam adjusted to a predetermined temperature. The superheated steam is supplied to the pad heater (11) via the superheated steam supply line (32) and sprayed from the pad heater (11) onto the polishing surface of the polishing pad (3). By this operation, the temperature of the polishing surface of the polishing pad (3) can be raised.

[0051] The heating fluid supply system (30) shown in FIG. 2 further comprises a flow regulator (first flow regulator) (35) placed in a superheated steam supply line (32) and an exhaust line (36) branching off from the superheated steam supply line (32) upstream of the flow regulator (35). Examples of the flow regulator (35) include a mass flow controller and a flow control valve. The flow rate of superheated steam supplied to the pad heater (11) can be adjusted by the flow regulator (35). Excess superheated steam passes through the exhaust line (36) and is discharged from the grinding device.

[0052] In one embodiment, the heating fluid supply system (30) may have an opening / closing valve (not shown) instead of a flow regulator (35). In this case, the control device (40) opens the opening / closing valve so that a predetermined amount of superheated steam (heating fluid) is supplied to the pad heater (11) and sprayed from the pad heater (11) onto the polishing surface of the polishing pad (3).

[0053] In the case where high-temperature gas is used as the heating fluid instead of superheated steam, the water supply line (33) is omitted in the heating fluid supply system (30), and the superheated steam generator (31) is replaced with a heating gas heater. Also, the superheated steam supply line (32) can be said to be a heating gas supply line.

[0054] The cooling fluid supply system (52) shown in FIG. 2 is equipped with a cooling gas supply line (53) that branches off from the gas main line (70) and extends to the pad cooler (51), and a flow regulator (second flow regulator) (54) placed in the cooling gas supply line (53). Examples of the flow regulator (54) include a mass flow controller and a flow control valve. The flow rate of the cooling gas supplied to the pad cooler (51) can be adjusted by the flow regulator (54). The cooling fluid is supplied to the pad cooler (51) via the cooling gas supply line (53) and sprayed from the pad cooler (51) onto the polishing surface of the polishing pad (3). By this operation, the temperature of the polishing surface of the polishing pad (3) can be lowered.

[0055] In one embodiment, the cooling fluid supply system (52) may have an opening / closing valve (not shown) instead of a flow regulator (54). In this case, the control device (40) opens the opening / closing valve so that a predetermined amount of cooling gas (cooling fluid) is supplied to the pad cooler (51) and sprayed from the pad cooler (51) onto the polishing surface of the polishing pad (3).

[0056] A control device (40) is connected to a superheated steam generator (31), a flow regulator (35, 54), a vacuum source (63), and a flow regulator (64) (see FIG. 1). The control device (40) controls the operation of at least one of the superheated steam generator (31), the flow regulator (35, 54), the vacuum source (63), and the flow regulator (64) based on the measurement value of the pad temperature measuring device (10), and matches the pad surface temperature to a predetermined target temperature. For example, the control device (40) controls the operation of the flow regulator (35, 54) to match the pad surface temperature to a predetermined target temperature, thereby adjusting the flow rate of the superheated steam and the flow rate of the cooling gas.

[0057] The control device (40) may control at least one of the operation of the superheated steam generator (31), the operation of the vacuum source (63), and the operation of the flow regulator (64) in addition to, or instead of, the operation of the flow regulator (35, 54). For example, the control device (40) may adjust the temperature of the superheated steam generated by the superheated steam generator (31), and may adjust the amount of air sucked in by controlling the operation of the vacuum source (63) and / or the flow regulator (64). The temperature of the polishing surface can be adjusted by changing the temperature of the superheated steam sprayed onto the polishing surface of the polishing pad (3). By increasing or decreasing the amount of air sucked in by the vacuum source (63) and / or the flow regulator (64), the amount of heat of vaporization removed from the slurry on the polishing surface changes, and consequently, the temperature of the polishing surface can be adjusted.

[0058] In one embodiment, by controlling the operation of the vacuum source (63) and / or flow regulator (64) of the suction mechanism (60) to increase the amount of air sucked from the suction nozzle (61), the suction mechanism (60) may be used as an auxiliary cooling mechanism for the cooling mechanism (50), or the cooling mechanism (50) may be omitted.

[0059] A pad temperature measuring device (10) (see FIG. 1) measures the pad surface temperature non-contactually and sends the measured value to a control device (40). In this embodiment, the control device (40) performs PID control on at least one of a superheated steam generator (31), a flow regulator (35, 54), a vacuum source (63), and a flow regulator (64) based on the measured pad surface temperature so that the pad surface temperature is maintained at a preset target temperature.

[0060] The method for controlling the temperature of the polishing surface of the polishing pad (3) by the control device (40) is not limited to PID control and any control method can be used as long as the measured pad surface temperature can be maintained at the target temperature. For example, the control device (40) may have an AI (artificial intelligence) function that predicts or determines at least one of the operating quantities of the superheated steam generator (31), the flow regulator (35, 54), the vacuum source (63), and the flow regulator (64) using a learned model constructed by performing machine learning.

[0061] FIG. 3(a) is a schematic diagram showing a pad heater according to one embodiment, FIG. 3(b) is a cross-sectional view of the pad heater shown in FIG. 3(a), and FIG. 3(c) is a plan view showing an example of the arrangement of the pad heater with respect to a polishing pad (3). As shown in FIG. 3(a) to FIG. 3(c), the heater (11) has an elongated portion (11a) extending approximately radially with respect to the polishing pad (3), and a nozzle (11b) for spraying a heating fluid toward the polishing surface of the polishing pad (3). A flow path (not shown) for superheated steam is formed inside the elongated portion (11a). It is preferable that the elongated portion (11a) of the pad heater (11) extends parallel to the polishing surface.

[0062] The nozzle (11b) has a slit shape formed along the length direction of the long section (11a). It is preferable that the nozzle (11b) is oriented at an angle to a virtual plane (P1) that extends vertically to the polishing surface of the polishing pad (3) through the central axis line (CL1) of the long section (11a) so that the heating fluid collides at an angle to the polishing surface of the polishing pad (3).

[0063] The shape of the elongated portion (11a) is arbitrary as long as it allows the heating fluid to be sprayed from the nozzle (11b) toward the polishing surface of the polishing pad (3). For example, the elongated portion (11a) may have a cylindrical shape, or a polygonal shape such as a square or pentagonal shape.

[0064] FIG. 4(a) is a schematic diagram of a pad cooler according to one embodiment, and FIG. 4(b) is a cross-sectional view of the pad cooler shown in FIG. 4(a). The pad cooler (51) shown in FIG. 4(a) and FIG. 4(b) has an elongated portion (51a) extending approximately radially in the direction of the polishing pad (3), and a plurality of nozzles (51b) for spraying a cooling fluid toward the polishing surface of the polishing pad (3). A passage for cooling gas (not shown) is formed inside the elongated portion (51a). It is preferable that the elongated portion (51a) of the pad cooler (51) extends parallel to the polishing surface.

