CMP device and control method for CMP device

Abstract

Provided are a CMP device which has a function for recycling a slurry after temperature adjustment, and a control method for the CMP device. This CMP device comprises a polishing unit 10, a slurry supply unit 50, and a control unit 120. The polishing unit 10 includes: a platen 11 that has a polishing pad; a polishing head that polishes a wafer by rotating in a state in which the wafer is pressed against the polishing pad; and a supply unit 16 that supplies a slurry S onto the platen 11. The slurry supply part 50 has a tank 51 that stores the slurry S, and is configured to be capable of supplying the slurry S to the supply part 16 after adjusting the temperature of the slurry S which has been collected into the tank 51. The control unit 120 adjusts the temperature of the slurry S in the tank 51 in accordance with a polishing state of the wafer.

Description

CMP Apparatus and Control Method for CMP Apparatus

[0001] The present disclosure relates to a CMP apparatus for polishing a workpiece such as a wafer and a control method for a CMP apparatus.

[0002] There are CMP apparatuses that polish workpieces such as wafers by chemical mechanical polishing (CMP). A CMP apparatus includes a platen having a polishing pad, and a polishing head that holds a wafer and presses the wafer against the polishing pad. Patent Document 1 describes that a CMP apparatus polishes a wafer by supplying a slurry, which is a mixture of an abrasive and various chemicals, onto the polishing pad and rotating the platen and the polishing head. In addition, Patent Document 2 describes separating impurities from post-polishing slurry and recovering the slurry.

[0003] Japanese Patent Application Laid-Open No. 2011-11307, Japanese Patent Application Laid-Open No. 2004-63858

[0004] Incidentally, in Patent Document 1, the temperature of the slurry during polishing is not adjusted. Therefore, depending on the polishing conditions, the slurry temperature may deviate from the steady temperature, which may lead to deterioration in the quality of the slurry. Furthermore, when slurry having a temperature different from the steady temperature is recovered into a recycling apparatus, there is a possibility that the recycling apparatus cannot adjust the temperature to a desired temperature.

[0005] A CMP apparatus that solves the above problems includes a polishing section, a slurry supply section, and a control section configured to be able to control the polishing section and the slurry supply section. The polishing section includes a platen having a polishing pad, a polishing head that polishes the workpiece by rotating while pressing the workpiece against the polishing pad, and a supply section that supplies slurry onto the platen. The slurry supply section has a tank for recovering the slurry supplied onto the platen, and is configured to be able to condition the slurry recovered in the tank and supply the conditioned slurry to the supply section.

[0006] In a control method for a CMP apparatus that solves the above problems, the CMP apparatus comprises a polishing unit having a platen having a polishing pad, a polishing head that polishes a workpiece by rotating while pressing the workpiece against the polishing pad, and a supply unit that supplies slurry onto the platen, a slurry supply unit having a tank for collecting the slurry supplied onto the platen, and capable of adjusting the temperature of the slurry collected in the tank and supplying it to the supply unit, and a control unit configured to control the polishing unit and the slurry supply unit. The control unit adjusts the temperature of the slurry in the tank according to the polishing status of the workpiece.

[0007] According to this disclosure, it is possible to provide a CMP apparatus that has the function of recycling slurry after temperature control.

[0008] Figure 1 is a perspective view showing the schematic configuration of the polishing section in one embodiment of a CMP device. Figure 2 is a cross-sectional view showing the schematic configuration of the polishing head. Figure 3 is a schematic diagram showing the schematic configuration of the slurry supply section. Figure 4 is a perspective view showing the schematic structure of the tank body. Figure 5 is a side view showing the tank body along with the cross-sectional structure near the exposed part. Figure 6 is a diagram showing the schematic configuration of the connection part of the recovery piping to the tank. Figure 7 is a schematic diagram showing an example of the positional relationship between the polishing section and the tank. Figure 8 is a schematic diagram showing another example of the positional relationship between the polishing section and the tank. Figure 9 is a block diagram showing an example of the hardware configuration of the control unit. Figure 10 is a functional block diagram of the CMP device. Figure 11 is a schematic diagram showing the slurry supply section in a state where cleaning liquid is being supplied to the platen. Figure 12 is a schematic diagram showing the slurry supply section in a state where cleaning liquid is being supplied to the tank. Figure 13 is a schematic diagram showing the slurry supply section in a state where the cleaning liquid is being purged by air. Figure 14 is a schematic diagram showing the cross-sectional structure of a modified polishing head. Figure 15 is a schematic top view showing the pressing member in the modified example.

[0009] An embodiment of a CMP (Chemical Mechanical Polishing) apparatus and a control method for the CMP apparatus will be described with reference to Figures 1 to 13. As shown in Figure 1, the CMP apparatus 1 includes a polishing unit 10. The polishing unit 10 includes a platen 11, a supply unit 16, a recovery pan 76 (see Figure 3), and a polishing head 20. The platen 11 has a disc shape. The platen 11 is driven by a platen drive unit 130 (see Figure 10). The platen 11 is connected to a rotating shaft 12. The platen 11 rotates in the direction of arrow 13 in Figure 1 as the rotating shaft 12 rotates. A polishing pad 14 is attached to the upper surface of the platen 11. The polishing pad 14 is configured to be replaceable. The polishing pad 14 is, for example, a foamed polyurethane pad in which a nonwoven fabric pad is laminated on a cushion layer. Slurry S is supplied onto the polishing pad 14 from the supply unit 16. Slurry S is a mixture of several slurry formulations containing abrasives and chemicals according to the material of the wafer 15 (see Figure 2), which is the workpiece to be polished. Slurry S may be a slurry used when polishing difficult-to-machine materials such as SiC wafers. Alternatively, Slurry S may be a slurry used when polishing ordinary wafers such as Si. Slurries for difficult-to-machine materials, such as SiC wafers, often contain manganese, and are characterized by being more prone to temperature rise due to grinding heat during polishing than ordinary wafer slurries, and more prone to temperature drop due to heat dissipation during transport through the piping after grinding. Furthermore, slurries for difficult-to-machine materials solidify more easily than ordinary wafer slurries and require constant stirring. In addition, slurries for difficult-to-machine materials have a strong oxidation-reduction effect, which can cause erosion of the transport piping. Therefore, it is preferable to minimize the time and distance over which Slurry S is transferred. The recovery pan 76 is provided to recover the slurry and liquid supplied onto the platen 11, allowing for prompt collection into the tank. For example, the recovery pan 76 is a recovery container located between the tank and the platen, that is, below the platen 11.

[0010] The polishing head 20 is formed in a disc shape with a smaller diameter than the platen 11. The polishing head 20 is driven by a head drive unit 131 (see Figure 10). The polishing head 20 is connected to a rotating shaft 21 located above it. As the rotating shaft 21 rotates, the polishing head 20 rotates in the direction of arrow 22 about the rotational axis 20A. The polishing head 20 is configured to be able to move up and down in the height direction Z by a lifting device (not shown). The polishing head 20 is configured to be able to hold a wafer 15 (see Figure 2).

[0011] The CMP apparatus 1 supplies slurry S to the polishing pad 14 to form a slurry layer on the surface of the polishing pad 14, and rotates the platen 11 and the polishing head 20. The CMP apparatus 1 then polishes the wafer 15 by pressing the wafer 15 held by the polishing head 20 against the polishing pad 14.

[0012] <Polishing Head> Referring to Figure 2, an example of the configuration of the polishing head 20 will be described. Note that the polishing head 20 does not need to be limited to the configuration described below, as it does not need to use a polishing pad 14 to which slurry S is supplied to polish the wafer 15.

[0013] As shown in Figure 2, the polishing head 20 comprises a head body 25 and a membrane film 45. The head body 25 includes a shaft connecting member 26, a carrier 27, a carrier pressing portion 33, a retainer pressing member 35, a retainer holder 36, a snap ring 38, a retainer ring 40, and a retainer pressing portion 41.

[0014] The shaft connecting member 26 is connected to the rotating shaft 21. The shaft connecting member 26 is configured to rotate together with the rotating shaft 21. The shaft connecting member 26 is connected to a carrier 27 located below the shaft connecting member 26 via a connecting portion 28. The carrier 27 is configured to rotate together with the shaft connecting member 26.

[0015] A carrier recess 30 is formed in the lower part of the carrier 27, with the rim 29 as its peripheral wall. The carrier 27 has a plurality of first air passages 31 that open into the carrier recess 30. The first air passages 31 open to the peripheral edge of the carrier recess 30. More specifically, one end of the first air passages 31 opens into the carrier recess 30 at equal intervals in the circumferential direction around the rotation axis 21 of the carrier 27. The other end of the first air passages 31 is connected to an air supply source 32.

[0016] The carrier pressing section 33 is provided between the axial connecting member 26 and the carrier 27. The carrier pressing section 33 is an airbag or the like that inflates when air is supplied from the air supply source 43. The carrier pressing section 33 presses the carrier 27 according to the pressure of the supplied air, thereby pressing the wafer 15 housed in the storage pocket 49 against the polishing pad 14.

