Polishing method and polishing equipment

Abstract

To provide a technique that enables suppression of increase of surface temperature of a polishing pad during the period of dressing, and consequently enables prevention of excessive dressing by the polishing pad.SOLUTION: In a polishing method, a polishing pad 2 having a polishing surface 2a is rotated and at the same time temperature of the polishing surface 2a is adjusted by pad temperature adjusting device 12; a workpiece W is pressed against the polishing surface 2a by a polishing head 7 to thereby polish the workpiece W; during polishing of the workpiece W, a dresser 50 is moved in a radial direction of the polishing pad 2 by a dresser arm 55 and at the same time the dresser 50 dresses the polishing surface 2a; and during dressing of the polishing surface 2a, cooling fluid is ejected from a first cooling nozzle 61 mounted on the dresser arm 55 to a first target region T1 on the polishing surface 2a to thereby cool the first target region T1.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a technique for polishing a workpiece such as a wafer, substrate, or panel on a polishing surface while controlling the temperature of the polishing surface of the polishing pad. [Background technology]

[0002] CMP (Chemical Mechanical Polishing) equipment is used in the process of polishing the surface of wafers in the manufacture of semiconductor devices. In a CMP equipment, a wafer with a film on it is rotated by a polishing head, which then presses the wafer against a polishing pad on a rotating polishing table, polishing the film that makes up the wafer's surface. During polishing, a polishing liquid is supplied to the polishing pad. The wafer's film 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 (also called removal rate) of a wafer depends not only on the polishing load of the wafer on 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 wafer film depends on temperature. Therefore, in order to achieve an appropriate wafer polishing rate, it is important to optimally control the surface temperature of the polishing pad during wafer polishing. Therefore, a pad temperature control device is used to adjust the surface temperature of the polishing pad (see, for example, Patent Document 1).

[0004] In a CMP apparatus, the polishing surface of a polishing pad is dressed using a dresser to maintain the polishing performance of the polishing pad. Specifically, the dresser brings a dressing surface, on which abrasive grains such as diamond particles are fixed, into sliding contact with the polishing surface of the polishing pad, slightly scraping away the polishing surface of the polishing pad and removing polishing residue, thereby restoring the polishing surface of the polishing pad and maintaining the wafer removal rate. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-155128 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when the surface temperature of the polishing pad is increased by the pad temperature adjustment device, the polishing pad becomes soft, and the dresser scrapes off an excessively large amount of the polishing pad compared to when the surface temperature of the polishing pad is not increased, resulting in a shortened life of the polishing pad.

[0007] Therefore, the present invention provides a technique that can prevent excessive cutting of the polishing pad by the dresser by suppressing an increase in the surface temperature of the polishing pad during dressing. [Means for solving the problem]

[0008] In one aspect, there is provided a polishing method for polishing a workpiece, the method comprising: rotating a polishing pad having a polishing surface; adjusting the temperature of the polishing surface with a pad temperature adjusting device; polishing the workpiece by pressing the workpiece against the polishing surface with a polishing head; dressing the polishing surface with a dresser while moving the dresser in a radial direction of the polishing pad with a dresser arm during polishing of the workpiece; and cooling the first target area on the polishing surface by ejecting a cooling fluid from a first cooling nozzle attached to the dresser arm onto the first target area, the first target area being located upstream of the dresser in the rotation direction of the polishing pad.

[0009] In one aspect, the polishing head presses the workpiece against the polishing surface whose temperature is adjusted by the pad temperature adjustment device, the dresser dresses the polishing surface cooled by the cooling fluid, and the pad temperature adjustment device adjusts the temperature of the dressed polishing surface. In one embodiment, the first cooling nozzle moves integrally with the dresser. In one embodiment, the polishing head, the first target area, and the dresser are arranged in the order of the polishing head, the first target area, and the dresser in the rotation direction of the polishing pad. In one aspect, the polishing method further includes, during dressing of the polishing surface, ejecting a cooling fluid from a second cooling nozzle attached to the dresser arm onto a second target area of ​​the polishing surface, the second target area being located downstream of the dresser in the direction of rotation of the polishing pad. In one aspect, the polishing method further includes, during dressing of the polishing surface, ejecting a cooling fluid from a second cooling nozzle attached to the dresser arm onto a second target area of ​​the polishing surface, the second target area being located between a center of the polishing surface and the first target area.

