Polishing apparatus and polishing method

Abstract

The present invention relates to a technique for polishing a workpiece while adjusting the surface temperature of a polishing pad. This polishing apparatus comprises: a pad temperature adjustment system (10) that adjusts the temperature of a polishing surface (3a) by selectively supplying a heating fluid or a cooling fluid to the polishing surface (3a); a polishing liquid temperature adjustment system (40) that adjusts the temperature of a polishing liquid before the polishing liquid is supplied to the polishing surface (3a); and an operation control unit (37) that imparts commands to the pad temperature adjustment system (10) and the polishing liquid temperature adjustment system (40), and causes the polishing liquid temperature adjustment system (40) to adjust the temperature of the polishing liquid while causing the pad temperature adjustment system (10) to supply either the heating fluid or the cooling fluid to the polishing surface (3a).

Description

Polishing Device and Polishing Method

[0001] The present invention relates to a technique for polishing a workpiece such as a wafer, a circular substrate, or a square substrate using a polishing pad, and particularly to a technique for polishing a workpiece while adjusting the surface temperature of the polishing pad.

[0002] A CMP (Chemical Mechanical Polishing) apparatus is used in the process of polishing the surface of a wafer in the manufacture of semiconductor devices. The CMP apparatus rotates a wafer having a film by a polishing head, and further presses the wafer against a polishing pad on a rotating polishing table by the polishing head to polish the film constituting the surface of the wafer. During polishing, a polishing liquid (slurry) is supplied to the polishing pad. The film of the wafer is planarized by the chemical action of the polishing liquid and the mechanical action of the abrasive grains contained in the polishing liquid and / or the polishing pad.

[0003] The polishing rate of a wafer depends not only on the polishing load of the wafer against the polishing pad but also on the surface temperature of the polishing pad. This is because the chemical action of the polishing liquid on the film of the wafer depends on temperature. Therefore, in order to achieve an appropriate polishing rate of the film, it is important to optimally control the surface temperature of the polishing pad during wafer polishing.

[0004] Therefore, a pad temperature adjustment device for adjusting the surface temperature of the polishing pad has been conventionally used (see, for example, Patent Document 1). The pad temperature adjustment device is configured to adjust the surface temperature of the polishing pad during wafer polishing to a desired temperature by guiding a heating fluid and a cooling fluid to the surface of the polishing pad.

[0005] Japanese Patent Application Laid-Open No. 2022-170648

[0006] However, in the supply of the heating fluid and the cooling fluid, it may not be possible to reach the target temperature of the surface temperature of the polishing pad. In particular, during wafer polishing, the surface temperature of the polishing pad tends to rise due to frictional heat, and there may be cases where the surface temperature of the polishing pad cannot be rapidly lowered.

[0007] Therefore, the present invention provides a polishing apparatus and polishing method that can quickly bring the surface temperature of the polishing pad to a target temperature.

[0008] In one embodiment, a polishing apparatus is provided, comprising: a polishing table that supports a polishing pad; a polishing liquid supply nozzle that supplies polishing liquid to the polishing surface of the polishing pad; a polishing head that presses a workpiece against the polishing pad to polish the workpiece; a pad temperature control system that adjusts the temperature of the polishing surface by selectively supplying a heating fluid or a cooling fluid to the polishing surface; a polishing liquid temperature control system that adjusts the temperature of the polishing liquid before it is supplied to the polishing surface; and an operation control unit that gives commands to the pad temperature control system and the polishing liquid temperature control system to supply either the heating fluid or the cooling fluid to the polishing surface from the pad temperature control system while adjusting the temperature of the polishing liquid using the polishing liquid temperature control system.

[0009] In one embodiment, the polishing fluid temperature control system includes a temperature controller having a function to heat the polishing fluid and a function to cool the polishing fluid, and the operation control unit is configured to give commands to the pad temperature control system and the polishing fluid temperature control system to heat the polishing fluid by the polishing fluid temperature control system while supplying the heating fluid from the pad temperature control system to the polishing surface, and to give commands to the pad temperature control system and the polishing fluid temperature control system to cool the polishing fluid by the polishing fluid temperature control system while supplying the cooling fluid from the pad temperature control system to the polishing surface. In one embodiment, the operation control unit is configured to give commands to the pad temperature control system and the polishing fluid temperature control system during polishing of the workpiece to simultaneously supply the heating fluid and the heated polishing fluid to the polishing surface, and then simultaneously supply the cooling fluid and the cooled polishing fluid to the polishing surface. In one embodiment, the operation control unit is configured to issue commands to the pad temperature control system and the polishing fluid temperature control system during polishing of the workpiece to simultaneously supply the cooling fluid and the cooled polishing fluid to the polishing surface, and then to simultaneously supply the heating fluid and the heated polishing fluid to the polishing surface.

[0010] In one embodiment, the polishing fluid supply nozzle has a plurality of outlets for the polishing fluid, the polishing device further comprises a plurality of polishing fluid valves communicating with each of the plurality of outlets, and the operation control unit is configured to control the operation of the plurality of polishing fluid valves separately. In one embodiment, the plurality of outlets are arranged radially to the polishing pad. In one embodiment, the polishing device further comprises a nozzle moving mechanism for moving the outlets of the polishing fluid supply nozzle radially to the polishing pad, and the operation control unit is configured to give commands to the nozzle moving mechanism to move the outlets of the polishing fluid supply nozzle radially to the polishing pad while the workpiece is being polished.

[0011] In one embodiment, a polishing method is provided in which a polishing pad supported on a polishing table is rotated, a workpiece is pressed against the polishing pad by a polishing head to polish the workpiece, and while the workpiece is being polished, either a heating fluid or a cooling fluid is supplied to the polishing surface from a pad temperature control system, and a polishing fluid whose temperature is controlled by a polishing fluid temperature control system is supplied to the polishing surface of the polishing pad from a polishing fluid supply nozzle.

[0012] In one embodiment, while polishing the workpiece, the heating fluid is supplied to the polishing surface from the pad temperature control system, and the polishing liquid heated by the polishing liquid temperature control system is supplied to the polishing surface from the polishing liquid supply nozzle. In one embodiment, after supplying the heating fluid and the heated polishing liquid to the polishing surface while polishing the workpiece, the cooling fluid is supplied to the polishing surface from the pad temperature control system, and the polishing liquid cooled by the polishing liquid temperature control system is supplied to the polishing surface from the polishing liquid supply nozzle. In one embodiment, while polishing the workpiece, the cooling fluid is supplied to the polishing surface from the pad temperature control system, and the polishing liquid cooled by the polishing liquid temperature control system is supplied to the polishing surface from the polishing liquid supply nozzle. In one embodiment, after supplying the cooling fluid and the cooled polishing liquid to the polishing surface while polishing the workpiece, the heating fluid is supplied to the polishing surface from the pad temperature control system, and the polishing liquid heated by the polishing liquid temperature control system is supplied to the polishing surface from the polishing liquid supply nozzle is supplied.