[0017] The retainer pressing member 35 and the retainer holder 36 are provided to surround the carrier 27. The retainer pressing member 35 is provided to surround the portion of the carrier 27 above the rim 29. The retainer holder 36 is provided to abut the bottom surface of the retainer pressing member 35 and surround the rim 29 of the carrier 27. The carrier 27 is surrounded by the retainer pressing member 35 and the retainer holder 36, forming a second air passage 37 in the polishing head 20. The second air passage 37 connects the space formed by the carrier recess 30 with the external space of the polishing head 20.

[0018] The retainer pressing member 35 and the retainer holder 36 may be detachably connected by a snap ring 38. The snap ring 38 connects the retainer pressing member 35 and the retainer holder 36 by fitting into fitting recesses formed on the outer circumference of each of the retainer pressing member 35 and the retainer holder 36. After the connection of the retainer pressing member 35 and the retainer holder 36, the snap ring 38 is protected by being covered by a ring cover 39. The head body 25 does not necessarily have to be equipped with a snap ring 38 and a ring cover 39. The retainer pressing member 35 may be connected to the retainer holder 36, or the retainer pressing member 35 and the retainer holder 36 may be integrated.

[0019] A retainer ring 40 is fastened to the retainer holder 36 by fastening members (not shown). The retainer ring 40 is formed in an annular shape. The retainer ring 40 has an inner surface that is in approximately the same position as the inner surface of the retainer holder 36. The retainer holder 36 and the retainer ring 40 sandwich the peripheral edge of the membrane film 45. The retainer ring 40 forms a storage pocket 49 in which a wafer 15 to be polished can be accommodated.

[0020] The retainer pressing portion 41 is located between the shaft connecting member 26 and the carrier 27, and is positioned outside the carrier pressing portion 33. The retainer pressing portion 41 is an airbag or the like that inflates when air is supplied from the air supply source 48. The retainer pressing portion 41 presses the retainer ring 40 against the polishing pad 14 via the retainer pressing member 35 and the retainer holder 36, in accordance with the pressure of the supplied air.

[0021] The membrane film 45 is formed, for example, in the shape of a disc. The membrane film 45 is provided so that its peripheral edge is sandwiched between the retainer holder 36 and the retainer ring 40. The membrane film 45 is provided so as to cover the carrier recess 30 from below. The membrane film 45 may have adsorption holes that communicate with the air chamber 46 and the storage pocket 49. The membrane film 45 is formed of an elastic material. The membrane film 45 is made of, for example, polyethylene terephthalate (PET) resin, fluororesin, or polyphenylene sulfide (PPS) resin. The space surrounded by the carrier recess 30 and the membrane film 45 is the air chamber 46. In other words, the air chamber 46 is the space between the carrier recess 30 and the membrane film 45 in the height direction Z.

[0022] When polishing the wafer 15, the air chamber 46 is controlled to a positive pressure by the supply of pressurized air from the air supply source 32. At this time, excess air in the air chamber 46 is discharged to the outside space through the second air passage 37, and the pressure in the storage pocket 49 is maintained at a pressure lower than the pressure in the air chamber 46, for example, atmospheric pressure. When the pressure in the storage pocket 49 is normal, the membrane film 45 flexes into the storage pocket 49, thereby properly pressing the wafer 15 against the polishing pad 14.

[0023] <Slurry Supply Unit> Referring to Figures 3 to 8, the slurry supply unit 50 that supplies slurry S to the supply unit 16 will be described.

[0024] As shown in Figure 3, the slurry supply unit 50 has a tank 51 for storing slurry S. The tank 51 is installed below the platen 11. The slurry supply unit 50 is configured to supply slurry S from the tank 51 to the platen 11 through the supply unit 16. The slurry supply unit 50 is configured to recycle the slurry S supplied to the platen 11. The slurry supply unit 50 is configured to replenish slurry S in the tank 51. The slurry supply unit 50 is configured to discharge the slurry S from the tank 51 to a waste tank (not shown).

[0025] The slurry supply unit 50 has a circulation circuit 52, a supply circuit 53, a recycling circuit 54, a replenishment circuit 55, and a discharge circuit 56. The slurry supply unit 50 has various valves in each of the circuits 52 to 56. The operation of the various valves is controlled by a control unit 120 that comprehensively controls the CMP device 1. The slurry supply unit 50 has functions corresponding to the operation of the various valves provided in each of the circuits 52 to 56. The following describes the configuration of the slurry supply unit 50 and some of its functions. The functions of the slurry supply unit 50 are not limited to those described below, as they are realized by the operation of the various valves.

[0026] <Circulation Circuit> The circulation circuit 52 is a circuit that circulates the slurry S stored in the tank 51. The circulation circuit 52 has circulation piping 61. In Figure 3, the circulation piping 61 is the part shown by the thick line. The circulation piping 61 has an upstream end connected to the bottom wall of the tank 51 and a downstream end connected to the lid of the tank 51. A pump 62 is provided in the circulation piping 61. The pump 62 is configured to pressurize the slurry S in the circulation piping 61 toward the downstream side.

[0027] A flow control valve 63 is provided in the circulation piping 61 on the upstream side of the pump 62. When the flow control valve 63 is open, it allows the flow of slurry S from the tank 51 to the pump 62. When the flow control valve 63 is closed, it prohibits the flow of slurry S from the tank 51 to the pump 62 and prevents backflow from the circulation piping 61 to the tank 51.

[0028] A circulation control valve 64 is provided in the circulation piping 61. When the circulation control valve 64 is open, it allows the return of slurry S from the circulation piping 61 to the tank 51. The circulation control valve 64 may be configured to allow adjustment of the return flow rate of slurry S from the circulation piping 61 to the tank 51.

[0029] Thus, the circulation circuit 52 is configured so that the slurry S circulates around the tank 51. This makes it less likely for the slurry S to stagnate in the tank 51, thereby suppressing the separation of solid and liquid components of the slurry S and the precipitation of solid components within the tank 51.

[0030] The circulation circuit 52 has an air pipe 67. The air pipe 67 is connected to the circulation pipe 61 between the flow control valve 63 and the pump 62. The air pipe 67 is configured to supply a predetermined flow rate of CDA (Clean Dry Air) to the circulation pipe 61. An air supply valve 68 is provided in the air pipe 67. When the air supply valve 68 is closed, it shuts off the supply of CDA to the circulation pipe 61. The air supply valve 68 is controlled to be open when the flow control valve 63 is closed, thereby supplying CDA to the circulation pipe 61.

[0031] The circulation circuit 52 has a first cleaning pipe 70. The first cleaning pipe 70 is connected to the circulation pipe 61 between the flow control valve 63 and the pump 62. The first cleaning pipe 70 is connected to the circulation pipe 61 downstream of the air pipe 67. The first cleaning pipe 70 is configured to supply a predetermined flow rate of cleaning fluid to the circulation pipe 61. The cleaning fluid is, for example, DIW (De-Ionized Water). The first cleaning pipe 70 is provided with a first cleaning valve 71. When the first cleaning valve 71 is closed, it blocks the supply of cleaning fluid to the circulation pipe 61. The first cleaning valve 71 is controlled to be open when the flow control valve 63 is closed, thereby supplying cleaning fluid to the circulation pipe 61.

[0032] <Supply Circuit> The supply circuit 53 is configured to supply slurry S flowing through the circulation pipe 61 to the supply unit 16. The supply circuit 53 has a supply pipe 65. The supply pipe 65 is connected between the pump 62 and the circulation control valve 64 in the circulation pipe 61.

[0033] A flow controller 66 is provided in the supply piping 65. The flow controller 66 is configured to be controllable between a supply state and a shut-off state. In the supply state, the flow controller 66 supplies a portion of the slurry S flowing through the circulation piping 61 to the supply unit 16. The flow controller 66 is configured to supply a preset target amount of slurry S to the supply unit 16. In the shut-off state, the flow controller 66 shuts off the circulation piping 61 and the supply piping 65.

[0034] The supply circuit 53 has a second cleaning pipe 72. The second cleaning pipe 72 is connected to the supply pipe 65 downstream of the flow controller 66. The second cleaning pipe 72 is configured to supply a predetermined flow rate of cleaning fluid to the supply pipe 65. The second cleaning pipe 72 is provided with a second cleaning valve 73. When the second cleaning valve 73 is closed, it shuts off the supply of cleaning fluid to the supply pipe 65. When the second cleaning valve 73 is open, it supplies cleaning fluid to the supply pipe 65.

[0035] <Recycling Circuit> The recycling circuit 54 is a circuit related to the post-treatment of liquids supplied to the platen 11, such as recycling the slurry S supplied to the platen 11 and disposing of the cleaning solution. The recycling circuit 54 includes a recovery pan 76, a common pipe 77, a switching valve 78, a recovery pipe 79, and a waste pipe 80. The recovery pan 76 constitutes a recovery port for recovering slurry S and other liquids that have flowed out of the platen 11. The outlet of the recovery pan 76 connected to the inlet of the common pipe 77 may constitute the recovery port, or the inlet of the common pipe 77 into which the slurry and other liquids recovered in the recovery pan 76 flow may constitute the recovery port. Furthermore, the recycling circuit 54 does not necessarily have to include a recovery pan 76.