[0010] In one aspect, a polishing apparatus for polishing a workpiece is provided, comprising: a polishing table that rotates a polishing pad having a polishing surface; a polishing head that presses the workpiece against the polishing surface; a pad temperature adjustment device that adjusts the temperature of the polishing surface; a dresser that dresses the polishing surface; a dresser arm that moves the dresser in a radial direction of the polishing pad; and a first cooling nozzle that ejects a cooling fluid onto a first target area of ​​the polishing surface, wherein the first cooling nozzle is attached to the dresser arm and is positioned upstream of the dresser in the rotation direction of the polishing pad.

[0011] In one embodiment, the pad temperature adjustment device, the polishing head, the first cooling nozzle, and the dresser are arranged in the following order in the rotation direction of the polishing pad: pad temperature adjustment device, polishing head, first cooling nozzle, dresser. In one embodiment, the first cooling nozzle is adjacent to the dresser. In one embodiment, the polishing apparatus further includes a second cooling nozzle that ejects a cooling fluid onto a second target area of ​​the polishing surface, the second cooling nozzle being attached to the dresser arm and positioned downstream of the dresser in the direction of rotation of the polishing pad. In one embodiment, the polishing apparatus further includes a second cooling nozzle that ejects cooling fluid onto a second target area of ​​the polishing surface, the second cooling nozzle being positioned between the first cooling nozzle and the center of the polishing surface. [Effects of the Invention]

[0012] The cooling fluid discharged from the first cooling nozzle can cool the first target area immediately before being dressed by the dresser. This prevents excessive cutting of the polishing pad by the dresser. Because the first cooling nozzle moves in synchronization with the dresser, the first cooling nozzle can discharge the cooling fluid to the first target area upstream of the dresser regardless of the movement of the dresser. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram illustrating an embodiment of a polishing apparatus. [Figure 2] FIG. 2 is a top view schematically showing the polishing apparatus shown in FIG. [Figure 3] FIG. 2 is a side view illustrating one embodiment of a dresser, a dresser arm, and a first cooling nozzle. [Figure 4] FIG. 10 is a top view showing another embodiment of the polishing apparatus. [Figure 5] 5 is a side view showing the dresser, the dresser arm, and the first cooling nozzle shown in FIG. 4. FIG. [Figure 6]FIG. 10 is a top view showing still another embodiment of the polishing apparatus. [Figure 7] FIG. 10 is a top view showing still another embodiment of the polishing apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing one embodiment of a polishing apparatus. The polishing apparatus is an apparatus for chemically and mechanically polishing a wafer W, which is an example of a workpiece used in the manufacture of semiconductor devices. As shown in FIG. 1, this polishing apparatus includes a polishing table 5 that supports a polishing pad 2 having a polishing surface 2a, a polishing head 7 that presses the wafer W against the polishing surface 2a, a polishing liquid supply nozzle 10 that supplies a polishing liquid (e.g., a slurry containing abrasive grains) to the polishing surface 2a, and a pad temperature adjustment device 12 that adjusts the temperature of the polishing surface 2a of the polishing pad 2.

[0015] The polishing head 7 is configured to hold a wafer W on its lower surface. The wafer W has a film to be polished. In the following embodiments, a wafer is used as an example of a workpiece, but the workpiece is not limited to a wafer and may be a circular substrate, rectangular substrate, panel, or the like used in the manufacture of semiconductor devices.

[0016] The polishing apparatus further includes a support shaft 14, a polishing head arm 16 connected to the upper end of the support shaft 14, and a polishing head shaft 18 rotatably supported at the free end of the polishing head arm 16. The polishing head 7 is fixed to the lower end of the polishing head shaft 18. A polishing head rotation mechanism (not shown) equipped with an electric motor and the like is disposed within the polishing head arm 16. This polishing head rotation mechanism is connected to the polishing head shaft 18 and is configured to rotate the polishing head shaft 18 and the polishing head 7 in the direction indicated by the arrow.