[0065] A plurality of nozzles (51b) are arranged along the length direction of the long section (51a). In this embodiment, each nozzle (51b) has a circular shape. It is preferable that the nozzles (51b) are oriented at an angle to a plane (P2) that extends vertically to the polishing surface of the polishing pad (3) through the central axis line (CL2) of the long section (51a) so that the cooling fluid collides at an angle to the polishing surface of the polishing pad (3).

[0066] The shape of the elongated portion (51a) is arbitrary as long as it allows for the injection of cooling fluid from the nozzle (51b) toward the polishing surface of the polishing pad (3). For example, the elongated portion (51a) may have a cylindrical shape, or a polygonal shape such as a square or pentagonal shape. In addition, the number and shape of the nozzle (51b) are also arbitrary. For example, the nozzle (51b) may be a single opening formed along the length direction of the elongated portion (51a) and having a slit shape, or each of the multiple nozzles (51b) may have a square or triangular shape.

[0067] FIG. 5(a) is a schematic diagram of a suction nozzle according to one embodiment, and FIG. 5(b) is a cross-sectional view of the suction nozzle shown in FIG. 5(a). The suction nozzle (61) shown in FIG. 5(a) and FIG. 5(b) has an elongated portion (61a) extending approximately radially from the polishing pad (3) and a suction port (61b) for sucking air above the polishing surface of the polishing pad (3). The suction port (61b) is preferably facing the polishing surface. A passage for the sucked air (not shown) is formed inside the elongated portion (61a). The elongated portion (61a) of the suction nozzle (61) is preferably extended parallel to the polishing surface.

[0068] As long as a desired amount of air can be sucked from the suction nozzle (61), the shape of the suction nozzle (61) is arbitrary, and the number and shape of the suction openings (61b) are also arbitrary. For example, the suction mechanism (60) may have a plurality of suction openings (61b) arranged along the length direction of the elongated portion (61a). In this case, each suction opening (61b) may have a circular shape, a square shape, or a triangular shape. Also, although not illustrated, the suction nozzle (61) may have a tip portion having a dome shape. In this case, an opening formed at the lowest part of the tip portion of the dome-shaped suction nozzle (61) functions as a suction opening (61b). Additionally, the elongated portion (11a) of the pad heater (11) and / or the elongated portion (51b) of the pad cooler (51) may be accommodated in the tip portion of the dome-shaped suction nozzle (61).

[0069] As shown in FIG. 6(a), the elongated portion (11a) of the pad heater (11) and the elongated portion (51b) of the pad cooler (51) may be formed integrally. Alternatively, as shown in FIG. 6(b), the pad temperature control device (5) may have a common elongated portion (80) that performs the functions of both the elongated portion (11a) of the pad heater (11) and the elongated portion (51b) of the pad cooler (51). In this case, a superheated steam supply line (32) and a cooling gas supply line (53) are connected to the common elongated portion (80) via a mixing valve (81). By adjusting the valve opening degree of the mixing valve (81) by the control device (40), a mixed gas of superheated steam and cooling gas having a desired temperature is supplied to the common elongated portion (80) and sprayed onto the polishing surface of the polishing pad (3) from the elongated portion (80). In the long section (80), for example, a nozzle having a slit shape is formed along the length direction of the long section (80).

[0070] When the pad temperature adjustment device (5) has a mixing valve (81), the control device (40) is configured to calculate the amount of operation of the mixing valve (81) required to eliminate the difference between the preset target temperature and the surface temperature of the polishing pad (3). The valve opening degree of the mixing valve (81) corresponds to the mixing ratio of superheated steam and cooling gas. By changing the amount of operation of the mixing valve (81), the control device (40) adjusts the mixing ratio of superheated steam and cooling gas, and consequently adjusts the temperature of the mixed gas sprayed onto the polishing pad (3) from the nozzle of the long piece (80). The control device (40) controls the amount of operation of the mixing valve (81) (i.e., the valve opening degree of the mixing valve (81)) so that the surface temperature of the polishing pad (3) matches the preset target temperature.

[0071] The arrangement order of the pad heater (11), pad cooler (51), and suction nozzle (61) is arbitrary. However, as shown in FIG. 1, it is preferable that the pad cooler (51) be positioned downstream of the pad heater (11) in the rotational direction of the polishing pad (3), and the suction nozzle (61) be positioned downstream of the pad cooler (51) in the rotational direction of the polishing pad (3). In this case, the pad cooler (51) is located between the pad heater (11) and the suction nozzle (61).

[0072] Additionally, it is preferable that the pad heater (11), pad cooler (51), and suction nozzle (61) be arranged adjacent to each other. In this case, the pad heater (11), pad cooler (51), and suction nozzle (61) may be connected to each other by a connecting member such as a connecting bar, a connecting block, or a connecting arm (all not shown). This connecting member may function as a base that integrates the pad heater (11), pad cooler (51), and suction nozzle (61) into a single structure.

[0073] According to the present embodiment, the pad heater (11), pad cooler (51), and suction nozzle (61) are positioned above the polishing pad (3). That is, the pad temperature control device (5) does not have components to which dirt, such as abrasive particles contained in the polishing liquid and wear powder of the polishing pad (3), adheres. As a result, defects such as scratches and contamination caused by dirt detached from the pad temperature control device (5) do not occur on the wafer (W). Furthermore, since the surface condition of the polishing pad (3) does not change due to dirt detached from the pad temperature control device (5), the wafer (W) can be polished at a desired polishing rate.

[0074] As shown in FIG. 7, the pad temperature control device (5) may be equipped with an up-and-down movement mechanism (85) that moves the pad heater (11) up and down relative to the polishing surface of the polishing pad (3). FIG. 7 is a schematic diagram showing an example of an up-and-down movement mechanism (85).

[0075] The vertical movement mechanism (85) shown in FIG. 7 is equipped with a support arm (86) connected to a pad heater (11) and a vertical movement actuator (87) that moves the pad heater (11) up and down through the support arm (86). The configuration of the vertical movement actuator (87) is arbitrary as long as it allows the pad heater (11) to be moved in the vertical direction. For example, the vertical movement actuator (87) may be a piston cylinder device equipped with a piston that moves the pad heater (11) up and down through the support arm (86), or it may be a motor (e.g., a servo motor or a step motor) that moves the pad heater (11) up and down through the support arm (86). In one embodiment, the vertical movement actuator (87) may be a piezo actuator that moves the pad heater (11) up and down via a support arm (86) using the piezoelectric effect of a piezo element.