[0013] In one embodiment, supplying the temperature-controlled polishing liquid from the polishing liquid supply nozzle to the polishing surface means supplying the temperature-controlled polishing liquid to the polishing surface from at least one of the plurality of discharge ports of the polishing liquid supply nozzle. In one embodiment, the plurality of discharge ports are arranged radially to the polishing pad. In one embodiment, supplying the temperature-controlled polishing liquid from the polishing liquid supply nozzle to the polishing surface means supplying the temperature-controlled polishing liquid to the polishing surface from the discharge port while moving the discharge port of the polishing liquid supply nozzle radially to the polishing pad.

[0014] During workpiece polishing, supplying both a heated fluid and heated polishing liquid simultaneously to the polishing surface of the polishing pad allows the temperature of the polishing surface to be rapidly raised to the target temperature. Conversely, supplying both a cooling fluid and cooled polishing liquid simultaneously to the polishing surface of the polishing pad during workpiece polishing allows the temperature of the polishing surface to be rapidly lowered to the target temperature.

[0015] This is a schematic diagram showing one embodiment of a polishing apparatus. This is a schematic diagram showing one embodiment of a polishing fluid temperature control system. This is a schematic diagram showing another embodiment of a polishing fluid temperature control system. This is a schematic diagram showing yet another embodiment of a polishing fluid temperature control system. This is a schematic diagram showing yet another embodiment of a polishing fluid temperature control system. This is a schematic diagram showing yet another embodiment of a polishing fluid temperature control system. This is a schematic diagram showing yet another embodiment of a polishing fluid temperature control system. This is a schematic diagram showing yet another embodiment of a polishing fluid temperature control system. This is a schematic diagram showing yet another embodiment of a polishing fluid temperature control system. This is a diagram showing one embodiment of a nozzle moving mechanism for moving a polishing fluid supply nozzle. This is a plan view of the polishing fluid supply nozzle, nozzle moving mechanism, pad heater, pad cooler, and polishing head. This is a side view showing another embodiment of a polishing fluid supply nozzle. This is a plan view of the polishing fluid supply nozzle, pad heater, pad cooler, and polishing head. This is a diagram showing one example of controlling the supply distribution of polishing fluid to the polishing surface of a polishing pad. This is a diagram showing another example of controlling the supply distribution of polishing fluid to the polishing surface of a polishing pad. This is a diagram showing yet another example of controlling the supply distribution of polishing fluid to the polishing surface of a polishing pad. This figure shows yet another example of controlling the supply distribution of polishing fluid to the polishing surface of the polishing pad. This figure shows an embodiment of controlling the temperature of the polishing surface of the polishing pad during wafer polishing. This figure shows an embodiment of controlling the temperature of the polishing surface of the polishing pad during wafer polishing. This graph shows experimental results verifying the temperature change of the polishing surface when polishing fluid is supplied to the polishing surface of the polishing pad from a polishing fluid supply nozzle having a single discharge port as shown in Figure 10. This graph shows experimental results verifying the temperature change of the polishing surface when polishing fluid is supplied to the polishing surface of the polishing pad from a polishing fluid supply nozzle having multiple discharge ports as shown in Figure 12. This graph shows experimental results verifying the pad temperature control system and the polishing fluid temperature control system.

[0016] Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a schematic diagram showing one embodiment of a polishing apparatus. The polishing apparatus includes a polishing table 2 that supports a polishing pad 3, a polishing head 1 that presses a wafer W, which is an example of a workpiece, against the polishing pad 3, a table rotation motor 6 that rotates the polishing table 2, and a polishing liquid supply nozzle 4 for supplying a polishing liquid (for example, a slurry containing abrasive particles, or an etching liquid that does not contain abrasive particles) onto the polishing pad 3. The surface (upper surface) of the polishing pad 3 constitutes a polishing surface 3a for polishing the wafer W. Specific examples of workpieces include wafers used in the manufacture of semiconductor devices, wiring boards, and square substrates. In the embodiments described below, a wafer W is used as the workpiece.

[0017] The wafer W is polished as follows: The wafer W to be polished is rotated by the polishing head 1, while the polishing pad 3 is rotated together with the polishing table 2 by the table rotation motor 6. In this state, polishing fluid is supplied from the polishing fluid supply nozzle 4 to the polishing surface 3a of the polishing pad 3, and the surface of the wafer W is pressed against the polishing surface 3a of the polishing pad 3 by the polishing head 1. The surface of the wafer W is flattened by the chemical action of the polishing fluid and the mechanical action of the abrasive particles contained in the polishing fluid and / or the polishing pad 3.

[0018] The polishing apparatus further includes a pad temperature control system 10 for adjusting the temperature of the polishing surface 3a of the polishing pad 3 (i.e., the surface temperature of the polishing pad 3). The pad temperature control system 10 is configured to adjust the temperature of the polishing surface 3a by selectively supplying a heating fluid or a cooling fluid to the polishing surface 3a. The pad temperature control system 10 includes a pad heater 24 for heating the polishing surface 3a of the polishing pad 3 and a pad cooler 25 for cooling the polishing surface 3a of the polishing pad 3. The pad heater 24 and pad cooler 25 are located above the polishing table 2 and the polishing pad 3, and are positioned opposite the polishing surface 3a of the polishing pad 3. The pad heater 24 and pad cooler 25 are not in contact with the polishing surface 3a of the polishing pad 3.

[0019] The pad heater 24 is supplied with superheated steam as the heating fluid. Superheated steam is produced by further heating saturated steam generated from water. In other embodiments, the heating fluid may be saturated steam. The pad cooler 25 is supplied with a cooling fluid. An example of a cooling fluid is a gas at room temperature (e.g., an inert gas such as nitrogen or argon, or air). However, the cooling fluid is not limited to this example. The cooling fluid may be a gas cooled to a temperature lower than room temperature, or a gas at a temperature lower than the target temperature of the polishing surface 3a of the polishing pad 3.

[0020] The pad temperature control system 10 further includes a heating fluid supply line 31 that supplies heating fluid to a pad heater 24, a heating flow control valve 32 that controls the flow rate of heating fluid flowing through the heating fluid supply line 31, a cooling fluid supply line 34 that supplies cooling fluid to a pad cooler 25, a cooling flow control valve 35 that controls the flow rate of cooling fluid flowing through the cooling fluid supply line 34, and an operation control unit 37 that controls the operation of the heating flow control valve 32 and the cooling flow control valve 35. The heating fluid supply line 31 is connected to the pad heater 24, and the cooling fluid supply line 34 is connected to the pad cooler 25. The heating flow control valve 32 and the cooling flow control valve 35 are actuator-driven valves such as electric valves, solenoid valves, and air-operated valves.