[0036] Common piping 77 is connected to a recovery pan 76 and a switching valve 78. A filter (not shown) is installed in common piping 77. The filter removes foreign matter, such as polishing debris from the polishing pad 14, from the slurry S flowing into the switching valve 78. The switching valve 78 is a switching unit. Recovery piping 79 and waste piping 80 are connected to the switching valve 78. The switching valve 78 is configured to switch the connection destination of the recovery pan 76 between recovery piping 79 and waste piping 80. Recovery piping 79 is connected to a tank 51. Waste piping 80 is connected to a waste liquid tank (not shown). When slurry S is supplied to the platen 11 from the supply circuit 53, the switching valve 78 is controlled so that the connection destination of the recovery pan 76 becomes the recovery piping 79. At this time, common piping 77 functions as part of the recovery piping 79. When cleaning liquid is supplied to the platen 11 from the supply circuit 53, the switching valve 78 is controlled so that the connection destination of the recovery pan 76 becomes the waste piping 80. In this case, the common piping 77 functions as part of the waste piping 80.

[0037] <Refill Circuit> The refill circuit 55 is the refill unit. The refill circuit 55 is configured to be able to refill various slurry formulations into the tank 51 individually. The refill circuit 55 has a refill pipe 81 and a refill unit 82 corresponding to the refill pipe 81. In Figure 3, the slurry supply unit 50 has three refill pipes 81 and a refill unit 82 corresponding to each refill pipe 81.

[0038] The replenishment piping 81 is connected to the tank 51 and the replenishment unit 82. Each of the replenishment units 82 is configured to supply a predetermined flow rate of slurry preparation liquid to the replenishment piping 81. Each of the replenishment units 82 is configured to circulate the slurry preparation liquid within the unit in order to suppress solid-liquid separation and sedimentation of solid components.

[0039] The replenishment piping 81 is equipped with a flow meter 83 and a replenishment control valve 84. The flow meter 83 detects the flow rate of the slurry mixture liquid flowing through the replenishment piping 81 and outputs a signal indicating the detected flow rate to the control unit 120. When the replenishment control valve 84 is open, it replenishes the slurry mixture liquid to the tank 51. When the replenishment control valve 84 is closed, it shuts off the replenishment of the slurry mixture liquid to the tank 51. When the control unit 120 controls the replenishment control valve 84 to be open as needed, it is maintained open until the replenishment amount based on the flow rate detected by the flow meter 83 reaches the desired amount.

[0040] <Discharge Circuit> The discharge circuit 56 is configured to discharge slurry S and the like from the tank 51. The discharge circuit 56 has a discharge pipe 86. The discharge pipe 86 is connected to the bottom wall of the tank 51 and a waste liquid tank (not shown). A discharge valve 88 is provided in the discharge pipe 86. When the discharge valve 88 is closed, it prevents the discharge of slurry S and the like from the tank 51. When the discharge valve 88 is open, it discharges slurry S and the like from the tank 51 to the waste tank.

[0041] <Other> In addition to these circuits, the slurry supply unit 50 has a third cleaning pipe 89. The third cleaning pipe 89 is configured to supply a predetermined flow rate of cleaning liquid to the tank 51. The third cleaning pipe 89 is provided with a third cleaning valve 90. When the third cleaning valve 90 is open, it supplies cleaning liquid to the tank 51. When the third cleaning valve 90 is closed, it shuts off the supply of cleaning liquid to the tank 51.

[0042] <Tank> As shown in Figure 3, the tank 51 has an agitator 91, a liquid level sensor 92, a slurry temperature sensor 93, and an overflow sensor 94. The agitator 91 is the stirring unit. The agitator 91 stirs the slurry S stored in the tank 51. The agitator 91 also stirs the cleaning liquid supplied to the tank 51 when the tank 51 is being cleaned. The liquid level sensor 92 is the liquid level measuring unit. The liquid level sensor 92 detects the liquid level position of the slurry S in the tank 51 and outputs a signal indicating the detected liquid level position to the control unit 120. The slurry temperature sensor 93 detects the slurry temperature Ts, which is the temperature of the slurry S in the tank 51, and outputs a signal indicating the detected slurry temperature Ts to the control unit 120. The overflow sensor 94 outputs an overflow signal to the control unit 120 when the slurry S in the tank 51 reaches the limit liquid level position. The limit liquid level position is higher than the liquid level 112 (see Figure 6) when the maximum amount of slurry S is stored in the tank 51.

[0043] As shown in Figures 4 and 5, the tank 51 has a tank body 100 that forms a storage space for the slurry S. The tank body 100 is composed of a peripheral wall portion 101 and a bottom wall portion 102 that closes the lower opening of the peripheral wall portion 101.

[0044] The peripheral wall portion 101 is configured in a double-wall structure including an inner peripheral wall portion 103 and an outer peripheral wall portion 104 that is in close contact with the inner peripheral wall portion 103 from the outside. The inner peripheral wall portion 103 has slurry resistance and is formed of a resin material, for example, polyvinyl chloride (PVC), which has higher heat conductivity than the ambient atmosphere around the tank 51 (for example, air). The outer peripheral wall portion 104 is formed of a heat transfer material having higher heat conductivity than the inner peripheral wall portion 103, for example, a metal material such as aluminum. Heat radiation fins may be formed on the outer peripheral wall portion 104. The bottom wall portion 102 is configured in a double-wall structure including an inner bottom wall portion made of a slurry-resistant resin material and an outer bottom wall portion made of a metal material.

[0045] Here, the temperature of the slurry S supplied to the platen 11 increases under the influence of frictional heat or the like accompanying the polishing of the wafer 15. Therefore, merely circulating the slurry S between the tank 51 and the platen 11 during polishing of the wafer 15 may cause the temperature of the slurry S supplied to the platen 11 to become excessively high. Further, when the CMP apparatus 1 is started up, the slurry temperature Ts before the start of polishing of the wafer 15 may be lower than an appropriate temperature suitable for polishing the wafer 15. In such a case, the polishing condition tends to be unstable immediately after the start of polishing of the wafer 15. For these reasons, the slurry supply unit 50 is provided with a temperature adjustment function capable of adjusting the slurry temperature Ts.

[0046] The tank 51 has a temperature controller 108. The temperature controller 108 adjusts the temperature of the slurry S inside the tank 51 via the peripheral wall portion 101. The temperature controller 108 is provided so as to be in surface contact with the outer surface of the side wall portion 107, which is part of the peripheral wall portion 101. That is, the temperature controller 108 adjusts the temperature of the slurry S inside the tank 51 by adjusting the temperature of the peripheral wall portion 104, which changes temperature due to the slurry S inside the tank 51. In this case, since the heat transfer properties of the inner peripheral wall portion 103 are higher than those of the ambient atmosphere (e.g., air), the temperature of the peripheral wall portion 104 adjusted by the temperature controller 108 is more easily transferred to the inner peripheral wall portion 103 than to the ambient atmosphere, and therefore the temperature of the slurry S stored inside the inner peripheral wall portion 103 can be adjusted. The peripheral wall portion 104 may be coated, for example, with a fluorine coating, for chemical protection and / or heat insulation. For example, the portion of the peripheral wall portion 104 where the temperature controller 108 is located may be coated. For example, the coating preferably has lower heat transfer properties than the inner circumferential wall portion 103 and / or lower heat transfer properties than the surrounding atmosphere (e.g., air). Furthermore, the coating preferably has slurry resistance and chemical resistance. The temperature controller 108 may be composed of a medium-type heat exchanger through which a temperature-controlled heat transfer medium flows, but it is preferable to be composed of a Peltier element, which has high responsiveness to temperature control and a large temperature control range. The temperature controller may also consist of a first temperature controller 108 composed of a Peltier element and a second temperature controller composed of a medium-type heat exchanger that covers at least a portion of the area other than the side wall portion 107.

[0047] Further, in the tank 51, an exposed portion 106 is provided on a side wall portion 105 which is a part of the peripheral wall portion 101 and located on the opposite side of the side wall portion 107. The exposed portion 106 is a part of the inner peripheral wall portion 103, and is a portion exposed from the lower end to the upper end at the central portion of the side wall portion 105 in the circumferential direction of the peripheral wall portion 101. A level indicator or the like that allows visual confirmation of the liquid level position of the slurry S in the tank 51 is attached to the exposed portion 106. This level indicator is used, for example, when calibrating a liquid level sensor. It should be noted that the exposed portion 106 only needs to allow the liquid level position to be visually checked; the level indicator may be arranged at a position different from the exposed portion 106, and the configuration may be such that whether the value of the level indicator or the like is accurate can be checked by confirming the liquid level position at the exposed portion 106. Further, the exposed portion 106 may be omitted; the configuration may be such that the entire surface of the inner peripheral wall portion 103 is covered by the outer peripheral wall portion 104, or a temperature adjuster 108 may be provided on the exposed portion 106 to increase the heat exchange rate.