[0076] The vertical movement mechanism (85) is connected to the control device (40). The control device (40) controls the operation of the vertical movement mechanism (85) (i.e., the amount of operation of the vertical movement actuator (87)) based on the measurement value of the pad temperature measuring device (10), and thereby the vertical position of the pad heater (11) relative to the polishing surface of the polishing pad (3) changes (see arrow A in (b) of FIG. 3). When the distance between the pad heater (11) and the polishing pad (3) changes, the temperature of the superheated steam that collides with the polishing surface of the polishing pad (3) changes. For example, when the pad heater (11) is brought closer to the polishing pad (3), superheated steam with a high temperature collides with the polishing surface of the polishing pad (3), and the pad surface temperature can be raised. Meanwhile, if the pad heater (11) is moved away from the polishing pad (3), superheated steam with a low temperature collides with the polishing surface of the polishing pad (3), thereby lowering the pad surface temperature. Therefore, the pad surface temperature can be adjusted by changing the distance between the pad heater (11) and the polishing surface of the polishing pad (3).

[0077] Additionally, as shown in FIG. 8(a), the pad temperature control device (5) may be equipped with a rotation mechanism (90) that rotates the pad heater (11) in a horizontal direction relative to the polishing surface of the polishing pad (3). FIG. 8(a) is a schematic diagram showing an example of the rotation mechanism (90), and FIG. 8(b) is a plan view showing the pad heater (11) rotated by the rotation mechanism (90).

[0078] The rotation mechanism (90) shown in FIG. 8(a) comprises a rotation shaft (91) connected to a pad heater (11) via a support arm (86) and a rotation actuator (92) that rotates the rotation shaft (91). The rotation actuator (92) is, for example, a motor (e.g., a servo motor or a step motor) or a rotary cylinder that rotates the rotation shaft (91). In one embodiment, the rotation actuator (92) may be a piston cylinder having a piston. In this case, the rotation mechanism (90) has a link mechanism that converts the movement of the piston of the piston cylinder into the rotation movement of the rotation shaft (91).

[0079] The rotation mechanism (90) is connected to a control device (40). The control device (40) controls the operation of the rotation mechanism (90) (i.e., the amount of operation of the rotation actuator (92)) based on the measurement value of the pad temperature measuring device (10), and thereby controls the rotation angle of the pad heater (11) relative to the polishing surface of the polishing pad (3).

[0080] As shown in FIG. 8(b), when the pad heater (11) is rotated from an initial position (see FIG. 3(c)) where the long portion (11a) of the pad heater (11) extends approximately parallel to the length direction of the polishing pad (3), the direction and amount of superheated steam colliding with the polishing surface of the polishing pad (3) are changed. As a result, the pad surface temperature can be adjusted by controlling the rotation angle of the pad heater (11) from the initial position.

[0081] FIG. 9(a) is a schematic diagram showing an example of a rotating mechanism (95) that rotates a pad heater (11) around its longitudinal axis, FIG. 9(b) is a cross-sectional view showing the pad heater (11) shown in FIG. 9(a) when rotated upward, and FIG. 9(c) is a cross-sectional view showing the pad heater (11) shown in FIG. 9(a) when rotated downward.

[0082] The rotating mechanism (95) shown in FIG. 9(a) is formed by a rotary actuator (96) attached to the end of the pad heater (11) to rotate the pad heater (11). The rotary actuator (96) is, for example, a servo motor or a stepper motor.

[0083] The rotation mechanism (95) is connected to a control device (40). The control device (40) controls the operation of the rotation mechanism (95) (i.e., the amount of operation of the rotation actuator (96)) based on the measurement value of the pad temperature sensor (10), thereby changing the direction of the nozzle (11b) of the pad heater (11) relative to the polishing surface of the polishing pad (3) (see arrow B in (b) of FIG. 3).

[0084] As shown in FIG. 9(b) and FIG. 9(c), changing the direction of the nozzle (11b) of the pad heater (11) relative to the polishing surface of the polishing pad (3) changes the amount and temperature of superheated steam impacting the polishing surface of the polishing pad (3). As shown in FIG. 9(b), rotating the pad heater (11) upward reduces the amount and temperature of superheated steam impacting the polishing surface of the polishing pad (3), thereby lowering the pad surface temperature. As shown in FIG. 9(c), rotating the pad heater (11) downward increases the amount and temperature of superheated steam impacting the polishing surface of the polishing pad (3), thereby increasing the pad surface temperature. Thus, the pad surface temperature can be adjusted by controlling the rotation angle of the pad heater (11) relative to the support arm (86).

[0085] The pad temperature adjustment device (5) may have a combination of any two of the above-described vertical movement mechanism (85), rotation mechanism (90), and rotation mechanism (90), or may have all of the vertical movement mechanism (85), rotation mechanism (90), and rotation mechanism (90).

[0086] FIG. 10 is a cross-sectional view schematically illustrating a pad heater according to another embodiment. The pad heater (11) shown in FIG. 10 further comprises a shutter mechanism (76) including a shutter (77) that opens and closes a nozzle (11b) and an actuator (78) that drives the shutter (77). In the example shown in FIG. 10, the shutter mechanism (76) has two shutters (77), but may have only one shutter (77). The actuator (78) may be, for example, a piston cylinder device having a piston that moves the shutter (77), or a motor that moves the shutter (77) (for example, a servo motor or a step motor). In one embodiment, the actuator (78) may be a piezo actuator that moves the shutter (77) using the piezoelectric effect of a piezo element.

[0087] The actuator (78) is connected to the control device (40). The control device (40) controls the operation of the actuator (78) (i.e., the amount of operation of the actuator (78)) based on the measurement value of the pad temperature measuring device (10), and thereby controls the opening degree of the nozzle (11b). In this embodiment, the opening degree of the nozzle (11b) corresponds to the width of the nozzle (11b) in a direction perpendicular to the length direction. When the opening degree of the nozzle (11b) is changed, the flow rate and temperature of the superheated steam colliding with the polishing surface of the polishing pad (3) change, and the pad surface temperature changes. Therefore, the pad surface temperature can be adjusted by controlling the opening degree of the nozzle (11b).

[0088] FIGS. 11(a) and FIGS. 11(b) are schematic drawings illustrating a shutter mechanism according to another embodiment. More specifically, FIGS. 11(a) is a perspective view of a shutter mechanism according to another embodiment viewed from the bottom side, and FIGS. 11(b) is a schematic diagram illustrating an example of the operation of the shutter mechanism shown in FIGS. 11(a). The configuration of the present embodiment that is not specifically described is the same as the embodiment described with reference to FIG. 10, so the redundant description thereof is omitted.