[0021] The heating flow control valve 32 and the cooling flow control valve 35 are electrically connected to the operation control unit 37, and the operation of the heating flow control valve 32 and the cooling flow control valve 35 (i.e., the flow rate of the heating fluid flowing through the heating fluid supply line 31 and the flow rate of the cooling fluid flowing through the cooling fluid supply line 34) is controlled by the operation control unit 37.

[0022] The operation control unit 37 includes a storage device 37a in which a program is stored, and an arithmetic unit 37b that performs calculations according to the instructions contained in the program. The heater control unit 67 consists of at least one computer (e.g., a programmable logic controller). The storage device 37a includes a main memory such as random access memory (RAM) and an auxiliary storage device such as a hard disk drive (HDD) or solid-state drive (SSD). Examples of the arithmetic unit 37b include a CPU (central processing unit) and a GPU (graphics processing unit). However, the specific configuration of the operation control unit 37 is not limited to these examples.

[0023] The heating fluid is discharged from the nozzle 24a of the pad heater 24 onto the polishing surface 3a of the polishing pad 3, thereby raising the temperature of the polishing surface 3a of the polishing pad 3. The cooling fluid is discharged from the nozzle (not shown) of the pad cooler 25 onto the polishing surface 3a of the polishing pad 3, thereby lowering the temperature of the polishing surface 3a of the polishing pad 3. The operation control unit 37 controls the flow rates of the heating fluid and cooling fluid supplied from the pad heater 24 and the pad cooler 25 to the polishing surface 3a of the polishing pad 3 by operating the heating flow control valve 32 and the cooling flow control valve 35, thereby controlling the temperature of the polishing surface 3a of the polishing pad 3.

[0024] For example, when raising the temperature of the polishing surface 3a of the polishing pad 3, the operation control unit 37 opens the heating flow control valve 32 and closes the cooling flow control valve 35 to supply heating fluid from the pad heater 24 to the polishing surface 3a, while simultaneously stopping the supply of cooling fluid from the pad cooler 25 to the polishing surface 3a. In another example, when lowering the temperature of the polishing surface 3a of the polishing pad 3, the operation control unit 37 opens the cooling flow control valve 35 and closes the heating flow control valve 32 to supply cooling fluid from the pad cooler 25 to the polishing surface 3a, while simultaneously stopping the supply of heating fluid from the pad heater 24 to the polishing surface 3a. The opening degrees of the heating flow control valve 32 and the cooling flow control valve 35 are controlled by the operation control unit 37. When lowering the temperature of the polishing surface 3a of the polishing pad 3, the supply of heating fluid consisting of superheated steam from the pad heater 24 to the polishing surface 3a may be continued. This prevents the polishing surface 3a of the polishing pad 3 from drying out due to the cooling fluid.

[0025] Although not shown in the figures, in one embodiment the pad temperature control system 10 may further include a suction nozzle adjacent to the pad cooler 25. The suction nozzle has a suction port facing the polishing surface 3a of the polishing pad 3. The suction nozzle is connected to a vacuum source such as a vacuum pump. By increasing or decreasing the amount of air drawn in from the suction nozzle, the amount of heat of vaporization removed from the polishing liquid on the polishing surface 3a changes, and as a result, the temperature of the polishing surface 3a can be adjusted.

[0026] The polishing apparatus further includes a polishing fluid temperature control system 40 that adjusts the temperature of the polishing fluid before it is supplied to the polishing surface 3a. The polishing fluid temperature control system 40 includes a pad fluid supply line 41 connected to the polishing fluid supply nozzle 4 and a temperature variable device 43 connected to the pad fluid supply line 41. The temperature variable device 43 is configured to raise or lower the temperature of the polishing fluid by heating or cooling the polishing fluid transferred from a polishing fluid supply source (not shown). The heated or cooled polishing fluid is transferred to the polishing fluid supply nozzle 4 through the pad fluid supply line 41. Furthermore, the heated or cooled polishing fluid is supplied from the polishing fluid supply nozzle 4 to the polishing surface 3a of the polishing pad 3.

[0027] Figure 2 is a schematic diagram showing one embodiment of the polishing fluid temperature control system 40. The temperature variable device 43 of the polishing fluid temperature control system 40 includes a flow control valve 45 and a heat exchanger 47 connected to the pad fluid supply line 41, a temperature controller 50 for heating and cooling the heat medium, and a heat medium circulation line 51 connecting the heat exchanger 47 and the temperature controller 50. The pad fluid supply line 41 is connected to a polishing fluid supply source (not shown), and the polishing fluid flows through the pad fluid supply line 41. The polishing fluid temperature control system 40 further includes a polishing fluid temperature measuring device 55 connected to the pad fluid supply line 41. The flow control valve 45, the heat exchanger 47, and the polishing fluid temperature measuring device 55 are arranged in the order of flow control valve 45, heat exchanger 47, and polishing fluid temperature measuring device 55 in the direction of polishing fluid flow.

[0028] The flow control valve 45 is configured to regulate the flow rate of polishing fluid supplied to the heat exchanger 47 and the polishing fluid supply nozzle 4 through the pad fluid supply line 41. The flow control valve 45 is electrically connected to the operation control unit 37, and the operation of the flow control valve 45 (i.e., the flow rate of the polishing fluid) is controlled by the operation control unit 37.

[0029] The temperature controller 50 is electrically connected to the operation control unit 37, and the operation of the temperature controller 50 is controlled by the operation control unit 37. The temperature controller 50 has both a function to heat the refrigerant and a function to cool the refrigerant. In one embodiment, the temperature controller 50 is configured to heat or cool the refrigerant within a range of 0 to 100°C. Examples of the temperature controller 50 include a combination of a heater (e.g., an electric heater) and a chiller, and a chiller that has both heating and cooling functions. The specific example of the heat transfer medium is not particularly limited, as long as it does not boil when heated by the temperature controller 50 and does not solidify when cooled by the temperature controller 50.

[0030] The heat transfer medium, heated or cooled by the temperature controller 50, is sent to the heat exchanger 47 through the heat transfer medium circulation line 51. After passing through the heat exchanger 47, the heat transfer medium is returned to the temperature controller 50 through the heat transfer medium circulation line 51. In other words, the heat transfer medium circulates between the temperature controller 50 and the heat exchanger 47 through the heat transfer medium circulation line 51.