[0048] It is preferable that such a tank 51 is removable with respect to the CMP apparatus 1. Accordingly, after removing the tank 51 from the CMP apparatus 1, cleaning using a cleaning tool or the like by an operator can be performed.

[0049] As shown in FIG. 6, the tank 51 has a lid portion 110 that closes the upper opening of the tank body 100. The circulation pipe 61, the recovery pipe 79, the replenishment pipe 81, and the third cleaning pipe 89 shown in FIG. 3 are connected to the lid portion 110.

[0050] Tank 51 has a guide member 111 below the inlet 110A to which the recovery piping 79 is connected. The guide member 111 is positioned above the liquid level 112 when tank 51 is storing the maximum amount of slurry S. The guide member 111 is attached to the lid 110 via a mounting fixture 113. The guide member 111 may also be attached to the peripheral wall 101. The guide member 111 is inclined downward toward the side wall 107. The guide member 111 guides the slurry S that flows into tank 51 from the inlet 110A toward the side wall 107. The slurry S guided by the guide member 111 travels along the inner surface of the side wall 107 to reach the liquid level 112. That is, the guide member 111 is configured so that the slurry S travels along the inner peripheral wall 103 at a temperature greater than that of the slurry S stored in tank 51 until it reaches the liquid level 112.

[0051] <Tank Arrangement> As shown in Figures 7 and 8, in the CMP apparatus 1, the tank 51 is provided adjacent to the polishing area 115 where the polishing section 10, including the platen 11, is installed.

[0052] As shown in Figure 7, in one example of the positional relationship between the polishing section 10 and the tank 51, the tank 51 is located in the lower region 116, which is below the polishing area 115 (or polishing section 10), and is situated in the tank region 117 (or tank 51) directly below the polishing area 115. In other words, the tank 51 is positioned adjacent to the polishing area 115 (or polishing section 10) from below.

[0053] As shown in Figure 8, in another example of the positional relationship between the polishing unit 10 and the tank 51, the tank 51 is located in a lower region 116 below the polishing area 115 (or polishing unit 10), in a tank region 117 (or tank 51) that is positioned horizontally away from or offset from the polishing area 115. That is, the tank 51 is positioned adjacent to the polishing area 115 (or polishing unit 10) from a diagonally downward direction. This configuration is selected in the design of the CMP apparatus 1 when other components are arranged directly below the polishing area 115.

[0054] With the tank area 117 (or tank 51) provided in this positional relationship, the tank area 117 (or tank 51) can be installed in a position close to the polishing area 115 (or polishing section 10). Note that the tank area 117 may be located in other areas of the lower area 116.

[0055] According to the positional relationship described above, the length of the pipes 61 and 79 connecting the tank 51 and the polishing section 10 can be shortened, and the slurry S can flow from the polishing section 10 to the tank 51 without stagnation. In other words, the time that the slurry S flows through the pipes 61 and 79 is shortened. As a result, the adhesion of the slurry S within the pipes 61 and 79 can be suppressed, and the deterioration of the slurry S in the pipes 61 and 79 can be suppressed. Furthermore, temperature changes of the slurry S before it reaches the supply section 16 can also be suppressed. These effects can be effectively obtained in the example of the positional relationship described above, where the movement path and movement time of the slurry S are further shortened.

[0056] Furthermore, in the recycling circuit 54, the common piping 77 is steeply connected to the recovery pan 76 so that the slurry S recovered by the recovery pan 76 flows smoothly into the common piping 77. Specifically, the common piping 77 is provided to extend vertically downward from the recovery pan 76 to the switching valve 78. Also, the recovery piping 79 is steeply connected to the tank 51 so that the slurry S flowing through the recovery piping 79 flows smoothly into the tank 51. Specifically, the connection portion of the recovery piping 79 to the tank 51 extends vertically upward from the tank 51. Here, "steep" refers to an angle at which the slurry S can flow smoothly from the polishing section 10 to the tank 51. For example, the angle with respect to the vertical is 45° or less, but it is not limited to an angle of 45° or less.

[0057] <Hardware Configuration of the Control Unit> As shown in Figure 9, the control unit 120 is centered around the information processing device H10. The information processing device H10 includes a communication device H11, an input device H12, an output device H13, a storage device H14, and a processor H15. Note that this hardware configuration is just one example, and it can also be implemented with other hardware.

[0058] Communication device H11 is an interface that establishes a communication path with other devices and performs data transmission and reception, such as a network interface card or a wireless interface. Input device H12 is a device that accepts input of various types of information. Input device H12 is such as a touch panel, mouse, or keyboard. Output device H13 is such as a display or speaker that displays various types of information. Storage device H14 stores data and various programs for executing various functions of the control device. Examples of storage device H14 include ROM, RAM, hard disk, and SSD.

[0059] The processor H15 controls each process using programs and data stored in the memory device H14. Examples of processor H15 include CPUs and MPUs. This processor H15 loads programs stored in ROM or the like into RAM and executes various instructions corresponding to various processes. For example, when the application program of the CMP device 1 is started, the processor H15 executes instructions corresponding to each process described later.

[0060] Processor H15 is not limited to performing software processing for all of the processes it executes. For example, processor H15 may have dedicated hardware circuits (e.g., application-specific integrated circuits: ASICs) that perform hardware processing for at least some of the processes it executes. That is, processor H15 can be configured as a circuit including (1) one or more processors that operate according to a computer program (software), (2) one or more dedicated hardware circuits that perform at least some of the various processes, or (3) a combination thereof. Processor H15 includes a CPU and memory such as RAM and ROM, where the memory stores program code or instructions configured to cause the CPU to execute processes. Memory, or non-temporary computer-readable media, includes any available media that can be accessed by a general-purpose or dedicated computer.

[0061] <Functions of the Control Unit> As shown in Figure 10, the control unit 120 has a status acquisition unit 121, a polishing control unit 122, and a slurry control unit 123, among other functions that operate through the execution of various programs.

[0062] The status acquisition unit 121 acquires the polishing status based on the detection results of the polishing status detection unit 126 and the driving status of each part. The polishing status detection unit 126 detects the values ​​of parameters related to the polishing status of the wafer 15 and outputs a signal indicating these values ​​to the control unit 120. For example, the polishing status detection unit 126 is a polishing temperature sensor that detects the polishing temperature Tp. The polishing temperature Tp is the temperature of the contact surface between the wafer 15 and the polishing pad 14 during polishing. The polishing status detection unit 126 is configured to include a non-contact thermometer capable of measuring the temperature of the contact surface, such as an infrared radiation thermometer. In this case, the status acquisition unit 121 acquires the polishing temperature Tp based on the signal output by the polishing temperature sensor as the polishing status.

[0063] For example, the polishing status detection unit 126 is an end point detection (EPD) sensor. The end point detection sensor is a sensor for detecting whether the polishing of the wafer 15 has reached the end point, that is, whether the polishing of the wafer 15 has been completed. In this case, the status acquisition unit 121 measures the time from the start of polishing until the end point detection sensor detects the end point, that is, the time from the start of polishing to the completion of polishing, and acquires the polishing rate R based on the measured time as the polishing status.

[0064] In addition, the status acquisition unit 121 acquires the rotation speed of the platen 11, the rotation speed of the polishing head 20, etc., as polishing status. The status acquisition unit 121 also acquires the polishing pressure P as polishing status. The polishing pressure P is the pressure exerted by the wafer 15 pressing against the polishing pad 14 during polishing. The status acquisition unit 121 acquires the polishing pressure P based on the driving status of the air supply sources 32, 43, and 48.

[0065] Furthermore, the status acquisition unit 121 acquires the liquid level position of the slurry S in the tank 51 based on the output signal of the liquid level sensor 92. The status acquisition unit 121 acquires the slurry temperature Ts based on the output signal of the slurry temperature sensor 93. The status acquisition unit 121 acquires the replenishment amount of each slurry mixture based on the output signal of the flow meter 83. The status acquisition unit 121 acquires the overflow signal from the overflow sensor 94.

[0066] The polishing control unit 122 is configured to control the operation of the platen 11 and the polishing head 20, among other things. The polishing control unit 122 controls each part of the polishing unit 10 by controlling the drive of the head drive unit 131. The polishing control unit 122 controls the rotation of the rotating shaft 12 so that the platen 11 rotates at a desired rotational speed. The polishing control unit 122 controls the rotation of the rotating shaft 21 so that the polishing head 20 rotates at a desired rotational speed. The polishing control unit 122 controls the air supply sources 32, 43, and 48 so that the wafer 15 is pressed against the polishing pad 14 with a desired pressing force.

[0067] <Operation of the Slurry Supply Unit> The slurry control unit 123 is configured to control the operation of the slurry supply unit 50. The slurry control unit 123 controls the operation of the flow controller 66, the operation of each valve 63, 64, 68, 71, 73, 84, 88, 90, and the operation of the agitator 91, etc.

