Polishing head and polishing device equipped with the same and substrate processing device

Abstract

Dust generated on the back side of the substrate by polishing with the polishing tool (96) is pushed out to the outer periphery of the polishing tool (96) by centrifugal force. Nitrogen gas is sprayed there from the nozzle (235). As a result, dust attached to the back side of the substrate is removed from the back side of the substrate. The dust is sucked in by the suction port (237). Therefore, it is difficult for dust to remain on the back side of the substrate, so the dust removal rate due to polishing can be increased.

Description

Technology Field

[0001] The present invention relates to a polishing head for polishing the back surface of a substrate, a polishing apparatus equipped with the same, and a substrate processing apparatus. Examples of substrates include semiconductor substrates, substrates for FPDs (Flat Panel Displays), glass substrates for photomasks, substrates for optical discs, substrates for magnetic discs, ceramic substrates, substrates for solar cells, etc. Examples of FPDs include liquid crystal display devices and organic EL (electroluminescence) display devices. Here, the back surface of a substrate refers to the side on which an electronic circuit is not formed, with respect to the surface of the substrate on which an electronic circuit is formed. Background Technology

[0002] There is a polishing device for polishing the back surface of a substrate, comprising a polishing tool, a head body, a concave portion, and a polishing head having a suction hole (for example, see Patent Document 1).

[0003] The grinding tool is equipped with a synthetic grinding wheel. The synthetic grinding wheel is formed by fixing abrasive material (grinding grains) with a resin binder. The synthetic grinding wheel is molded into a toroidal shape. The head body holds the grinding tool. The concave portion has an opening formed facing the back surface of the substrate. A suction hole is formed in the head body and communicates with the concave portion, connecting to a suction pump. Grinding using this grinding head is dry chemical mechanical grinding and is also called CMG (Chemo-Mechanical Grinding).

[0004] In a polishing device using a polishing head configured in this manner, the central part of the polishing hole is sucked in through the suction hole of the polishing head. Accordingly, dust generated by polishing with the polishing hole is sucked in by a suction pump through the suction hole. As a result, processing can be performed to minimize dust residue on the substrate surface. Prior art literature

[0005] Japanese Patent Publication No. 2020-4948 The problem to be solved

[0006] However, in the case of conventional examples having such a configuration, the following problems exist.

[0007] In other words, recently there has been a problem with defocus (so-called blurring) in EUV (Extreme Ultraviolet) lithography machines caused by the flatness of the back side of the substrate (e.g., wafer). The cause of poor flatness is thought to be particles, scratches, film residues, etc. Therefore, removing these using a polishing head is being considered.

[0008] However, conventional polishing heads only suction the central portion. Consequently, some of the dust generated near the outer periphery of the polishing tool is not removed by suction and remains attached to the substrate surface. As a result, the problem of defocusing is not resolved, raising concerns that it may adversely affect post-polishing processing. In other words, there is a problem with a low dust removal rate from the substrate surface resulting from polishing.

[0009] The present invention has been made in consideration of these circumstances and aims to provide a polishing head capable of increasing the dust removal rate resulting from polishing, a polishing device equipped with the same, and a substrate processing device. means of solving the problem

[0010] To achieve this objective, the present invention takes the following configuration.

[0011] That is, the invention described in claim 1 is characterized in that, in a polishing head for polishing a substrate, it comprises a polishing tool having a resin body in which abrasive particles are dispersed, a nozzle for spraying gas onto dust generated by polishing with said polishing tool, and a suction nozzle for sucking up dust generated by polishing with said polishing tool.

[0012] [Operation and Effect] According to the invention described in Claim 1, gas is sprayed from a nozzle onto dust generated by polishing with a polishing tool. As a result, dust attached to the substrate surface is removed from the substrate surface. The dust is then sucked in by a suction port. Consequently, it becomes difficult for dust to remain on the substrate surface, thereby increasing the dust removal rate resulting from polishing.

[0013] The invention described in claim 2 is preferably such that the nozzle is formed along the outer surface of the grinding nozzle, the suction nozzle is formed along the outer surface of the grinding nozzle, and is also formed symmetrically with respect to the nozzle when viewed in a planar view.

[0014] When viewed from a planar perspective, the outer surface of the grinding tool is divided symmetrically, with each section serving as a nozzle and a suction port. Consequently, a good balance between gas supply and suction can be maintained on the outer surface of the grinding tool. As a result, dust can be effectively removed.

[0015] In addition, in the present invention, it is preferable that the polishing hole is formed as an annular shape when viewed from a planar view, the spraying hole is formed in the center of the polishing hole, and the suction hole is formed along the entire circumference of the outer surface of the polishing hole (Claim 3).