[0017] The polishing apparatus further includes a table rotation motor 21 that rotates the polishing pad 2 and polishing table 5 around their respective axes. The table rotation motor 21 is disposed below the polishing table 5, and the polishing table 5 is connected to the table rotation motor 21 via a table shaft 5a. The polishing table 5 and polishing pad 2 are rotated by the table rotation motor 21 around the table shaft 5a in the direction indicated by the arrow. The polishing pad 2 is affixed to the upper surface of the polishing table 5. The exposed surface of the polishing pad 2 forms a polishing surface 2a that polishes the wafer W.

[0018] The polishing liquid supply nozzle 10 is disposed above a position close to the center of the polishing surface 2a of the polishing pad 2. The polishing liquid supply nozzle 10 supplies the polishing liquid near the center of the polishing surface 2a. The polishing liquid spreads over the polishing surface 2a due to centrifugal force generated by the rotation of the polishing pad 2.

[0019] The wafer W is polished as follows. The wafer W is held by the polishing head 7 with its surface to be polished facing downward. While the polishing head 7 and polishing table 5 are rotating, a polishing liquid (e.g., a slurry containing abrasive grains) is supplied onto the polishing surface 2a of the polishing pad 2 from a polishing liquid supply nozzle 10 provided above the polishing table 5. The polishing pad 2 rotates integrally with the polishing table 5 around its central axis. The polishing head 7 is moved to a predetermined height by a polishing head lifting mechanism (not shown). The polishing head 7 is then maintained at the predetermined height and presses the wafer W against the polishing surface 2a of the polishing pad 2. The wafer W rotates integrally with the polishing head 7. With the polishing liquid present on the polishing surface 2a of the polishing pad 2, the wafer W is brought into sliding contact with the polishing surface 2a. The surface of the wafer W is polished by a combination of 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 2.

[0020] The polishing apparatus includes an operation control unit 15 that controls the operation of the entire polishing apparatus, including the polishing head 7, the pad temperature adjustment unit 12, and the table rotation motor 21. The operation control unit 15 includes a storage device 15a that stores a program, and an arithmetic unit 15b that executes calculations according to instructions included in the program. The operation control unit 15 is composed of at least one computer. The storage device 15a includes a main storage device such as a random access memory (RAM) and an auxiliary storage device such as a hard disk drive (HDD) or a solid state drive (SSD). Examples of the arithmetic unit 15b include a CPU (central processing unit) and a GPU (graphics processing unit). However, the specific configuration of the operation control unit 15 is not limited to these examples.

[0021] The pad temperature adjustment device 12 includes a pad heater 24 that heats the polishing surface 2a of the polishing pad 2, and a pad cooler 25 that cools the polishing surface 2a of the polishing pad 2. The pad heater 24 and the pad cooler 25 are located above the polishing table 2 and the polishing pad 2, and are arranged facing the polishing surface 2a of the polishing pad 2. The pad heater 24 and the pad cooler 25 are not in contact with the polishing surface 2a of the polishing pad 2. The polishing apparatus further includes a heating fluid supply line 27 that supplies heating fluid to the pad heater 24, a heating flow rate control valve 31 that controls the flow rate of the heating fluid flowing through the heating fluid supply line 27, a cooling fluid supply line 28 that supplies cooling fluid to the pad cooler 25, and a cooling flow rate control valve 32 that controls the flow rate of the cooling fluid flowing through the cooling fluid supply line 28.

[0022] The heating flow rate control valve 31 and the cooling flow rate control valve 32 are electrically connected to the operation control unit 15, and the operation of the heating flow rate control valve 31 and the cooling flow rate control valve 32 (i.e., the flow rate of the heating fluid flowing through the heating fluid supply line 27 and the flow rate of the cooling fluid flowing through the cooling fluid supply line 28) is controlled by the operation control unit 15.

[0023] The heating fluid is discharged from the discharge port 24a of the pad heater 24 onto the polishing surface 2a of the polishing pad 2, thereby increasing the temperature of the polishing surface 2a of the polishing pad 2. The cooling fluid is discharged from the discharge port (not shown) of the pad cooler 25 onto the polishing surface 2a of the polishing pad 2, thereby decreasing the temperature of the polishing surface 2a of the polishing pad 2. The operation control unit 15 adjusts the flow rates of the heating fluid and the cooling fluid supplied from the pad heater 24 and the pad cooler 25 to the polishing surface 2a of the polishing pad 2 by operating the heating flow rate control valve 31 and the cooling flow rate control valve 32, thereby controlling the temperature of the polishing surface 2a of the polishing pad 2.