[0068] <Supply Operation> The slurry control unit 123 performs a supply operation as the operation of the slurry supply unit 50, supplying slurry S to the platen 11 while the wafer 15 is being polished. In the supply operation, the slurry control unit 123 drives the pump 62 and controls the flow control valve 63 and the circulation control valve 64 to the open state. The slurry control unit 123 also supplies a preset target amount of slurry S to the supply unit 16 by controlling the flow controller 66 to the supply state.

[0069] <Replenishment Operation> The slurry control unit 123 performs a replenishment operation as an operation of the slurry supply unit 50, replenishing the slurry mixture liquid in the tank 51 so that the amount of slurry S in the tank 51 is maintained at a constant level. Here, the amount of slurry S recovered by the recovery pan 76 is less than the amount of slurry S supplied to the platen 11. The replenishment operation is the operation of replenishing the reduced amount of slurry S in the tank 51. During the replenishment operation, when the liquid level position detected by the liquid level sensor 92 falls below the replenishment position, the slurry control unit 123 controls the operation of the replenishment control valve 84 so that the liquid level position detected by the liquid level sensor 92 becomes the reference position. The replenishment operation is one of the operations to adjust the slurry S recovered in the tank 51 through the recycling circuit 54. During the replenishment operation, the slurry control unit 123 may calculate the amount of each slurry mixture liquid to be replenished based on the liquid level position immediately before starting the replenishment operation.

[0070] <Overflow Operation> The slurry control unit 123 performs an overflow operation as an operation of the slurry supply unit 50 to prevent the slurry S from overflowing from the tank 51 during the polishing of the wafer 15. In the overflow operation, when the status acquisition unit 121 acquires an overflow signal, the slurry control unit 123 controls the operation of the switching valve 78 so that the slurry S collected by the recovery pan 76 flows into the waste piping 80.

[0071] <Platen Cleaning Operation> As shown in Figure 11, the slurry control unit 123 performs a platen cleaning operation to clean the platen 11 as an operation of the slurry supply unit 50. During the platen cleaning operation, the slurry control unit 123 controls the operation of the switching valve 78 to shut off the flow controller 66 and to connect the common pipe 77 to the waste pipe 80. The slurry control unit 123 then controls the second cleaning valve 73 to open. As a result, the cleaning liquid supplied from the second cleaning pipe 72 to the supply pipe 65 is supplied to the platen 11 through the supply unit 16, thereby cleaning the platen 11. The cleaning liquid that flows out of the platen 11 is collected by the recovery pan 76 and then discarded to the waste tank through the waste pipe 80.

[0072] <Flushing> The slurry control unit 123 performs flushing to clean the tank 51 as an operation of the slurry supply unit 50.

[0073] For example, the slurry control unit 123 starts flushing when a flushing operation is input to the input device H12 by the operator. Alternatively, the slurry control unit 123 may start flushing when the change in slurry temperature Ts ΔTs falls below a predetermined minimum change ΔTs1. This is because when solid contents of the slurry S settle or solidify in the tank 51, the heat capacity of the tank 51 including the slurry S increases, which reduces the change in slurry temperature Ts ΔTs. For example, if the slurry control unit 123 starts flushing on the condition that the change in slurry temperature Ts ΔTs falls below a predetermined minimum change ΔTs1, it may be configured to supply a cleaning solution for cleaning the slurry S to the tank 51 from a replenishment unit 82 or the like. For example, the slurry control unit 123 may start flushing periodically. When flushing is started, the slurry supply unit 50 stops supplying slurry S to the platen 11 and circulates the slurry S through the circulation piping 61.

[0074] During flushing, the slurry control unit 123 first discharges the slurry S from the tank 51. Specifically, the slurry control unit 123 stops the pump 62 and controls the flow control valve 63 and the circulation control valve 64 to a closed state. Then, the slurry control unit 123 controls the discharge valve 88 to an open state. As a result, the slurry S from the tank 51 is discharged to the waste tank through the discharge pipe 86.

[0075] Next, as shown in Figure 12, the slurry control unit 123 controls the discharge valve 88 to a closed state, and then controls the flow control valve 63, circulation control valve 64, first cleaning valve 71, and third cleaning valve 90 to an open state. As a result, cleaning fluid from the first cleaning pipe 70 is supplied to the tank 51 through the circulation pipe 61, and cleaning fluid from the third cleaning pipe 89 is supplied directly to the tank 51.

[0076] When the liquid level detected by the liquid level sensor 92 reaches the agitation position, the slurry control unit 123 controls the first wash valve 71 and the third wash valve 90 to a closed state, and then drives the agitator 91 for a predetermined time to agitate the cleaning liquid in the tank 51. After that, the slurry control unit 123 controls the flow control valve 63 and the first wash valve 71 to a closed state and the discharge valve 88 to an open state. As a result, the cleaning liquid in the tank 51 is discharged through the discharge pipe 86. The slurry control unit 123 repeats this supply and agitation of the cleaning liquid and discharge of the cleaning liquid a predetermined number of times.

[0077] Next, as shown in Figure 13, the slurry control unit 123 controls the first cleaning valve 71 to the closed state and the air supply valve 68 to the open state. As a result, the cleaning fluid in the circulation piping 61 and tank 51 is discharged through the discharge piping 86 by air from the air piping 67. Then, the slurry control unit 123 controls the discharge valve 88 and the air supply valve 68 to the closed state. Thus, flushing is completed.

[0078] Once flushing is complete, the slurry control unit 123 controls the replenishment control valve 84 based on the flow meter 83's detection value so that a predetermined amount of various slurry mixtures is supplied to the tank 51. When resuming the supply of slurry S to the supply unit 16, the slurry control unit 123 controls the flow control valve 63 to the open state and starts pumping the slurry S with the pump 62. Then, the slurry control unit 123 controls the flow controller 66 so that the target amount of slurry S is supplied to the supply unit 16.

[0079] <Alarm Operation> The slurry control unit 123 performs an alarm operation as part of the operation of the slurry supply unit 50. The slurry control unit 123 performs an alarm operation when the polishing temperature Tp acquired by the status acquisition unit 121 exceeds the limit temperature. In the alarm operation, the slurry control unit 123 activates the alarm device 125 to signal that the polishing temperature Tp has exceeded the limit temperature.

[0080] <Polishing Control> The polishing control unit 122 of the control unit 120 may control the polishing unit 10 so that the wafer 15 is polished to a desired polishing condition. Alternatively, the polishing control unit 122 may control the polishing unit 10 so that the wafer 15 is polished to a desired polishing condition according to the temperature of the slurry S in the tank 51.

[0081] <First Polishing Control> The polishing control unit 122 may be configured to perform a first polishing control that controls the polishing unit 10 so that the polishing rate R acquired by the status acquisition unit 121 becomes a desired target rate R1.

[0082] In the first polishing control, the polishing control unit 122 may control the platen drive unit 130 based on the rate deviation ΔR between the target rate R1 and the polishing rate R. For example, when the polishing rate R is lower than the target rate R1, the polishing control unit 122 controls the platen drive unit 130 so that the larger the rate deviation ΔR, the higher the rotational speed of the platen 11. When the polishing rate R is higher than the target rate R1, the polishing control unit 122 controls the platen drive unit 130 so that the larger the rate deviation ΔR, the lower the rotational speed of the platen 11.

[0083] In the first polishing control, the polishing control unit 122 may control the head drive unit 131 based on the rate deviation ΔR. For example, when the polishing rate R is lower than the target rate R1, the polishing control unit 122 controls the head drive unit 131 so that the rotation speed of the polishing head 20 increases as the rate deviation ΔR increases. When the polishing rate R is higher than the target rate R1, the polishing control unit 122 controls the head drive unit 131 so that the rotation speed of the polishing head 20 decreases as the rate deviation ΔR increases.

[0084] For example, when the polishing rate R is lower than the target rate R1, the polishing control unit 122 controls the head drive unit 131 so that the polishing pressure P increases as the rate deviation ΔR increases. When the polishing rate R is higher than the target rate R1, the polishing control unit 122 controls the head drive unit 131 so that the polishing pressure P decreases as the rate deviation ΔR increases.

[0085] <Second Polishing Control> The polishing control unit 122 may be configured to perform a second polishing control that controls the polishing unit 10 so that the polishing temperature Tp acquired by the status acquisition unit 121 becomes the target temperature Tp1. The target temperature Tp1 is the optimal polishing temperature for polishing the wafer 15.

[0086] In the second polishing control, the polishing control unit 122 may control the platen drive unit 130 based on the temperature deviation ΔTp between the polishing temperature Tp and the target temperature Tp1. For example, when the polishing temperature Tp is lower than the target temperature Tp1, the polishing control unit 122 controls the platen drive unit 130 so that the rotation speed of the platen 11 increases as the temperature deviation ΔTp increases. When the polishing temperature Tp is higher than the target temperature Tp1, the polishing control unit 122 controls the platen drive unit 130 so that the rotation speed of the platen 11 decreases as the temperature deviation ΔTp increases.