[0031] The heat exchanger 47 is configured to heat or cool the polishing fluid by exchanging heat between the heat transfer medium sent from the temperature controller 50 through the heat transfer medium circulation line 51 and the polishing fluid sent through the pad fluid supply line 41. The heated or cooled polishing fluid flows through the pad fluid supply line 41 and into the polishing fluid supply nozzle 4, and is then supplied from the polishing fluid supply nozzle 4 onto the polishing surface 3a of the polishing pad 3. The polishing fluid temperature measuring device 55 is positioned between the heat exchanger 47 and the polishing fluid supply nozzle 4. The polishing fluid temperature measuring device 55 measures the temperature of the polishing fluid flowing from the heat exchanger 47 towards the polishing fluid supply nozzle 4 (i.e., the polishing fluid heated or cooled by the heat exchanger 47) and sends the measured temperature of the polishing fluid to the operation control unit 37.

[0032] The polishing apparatus further includes a pad temperature measuring device 58 for measuring the temperature of the polishing surface 3a of the polishing pad 3. The pad temperature measuring device 58 measures the temperature of the polishing surface 3a non-contact and sends the measured temperature of the polishing surface 3a to the operation control unit 37. The pad temperature measuring device 58 may be an infrared radiation thermometer or a thermocouple thermometer for measuring the temperature of the polishing surface 3a, or it may be a temperature distribution measuring device that acquires the temperature distribution (temperature profile) of the polishing surface 3a along the radial direction of the polishing pad 3. Examples of temperature distribution measuring devices include thermography, thermopiles, and infrared cameras. If the pad temperature measuring device 58 is a temperature distribution measuring device, it is configured to measure the temperature distribution of the polishing surface 3a along the radial direction of the polishing pad 3.

[0033] The operation control unit 37 is configured to control the temperature of the polishing fluid before it is supplied to the polishing surface 3a by controlling the operation of the polishing fluid temperature control system 40. More specifically, the operation control unit 37 determines a target temperature for the polishing fluid to minimize the difference between the temperature of the polishing surface 3a measured by the pad temperature measuring device 58 and the target temperature of the polishing surface 3a, and controls the operation of the temperature controller 50 so that the difference between the temperature of the polishing fluid measured by the polishing fluid temperature measuring device 55 and the target temperature of the polishing fluid is minimized. The temperature of the heat transfer medium sent to the heat exchanger 47 is adjusted by the temperature controller 50, thereby bringing the temperature of the polishing fluid sent to the polishing fluid supply nozzle 4 closer to the target temperature of the polishing fluid.

[0034] The operation control unit 37 is configured to quickly bring the current temperature of the polishing surface 3a of the polishing pad 3 up to the target temperature of the polishing surface 3a by controlling the operation of both the pad temperature control system 10 and the polishing fluid temperature control system 40 during wafer polishing.

[0035] In one embodiment, the operation control unit 37 issues commands to the pad temperature control system 10 and the polishing fluid temperature control system 40 to simultaneously supply the heating fluid and heated polishing fluid to the polishing surface 3a, thereby quickly raising the temperature of the polishing surface 3a to its target temperature. More specifically, the operation control unit 37 determines the flow rate of the heating fluid (i.e., the opening degree of the heating flow control valve 32) to minimize the difference between the temperature of the polishing surface 3a measured by the pad temperature measuring instrument 58 and the target temperature of the polishing surface 3a, and operates the heating flow control valve 32 while closing the cooling flow control valve 35, thereby supplying the determined flow rate of heating fluid from the pad heater 24 to the polishing surface 3a of the polishing pad 3. Simultaneously, the operation control unit 37 determines a target temperature for the polishing fluid to minimize the difference between the temperature of the polishing surface 3a measured by the pad temperature measuring device 58 and the target temperature of the polishing surface 3a. The temperature controller 50 then heats the heat transfer medium so that the difference between the temperature of the polishing fluid measured by the polishing fluid temperature measuring device 55 and the target temperature of the polishing fluid is minimized, and the polishing fluid heated by the heat transfer medium is supplied to the polishing surface 3a of the polishing pad 3 from the polishing fluid supply nozzle 4. In this way, during wafer polishing, the heating fluid is supplied to the polishing surface 3a from the pad temperature control system 10, while the polishing fluid heated by the polishing fluid temperature control system 40 is supplied to the polishing surface 3a of the polishing pad 3 from the polishing fluid supply nozzle 4.

[0036] In other embodiments, the operation control unit 37 issues commands to the pad temperature control system 10 and the polishing fluid temperature control system 40 to simultaneously supply cooling fluid and cooled polishing fluid to the polishing surface 3a, thereby quickly bringing the temperature of the polishing surface 3a to its target temperature. More specifically, the operation control unit 37 determines the flow rate of the cooling fluid (i.e., the opening degree of the cooling flow control valve 35) to reduce the difference between the temperature of the polishing surface 3a measured by the pad temperature measuring instrument 58 and the target temperature of the polishing surface 3a, and operates the cooling flow control valve 35 while closing the heating flow control valve 32, thereby supplying the determined flow rate of cooling fluid from the pad cooler 25 to the polishing surface 3a of the polishing pad 3. Simultaneously, the operation control unit 37 determines a target temperature for the polishing fluid to minimize the difference between the temperature of the polishing surface 3a measured by the pad temperature measuring device 58 and the target temperature of the polishing surface 3a. The temperature controller 50 then cools the heat transfer medium so that the difference between the temperature of the polishing fluid measured by the polishing fluid temperature measuring device 55 and the target temperature of the polishing fluid is minimized, and the polishing fluid cooled by the heat transfer medium is supplied to the polishing surface 3a of the polishing pad 3 from the polishing fluid supply nozzle 4. In this way, during wafer polishing, the cooling fluid is supplied to the polishing surface 3a from the pad temperature control system 10, while the polishing fluid cooled by the polishing fluid temperature control system 40 is supplied to the polishing surface 3a of the polishing pad 3 from the polishing fluid supply nozzle 4.

[0037] Thus, according to this embodiment, either the heating fluid or the cooling fluid is supplied to the polishing surface 3a from the pad temperature control system 10, while the polishing fluid, whose temperature is controlled by the polishing fluid temperature control system 40, is supplied to the polishing surface 3a of the polishing pad 3 from the polishing fluid supply nozzle 4. As a result, the temperature of the polishing surface 3a of the polishing pad 3 can quickly reach its target temperature.