[0024] The polishing apparatus further includes a pad temperature measuring device 35 that measures the temperature of the polishing surface 2a of the polishing pad 2. The pad temperature measuring device 35 measures the temperature of the polishing surface 2a of the polishing pad 2 in a non-contact manner and sends the measured value to the operation control unit 15. Examples of the pad temperature measuring device 35 include an infrared radiation thermometer and a thermocouple thermometer. The operation control unit 15 operates the heating flow rate control valve 31 and the cooling flow rate control valve 32 based on the measured temperature value so that the temperature of the polishing surface 2a of the polishing pad 2 reaches a preset target temperature.

[0025] In one embodiment, the heating fluid is steam. Examples of steam include water vapor produced by evaporating water and superheated steam produced by further heating saturated steam. In other embodiments, the heating fluid may be a hot gas (e.g., hot air, nitrogen gas, or argon gas).

[0026] In one embodiment, the cooling fluid is a gas at room temperature (e.g., air or an inert gas such as nitrogen gas or argon gas). 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 may be a gas at a temperature lower than the target temperature of the polishing surface 2a of the polishing pad 2.

[0027] 1 is configured to bring the heating fluid and the cooling fluid into direct contact with the polishing surface 2a of the polishing pad 2, but the configuration of the pad temperature adjustment device 12 is not limited to the above embodiment as long as it is possible to adjust the temperature of the polishing surface 2a of the polishing pad 2. For example, the pad temperature adjustment device 12 may be configured to flow the heating fluid and the cooling fluid through a heat exchanger disposed opposite the polishing surface 2a of the polishing pad 2, to perform heat exchange between the heating fluid and the polishing pad 2 via the bottom of the heat exchanger, and to perform heat exchange between the cooling fluid and the polishing pad 2 via the bottom of the heat exchanger.

[0028] The polishing apparatus includes a dresser 50 that dresses the polishing surface 2a of the polishing pad 2, a dresser shaft 52 to which the dresser 50 is connected, a dresser arm 55 that rotatably supports the dresser shaft 52, and a support shaft 58 connected to the dresser arm 55. The lower surface of the dresser 50 forms a dressing surface 50a, and this dressing surface 50a is made of abrasive grains (e.g., diamond particles).

[0029] The dresser shaft 52 is connected to a disk pressing mechanism (including, for example, an air cylinder) (not shown) disposed within the dresser arm 55. This disk pressing mechanism is configured to press the dressing surface 50a of the dresser 50 against the polishing surface 2a of the polishing pad 2 via the dresser shaft 52. Furthermore, the dresser shaft 52 is connected to a dresser rotation mechanism (including, for example, an electric motor) (not shown) disposed within the dresser arm 55. This dresser rotation mechanism is configured to rotate the dresser 50 via the dresser shaft 52 in the direction indicated by the arrow.

[0030] Dressing of the polishing surface 2a of the polishing pad 2 is performed as follows. The polishing pad 2 is rotated together with the polishing table 5 by the table rotation motor 21. While the dresser 50 is rotated around the dresser shaft 52 by a dresser rotation mechanism (not shown), the dressing surface 50a of the dresser 50 is pressed against the polishing surface 2a by a disk pressing mechanism (not shown) and brought into sliding contact with the polishing surface 2a. While the dresser 50 is rotating, the dresser arm 55 is rotated around the support shaft 58 to move the dresser 50 in the radial direction of the polishing surface 2a. The polishing pad 2 is slightly scraped away by the dresser 50, thereby dressing (regenerating) the polishing surface 2a. Dressing of the polishing surface 2a of the polishing pad 2 is performed while the wafer W is being polished.

[0031] The polishing apparatus further includes a first cooling nozzle 61 that cools a region of the polishing surface 2a located upstream of the dresser 50 in the rotation direction of the polishing pad 2. More specifically, the first cooling nozzle 61 is configured to cool a first target region T1 on the polishing surface 2a by ejecting a cooling fluid onto the first target region T1. The first cooling nozzle 61 is connected to a cooling fluid supply line 62. The cooling fluid is supplied to the first cooling nozzle 61 through the cooling fluid supply line 62.