[0087] In the second polishing control, the polishing control unit 122 may control the head drive unit 131 based on the temperature deviation ΔTp between the polishing temperature Tp and the target temperature Tp1. For example, when the polishing temperature Tp is lower than the target temperature Tp1, the polishing control unit 122 controls the head drive unit 131 so that the rotation speed of the polishing head 20 increases as the temperature deviation ΔTp increases. When the polishing temperature Tp is higher than the target temperature Tp1, the polishing control unit 122 controls the head drive unit 131 so that the rotation speed of the polishing head 20 decreases as the temperature deviation ΔTp increases.

[0088] For example, when the polishing temperature Tp is lower than the target temperature Tp1, the polishing control unit 122 controls the head drive unit 131 so that the larger the temperature deviation ΔTp, the higher the polishing pressure P. When the polishing temperature Tp is higher than the target temperature Tp1, the polishing control unit 122 controls the head drive unit 131 so that the larger the temperature deviation ΔTp, the lower the polishing pressure P.

[0089] <Third Polishing Control> The polishing control unit 122 may be configured to perform a third polishing control that controls the polishing unit 10 so that the polishing rate R acquired by the status acquisition unit 121 becomes a desired target rate R1, according to the temperature of the slurry S acquired by the status acquisition unit 121.

[0090] In the third polishing control, the polishing control unit 122 may control the platen drive unit 130 or the head drive unit 131 based on the temperature of the slurry S. For example, if the temperature of the slurry S is lower than the appropriate temperature for polishing the wafer 15, the polishing control unit 122 may control the platen drive unit 130 to increase the rotation speed of the platen 11, or control the head drive unit 131 to increase the rotation speed of the polishing head 20.

[0091] For example, if the temperature of the slurry S is higher than the appropriate temperature for polishing the wafer 15, the polishing control unit 122 may control the platen drive unit 130 to reduce the rotation speed of the platen 11, or it may control the head drive unit 131 to reduce the rotation speed of the polishing head 20.

[0092] <Slurry Temperature Control> The slurry control unit 123 of the control unit 120 may control the slurry supply unit 50 so that the wafer 15 is polished under the desired polishing conditions.

[0093] <First Temperature Control> The slurry control unit 123 may be configured to perform a first temperature control that controls the slurry supply unit 50 so that the polishing rate R acquired by the status acquisition unit 121 becomes the target rate R1.

[0094] In the first temperature control, the slurry control unit 123 may control the temperature controller 108 based on the rate deviation ΔR. For example, when the polishing rate R is lower than the target rate R1, the slurry control unit 123 controls the temperature controller 108 so that the slurry temperature Ts increases as the rate deviation ΔR increases, because the polishing temperature will be lower and the temperature of the slurry used for polishing may also be lower. When the polishing rate R is higher than the target rate R1, the slurry control unit 123 controls the temperature controller 108 so that the slurry temperature Ts decreases as the rate deviation ΔR increases, because the polishing temperature will be higher and the temperature of the slurry used for polishing may also be higher.

[0095] <Second Temperature Control> The slurry control unit 123 may be configured to perform a second temperature control, which controls the slurry supply unit 50 so that the polishing temperature Tp acquired by the status acquisition unit 121 becomes the target temperature Tp1. In the second temperature control, the slurry control unit 123 controls the temperature regulator 108 based on the temperature deviation ΔTp between the polishing temperature Tp and the target temperature Tp1.

[0096] For example, when the polishing temperature Tp is higher than the target temperature Tp1, the slurry control unit 123 controls the temperature controller 108 so that the slurry temperature Ts decreases as the temperature deviation ΔTp increases. When the polishing temperature Tp is lower than the target temperature Tp1, the slurry control unit 123 controls the temperature controller 108 so that the slurry temperature Ts increases as the temperature deviation ΔTp increases.

[0097] <Third Temperature Control> The slurry control unit 123 may be configured to perform a third temperature control that controls the slurry supply unit 50 so that the polishing temperature T0 acquired by the status acquisition unit 121 before starting to polish the wafer 15, that is, the temperature of the contact surface between the wafer 15 and the polishing pad 14 (pre-polishing temperature) Tp0 before polishing becomes the starting temperature Tp2. The starting temperature Tp2 is the slurry temperature Ts at which the desired polishing conditions are obtained.

[0098] In the third temperature control, the slurry control unit 123 controls the temperature controller 108 based on the temperature deviation ΔTp2 between the pre-polishing temperature Tp0 and the start temperature Tp2. For example, when the pre-polishing temperature Tp0 is higher than the start temperature Tp2, the slurry control unit 123 controls the temperature controller 108 so that the larger the temperature deviation ΔTp2, the lower the slurry temperature Ts. When the pre-polishing temperature Tp0 is lower than the start temperature Tp2, the slurry control unit 123 controls the temperature controller 108 so that the larger the temperature deviation ΔTp2, the higher the slurry temperature Ts.

[0099] The control unit 120 may be configured to execute multiple controls from the first polishing control, second polishing control, third polishing control, first temperature control, and second temperature control described above during the polishing of the wafer 15. For example, the control unit may execute all of the first polishing control, second polishing control, third polishing control, first temperature control, and second temperature control. In this case, the control unit 120 controls each part based on control value data stored in advance in the storage device H14. The control value data is created based on the results of polishing experiments of the wafer 15 using the CMP apparatus 1 or simulations using a computer. The control value data specifies the rotation speed of the platen 11, the rotation speed of the polishing head 20, the polishing pressure, and the slurry temperature as control values ​​corresponding to the rate deviation ΔR and the temperature deviation ΔTp. The control unit 120 obtains the control values ​​corresponding to the rate deviation ΔR and the temperature deviation ΔTp from the control value data and controls each part so that these control values ​​are realized.

[0100] The operation and effects of this embodiment will now be described. (1) The CMP apparatus 1 comprises a polishing unit 10 and a slurry supply unit 50. The polishing unit 10 includes a platen 11 having a polishing pad 14, a polishing head 20 that polishes the wafer 15 by rotating while pressing the wafer 15 against the polishing pad 14, a supply unit 16 that supplies slurry S onto the platen 11, and a recovery pan 76. The slurry supply unit 50 has a tank 51 provided adjacent to the polishing unit 10, and is configured to collect slurry S in the tank 51, adjust the collected slurry S, and supply it to the supply unit 16.

[0101] This configuration makes it possible to provide a CMP device 1 that has the function of recycling slurry. Furthermore, because a slurry supply unit 50 capable of recycling slurry S is integrally incorporated into the CMP device 1, the tank 51 for storing the recycled slurry S is positioned close to the platen 11. This allows the supply of slurry S to the platen 11 and the recovery of the slurry S supplied to the platen 11 to be carried out in a short time, and the deterioration of slurry S during the recycling process is suppressed. In addition, in the tank 51, the slurry S, whose flowable amount and temperature have been adjusted in the slurry supply unit 50, is supplied to the platen 11. As a result, the quality of the recycled slurry S can be guaranteed.

[0102] (2) The tank 51 is installed below the polishing section 10. With this configuration, the weight of the slurry S can be used to guide the flow of slurry S from the platen 11 to the tank 51. As a result, slurry S flows from the platen 11 to the tank 51 even without a pump or other pressurizing device, allowing the recycling circuit 54 to be constructed with fewer components.

[0103] (3) The slurry supply unit 50 includes a recycling circuit 54 that connects the polishing unit 10 and the tank 51. The recycling circuit 54 has piping that is steeply connected to a recovery pan 76 that recovers the slurry S supplied to the polishing unit 10 and an inlet 110A that allows the slurry S recovered by the recovery pan 76 to flow into the tank 51. With this configuration, the slurry S is less likely to accumulate in the recycling circuit 54. As a result, the solidification of the slurry S in the recycling circuit 54 can be suppressed.

[0104] (4) The slurry supply unit 50 has a temperature controller 108 that can adjust the temperature of the slurry S in the tank 51. With this configuration, the temperature of the slurry S supplied to the platen 11 can be adjusted so that the polishing conditions are appropriate at any given time.

[0105] (5) The temperature controller 108 is configured to cool the slurry S in the tank 51. With this configuration, it is possible to suppress the overheating of the slurry S in the tank 51 and the deterioration of the slurry S caused by the recycling of the slurry S. As a result, it becomes easier to maintain the polishing condition of the wafer 15 properly.

[0106] (6) The tank 51 has an inner circumferential wall portion 103 which has higher heat transfer properties than the surrounding atmosphere, for example, air, and is resistant to slurry, and an outer circumferential wall portion 104 which is made of a heat transfer material which has higher heat transfer properties than the inner circumferential wall portion 103. The temperature controller 108 is provided so as to cover the side wall portion 107, which is part of the inner circumferential wall portion 103, from the outside.

[0107] With this configuration, the outer peripheral wall portion 104 is formed of a heat transfer material, which increases the heat transfer efficiency between the side wall portion 107 and other side wall portions of the tank body 100. As a result, the heat transfer efficiency between the temperature controller 108 and the slurry S in the tank 51 is increased, allowing the temperature of the slurry S in the tank 51 to be adjusted efficiently.