[0016] Gas injected from the center is directed from the substrate surface toward the outer circumference of the grinding hole. Therefore, gas containing dust can be efficiently sucked in through the suction port.

[0017] In addition, in the present invention, the grinding member is preferably composed of a porous member having a hole, the nozzle is formed on the lower surface of the grinding member, and the suction hole is formed over the entire circumference of the outer side of the grinding member (Claim 4).

[0018] Gas can be supplied to the abrasive hole of a porous member and sprayed onto the dust from almost the entire surface of its underside. Therefore, the dust can be efficiently pushed outward.

[0019] In addition, in the present invention, it is preferable that the nozzle sprays gas discontinuously (Claim 5).

[0020] If gas is sprayed continuously, there are cases where dust is compressed against the substrate surface and cannot be removed. Therefore, if gas is sprayed intermittently and discontinuously, it is possible to make it easier to detach the dust.

[0021] In addition, the invention described in claim 6 is characterized in that, in a polishing device for polishing a substrate, it comprises a polishing head described in any one of claims 1 to 5, a head driving mechanism for rotating the polishing head around a vertical axis, a holding rotating part for rotating the substrate while maintaining the substrate in a horizontal position, a gas supply pipe for supplying gas to a nozzle of the polishing head, and a suction pipe for performing suction from a suction port of the polishing head.

[0022] [Operation and Effect] According to the invention described in claim 6, a polishing head is rotated around a vertical axis by a head driving mechanism. A substrate is rotated in a horizontal position by a holding rotating part. In this state, polishing is performed by bringing the polishing hole of the polishing head into contact with the substrate surface. At that time, gas is supplied to the polishing head through a gas supply pipe, so that dust attached to the substrate surface is removed from the substrate surface. In addition, the dust is sucked in through the suction port along with the gas through a suction pipe. Therefore, it becomes difficult for dust to remain on the substrate surface, so the dust removal rate during polishing can be increased.

[0023] In addition, the present invention further comprises a control valve for controlling the flow of gas in the gas supply pipe and a control unit for operating the control valve, wherein the control unit preferably operates the control valve so that the injection of gas from the polishing head is performed intermittently (Claim 7).

[0024] If gas is sprayed continuously, there are cases where dust is pressed against the substrate surface and cannot be removed. Therefore, the control unit operates the control valve to spray gas from the polishing head intermittently. Spraying gas intermittently makes it easier to remove the dust.

[0025] In addition, in the present invention, the control unit preferably operates the control valve so that the flow rate of the gas sprayed from the nozzle does not exceed the flow rate sucked from the suction pipe (Claim 8).

[0026] By controlling the flow rate in this way, dust is not sucked in from the suction port due to the injection of gas from the nozzle, thereby preventing it from scattering into the surroundings.

[0027] In addition, the substrate processing device described in claim 9 is characterized by having a polishing device described in any one of claims 1 to 6.

[0028] [Operation and Effect] According to the invention described in Claim 9, when polishing a substrate with a polishing device, the polishing head is rotated around a vertical axis by means of a head driving mechanism. The substrate is rotated in a horizontal position by means of a holding rotating part. In this state, polishing is performed by bringing the polishing hole of the polishing head into contact with the substrate surface. At that time, gas is supplied to the polishing head through a gas supply pipe, so that dust attached to the substrate surface is removed from the substrate surface. In addition, the dust is sucked in through the suction port along with the gas through a suction pipe. Therefore, it becomes difficult for dust to remain on the substrate surface, so the dust removal rate resulting from polishing can be increased. As a result, the substrate can be treated cleanly. Effects of the invention

[0029] According to the polishing head of the present invention, gas is sprayed from a nozzle onto dust generated by polishing with a polishing tool. As a result, dust attached to the substrate surface is detached from the substrate surface. The dust is then sucked in by a suction port. Consequently, it becomes difficult for dust to remain on the substrate surface, thereby increasing the dust removal rate resulting from polishing. Brief explanation of the drawing