[0032] Examples of the cooling fluid used include a cooling gas (e.g., compressed air or an inert gas). The first cooling nozzle 61 supplies the cooling fluid to the polishing surface 2a of the polishing pad 2 during polishing of the wafer W. Therefore, the cooling fluid in this embodiment is a cooling gas so that the polishing liquid (e.g., slurry) used in polishing the wafer W is not diluted by the cooling fluid. In one embodiment, a liquid containing components of the polishing liquid may be used as the cooling fluid.

[0033] The first cooling nozzle 61 is attached to the dresser arm 55. Therefore, the first cooling nozzle 61 moves together with the dresser 50 in the radial direction of the polishing pad 2. In the embodiment shown in FIG. 1 , the first cooling nozzle 61 is fixed to the lower surface of the dresser arm 55. The first cooling nozzle 61 is located upstream of the dresser 50 in the rotational direction of the polishing pad 2. Therefore, while moving together with the dresser 50 in the radial direction of the polishing pad 2, the first cooling nozzle 61 can eject a cooling fluid onto a first target area T1 on the polishing surface 2a located upstream of the dresser 50 to cool the first target area T1. The first target area T1 moves in accordance with the movement of the first cooling nozzle 61, but is always located upstream of the dresser 50.

[0034] FIG. 2 is a top view schematically showing the polishing apparatus shown in FIG. 1. FIG. 3 is a side view showing one embodiment of the dresser 50, the dresser arm 55, and the first cooling nozzle 61. The polishing liquid supply nozzle 10 is located near the center O of the polishing surface 2a of the polishing pad 2. The first cooling nozzle 61 is adjacent to the dresser 50. In this embodiment, two first cooling nozzles 61 are provided, but the number of first cooling nozzles 61 is not limited to this embodiment. For example, a single first cooling nozzle 61 may be provided, or three or more first cooling nozzles 61 may be provided.

[0035] In this embodiment, the pad temperature adjustment device 12, the polishing head 7, the first cooling nozzle 61, and the dresser 50 are arranged in the following order in the rotation direction of the polishing pad 2. The polishing head 7, the first target area T1, and the dresser 50 are arranged in the following order in the rotation direction of the polishing pad 2.

[0036] With this arrangement, the polishing head 7 presses the wafer W against the polishing surface 2a whose temperature is adjusted by the pad temperature adjustment device 12, the dresser 50 dresses the polishing surface 2a cooled by the cooling fluid, and the pad temperature adjustment device 12 adjusts the temperature of the dressed polishing surface 2a.

[0037] The cooling fluid discharged from the first cooling nozzle 61 can cool the first target area T1 immediately before it is dressed by the dresser 50. This prevents the dresser 50 from cutting the polishing pad 2 excessively. Because the first cooling nozzle 61 moves in synchronization with the dresser 50, the first cooling nozzle 61 can discharge the cooling fluid onto the first target area T1 upstream of the dresser 50 regardless of the movement of the dresser 50.

[0038] 3, the first cooling nozzle 61 is inclined obliquely with respect to the polishing surface 2a and faces radially outward from the dresser 50. In other embodiments, the first cooling nozzle 61 may be perpendicular to the polishing surface 2a and disposed upstream of the dresser 50 in the rotation direction of the polishing pad 2. Even in this case, the first cooling nozzle 61 can cool the first target region T1 located upstream of the dresser 50.

[0039] Fig. 4 is a top view showing another embodiment of the polishing apparatus, and Fig. 5 is a side view showing the dresser 50, the dresser arm 55, and the first cooling nozzle 61 shown in Fig. 4. The configuration and operation of this embodiment, which will not be particularly described, are the same as those of the embodiment described with reference to Figs. 1 to 3, and therefore, redundant description will be omitted.

[0040] In addition to the first cooling nozzle 61, the polishing apparatus of this embodiment further includes a second cooling nozzle 65 that sprays a cooling fluid onto a second target region T2 on the polishing surface 2a. The second cooling nozzle 65 is connected to the cooling fluid supply line 62 shown in FIG. 1. The second cooling nozzle 65 is attached to the dresser arm 55 and moves integrally with the dresser 50. The second cooling nozzle 65 is disposed downstream of the dresser 50 in the rotation direction of the polishing pad 2.