[0108] Furthermore, because the outer periphery wall portion 104 is formed of a heat transfer material, the amount of heat dissipated from the outer periphery wall portion 104 can be increased when cooling the slurry S in the tank 51. This amount of heat dissipation can be further increased by forming heat dissipation fins on the outer periphery wall portion 104.

[0109] Furthermore, the tank 51 may be configured to include a medium-type heat exchanger that covers at least a portion of the outer peripheral wall portion 104. With this configuration, the temperature of the slurry S inside the tank 51 can be adjusted more efficiently via the outer peripheral wall portion 101 of the tank body 100.

[0110] (7) Here, the exposed portion 106 to which the level indicator and the like are attached can also be provided in a position adjacent to the temperature controller 108. However, in this configuration, the outer peripheral wall portion 104 is divided near the temperature controller 108. As a result, the part on the outer peripheral wall portion 104 furthest from the temperature controller 108 will be located approximately one full circle around the outer peripheral wall portion 101, starting from the temperature controller 108. In other words, if the exposed portion 106 is provided in a position adjacent to the temperature controller 108, the average distance from each position on the outer peripheral wall portion 104 to the temperature controller 108 will become large.

[0111] In this regard, in the above configuration, the exposed portion 106 is provided on the side wall portion 105 opposite to the side wall portion 107. With this configuration, since the outer peripheral wall portion 104 is divided at the side wall portion 105, the part on the outer peripheral wall portion 104 furthest from the temperature controller 108 is located approximately half a turn around the outer peripheral wall portion 101, starting from the temperature controller 108. In other words, by providing the exposed portion 106 on the side wall portion 105, the average distance from each position on the outer peripheral wall portion 104 to the temperature controller 108 can be reduced. As a result, the temperature of the outer peripheral wall portion 104 by the temperature controller 108, and consequently the temperature of the slurry S in the tank 51, can be adjusted efficiently. However, even if the exposed portion 106 is provided so as not to divide the outer peripheral wall portion 104, the exposed portion 106 will still create a part of the outer peripheral wall portion 104 with low heat transfer efficiency. Therefore, the above is also true even if the exposed portion 106 is provided so as not to divide the outer peripheral wall portion 104.

[0112] (8) The tank 51 has a guide material 111 that guides the slurry S flowing in from the inlet 110A to the inner surface of the side wall 107. With this configuration, the temperature of the slurry S is adjusted in the side wall 107 at a temperature difference greater than that of the slurry S stored in the tank 51 until it reaches the liquid level 112. As a result, the temperature of the slurry S can be adjusted efficiently.

[0113] (9) The slurry supply unit 50 has cleaning pipes 70 and 89 as cleaning liquid supply units that can supply cleaning liquid to the tank 51 for cleaning the tank 51. The slurry supply unit 50 is configured to perform flushing by supplying cleaning liquid to the tank 51 in accordance with the temperature change of the slurry temperature Ts. With this configuration, when the amount of change ΔTs of the slurry temperature Ts falls below the minimum change ΔTs1, the tank 51 can be flushed automatically.

[0114] (10) The recycling circuit 54 includes a recovery pipe 79 connected to the recovery pan 76 and the inlet 110A of the tank 51, a waste pipe 80 for disposing of the slurry S and cleaning liquid recovered by the recovery pan 76, and a switching valve 78 that can switch the connection destination of the recovery pan 76 between the recovery pipe 79 and the waste pipe 80. The slurry control unit 123 is configured to control the switching valve 78 so that the connection destination of the recovery pan 76 becomes the waste pipe 80 when cleaning liquid is supplied to the platen 11.

[0115] With this configuration, the cleaning solution used to clean the platen 11 is prevented from flowing into the tank 51. In addition, by controlling the flow controller 66 to a shut-off state, the slurry control unit 123 can clean the platen 11 while circulating the slurry S through the circulation circuit 52.

[0116] (11) The slurry supply unit 50 includes a liquid level sensor 92 for measuring the liquid level of the slurry S in the tank 51, and a replenishment circuit 55 for replenishing the slurry mixture in the tank 51. The control unit 120 is configured to control the replenishment circuit 55 so that the slurry mixture is replenished in the tank 51 when the liquid level falls below the replenishment position.

[0117] With this configuration, the amount of slurry S lost due to the polishing of the wafer 15 can be replenished in the tank 51. As a result, the temperature rise of the slurry S in the tank 51 caused by the supply of slurry S to the platen 11 can be suppressed.

[0118] (12) The CMP apparatus 1 includes a control unit 120 that controls the polishing unit 10 and the slurry supply unit 50. The slurry control unit 123 of the control unit 120 is configured to control the slurry supply unit 50 so that the slurry S recovered in the tank 51 by the recycling circuit 54 is temperature-adjusted and then supplied to the supply unit 16. With this configuration, the slurry temperature Ts in the tank 51 can be adjusted according to the polishing status of the wafer 15.

[0119] (13) In the CMP apparatus 1, the slurry control unit 123 is configured to adjust the slurry temperature Ts in the tank 51 according to the polishing status of the wafer 15. With this configuration, the polishing status at any given time can be brought closer to the optimal polishing status.

[0120] (14) In the CMP apparatus 1, the slurry control unit 123 is configured to adjust the slurry temperature Ts in the tank 51 according to the polishing temperature Tp when polishing the wafer 15. With this configuration, the polishing temperature Tp can be brought closer to the target temperature Tp1.

[0121] (15) In the CMP apparatus 1, the polishing control unit 122 is configured to adjust the rotation speed of the polishing head 20 according to the polishing temperature Tp. With this configuration, the polishing temperature Tp can be brought closer to the target temperature Tp1.

[0122] (16) In the CMP apparatus 1, the control unit 120 is configured to adjust the slurry temperature Ts in the tank 51 and the rotation speed of the polishing head 20 so that the polishing temperature Tp remains constant. With this configuration, the polishing temperature Tp can be maintained at the target temperature Tp1.

[0123] (17) In the CMP apparatus 1, the control unit 120 is configured to adjust the polishing pressure P of the polishing head 20 according to the polishing temperature Tp. With this configuration, the polishing temperature Tp can be brought closer to the target temperature Tp1.

[0124] (18) The slurry supply unit 50 includes a circulation pipe 61 configured to circulate slurry S in the tank 51, a supply pipe 65 configured to supply slurry S flowing through the circulation pipe 61 to the supply unit 16, and a discharge pipe 86 for discharging slurry S from the tank 51. The tank 51 has a stirrer 91 for stirring the substances inside. The slurry control unit 123 is configured to perform flushing by discharging slurry S from the tank 51 through the discharge pipe 86, then introducing cleaning liquid into the tank 51 through the circulation pipe 61, stirring the cleaning liquid with the stirrer 91 to clean the tank 51, and then blocking the connection between the circulation pipe 61 and the supply pipe 65 to discharge the cleaning liquid from the discharge pipe 86, thereby cleaning the circulation pipe 61 and the discharge pipe 86. With this configuration, slurry S and other substances adhering to the tank 51, circulation pipe 61, and discharge pipe 86 can be removed.

[0125] (19) The slurry control unit 123 performs flushing in accordance with the change in slurry temperature Ts. Specifically, the slurry control unit 123 performs flushing when the amount of change ΔTs in slurry temperature Ts falls below the minimum change ΔTs1. The slurry control unit 123 supplies cleaning liquid to the tank 51 in accordance with the temperature change state of the tank 51. With this configuration, flushing is performed in accordance with the state of the slurry S in the tank 51, so flushing can be performed periodically and as needed.

[0126] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they are not technically contradictory. As shown in Figures 14 and 15, the carrier recess 30 is provided with a pressing member 140 that is arranged coaxially with the rotational center axis 20A. The pressing member 140 is formed in a circular shape when viewed from below. The pressing member 140 can be made of an elastic resin material, such as polyethylene terephthalate resin (PET) or fluororesin (PFA), as well as polyphenylene sulfide (PPS).

[0127] Four rims 141 are formed on the upper surface of the pressing member 140. Each rim 141 is formed in an annular shape when viewed from above. Each rim 141 is fitted into an annular groove of the layout base 142, which is provided between the carrier recess 30 and the pressing member 140. Each rim 141 of the pressing member 140 is attached to the layout base 142 with adhesive. The layout base 142 is fastened to the carrier 27 by fastening members (not shown).

[0128] The pressing member 140 is divided into four regions 146, 147, 148, and 149 with the rim 141 as the boundary. Air lines 143 are formed on the layout base 142 to correspond to each of the regions 146, 147, 148, and 149. The air lines 143 are connected to an air supply source 150. The air supply source 150 is configured to supply pressurized air to each of the air lines 143. Furthermore, the air supply source 150 is configured to control the pressure of the pressurized air for each of the air lines 143. The pressing member 140 is configured to be able to expand individually toward the membrane film 45 in each of the regions 146, 147, 148, and 149 by the pressurized air supplied from the air supply source 150. In Figure 14, the expanded portion corresponding to region 148 is shown by a dotted line. That is, the pressing member 140 is configured to allow adjustment of the pressing force toward the membrane film 45 for each of the regions 146, 147, 148, and 149. The supply of pressurized air from the air supply source 150 to each region 146, 147, 148, and 149 is controlled by the polishing control unit 122 of the control unit 120.