[0089] The shutter mechanism (76) shown in FIG. 11 (a) has a shutter (77) composed of a plurality of piezo elements (101). The plurality of piezo elements (101) are arranged along the length direction of the nozzle (11b) (i.e., along the length direction of the elongated portion (11a). In this embodiment, the elongated portion (11a) of the pad heater (11) has a rectangular cross-section, but as described above, the cross-sectional shape of the elongated portion (11a) is not limited to this example. The shutter (77) shown in FIG. 11 (a) adjusts the degree of opening of the nozzle (11b) of the pad heater (11) by the extension and retraction movement caused by the inverse piezoelectric effect of the piezo elements.

[0090] Each piezo element (101) is connected to a piezo element driver (103), and the piezo element driver (103) is connected to a control device (40). In FIG. 11 (a), only control lines extending from several piezo elements (101) to the piezo element driver (103) are shown to prevent the drawing from becoming cluttered. The control device (40) can independently control the extension and retraction operation of each piezo element (101) by controlling the operation of the piezo element driver (103) (see, for example, FIG. 11 (b)). The piezo element driver (103) functions as an actuator that adjusts the degree of opening of the nozzle (11b) of the pad heater (11).

[0091] When the pad temperature measuring device (10) is the temperature distribution measuring device described above, the control device (40) can acquire the temperature distribution (temperature profile) of the polishing pad (3) along the diameter direction of the polishing pad (3). FIG. 12 is a graph showing an example of a target temperature profile of the polishing pad and a temperature profile acquired by the pad temperature measuring device. In FIG. 12, the vertical axis represents the pad surface temperature, and the horizontal axis represents the diameter direction position of the polishing pad.

[0092] In order to precisely control the in-plane uniformity (flatness) of the entire surface of the wafer (W) after polishing, it is desirable to always keep the temperature profile aligned with the target temperature. Therefore, in this embodiment, the control device (40) controls the expansion and contraction operation of each piezo element (101) so that the temperature profile acquired by the pad temperature measuring device (10) matches the target temperature. For example, as shown in FIG. 12, the control device (40) significantly reduces the piezo element (101) corresponding to the position (Pa) of the polishing pad (3) where the difference (Da) between the target temperature and the measured temperature is large, thereby increasing the amount of superheated steam injected. On the other hand, the control device (40) reduces the amount of expansion and contraction of the piezo element (101) corresponding to the position (Pb) of the polishing pad (3) where the difference (Db) between the target temperature and the measured temperature is small, thereby reducing the amount of superheated steam injected compared to the amount injected at position (Pa).

[0093] The control device (40) controls the operation of the piezo element driver (103) (i.e., the amount of expansion of each piezo element (101)) based on the measurement value of the pad temperature measuring device (10), and thereby freely controls the opening degree of the nozzle (11b) along the radial direction of the polishing pad (3). As described above, when the opening degree of the nozzle (11b) is changed, the flow rate and temperature of the superheated steam colliding with the polishing surface of the polishing pad (3) change, and the pad surface temperature changes. By performing such pad temperature control, the temperature profile of the entire polishing pad (3) can be matched to the target temperature. As a result, the wafer (W) can be polished precisely.

[0094] FIG. 13 is a cross-sectional view schematically illustrating a pad heater (11) according to another embodiment. FIG. 13 shows a cross-section of the elongated portion (11a) of the pad heater (11). The pad heater (11) shown in FIG. 13 has a heater (79) disposed inside the elongated portion (11a). The heater (79) is also connected to a control device (40), and the control device (40) controls the operation of the heater (79) (e.g., ON / OFF operation). By the heater (79), superheated steam that has cooled down while flowing from the superheated steam generator (31) to the pad heater (11) can be reheated. By reheating the superheated steam, inconveniences such as condensation of superheated steam in the pad heater (11) are prevented.

[0095] FIG. 14 is a schematic diagram showing a polishing device equipped with a pad temperature control device according to another embodiment. FIG. 14 corresponds to a plan view of the polishing device. Since the configuration of the present embodiment that is not specifically described is the same as the above-described embodiment, the redundant description thereof is omitted.

[0096] In the embodiment shown in FIG. 14, components such as a polishing table (2), a polishing pad (3), and a polishing head (1) are placed in a polishing chamber (PR), and polishing of a wafer (W) is performed in the polishing chamber (PR). The polishing chamber (PR) is a space partitioned by four partition walls (58), and the pressure inside is maintained at a predetermined pressure (for example, a pressure lower than that outside the polishing chamber (PR)). Also, in FIG. 14, three of the four partition walls (58) are shown.

[0097] When superheated steam is sprayed from the pad heater (11) and cooling gas is sprayed from the pad cooler (51), the pressure in the polishing chamber (PR) rises above a predetermined pressure, and there is a risk that it may exceed the allowable value provided for the set pressure of the polishing chamber (PR). Therefore, in this embodiment, the pad temperature control device (5) is equipped with a polishing chamber suction device (66) that sucks air from the polishing chamber (PR) so that the pressure inside the polishing chamber (PR) is maintained at a predetermined value. The polishing chamber suction device (66) shown in FIG. 14 is equipped with a vacuum device (67), such as a vacuum pump or a suction pump, a polishing chamber suction line (68) extending from the polishing chamber (PR), and a damper (69) disposed in the polishing chamber suction line (68).

[0098] The control device (40) is connected to the damper (69), and the control device (40) adjusts the opening degree of the damper (69) so that the pressure inside the polishing chamber (PR) is maintained at a predetermined value. For example, the control device (40) adjusts the opening degree of the damper (69) so that the flow rate of air flowing through the polishing chamber suction line (68) becomes equal to the sum of the measured values ​​of the flow rate regulators (35, 54). In one embodiment, the control device (40) may also be connected to the vacuum device (67) and control the opening degree of the damper (69) and / or the operation of the vacuum device (67) so that the pressure inside the polishing chamber (PR) is maintained at a predetermined value.

[0099] FIG. 15(a) is a schematic diagram showing a pad cooler of a cooling mechanism according to another embodiment, and FIG. 15(b) is a cross-sectional view of the pad cooler shown in FIG. 15(a). The configuration of the present embodiment, which is not specifically described, is the same as the embodiment shown in FIG. 4(a) and FIG. 4(b), so the redundant description is omitted.

[0100] The pad cooler (51) shown in FIG. 15 (a) and FIG. 15 (b) further comprises a shutter mechanism (110) including a shutter (111) for opening and closing a nozzle (51b) and an actuator (113) for driving the shutter (111). In the example shown in FIG. 15, the elongated portion (51a) of the pad cooler (51) has a rectangular cross-section, and the shutter mechanism (110) has a pair of shutters (111) capable of adjusting the opening degree of all nozzles (51b). In one embodiment, the shutter mechanism (110) may have only one shutter (111) capable of adjusting the opening degree of all nozzles (51b). The actuator (113) may be, for example, a piston cylinder device having a piston that moves the shutter (111), or a motor that moves the shutter (111) (for example, a servo motor or a step motor). In one embodiment, the actuator (113) may be a piezo actuator that moves the shutter (111) using the inverse piezoelectric effect of a piezo element.