[0041] In this embodiment, two second cooling nozzles 65 are provided, but the number of second cooling nozzles 65 is not limited to this embodiment. For example, a single second cooling nozzle 65 may be provided, or three or more second cooling nozzles 65 may be provided.

[0042] The second target area T2 is located downstream of the dresser 50 and the first target area T1 in the rotation direction of the polishing pad 2, and is disposed upstream of the pad temperature adjustment device 12. The first cooling nozzle 61 and the second cooling nozzle 65 move together with the dresser 50 in the radial direction of the polishing pad 2, and eject cooling fluid onto the first target area T1 and the second target area T2 during dressing of the polishing surface 2a. The second target area T2 moves in conjunction with the movement of the second cooling nozzle 65, but is always located downstream of the dresser 50.

[0043] Frictional heat is generated during dressing of the polishing pad 2, causing the temperature of the dressed polishing surface 2a to rise. Such a local rise in the temperature of the polishing surface 2a can affect the temperature adjustment of the polishing surface 2a by the pad temperature adjustment device 12 located downstream of the dresser 50. Therefore, in this embodiment, the second cooling nozzle 65 can cool the polishing surface 2a immediately after it has been dressed by the dresser 50. As a result, the pad temperature adjustment device 12 can more easily adjust the polishing surface 2a of the polishing pad 2 to a desired temperature.

[0044] 6 is a top view showing another embodiment of the polishing apparatus. The configuration and operation of this embodiment, which are not particularly described, are the same as those of the embodiment described with reference to FIGS. 4 and 5, and therefore, redundant description will be omitted.

[0045] The polishing apparatus of this embodiment is the same as the embodiment described with reference to Figures 4 and 5 in that, in addition to the first cooling nozzle 61, it is equipped with a second cooling nozzle 65 that ejects cooling fluid onto a second target area T2 of the polishing surface 2a. However, it differs in that the second cooling nozzle 65 is positioned between the first cooling nozzle 61 and the center O of the polishing surface 2a of the polishing pad 2.

[0046] The second cooling nozzle 65 is attached to the dresser arm 55 and moves integrally with the dresser 50. The second cooling nozzle 65 faces inward in the radial direction of the polishing pad 2. The second target area T2 is located between the center O of the polishing surface 2a of the polishing pad 2 and the first target area T1. Furthermore, the second target area T2 is located between the center O of the polishing surface 2a of the polishing pad 2 and the dresser 50.

[0047] During polishing of the wafer W, a polishing liquid is supplied onto the polishing surface 2a from a polishing liquid supply nozzle 10 disposed near the center O of the polishing surface 2a. The polishing liquid spreads over the polishing surface 2a due to centrifugal force generated by the rotation of the polishing pad 2. A cooling fluid discharged from a second cooling nozzle 65 cools the polishing liquid flowing toward the outer periphery of the polishing surface 2a. Furthermore, the cooled polishing liquid cools the polishing surface 2a being dressed as it flows under the dresser 50.

[0048] According to this embodiment, the cooling fluid discharged from the first cooling nozzle 61 cools the first target area T1 immediately before being dressed by the dresser 50, and the cooling fluid discharged from the second cooling nozzle 65 cools the polishing surface 2a of the polishing pad 2 being dressed. Therefore, excessive cutting of the polishing pad 2 by the dresser 50 can be prevented.

[0049] 7 is a top view showing another embodiment of the polishing apparatus. The configuration and operation of this embodiment, which will not be specifically described, are the same as those of the embodiment described with reference to FIG. 6, and therefore, redundant description will be omitted.

[0050] The polishing apparatus of this embodiment is the same in that the second cooling nozzle 65 is positioned between the first cooling nozzle 61 and the center O of the polishing surface 2a of the polishing pad 2, but differs in that the second cooling nozzle 65 faces the center O of the polishing surface 2a.

[0051] According to this embodiment, the cooling fluid discharged from the first cooling nozzle 61 cools the first target region T1 on the polishing surface 2a of the polishing pad 2 immediately before being dressed by the dresser 50, and the cooling fluid discharged from the second cooling nozzle 65 can cool the polishing surface 2a of the polishing pad 2 being dressed. Therefore, excessive cutting of the polishing pad 2 by the dresser 50 can be prevented.