[0038] Figure 3 is a schematic diagram showing another embodiment of the polishing fluid temperature control system 40. The configuration and operation of this embodiment, which are not specifically described, are the same as those of the embodiment described with reference to Figures 1 and 2, so redundant descriptions are omitted. In this embodiment, the pad fluid supply line 41 is connected to a pure water supply source (not shown), and pure water is sent to the heat exchanger 47 through the pad fluid supply line 41. The polishing fluid supply line 60 is connected to the pad fluid supply line 41 at a position downstream of the heat exchanger 47. In this embodiment, the polishing fluid supply line 60 is connected to the pad fluid supply line 41 at a position between the heat exchanger 47 and the polishing fluid supply nozzle 4 (more specifically, at a position between the heat exchanger 47 and the polishing fluid temperature measuring instrument 55). A flow rate control valve 61 is attached to the polishing fluid supply line 60, and the flow rate of the polishing fluid flowing through the polishing fluid supply line 60 is controlled by the flow rate control valve 61.

[0039] The heat exchanger 47 is configured to heat or cool the pure water by exchanging heat between the heat transfer medium, which is sent from the temperature controller 50 through the heat transfer medium circulation line 51, and the pure water. The heated or cooled pure water is mixed with the polishing fluid transferred from the polishing fluid supply line 60, thereby heating or cooling the polishing fluid with the pure water. The heated or cooled polishing fluid flows through the pad fluid supply line 41 and into the polishing fluid supply nozzle 4, and is then supplied from the polishing fluid supply nozzle 4 onto the polishing surface 3a of the polishing pad 3.

[0040] The embodiment shown in Figure 3 is suitable for cases where a polishing solution that needs to be diluted with pure water is used, while the embodiment shown in Figure 2 is suitable for cases where a polishing solution that does not need to be diluted with pure water, or a polishing solution that has already been diluted with pure water, is used.

[0041] Figure 4 is a schematic diagram showing another embodiment of the polishing fluid temperature control system 40. The configuration and operation of this embodiment, which are not specifically described, are the same as those of the embodiment described with reference to Figures 1 and 2, so redundant descriptions are omitted. In this embodiment, the temperature variable device 43 of the polishing fluid temperature control system 40 includes a flow control valve 45 and a tank 64 connected to the pad fluid supply line 41, a heat exchanger 47, a tank circulation line 65 connecting the heat exchanger 47 and the tank 64, a temperature controller 50 for heating and cooling the heat transfer medium, and a heat transfer medium circulation line 51 connecting the heat exchanger 47 and the temperature controller 50. The heat exchanger 47 is not connected to the pad fluid supply line 41. The flow control valve 45 is located downstream of the tank 64 in the direction of polishing fluid flow.

[0042] The polishing fluid flows into the tank 64 through the pad fluid supply line 41 and is stored in the tank 64. The polishing fluid circulates between the tank 64 and the heat exchanger 47 through the tank circulation line 65. The heat exchanger 47 performs heat exchange between the polishing fluid transferred from the tank 64 and the heat transfer medium transferred from the temperature controller 50, thereby heating or cooling the polishing fluid. The heated or cooled polishing fluid is returned from the heat exchanger 47 to the tank 64. As this heat exchange between the polishing fluid and the heat transfer medium continues, the heated or cooled polishing fluid is stored in the tank 64. The heated or cooled polishing fluid is supplied from the tank 64 to the polishing fluid supply nozzle 4 through the flow control valve 45, and further supplied from the polishing fluid supply nozzle 4 to the polishing surface 3a of the polishing pad 3.

[0043] FIG. 5 is a schematic diagram showing another embodiment of the polishing liquid temperature control system 40. The configuration and operation of this embodiment not specifically described are the same as those of the embodiment described with reference to FIG. 4, and thus the overlapping description thereof is omitted. In this embodiment, the heat exchanger 47 is disposed within the tank 64. The tank circulation line 65 shown in FIG. 4 is not provided. The heat exchanger 47 performs heat exchange between the polishing liquid within the tank 64 and the heat medium transferred from the temperature controller 50, thereby heating or cooling the polishing liquid. By performing such heat exchange between the polishing liquid and the heat medium within the tank 64, the polishing liquid within the tank 64 is heated or cooled. The heated or cooled polishing liquid is supplied from the tank 64 through the flow rate control valve 45 to the polishing liquid supply nozzle 4, and further supplied from the polishing liquid supply nozzle 4 to the polishing surface 3a of the polishing pad 3.

[0044] FIG. 6 is a schematic diagram showing another embodiment of the polishing liquid temperature control system 40. The configuration and operation of this embodiment not specifically described are the same as those of the embodiment described with reference to FIG. 4, and thus the overlapping description thereof is omitted. In this embodiment, the heat exchanger 47 and the heat medium circulation line 51 shown in FIG. 4 are not provided. The tank circulation line 65 connects between the tank 64 and the temperature controller 50.

[0045] The polishing liquid circulates between the tank 64 and the temperature controller 50 through the tank circulation line 65. The temperature controller 50 heats or cools the polishing liquid transferred from the tank 64. The heated or cooled polishing liquid is returned from the temperature controller 50 to the tank 64. By continuously heating or cooling such polishing liquid, the heated or cooled polishing liquid is stored within the tank 64. The heated or cooled polishing liquid is supplied from the tank 64 through the flow rate control valve 45 to the polishing liquid supply nozzle 4, and further supplied from the polishing liquid supply nozzle 4 to the polishing surface 3a of the polishing pad 3.

[0046] The embodiment described with reference to FIGS. 4 to 6 may be combined with the embodiment described with reference to FIG. 3. FIG. 7 is a schematic diagram showing an embodiment in which the embodiment described with reference to FIG. 4 is combined with the embodiment described with reference to FIG. 3. In the embodiment shown in FIG. 7, pure water flows into the tank 64 through the pad liquid supply line 41 and is stored in the tank 64. The pure water circulates between the tank 64 and the heat exchanger 47 through the tank circulation line 65. The heat exchanger 47 performs heat exchange between the pure water transferred from the tank 64 and the heat medium transferred from the temperature regulator 50, thereby heating or cooling the pure water. The heated or cooled pure water flows out of the tank 64 through the pad liquid supply line 41 and is further mixed with the polishing liquid transferred from the polishing liquid supply line 60, whereby the polishing liquid is heated or cooled by the pure water.

[0047] FIG. 8 is a schematic diagram showing an embodiment in which the embodiment described with reference to FIG. 5 is combined with the embodiment described with reference to FIG. 3. In the embodiment shown in FIG. 8, the heat exchanger 47 performs heat exchange between the pure water in the tank 64 and the heat medium transferred from the temperature regulator 50, thereby heating or cooling the pure water. The heated or cooled pure water flows out of the tank 64 through the pad liquid supply line 41 and is further mixed with the polishing liquid transferred from the polishing liquid supply line 60, whereby the polishing liquid is heated or cooled by the pure water.