[0101] The actuator (113) is connected to the control device (40). The control device (40) controls the operation of the actuator (78) of the pad heater (11) or the operation of the piezo element driver (103) and the operation of the actuator (113) (i.e., the amount of operation of the nozzle (51b)) based on the measurement value of the pad temperature measuring device (10), and thereby controls the opening degree of the nozzle (11b) and the nozzle (51b). In this embodiment, the opening degree of the nozzle (51b) corresponds to the size of the width of the nozzle (51b) in the direction perpendicular to the length direction. When the opening degree of the nozzle (11b) and the nozzle (51b) is changed, the flow rate and temperature of the superheated steam colliding with the polishing surface of the polishing pad (3) and the flow rate and temperature of the cooling gas change, and the pad surface temperature changes. Therefore, by controlling the opening degree of the nozzle (11b) and the nozzle (51b), the pad surface temperature can be precisely adjusted.

[0102] FIG. 16 is a cross-sectional view schematically illustrating a pad cooler of a cooling mechanism according to another embodiment. As shown in FIG. 16, the pad cooler (51) may have a guide plate (120) mounted on the lower part of the pad cooler (51). Specifically, the guide plate (120) is attached to the lower part of the long section (51a). The guide plate (120) may be a single plate body extending over the entire long section (51a), or a plurality of plate bodies attached corresponding to each nozzle (51b). The guide plate (120) has a shaft (120a) at its end, and the shaft (120a) is freely rotatably attached to a bearing (121) fixed to the lower surface of the long section (51a). The cooling mechanism (50) further has a rotation actuator (122) that rotates the guide plate (120) along the axis (120a), and the rotation actuator (122) is connected to a control device (40).

[0103] When the guide plate (120) is rotated, the position and amount of cooling gas colliding with the polishing surface of the polishing pad (3) change. As a result, the pad surface temperature can be adjusted by controlling the rotation angle of the guide plate (120).

[0104] In the case where the pad cooler (51) has a plurality of guide plates (120) attached corresponding to each nozzle (51b), the pad temperature measuring device (10) is preferably a temperature distribution measuring device capable of acquiring the temperature distribution (temperature profile) of the polishing pad (3) along the diameter direction of the polishing pad (3). The control device (40) can independently control the rotation angle of each guide plate (120) based on the temperature profile acquired by the pad temperature measuring device (10). That is, the control device (40) can independently control the rotation angle of each guide plate (120) so that the temperature profile of the entire polishing pad (3) matches the target temperature. As a result, the wafer (W) can be polished precisely.

[0105] FIG. 17 is a schematic diagram showing a pad cooler of a cooling mechanism according to another embodiment. As shown in FIG. 17, the pad temperature control device (5) may have a rotating mechanism (130) that rotates the pad cooler (51) around its longitudinal axis.

[0106] The rotary mechanism (130) shown in FIG. 17 is composed of a rotary actuator (131) attached to the end of a pad cooler (51) and rotating the pad cooler (51). The rotary actuator (131) is, for example, a servo motor or a step motor.

[0107] The rotation mechanism (130) is connected to the control device (40). The control device (40) controls the operation of the rotation mechanism (130) (i.e., the amount of operation of the rotation actuator (131)) based on the measurement value of the pad temperature measuring device (10), and thereby can change the direction of the nozzle (51b) of the pad cooler (51) relative to the polishing surface of the polishing pad (3). By changing the direction of the nozzle (51b) of the pad cooler (51) relative to the polishing surface of the polishing pad (3), the amount of cooling gas and the temperature colliding with the polishing surface of the polishing pad (3) change. Thus, the pad surface temperature can be adjusted by controlling the rotation angle of the pad cooler (51) relative to the polishing surface of the polishing pad (3).

[0108] In the pad temperature control device (5) according to the above-described embodiment, the control device (40) controls the temperature of the polishing surface of the polishing pad (3) by controlling at least one of the temperature, flow rate, injection amount, injection position, and injection range of the superheated steam and cooling gas based on the measurement value of the pad temperature measuring device (10). More specifically, the control device (40) controls at least one of the operation of the flow rate regulator (35, 54), superheated steam generator (31), up-and-down movement mechanism (85), rotation mechanism (90), rotation mechanism (95, 130), shutter mechanism (77, 110), heater (79), mixing valve (81), and guide plate (120) based on the measurement value of the pad temperature measuring device (10), thereby bringing the temperature of the polishing surface of the polishing pad (3) to a target temperature and maintaining it at the target temperature. By doing so, the wafer (W) can be precisely polished to a desired film thickness. In particular, in an embodiment in which the shutter (77) is composed of a plurality of piezo elements (10) and the pad cooler (51) has a plurality of guide plates (120) attached corresponding to each nozzle (51b), the temperature profile of the entire polishing pad (3) can be matched to the target temperature.

[0109] In one embodiment, the control device (40) may control the pad surface temperature by adjusting the flow rate and / or temperature of the cooling gas while supplying superheated steam adjusted to a predetermined temperature from the pad heater (11) to the polishing pad (3) at a constant flow rate.

[0110] In one embodiment, the control device (40) may temporarily increase the flow rate and / or temperature of the superheated steam when starting to control the surface temperature of the polishing pad (3). More specifically, the control device (40) supplies superheated steam to the pad heater (11) having a flow rate and / or temperature greater than the flow rate and / or temperature of the superheated steam calculated to reach the target temperature of the surface temperature of the polishing pad (3).

[0111] In this specification, a control operation that temporarily increases the flow rate and / or temperature of superheated steam when initiating control of the surface temperature of the polishing pad (3) is referred to as a "pad temperature control initiation operation." Additionally, in this specification, the flow rate and temperature of superheated steam calculated to reach the surface temperature of the polishing pad (3) at a target temperature are referred to as a "set flow rate" and a "set temperature," respectively.

[0112] In the pad temperature control initiation operation, the control device (40) controls the operation of, for example, the flow rate regulator (35) to increase the flow rate of superheated steam ejected from the nozzle (11a) of the pad heater (11) beyond the set flow rate. Alternatively, in the pad temperature control initiation operation, the control device (40) may control the operation of the superheated steam generator (31) and / or heater (79) to increase the temperature of the superheated steam ejected from the nozzle (11a) of the pad heater (11) beyond the set temperature. The control device (40) may control the operation of the flow rate regulator (35) and the operation of the superheated steam generator (31) and / or heater (79) to increase the flow rate and temperature of the superheated steam ejected from the nozzle (11a) of the pad heater (11) beyond the set flow rate and set temperature. Through such operation, the pad surface temperature can be rapidly reached to the target temperature.