[0030] FIG. 1 is a plan view showing the configuration of a substrate processing device according to Example 1. Figures 2 (a) to (d) are drawings for explaining an inversion unit. Figure 3 is a side view showing the configuration of the polishing unit. Figure 4 (a) is a plan view showing the configuration of the holding rotating part, and (b) is a cross-sectional view showing a partial enlargement of the configuration of the holding rotating part. Figure 5 is a diagram showing the configuration of the polishing mechanism of the polishing unit. Figure 6 is a diagram showing the configuration of an inspection unit. FIG. 7 is a flowchart showing the operation of a substrate processing device according to Example 1. Figure 8 (a) is a cross-sectional view schematically showing a substrate in a state before the etching process, (b) is a cross-sectional view schematically showing a substrate after the etching process (before the back polishing process), and (c) is a cross-sectional view schematically showing a substrate after the back polishing process. Figure 9 is a flowchart showing the details of the wet etching process. Figure 10 is a diagram showing the relationship between the heating temperature of the substrate and the polishing rate. Figure 11 is a flowchart showing the details of the substrate cleaning process. FIG. 12 is a drawing showing a preferred configuration of the polishing mechanism of a polishing unit. FIG. 13 is a cross-sectional view of a grinding head according to Example 1. FIG. 14 is a bottom view of a grinding head according to Example 1. FIG. 15 is a cross-sectional view of a grinding head according to Example 2. FIG. 16 is a bottom view of a grinding head according to Example 2. FIG. 17 is a cross-sectional view of a grinding head according to Example 3. FIG. 18 is a bottom view of a grinding head according to Example 3. Specific details for implementing the invention

[0031] The present invention will be explained below with reference to examples.

[0032] Example 1

[0033] Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing the configuration of a substrate processing apparatus according to Embodiment 1.

[0034] (1) Configuration of the substrate processing device

[0035] Refer to FIG. 1. A substrate processing device (1) comprises an indexer block (3) and a processing block (5). Additionally, the block is also referred to as a region.

[0036] The indexer block (3) is equipped with a plurality (e.g., 4) of carrier mounting stands (7) and an indexer robot (9). The 4 carrier mounting stands (7) are arranged on the outer surface of the housing (10). Each of the 4 carrier mounting stands (7) holds a carrier (C). The carrier (C) accommodates a plurality of substrates (W). Each substrate (W) within the carrier (C) is in a horizontal position with the device surface facing upward. For example, the carrier (C) can be a Front Open Unified Pod (FOUP), a Standard Mechanical Interface (SMIF) pod, or an open cassette. The substrate (W) is a silicon substrate and is formed, for example, in the shape of a disc.

[0037] The indexer robot (9) extracts a substrate (W) from a carrier (C) placed on each carrier mounting stand (7) and also stores the substrate (W) in the carrier (C). The indexer robot (9) is placed inside the housing (10). The indexer robot (9) has two hands (11) (11A, 11B), two multi-joint arms (13, 14), a lifting platform (15), and a guide rail (16). Each of the two hands (11) holds a substrate (W). The first hand (11A) is connected to the tip of the multi-joint arm (13). The second hand (11B) is connected to the tip of the multi-joint arm (14).

[0038] Each of the two multi-joint arms (13, 14) is configured, for example, as a scalar type. The base of each of the two multi-joint arms (13, 14) is mounted on a lifting platform (15). The lifting platform (15) is configured to be extendable in the vertical direction. As a result, the two hands (11) and the two multi-joint arms (13, 14) are raised. The lifting platform (15) is rotatable around a central axis (AX1) that extends in the vertical direction. As a result, the direction of the two hands (11) and the two multi-joint arms (13, 14) can be changed. The lifting platform (15) of the indexer robot (9) can move along a guide rail (16) that extends in the Y direction.

[0039] The indexer robot (9) is equipped with a plurality of electric motors. The indexer robot (9) is driven by a plurality of electric motors. The indexer robot (9) conveys a substrate (W) between a carrier (C) placed on each of the four carrier racks (7) and a reversal unit (RV) described later.

[0040] The processing block (5) is equipped with a return space (18), a substrate return robot (CR), an inversion unit (RV), and a plurality (e.g., 8) of processing units (processing chambers) (U1 to U4). In FIG. 1, each processing unit (U1 to U4) is configured in two layers, for example, in the vertical direction. Processing unit (U1) is an inspection unit (20). Processing units (U2, U3, U4) are polishing units (22). The number and type of processing units can be appropriately changed.

[0041] In the return space (18), a substrate return robot (CR) and an inversion unit (RV) are arranged. The inversion unit (RV) is arranged between the indexer robot (9) and the substrate return robot (CR). Processing units (U1, U3) are arranged side by side in the X direction along the return space (18). Additionally, processing units (U2, U4) are arranged side by side in the X direction along the return space (18). The return space (18) is arranged between the processing units (U1, U3) and the processing units (U2, U4).