[0048] FIG. 9 is a schematic diagram showing an embodiment in which the embodiment described with reference to FIG. 6 is combined with the embodiment described with reference to FIG. 3. In the embodiment shown in FIG. 9, the pure water circulates between the tank 64 and the temperature regulator 50 through the tank circulation line 65. The temperature regulator 50 heats or cools the pure water transferred from the tank 64. The heated or cooled pure water is returned from the temperature regulator 50 to the tank 64. The heated or cooled pure water flows out of the tank 64 through the pad liquid supply line 41 and is further mixed with the polishing liquid transferred from the polishing liquid supply line 60, whereby the polishing liquid is heated or cooled by the pure water.

[0049] Figure 10 shows one embodiment of a nozzle moving mechanism 68 for moving the polishing fluid supply nozzle 4, and Figure 11 is a plan view of the polishing fluid supply nozzle 4, nozzle moving mechanism 68, pad heater 24, pad cooler 25, and polishing head 1 shown in Figure 10. The polishing apparatus includes a nozzle support shaft 69 that supports the polishing fluid supply nozzle 4 and a nozzle moving mechanism 68 connected to the nozzle support shaft 69. The polishing fluid supply nozzle 4 has a single discharge port 70 for discharging polishing fluid onto the polishing surface 3a of the polishing pad 3. The discharge port 70 communicates with the pad fluid supply line 41. The nozzle moving mechanism 68 is electrically connected to an operation control unit 37, and the operation of the nozzle moving mechanism 68 is controlled by the operation control unit 37.

[0050] As shown in Figure 11, the nozzle moving mechanism 68 is configured to move the discharge port 70 of the polishing fluid supply nozzle 4 in the radial direction of the polishing pad 3 by rotating the nozzle support shaft 69 within a predetermined rotation angle range. The configuration of the nozzle moving mechanism 68 is not particularly limited, but for example, the nozzle moving mechanism 68 includes an electric motor connected to the nozzle support shaft 69.

[0051] During wafer polishing, the motion control unit 37 commands the nozzle movement mechanism 68 to move the discharge port 70 of the polishing fluid supply nozzle 4 in the radial direction of the polishing pad 3. In one embodiment, the discharge port 70 of the polishing fluid supply nozzle 4 may be moved back and forth once or more times in the radial direction of the polishing pad 3. This operation of the polishing fluid supply nozzle 4 allows the temperature-controlled polishing fluid to spread quickly over the polishing surface 3a of the polishing pad 3, and the temperature of the polishing surface 3a to reach the target temperature quickly.

[0052] Figure 12 is a side view showing another embodiment of the polishing fluid supply nozzle 4, and Figure 13 is a plan view of the polishing fluid supply nozzle 4, pad heater 24, pad cooler 25, and polishing head 1 shown in Figure 12. The polishing fluid supply nozzle 4 has a plurality of discharge ports 70a, 70b, 70c, 70d, and 70e for discharging polishing fluid onto the polishing surface 3a of the polishing pad 3. These discharge ports 70a to 70e are arranged in the radial direction of the polishing pad 3. The plurality of discharge ports 70a to 70e are arranged from the central region to the outer peripheral region of the polishing surface 3a of the polishing pad 3. In this embodiment, the nozzle moving mechanism 68 shown in Figures 10 and 11 is not provided.

[0053] The polishing apparatus includes a plurality of branch lines L1, L2, L3, L4, L5 connected to a pad fluid supply line 41 and a polishing fluid supply nozzle 4, and a plurality of polishing fluid valves V1, V2, V3, V4, V5 attached to each of these branch lines L1, L2, L3, L4, L5. The plurality of branch lines L1 to L5 are in parallel and communicate with a plurality of discharge ports 70a to 70e of the polishing fluid supply nozzle 4, respectively. One end of the plurality of branch lines L1 to L5 is connected to the pad fluid supply line 41, and the other end of the plurality of branch lines L1 to L5 is connected to the polishing fluid supply nozzle 4. In this embodiment, five discharge ports 70a to 70e and five corresponding polishing fluid valves V1 to V5 are provided, but the number of discharge ports and polishing fluid valves is not limited to this embodiment. For example, four or fewer discharge ports and four or fewer polishing fluid valves may be provided, or six or more discharge ports and six or more polishing fluid valves may be provided.

[0054] The polishing fluid, whose temperature is regulated by the polishing fluid temperature control system 40, is supplied to the polishing fluid supply nozzle 4 through the pad fluid supply line 41 and a plurality of branch lines L1 to L5. The plurality of polishing fluid valves V1 to V5 are electrically connected to the operation control unit 37, and the operation control unit 37 is configured to control the operation of the plurality of polishing fluid valves V1 to V5 separately. Each of the polishing fluid valves V1 to V5 is an actuator-driven valve, such as an electric valve or an air-operated valve.

[0055] The operation control unit 37 can control the supply distribution of polishing fluid to the polishing surface 3a of the polishing pad 3 by individually opening and closing the multiple polishing fluid valves V1 to V5. In the example shown in Figure 14, all of the multiple polishing fluid valves V1 to V5 are open during the polishing of the wafer W. The temperature-controlled polishing fluid spreads quickly from all the discharge ports 70a to 70e over the entire polishing surface 3a of the polishing pad 3, allowing the temperature of the polishing surface 3a to quickly reach the target temperature.

[0056] In the example shown in Figure 15, during the polishing of the wafer W, polishing fluid valves V1, V2, and V3 are open, while polishing fluid valves V4 and V5 are closed. The temperature-controlled polishing fluid is preferentially supplied from the discharge ports 70a, 70b, and 70c to the central region of the polishing surface 3a. As a result, the polishing rate of the area of ​​the wafer W that is in contact with the central region of the polishing surface 3a can be changed.

[0057] In the example shown in Figure 16, during the polishing of the wafer W, the polishing fluid valves V1, V2, and V3 are closed, while the polishing fluid valves V4 and V5 are open. The temperature-controlled polishing fluid is preferentially supplied from the discharge ports 70d and 70e to the outer peripheral region of the polishing surface 3a. As a result, the polishing rate of the area of ​​the wafer W that is in contact with the outer peripheral region of the polishing surface 3a can be changed.

[0058] In the example shown in Figure 17, during the polishing of the wafer W, polishing fluid valves V1, V2, V4, and V5 are closed, while polishing fluid valve V3 is open. The temperature-controlled polishing fluid is preferentially supplied from the discharge port 70c to the intermediate region of the polishing surface 3a. As a result, the polishing rate of the area of ​​the wafer W that is in contact with the intermediate region of the polishing surface 3a can be changed.