[0113] FIG. 18 is a graph illustrating an example of a pad temperature control initiation operation. In the graph shown in FIG. 18, the vertical axis represents the pad surface temperature, and the horizontal axis represents time. In FIG. 18, the target temperature is shown as a horizontal solid line, and the change in the pad surface temperature when the pad temperature control initiation operation is performed is shown as a dotted line. In FIG. 18, the curve shown as a dotted line represents the change in the pad surface temperature when the pad temperature control initiation operation is not performed. The point (Ts) in FIG. 18 indicates the point in time when the pad temperature control device (5) starts temperature control of the polishing pad (3).

[0114] As described above, in the pad temperature control initiation operation, the flow rate and / or temperature of the superheated steam are temporarily increased above the set flow rate and / or set temperature. In the graph shown in FIG. 18, the flow rate of the superheated steam is increased above the set flow rate. Below, a pad temperature control initiation operation that discharges superheated steam at a flow rate greater than the set flow rate is described. A pad temperature control initiation operation that discharges superheated steam at a temperature greater than the set temperature can also be performed by the same control operation.

[0115] As shown in FIG. 18, the control device (40) stores in advance a set time (Ta) that determines the maximum execution time of the pad temperature control start operation. The above-mentioned set flow rate and set time (Ta) can be arbitrarily determined. For example, the set time (Ta) may be obtained from an experiment in which a predetermined flow rate of superheated steam is sprayed onto the polishing surface of the polishing pad (3) from the nozzle (11a) of the pad heater (11) while the pad temperature control start operation is not executed. In this experiment, the time until the pad surface temperature reaches the target temperature after the temperature control of the polishing pad (3) is started is measured, and the measured time is determined as the set time (Ta).

[0116] The control device (40) calculates the flow rate of superheated steam to bring the pad surface temperature to a target temperature during the period from the start of temperature control of the polishing pad (3) (i.e., time (Ts)) until the set time (Ta) is reached. To execute the pad temperature control start operation, the control device (40) sprays superheated steam from the nozzle (11a) of the pad heater (11) at a flow rate greater than the calculated flow rate of superheated steam. By doing so, the pad surface temperature quickly reaches the target temperature, and thus the polishing conditions of the wafer (W) can be quickly brought to an optimal condition.

[0117] During the execution of the pad temperature control initiation operation, the control device (40) stops the operation of the cooling mechanism (50) and the suction mechanism (60). At the point when the pad surface temperature reaches the target temperature (see point (Tb) in FIG. 18), the control device (40) terminates the pad temperature control initiation operation and initiates normal pad temperature control to maintain the pad surface temperature at the target temperature. More specifically, the control device (40) initiates the operation of the cooling mechanism (50) and the suction mechanism (60) and initiates normal control to control at least one of the temperature, flow rate, injection amount, injection position, and injection range of the superheated steam and cooling gas described above. By doing so, the overshoot, which is a phenomenon where the pad surface temperature exceeds the target temperature, can be suppressed to the maximum extent.

[0118] Even if the pad surface temperature does not reach the target temperature and the elapsed time of the pad temperature control start operation measured from time (Ts) reaches the set time (Ta), the control device (40) initiates normal control to control at least one of the temperature, flow rate, injection amount, injection position, and injection range of the superheated steam and cooling gas. In one embodiment, the control device (40) may stop the polishing process of the wafer (W) by determining that an abnormality has occurred in the pad temperature control device (5).

[0119] FIG. 19 is a schematic diagram showing a polishing device equipped with a pad temperature control device according to another embodiment. Since the configuration of the present embodiment, which is not specifically described, is the same as the embodiment described above, the redundant description thereof is omitted.

[0120] The pad temperature control device (5) shown in FIG. 19 is equipped with a cleaning device (45) that cleans the pad heater (11), pad cooler (51), and suction nozzle (61) at an evacuation position on the side of the polishing pad (3). A control device (40) is connected to the cleaning device (45) and controls the operation of the cleaning device (45). In FIG. 19, only the pad heater (11), pad cooler (51), suction nozzle (61), and cleaning device (45) of the pad temperature control device (5) are shown, and the illustration of other components is omitted.

[0121] In this embodiment, the pad temperature adjustment device (5) is equipped with the aforementioned rotation mechanism (90), and the control device (40) operates the rotation actuator (92) (see FIG. 8 (a)) of the rotation mechanism (90) to move the pad heater (11), pad cooler (51), and suction nozzle (61) from the initial position shown in FIG. 3 (c) to the evacuation position shown in FIG. 19.

[0122] The cleaning device (45) is equipped with a plurality of sprays (46) that spray a cleaning liquid (e.g., pure water) from above and below onto the pad heater (11), pad cooler (51), and suction nozzle (61) that have moved to the evacuation position. The control device (40) sprays the cleaning liquid from the sprays (46) onto the pad heater (11), pad cooler (51), and suction nozzle (61) after the pad heater (11), pad cooler (51), and suction nozzle (61) have moved to the evacuation position. By this operation, dirt attached to the pad heater (11), pad cooler (51), and suction nozzle (61) is cleaned.

[0123] When cleaning of the pad heater (11), pad cooler (51), and suction nozzle (61) is completed, the control device (40) controls the operation of the rotation mechanism (90) to move the pad heater (11), pad cooler (51), and suction nozzle (61) to an initial position (see (c) of FIG. 3). If droplets of cleaning liquid fall onto the polishing pad (3) from the pad heater (11), pad cooler (51), and suction nozzle (61) that have moved to the initial position, the concentration of the polishing liquid (slurry) changes, and there is a risk that it will have an adverse effect on polishing performance. Therefore, in this embodiment, the cleaning device (45) may have a plurality of nozzles (47) that spray gas (e.g., air, nitrogen, or argon) onto the pad heater (11), pad cooler (51), and suction nozzle (61) after cleaning with the cleaning liquid.

[0124] The cleaning liquid attached to the pad heater (11), pad cooler (51), and suction nozzle (61) can be blown away by the gas emitted from the nozzle (47), thereby drying the pad heater (11), pad cooler (51), and suction nozzle (61). This drying process prevents droplets of cleaning liquid from falling onto the polishing pad (3) from the pad heater (11), pad cooler (51), and suction nozzle (61) that have moved to their initial positions. In one embodiment, the spray (46) may have the function of emitted gas to the pad heater (11), pad cooler (51), and suction nozzle (61) separately from the cleaning liquid.

[0125] In the above-described embodiment, the pad temperature adjustment device (5) is equipped with a pad heater (11), as well as a cooling mechanism (50) and a suction mechanism (60). However, the pad temperature adjustment device (5) may omit either or both of the pad cooler (51) and the suction nozzle (61). When either or both of the pad cooler (51) and the suction nozzle (61) are omitted, it is preferable that the pad temperature adjustment device (5) has at least one of the above-described vertical movement mechanism (85), rotation mechanism (90), and rotation mechanism (95). Fine adjustment of the pad surface temperature is made possible by these mechanisms (85, 90, 95).