[0129] The membrane film 45, receiving the force of being pressed by the pressurized air in the air chamber 46 and the force of being pressed by each of the regions 146, 147, 148, and 149 of the pressing member 140, flexes into the receiving pocket 49, thereby pressing the wafer 15 against the polishing pad 14. In other words, the polishing head 20 is configured so that the polishing pressure P can be adjusted for each of the regions 146, 147, 148, and 149 that are aligned radially around the rotational axis 20A.

[0130] In such a CMP apparatus 1, the polishing status detection unit 126 is configured to include polishing temperature sensors corresponding to each region 146, 147, 148, and 149. The status acquisition unit 121 is configured to acquire the polishing temperature Tp for each region 146, 147, 148, and 149 as the polishing status. The polishing control unit 122 controls the air supply source 150 and adjusts the polishing pressure P in each region 146, 147, 148, and 149 so that the polishing temperature Tp in each region becomes the target temperature Tp1 or a temperature within a predetermined temperature range. For example, the polishing control unit 122 may adjust the polishing pressure P in each region 146, 147, 148, and 149 so that the polishing temperature Tp in each region becomes the target temperature Tp1 or a temperature within a predetermined temperature range based on the slurry temperature Ts acquired by the slurry temperature sensor 93. This enables good polishing of the wafer 15. The slurry control unit 123 may also be configured to perform a second temperature control that controls the slurry supply unit 50 so that each or at least one of the polishing temperatures Tp for each region 146, 147, 148, 149 acquired by the status acquisition unit 121 is at the target temperature Tp1 or a temperature within a predetermined temperature range.

[0131] Regarding the replenishment of slurry S, the slurry supply unit 50 may be configured such that, for example, a predetermined amount of slurry preparation liquid is replenished into the tank 51 from the replenishment circuit 55 each time the polishing of one wafer 15 is completed.

[0132] The slurry supply unit 50 is not limited to a configuration in which the connection destination of the recovery pan 76 can be switched between the recovery pipe 79 and the waste pipe 80. The slurry supply unit 50 may also be configured in a way that only the recovery pipe 79 is connected to the recovery pan 76. In this case, the excess slurry S flows into the tank 51 and is then discarded through the discharge pipe 86.

[0133] The tank 51 only needs to be installed adjacent to the polishing section 10. Therefore, the tank 51 may be installed directly below the polishing section 10, or it may be installed diagonally above the polishing section 10.

[0134] - The polishing control unit 122 may control the air supply sources 32, 43, and 48 so that the polishing pressure P is kept constant. - The polishing control unit 122 may also control the rotating shaft 12 so that the rotational speed of the platen 11 is kept constant.

[0135] - The polishing control unit 122 may control the rotating shaft 21 so that the rotation speed of the polishing head 20 remains constant. - The slurry control unit 123 may drive the temperature controller 108 in a steady state so that a constant state is maintained.

[0136] This disclosure is not limited to the embodiments and modifications described above, and can be implemented in various ways without departing from the spirit of this disclosure. All such modifications are included in the technical concept of this disclosure. Furthermore, unless otherwise specified in the specification, each component of this disclosure is not limited to one, but may exist in multiple forms.

[0137] H10... Information processing device, H11... Communication device, H12... Input device, H13... Output device, H14... Memory device, H15... Processor, S... Slurry, 1... CMP device, 10... Polishing section, 11... Platen, 12... Rotating shaft, 13... Arrow, 14... Polishing pad, 15... Wafer as workpiece, 16... Supply section, 20... Polishing head, 20A... Rotational center axis, 21... Rotating shaft, 22... Arrow, 25... Head body, 26... Shaft connecting material, 27... Carrier, 28... Connecting section, 29... Rim, 30... Carrier recess, 31... First air passage, 32... Air supply source, 33... Carrier pressing section, 35... 36...Retainer pressing member, 37...Retainer holder, 38...Second air passage, 39...Snap ring, 40...Ring cover, 41...Retainer pressing part, 43...Air supply source, 45...Membrane film, 46...Air chamber, 48...Air supply source, 49...Storage pocket, 50...Slurry supply part, 51...Tank, 52...Circulation circuit, 53...Supply circuit, 54...Recycling circuit, 55...Replenishment circuit, 56...Discharge circuit, 61...Circulation piping, 62...Pump, 63...Flow control valve, 64...Circulation control valve, 65...Supply piping, 66...Flow controller, 67...Air piping, 68...Air supply valve, 70...First cleaning pipe, 71...First cleaning valve, 72...Second cleaning pipe, 73...Second cleaning valve, 76...Recovery pan, 77...Common piping, 78...Switching valve, 79...Recovery pipe, 80...Disposal pipe, 81...Refill pipe, 82...Refill unit, 83...Flow meter, 84...Refill control valve, 86...Discharge pipe, 88...Discharge valve, 89...Third cleaning pipe, 90...Third cleaning valve, 91...Agitator, 92...Liquid level sensor, 93...Slurry temperature sensor, 94...Overflow sensor, 100...Tank body, 101...Surface wall section, 102...Bottom wall section, 103...Inner circumferential wall section, 104...Outer circumferential wall section, 1 05...Side wall section, 106...Exposed section, 108...Temperature controller, 110...Lid section, 110A...Inlet, 111...Guide material, 112...Liquid level, 113...Mounting fixture, 115...Polishing area, 116...Lower area, 117...Tank area, 120...Control unit, 121...Status acquisition unit, 122...Polishing control unit, 123...Slurry control unit, 125...Alarm, 126...Polishing status detection unit, 130...Platen drive unit, 131...Head drive unit, 140...Pressing member, 141...Rim, 142...Layout base, 143...Airline, 146, 147, 148, 149...Area, 150...Air supply source.

Claims

1. A CMP apparatus comprising: a polishing unit having a platen with a polishing pad, a polishing head that polishes a workpiece by rotating while pressing the workpiece against the polishing pad, and a supply unit that supplies slurry onto the platen; a slurry supply unit having a tank for collecting the slurry supplied onto the platen, and capable of adjusting the temperature of the slurry collected in the tank and supplying it to the supply unit; and a control unit configured to control the polishing unit and the slurry supply unit.

2. The CMP apparatus according to claim 1, wherein the control unit is configured to adjust the temperature of the slurry in the tank according to the polishing status of the workpiece.

3. The CMP apparatus according to claim 2, wherein the control unit is configured to adjust the temperature of the slurry in the tank according to the polishing temperature when polishing the workpiece.

4. The CMP apparatus according to claim 3, wherein the control unit is configured to adjust the rotation speed of the polishing head according to the polishing temperature.

5. The CMP apparatus according to claim 4, wherein the control unit is configured to adjust the temperature of the slurry in the tank and the rotation speed of the polishing head so that the polishing temperature remains constant.

6. The CMP apparatus according to claim 3, wherein the control unit is configured to adjust the polishing pressure of the polishing head according to the polishing temperature.

7. The CMP apparatus according to claim 6, wherein the polishing head is configured to adjust the polishing pressure applied to the workpiece in a plurality of radially partitioned regions, and the control unit is configured to adjust the polishing pressure for each of the plurality of regions so that the polishing temperature remains constant.

8. The CMP apparatus according to claim 1, wherein the slurry supply unit further comprises a circulation pipe capable of circulating the slurry in the tank, a supply pipe capable of supplying the slurry flowing through the circulation pipe to the supply unit, and a discharge pipe capable of discharging the slurry from the tank, the tank having a stirring unit configured to stir the substance inside, and the control unit being configured to discharge the slurry in the tank through the discharge pipe, to introduce a cleaning liquid into the tank through the circulation pipe and then stir the cleaning liquid with the stirring unit to clean the inside of the tank, and to block the connection between the supply pipe and the circulation pipe and discharge the cleaning liquid from the discharge pipe to clean the circulation pipe and the discharge pipe.

9. The CMP apparatus according to claim 8, wherein the control unit is configured to allow the cleaning liquid to flow into the tank in response to a change in the temperature of the tank.

10. A control method for a CMP apparatus applied to a CMP apparatus, comprising: a polishing unit having a platen having a polishing pad; a polishing head that polishes a workpiece by rotating while pressing the workpiece against the polishing pad; and a supply unit that supplies slurry onto the platen; a slurry supply unit having a tank for collecting the slurry supplied onto the platen, and capable of adjusting the temperature of the slurry collected in the tank and supplying it to the supply unit; and a control unit configured to control the polishing unit and the slurry supply unit, wherein the control method for a CMP apparatus adjusts the temperature of the slurry in the tank according to the polishing status of the workpiece.

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