[0052] The above-described embodiments have been described for the purpose of enabling a person of ordinary skill in the art to practice the present invention. Various modifications of the above-described embodiments would be obvious to a person skilled in the art, and the technical concept of the present invention may be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but is to be interpreted in the broadest scope in accordance with the technical concept defined by the claims. [Explanation of symbols]

[0053] 2 polishing pads 2a Polished surface 5 Polishing table 5a Table axis 7 Polishing Head 10 Polishing liquid supply nozzle 12 Pad temperature control device 14 Spindle 15 Operation control section 16 Polishing head swing arm 18 Polished head shaft 21 Table rotation motor 24 Pad Heater 25 Pad Cooler 27 Heated fluid supply line 28 Cooling fluid supply line 31 Heating flow control valve 32 Cooling flow control valve 35 Pad Temperature Meter 50 Dresser 50a Dressing surface 52 Dresser shaft 55 Dresser arm 58 Spindle 61 First cooling nozzle 62 Cooling fluid supply line 65 Second cooling nozzle T1 First target area T2 Second target area W wafer

Claims

1. 1. A polishing method for polishing a workpiece, comprising: While rotating a polishing pad having a polishing surface, a temperature of the polishing surface is adjusted by a pad temperature adjustment device; polishing the workpiece by pressing the workpiece against the polishing surface with a polishing head; dressing the polishing surface with the dresser while moving the dresser in a radial direction of the polishing pad by a dresser arm during polishing of the workpiece; a dresser arm attached to the polishing pad, the dresser arm discharging a cooling fluid from the cooling nozzle onto a first target area of ​​the polishing surface during dressing of the polishing surface, the first target area being located upstream of the dresser arm in the rotation direction of the polishing pad.

2. The polishing head presses the workpiece against the polishing surface whose temperature is controlled by the pad temperature control device; the dresser dresses the polishing surface cooled by the cooling fluid; The polishing method according to claim 1 , wherein the pad temperature adjusting device adjusts the temperature of the dressed polishing surface.

3. The polishing method according to claim 1 , wherein the first cooling nozzle moves integrally with the dresser.

4. 2. The polishing method according to claim 1, wherein the polishing head, the first target area, and the dresser are arranged in the following order in the rotation direction of the polishing pad: polishing head, first target area, dresser.

5. 2. The polishing method according to claim 1, further comprising: ejecting a cooling fluid from a second cooling nozzle attached to the dresser arm onto a second target area of ​​the polishing surface during dressing of the polishing surface, the second target area being located downstream of the dresser in a rotational direction of the polishing pad.

6. 2. The polishing method according to claim 1, further comprising: ejecting a cooling fluid from a second cooling nozzle attached to the dresser arm onto a second target area of ​​the polishing surface during dressing of the polishing surface, the second target area being located between a center of the polishing surface and the first target area.

7. A polishing apparatus for polishing a workpiece, comprising: a polishing table that rotates a polishing pad having a polishing surface; a polishing head for pressing the workpiece against the polishing surface; a pad temperature adjusting device for adjusting the temperature of the polishing surface; a dresser for dressing the polishing surface; a dresser arm that moves the dresser in a radial direction of the polishing pad; a first cooling nozzle for ejecting a cooling fluid onto a first target area of ​​the polishing surface; The polishing apparatus, wherein the first cooling nozzle is attached to the dresser arm and is disposed upstream of the dresser in the rotation direction of the polishing pad.

8. 8. The polishing apparatus according to claim 7, wherein the pad temperature adjustment device, the polishing head, the first cooling nozzle, and the dresser are arranged in the following order in a rotation direction of the polishing pad: pad temperature adjustment device, polishing head, first cooling nozzle, and dresser.

9. 8. The polishing apparatus according to claim 7, wherein the first cooling nozzle is adjacent to the dresser.

10. the polishing apparatus further comprising a second cooling nozzle that discharges cooling fluid onto a second target area of ​​the polishing surface; 8. The polishing apparatus according to claim 7, wherein the second cooling nozzle is attached to the dresser arm and is disposed downstream of the dresser in the rotation direction of the polishing pad.

11. the polishing apparatus further comprising a second cooling nozzle that discharges cooling fluid onto a second target area of ​​the polishing surface; 8. The polishing apparatus according to claim 7, wherein the second cooling nozzle is located between the first cooling nozzle and the center of the polishing surface.

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