[0126] FIG. 20 is a schematic diagram showing a heating fluid supply system and a cooling fluid supply system according to another embodiment. Since the configuration of the present embodiment that is not specifically described is the same as the configuration of the embodiment shown in FIG. 2, the redundant description thereof is omitted.

[0127] The heating fluid supply system (30) shown in FIG. 20 is equipped with a thermometer (71) placed in a superheated steam supply line (32), and a flow meter (72) and a flow regulator (73) (e.g., a flow regulator valve) placed in a gas supply line (34). The thermometer (71) is connected to a control device (40) and transmits a measured value of the temperature of the superheated steam to the control device (40). The flow meter (72) and the flow regulator (73) are also connected to the control device (40). The flow meter (72) transmits a measured value of the flow rate of the gas flowing through the gas supply line (34) to the control device (40), and the control device (40) controls the operation of the flow regulator (73).

[0128] In this embodiment, the control device (40) calculates the temperature of the steam heated in the superheated steam generator (31) based on the pad surface temperature measured by the pad temperature measuring device (10). The control device (40) controls the operation of the superheated steam generator (31) so that the temperature of the superheated steam flowing through the superheated steam supply line (32) matches the calculated steam temperature.

[0129] The control device (40) may control the operation of the flow regulator (73) based on the pad surface temperature measured by the pad temperature measuring device (10), in addition to or instead of controlling the operation of the superheated steam generator (31). In this case, the control device (40) calculates the temperature of the steam heated in the superheated steam generator (31) and / or the flow rate of the gas flowing through the gas supply line (34). The control device (40) controls the operation of the superheated steam generator (31) and / or the operation of the flow regulator (73) so that the temperature of the superheated steam flowing through the superheated steam supply line (32) matches the calculated steam temperature and / or the flow rate of the gas flowing through the gas supply line (34) matches the calculated gas flow rate.

[0130] FIG. 21 is a schematic diagram showing a heating fluid supply system according to another embodiment. Since the configuration of the present embodiment, which is not specifically described, is the same as the heating fluid supply system of the embodiment shown in FIG. 2, the redundant description thereof is omitted.

[0131] The heating fluid supply system shown in FIG. 21 has a drainage tank (37) to which an exhaust line (36) is connected. A water branch line (38) branched from a water supply line (33) is also connected to the drainage tank (37), and a valve (39) is provided in the water branch line (38). When the valve (39) is opened, water at room temperature is supplied to the drainage tank (37).

[0132] Excess superheated steam flowing through the exhaust line (36) is supplied to the drain tank (37) and condenses within the drain tank (37) to return to water. In order to efficiently condense the excess superheated steam, ambient temperature water is supplied to the drain tank (37) through the water branch line (38) to lower the ambient temperature within the drain tank (37). A drain line (83) is connected to the bottom of the drain tank (37), and the condensate from the superheated steam is discharged from the polishing device through the drain line (83).

[0133] Although not shown in the diagram, the water branch line (38) may be omitted and the drain line (83) connected to the superheated steam generator (31). In this case, the high-temperature water stored in the drain tank (37) is supplied to the superheated steam generator (31) and used once again to generate superheated steam. With this configuration, energy-saving operation of the superheated steam generator (31) can be expected.

[0134] FIG. 22 is a schematic diagram showing a combination of a cooling fluid supply system (50) and a suction mechanism (60) according to another embodiment. The vacuum source (63) of the suction mechanism (60) shown in FIG. 22 is an ejector. A gas branch line (55) branched from the cooling gas supply line (53) of the cooling fluid supply system (52) is connected to the vacuum source (63), and the driving fluid of the vacuum source (63) is a gas at room temperature supplied to the vacuum source (63) through the gas branch line (55). A flow regulator (74) (e.g., a flow control valve) for adjusting the flow rate of the driving fluid is disposed in the gas branch line (55). With this configuration, the running cost of the vacuum source (63) can be reduced.

[0135] FIG. 23 is a schematic diagram showing a combination of a heating fluid supply system (30), a cooling fluid supply system (50), and a suction mechanism (60) according to another embodiment. An embodiment not specifically described is similar to the embodiment described with reference to FIG. 21 and FIG. 22, so a redundant description thereof is omitted.

[0136] In the cooling fluid supply system (50) shown in FIG. 23, a gas branch line (56) different from the gas branch line (55) for supplying driving fluid to the vacuum source (63) which is an ejector branches off from the cooling gas supply line (53). In the following description, the gas branch line (55) is referred to as the first branch line (55), and the gas branch line (56) is referred to as the second branch line (56).

[0137] The second branch line (56) is connected to the exhaust line (36). The ambient temperature gas flowing through the second branch line (56) to the exhaust line (36) is mixed with excess superheated steam in the exhaust line (36) to cool the superheated steam. Accordingly, the cooled superheated steam and water condensed from the superheated steam are supplied to the drainage tank (37).

[0138] A gas discharge line (41) is connected to the drainage tank (37), and the gas discharge line (41) is connected to the discharge line (65) of the vacuum source (63) which is an ejector. The gas flowing from the exhaust line (36) to the drainage tank (37) flows into the discharge line (65) through the gas discharge line (41) and is discharged from the polishing device via the discharge line (65).

[0139] The embodiments described above are provided for the purpose that a person skilled in the art to which the present invention pertains can practice the present invention. Various modifications of the above embodiments are naturally achievable by those skilled in the art, and the technical concept of the present invention may be applied to other embodiments. Accordingly, the present invention is not limited to the described embodiments and is to be interpreted within the broadest scope according to the technical concept defined by the claims. Explanation of the symbols

[0140] 1...Grinding head 2...Grinding table 3... Grinding pad 9...heating device 10...Pad temperature gauge 11...Pad heater 30...Heating fluid supply system 31...Superheated steam generator 32...Superheated steam supply line 35...flow regulator 40...control unit 50...cooling mechanism 51...Pad cooler 52...Cooling fluid supply system 53...Cooling gas supply line 54...flow regulator 60...Suction device 61...Suction nozzle 62...Suction line 63...Vacuum device 64...flow regulator