[0059] Generally, a higher temperature of the polishing surface 3a strengthens the chemical action of the polishing solution, increasing the wafer polishing rate. Therefore, to increase the wafer polishing rate, the temperature of the polishing surface 3a can be rapidly increased by supplying a heating fluid and heated polishing solution to the polishing surface 3a.

[0060] In contrast, if the temperature of the polishing surface 3a is low, the wafer polishing rate decreases, but the wafer surface can be polished more smoothly. In particular, lowering the temperature of the polishing surface 3a can prevent wafer dishing. Therefore, when it is desired to prevent wafer dishing, the temperature of the polishing surface 3a can be rapidly reduced by supplying a cooling fluid and cooled polishing liquid to the polishing surface 3a.

[0061] Figures 18 and 19 show several embodiments for controlling the temperature of the polishing surface 3a of the polishing pad 3 during wafer polishing. In Figure 18, the vertical axis represents the target temperature of the polishing surface 3a of the polishing pad 3, and the horizontal axis represents the wafer polishing time.

[0062] In Example 1, both a cooling fluid and a cooled polishing solution are supplied to the polishing surface 3a of the polishing pad 3 from the start t1 of wafer polishing to the end point t2. Therefore, in Example 1, the wafer is polished at a low polishing rate. The temperature of the cooled polishing solution may be changed during wafer polishing. In Example 2, both a heating fluid and a heated polishing solution are supplied to the polishing surface 3a of the polishing pad 3 from the start point t1 of wafer polishing to the end point t2. Therefore, in Example 2, the wafer is polished at a high polishing rate. The temperature of the heated polishing solution may be changed during wafer polishing.

[0063] In Example 3, both a heating fluid and heated polishing liquid are supplied to the polishing surface 3a of the polishing pad 3 from the start point t1 of wafer polishing to the intermediate point t2 of polishing. From the intermediate point t2 to the end point t3 of polishing, both a cooling fluid and cooled polishing liquid are supplied to the polishing surface 3a of the polishing pad 3. In this Example 3, the wafer is initially polished at a high polishing rate, and then polished at a low polishing rate. During wafer polishing, the temperature of the heated polishing liquid or the temperature of the cooled polishing liquid may be changed.

[0064] In Example 4, during the initial stage of wafer polishing from polishing time t1 to t2, the wafer polishing rate is increased by supplying both a heating fluid and a polishing solution heated to a first temperature to the polishing surface 3a of the polishing pad 3. During the intermediate stage of wafer polishing from polishing time t2 to t3, the wafer polishing rate is further increased by supplying both a heating fluid and a polishing solution heated to a second temperature higher than the first temperature to the polishing surface 3a of the polishing pad 3. During the final stage of wafer polishing from polishing time t3 to t4, the wafer polishing rate is decreased by supplying both a cooling fluid and a polishing solution cooled to a third temperature lower than the first temperature to the polishing surface 3a of the polishing pad 3. Similar to the heated polishing solution, the temperature of the cooled polishing solution may be changed during wafer polishing.

[0065] In Example 5, both the cooling fluid and the cooled polishing solution are supplied to the polishing surface 3a of the polishing pad 3 from the start point t1 of wafer polishing to the intermediate point t2 of polishing. From the intermediate point t2 to the end point t3 of polishing, both the heating fluid and the heated polishing solution are supplied to the polishing surface 3a of the polishing pad 3. In this Example 3, the wafer is initially polished at a low polishing rate, and then polished at a high polishing rate. During wafer polishing, the temperature of the cooled polishing solution or the temperature of the heated polishing solution may be changed.

[0066] Figure 20 is a graph showing the experimental results of verifying the temperature change of the polishing surface 3a when polishing fluid is supplied to the polishing surface 3a of the polishing pad 3 from a polishing fluid supply nozzle 4 having a single discharge port as shown in Figure 10. In this experiment, the temperature of the polishing surface 3a was measured while supplying room temperature polishing fluid to the polishing surface 3a of the polishing pad 3 during wafer polishing. Furthermore, the temperature of the polishing surface 3a was measured while supplying cooled polishing fluid to the polishing surface 3a of the polishing pad 3 during wafer polishing. No heating fluid or cooling fluid was supplied to the polishing surface 3a.

[0067] During wafer polishing, the temperature of the polishing surface 3a rises over time due to frictional heat between the wafer and the polishing pad 3. As shown in Figure 20, when the polishing solution is cooled by the polishing solution temperature control system 40, the temperature rise of the polishing surface 3a is suppressed compared to when the polishing solution is supplied at room temperature.

[0068] Figure 21 is a graph showing the experimental results of verifying the temperature change of the polishing surface 3a when polishing fluid is supplied to the polishing surface 3a of the polishing pad 3 from a polishing fluid supply nozzle 4 having multiple discharge ports as shown in Figure 12. In this experiment, the temperature of the polishing surface 3a was measured while supplying room temperature polishing fluid to the polishing surface 3a of the polishing pad 3 during wafer polishing. Furthermore, the temperature of the polishing surface 3a was measured while supplying cooled polishing fluid to the polishing surface 3a of the polishing pad 3 during wafer polishing. No heating fluid or cooling fluid was supplied to the polishing surface 3a.

[0069] Similar to the case in Figure 20, during wafer polishing, the temperature of the polishing surface 3a rises over time due to frictional heat between the wafer and the polishing pad 3. As shown in Figure 21, compared to supplying polishing fluid at room temperature, supplying polishing fluid cooled by the polishing fluid temperature control system 40 suppresses the temperature rise of the polishing surface 3a. Furthermore, compared to using a polishing fluid supply nozzle 4 with a single discharge port as shown in Figure 20, a polishing fluid supply nozzle 4 with multiple discharge ports can more effectively suppress the temperature rise of the polishing surface 3a.

[0070] Figure 22 is a graph showing the results of an experiment to verify the pad temperature control system 10 and the polishing fluid temperature control system 40. In this experiment, the temperature of the polishing surface 3a was measured when (i) only the cooling fluid was supplied to the polishing surface 3a of the polishing pad 3 from the pad cooler 25, (ii) both the cooling fluid and the cooled polishing fluid from the polishing fluid supply nozzle 4 were supplied to the polishing surface 3a of the polishing pad 3 from the pad cooler 25, and (iii) neither the cooling fluid nor the cooled polishing fluid was supplied. No wafer polishing was performed during the experiment.

[0071] As can be seen from Figure 22, when both the cooling fluid and the cooled polishing liquid were supplied to the polishing surface 3a of the polishing pad 3, the temperature of the polishing surface 3a decreased significantly. From this experimental result, it can be seen that by simultaneously supplying both the heating fluid or the cooling fluid and the temperature-controlled polishing liquid to the polishing surface 3a, the temperature of the polishing surface 3a can be quickly brought up to the target temperature.