Claims

Claim 1 A polishing device comprising: a polishing table for supporting a polishing pad; a polishing head for polishing a substrate by pressing it against the polishing surface of the polishing pad; a pad temperature measuring device for measuring the temperature of the polishing surface; a pad temperature adjusting device for adjusting the temperature of the polishing surface; and a control device for controlling the operation of the pad temperature adjusting device based on the temperature of the polishing surface measured by the pad temperature measuring device. The pad temperature adjusting device includes a pad heater positioned above the polishing surface. The pad heater has a long section extending in the radial direction of the polishing pad and a slit-shaped nozzle formed along the length direction of the long section for spraying a heating fluid toward the polishing surface. The pad temperature adjusting device further comprises a shutter mechanism for adjusting the opening degree of the nozzle. The pad temperature measuring device is a measuring device capable of measuring a temperature profile along the radial direction of the polishing pad. The shutter mechanism is composed of piezo elements arranged along the length direction of the nozzle of the pad heater. Claim 2 A polishing device according to claim 1, wherein the pad temperature adjustment device further comprises an up-and-down movement mechanism for moving the pad heater up and down relative to the polishing surface. Claim 3 A polishing device according to claim 1 or 2, wherein the pad temperature adjusting device further comprises a rotating mechanism for rotating the pad heater in a horizontal direction relative to the polishing surface. Claim 4 A polishing device according to claim 1 or 2, wherein the pad temperature adjusting device further comprises a rotating mechanism that rotates the pad heater around its longitudinal axis. Claim 5 delete Claim 6 delete Claim 7 In claim 1, the control device is a polishing device that adjusts the amount of expansion of each piezo element based on the temperature profile. Claim 8 A polishing device according to claim 1 or 2, wherein the pad temperature adjusting device further comprises a cooling mechanism that cools the polishing surface by spraying a cooling fluid onto the polishing surface. Claim 9 A polishing device according to claim 8, wherein the cooling mechanism comprises a pad cooler disposed above the polishing surface, and the pad temperature control device further comprises a rotation mechanism for rotating the pad cooler around its longitudinal axis. Claim 10 A polishing device according to claim 8, wherein the cooling mechanism comprises a pad cooler disposed above the polishing surface, the pad cooler comprises a long portion extending radially from the polishing pad and a plurality of nozzles arranged along the length direction of the long portion for spraying the cooling fluid toward the polishing surface, and the cooling mechanism further comprises a shutter mechanism for adjusting the opening degree of the plurality of nozzles of the pad cooler. Claim 11 A polishing device according to claim 8, wherein the cooling mechanism comprises a pad cooler disposed above the polishing surface, and the cooling mechanism further comprises a guide plate mounted on the pad cooler and an actuator for rotating the guide plate. Claim 12 A polishing device according to claim 1 or 2, wherein the pad temperature adjusting device further comprises a suction mechanism disposed above the polishing surface and sucking in air above the polishing surface. Claim 13 A polishing device according to claim 1 or 2, wherein the pad temperature adjusting device further comprises a heater disposed within the pad heater. Claim 14 A polishing device according to claim 1 or 2, wherein the polishing table is disposed in a polishing chamber, and the pad temperature control device further comprises a polishing chamber suction device that sucks in air in the polishing chamber so that the pressure in the polishing chamber is maintained at a predetermined value. Claim 15 A polishing device according to claim 1 or 2, further comprising a cleaning device for cleaning the pad heater at an evacuation position on the side of the polishing pad. Claim 16 A grinding device according to claim 1 or 2, wherein the heating fluid is superheated steam. Claim 17 A polishing device according to claim 1 or 2, wherein the control device executes a pad temperature control initiation operation when initiating control of the surface temperature of the polishing pad, and the pad temperature control initiation operation is an operation of supplying the heating fluid having a flow rate and / or temperature greater than the flow rate and / or temperature of the heating fluid calculated to reach the temperature of the polishing surface to the pad heater. Claim 18 In claim 17, the pad temperature control device further comprises a heating fluid supply line that supplies the heating fluid to the pad heater and a flow regulator disposed in the heating fluid supply line, and the control device is a polishing device that increases the flow rate of the heating fluid using the flow regulator during the pad temperature control start operation. Claim 19 In claim 17, the control device is a polishing device that terminates the pad temperature control start operation when the temperature of the polishing surface of the polishing pad reaches the target temperature. Claim 20 A polishing method for polishing a substrate by pressing the substrate against the polishing surface while adjusting the temperature of the polishing surface of the polishing pad using a pad heater positioned above the polishing surface, wherein, when initiating the control of the temperature of the polishing surface, a pad temperature control initiation operation is executed to bring the temperature of the polishing surface to a target temperature, and during the polishing of the substrate, based on the temperature of the polishing surface measured by a pad temperature measuring device, a heating fluid is sprayed from a slit-shaped nozzle formed in the long section of the pad heater to maintain the temperature of the polishing surface at the target temperature, wherein the pad temperature control initiation operation is an operation of supplying the heating fluid having a flow rate and / or temperature greater than the flow rate and / or temperature of the heating fluid calculated to bring the temperature of the polishing surface to the target temperature, and the process of maintaining the temperature of the polishing surface at the target temperature comprises: adjusting the temperature and / or flow rate of the heating fluid, adjusting the vertical movement of the pad heater relative to the polishing surface, adjusting the horizontal rotational movement of the pad heater relative to the polishing surface, and the pad heater A polishing method in which at least one of the adjustments of rotational motions rotating around a longitudinal axis is performed, the adjustment of the flow rate of the heating fluid is performed by a shutter capable of adjusting the opening degree of the nozzle of the pad heater, the pad temperature measuring device is a measuring device capable of measuring a temperature profile along the radial direction of the polishing pad, the shutter is composed of piezo elements arranged along the longitudinal direction of the nozzle of the pad heater, and the adjustment of the flow rate of the heating fluid is performed by adjusting the amount of expansion of each piezo element based on the temperature profile. Claim 21 delete Claim 22 delete Claim 23 delete Claim 24 In claim 20, the process of maintaining the temperature of the polishing surface at the target temperature is a polishing method performed by the pad heater and a cooling mechanism that cools the polishing surface by spraying a cooling fluid onto the polishing surface. Claim 25 In claim 24, the cooling mechanism comprises a pad cooler positioned above the polishing surface, and the pad cooler comprises a long portion extending radially from the polishing pad and a plurality of nozzles arranged along the length direction of the long portion for spraying the cooling fluid toward the polishing surface, and the polishing method further comprises: a process of maintaining the temperature of the polishing surface at the target temperature, wherein at least one of the following is added: adjustment of a rotational movement of rotating the pad cooler around its length axis, adjustment of the opening degree of the plurality of nozzles of the pad cooler by a shutter, and adjustment of a rotational movement of a guide plate mounted on the pad cooler. Claim 26 A polishing method according to claim 20, wherein the pad temperature control initiation operation is an operation of increasing the flow rate of the heating fluid using a flow regulator disposed in a heating fluid supply line that supplies the heating fluid to the pad heater. Claim 27 A polishing method according to claim 20, wherein when the temperature of the polishing surface of the polishing pad reaches the target temperature, the pad temperature control initiation operation is terminated.

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