[0072] The embodiments described above are intended to enable persons with ordinary skill in the art to implement the present invention. Various modifications of the above embodiments can be made naturally by those skilled in the art, and the technical idea of ​​the present invention can be applied to other embodiments as well. Therefore, the present invention is not limited to the embodiments described, but is to be interpreted in the broadest sense according to the technical idea defined by the claims.

[0073] The present invention can be used in techniques for polishing workpieces such as wafers, circular substrates, and square substrates using a polishing pad, and in particular in techniques for polishing workpieces while adjusting the surface temperature of the polishing pad.

[0074] W Wafer 1 Polishing head 2 Polishing table 3 Polishing pad 3a Polishing surface 4 Polishing fluid supply nozzle 6 Table rotation motor 10 Pad temperature control system 24 Pad heater 25 Pad cooler 31 Heating fluid supply line 32 Heating flow control valve 34 Cooling fluid supply line 35 Cooling flow control valve 37 Operation control unit 40 Polishing fluid temperature control system 41 Pad fluid supply line 43 Temperature variable device 45 Flow control valve 47 Heat exchanger 50 Temperature controller 51 Heat transfer medium circulation line 55 Polishing fluid temperature measuring device 58 Pad temperature measuring device 60 Polishing fluid supply line 61 Flow control valve 64 Tank 65 Tank circulation line 68 Nozzle movement mechanism 69 Nozzle support shaft 70, 70a, 70b, 70c, 70d, 70e Discharge port L1, L2, L3, L4, L5 Branch lines V1, V2, V3, V4, V5 Polishing fluid valves

Claims

1. A polishing apparatus comprising: a polishing table that supports a polishing pad; a polishing fluid supply nozzle that supplies polishing fluid to the polishing surface of the polishing pad; a polishing head that presses a workpiece against the polishing pad to polish the workpiece; a pad temperature control system that adjusts the temperature of the polishing surface by selectively supplying a heating fluid or a cooling fluid to the polishing surface; a polishing fluid temperature control system that adjusts the temperature of the polishing fluid before it is supplied to the polishing surface; and an operation control unit that gives commands to the pad temperature control system and the polishing fluid temperature control system to supply either the heating fluid or the cooling fluid to the polishing surface from the pad temperature control system while adjusting the temperature of the polishing fluid using the polishing fluid temperature control system.

2. The polishing apparatus according to claim 1, wherein the polishing fluid temperature control system comprises a temperature controller having a function to heat the polishing fluid and a function to cool the polishing fluid, and the operation control unit is configured to give commands to the pad temperature control system and the polishing fluid temperature control system to heat the polishing fluid by the polishing fluid temperature control system while supplying the heating fluid from the pad temperature control system to the polishing surface, and to give commands to the pad temperature control system and the polishing fluid temperature control system to cool the polishing fluid by the polishing fluid temperature control system while supplying the cooling fluid from the pad temperature control system to the polishing surface.

3. The polishing apparatus according to claim 2, wherein the operation control unit is configured to issue commands to the pad temperature control system and the polishing fluid temperature control system during polishing of the workpiece to simultaneously supply the heating fluid and the heated polishing fluid to the polishing surface, and thereafter simultaneously supply the cooling fluid and the cooled polishing fluid to the polishing surface.

4. The polishing apparatus according to claim 2, wherein the operation control unit is configured to issue commands to the pad temperature control system and the polishing fluid temperature control system to simultaneously supply the cooling fluid and the cooled polishing fluid to the polishing surface during polishing of the workpiece, and thereafter simultaneously supply the heating fluid and the heated polishing fluid to the polishing surface.

5. The polishing apparatus according to claim 1, wherein the polishing liquid supply nozzle has a plurality of outlets for the polishing liquid, the polishing apparatus further comprises a plurality of polishing liquid valves communicating with each of the plurality of outlets, and the operation control unit is configured to control the operation of the plurality of polishing liquid valves separately.

6. The polishing apparatus according to claim 5, wherein the plurality of discharge ports are arranged radially with respect to the polishing pad.

7. The polishing apparatus according to claim 1, further comprising a nozzle moving mechanism for moving the discharge port of the polishing liquid supply nozzle in the radial direction of the polishing pad, wherein the operation control unit is configured to give a command to the nozzle moving mechanism to move the discharge port of the polishing liquid supply nozzle in the radial direction of the polishing pad while the workpiece is being polished.

8. A polishing method comprising: rotating a polishing pad supported on a polishing table, pressing a workpiece against the polishing pad with a polishing head to polish the workpiece; and while polishing the workpiece, supplying either a heating fluid or a cooling fluid to the polishing surface from a pad temperature control system, while supplying a polishing fluid whose temperature is controlled by a polishing fluid temperature control system to the polishing surface of the polishing pad from a polishing fluid supply nozzle.

9. The polishing method according to claim 8, wherein, while polishing the workpiece, the heating fluid is supplied to the polishing surface from the pad temperature control system, and the polishing liquid heated by the polishing liquid temperature control system is supplied to the polishing surface from the polishing liquid supply nozzle.

10. The polishing method according to claim 9, further comprising supplying the heating fluid and the heated polishing liquid to the polishing surface during the polishing of the workpiece, and then supplying the cooling fluid to the polishing surface from the pad temperature control system, while supplying the polishing liquid cooled by the polishing liquid temperature control system to the polishing surface from the polishing liquid supply nozzle.

11. The polishing method according to claim 8, wherein, while polishing the workpiece, the cooling fluid is supplied to the polishing surface from the pad temperature control system, and the polishing liquid cooled by the polishing liquid temperature control system is supplied to the polishing surface from the polishing liquid supply nozzle.

12. The polishing method according to claim 11, further comprising supplying the cooling fluid and the cooled polishing liquid to the polishing surface during the polishing of the workpiece, and then supplying the heating fluid to the polishing surface from the pad temperature control system, while supplying the polishing liquid heated by the polishing liquid temperature control system to the polishing surface from the polishing liquid supply nozzle.

13. The polishing method according to claim 8, wherein supplying the temperature-controlled polishing liquid from the polishing liquid supply nozzle to the polishing surface means supplying the temperature-controlled polishing liquid to the polishing surface from at least one of the plurality of discharge ports of the polishing liquid supply nozzle.

14. The polishing method according to claim 13, wherein the plurality of discharge ports are arranged radially on the polishing pad.

15. The polishing method according to claim 8, wherein supplying the temperature-controlled polishing liquid from the polishing liquid supply nozzle to the polishing surface is performed by supplying the temperature-controlled polishing liquid from the discharge port to the polishing surface while moving the discharge port of the polishing liquid supply nozzle in the radial direction of the polishing pad.

Images