[0042] The substrate transport robot (CR) is configured almost identically to the indexer robot (9). That is, the substrate transport robot (CR) has two hands (24). In addition, other components of the substrate transport robot (CR) are given the same designation as the indexer robot (9). Unlike the lifting platform (15) of the indexer robot (9), the lifting platform (CR) of the substrate transport robot (CR) is fixed to the floor surface. However, the lifting platform (15) of the substrate transport robot (CR) may be configured to move in the X direction by having a guide rail extending in the X direction. The substrate transport robot (CR) transports the substrate (W) between the inversion unit (RV) and eight processing units (U1 to U4).

[0043] (1-1) Reverse Unit (RV)

[0044] FIGS. 2(a) to FIGS. 2(d) are drawings for explaining an inversion unit (RV). The inversion unit (RV) is equipped with a support member (26), a mounting member (28A, 28B), a clamping member (30A, 30B), a slide shaft (32), and a plurality of electric motors (not shown). Mounting members (28A, 28B) are installed on the left and right support members (26), respectively. Also, clamping members (30A, 30B) are installed on the left and right slide shafts (32), respectively. The plurality of electric motors drive the support member (26) and the slide shaft (32). Additionally, the mounting members (28A, 28B) and the clamping members (30A, 30B) are installed in positions where they do not interfere with each other.

[0045] Refer to FIG. 2(a). A substrate (W), conveyed by, for example, an indexer robot (9), is placed on the placement members (28A, 28B). Refer to FIG. 2(b). The left and right slide axes (32) move closer together along the horizontal axis (AX2). As a result, the clamping members (30A, 30B) clamp two substrates (W). Refer to FIG. 2(c). After that, the left and right placement members (28A, 28B) move away from each other and descend. After that, the clamping members (30A, 30B) rotate 180° around the horizontal axis (AX2). As a result, each substrate (W) is inverted.

[0046] Refer to FIG. 2(d). After that, the left and right mounting members (28A, 28B) move closer together and rise. After that, the left and right slide axes (32) move further apart along the horizontal axis (AX2). As a result, the clamping of the two substrates (W) by the clamping members (30A, 30B) is opened, and the two substrates (W) are mounted on the mounting members (28A, 28B). In FIG. 2(a) to FIG. 2(d), the inversion unit (RV) can invert two substrates (W), but the inversion unit (RV) may be configured to invert three or more substrates (W).

[0047] (1-2) Grinding unit (22)

[0048] FIG. 3 is a drawing showing a polishing unit (22). The polishing unit (22) is equipped with a holding rotating part (35), a polishing mechanism (37), and a substrate thickness measuring device (39).

[0049] The holding rotation unit (35) holds a single substrate (W) in a horizontal position with the back side of the substrate (W) facing upward, and rotates the held substrate (W). Here, the back side of the substrate (W) refers to the side on which an electronic circuit is not formed, with respect to the surface of the substrate (W) on which an electronic circuit is formed (device side). The device side of the substrate (W) held by the holding rotation unit (35) is facing downward.

[0050] The holding rotation unit (35) is equipped with a spin base (41), six holding pins (43), a hot plate (45), and a gas discharge port (47). The spin base (41) is formed in a disc shape and is positioned in a horizontal position. A rotation axis (AX3) extending in the vertical direction passes through the center of the spin base (41). The spin base (41) can rotate around the rotation axis (AX3).

[0051] FIG. 4(a) is a plan view showing the spin base (41) and six retaining pins (43) of the retaining rotation part (35). The six retaining pins (43) are installed on the upper surface of the spin base (41). The six retaining pins (43) are installed in a ring shape to surround the rotation axis (AX3). Additionally, the six retaining pins (43) are installed at equal intervals on the outer edge side of the spin base (41). The six retaining pins (43) hold the substrate (W) away from the spin base (41) and the hot plate (45) described later. Furthermore, the six retaining pins (43) are configured to insert the side of the substrate (W). That is, the six retaining pins (43) can hold the substrate (W) while spaced apart from the upper surface of the spin base (41).

[0052] The six retaining pins (43) are divided into three retaining pins (43A) that rotate and three retaining pins (43B) that do not rotate. The three retaining pins (43A) can rotate around a rotation axis (AX4) that extends in the vertical direction. By rotating each retaining pin (43A) around the rotation axis (AX4), the three retaining pins (43A) hold the substrate (W) and release the held substrate (W). The rotation of each retaining pin (43A) around the rotation axis (AX4) is performed, for example, by magnetic attraction or repulsion force by a magnet. The number of retaining pins (43) is not limited to six, but can be three or more. The holding of the substrate (W) may be performed by three or more retaining pins (43), including the retaining pins (43A) that rotate and the retaining pins (43B) that do not rotate.

[0053] A hot plate (45) is installed on the upper surface of the spin base (41). The hot plate (45) is equipped with an electric heater, for example, having a nichrome wire, inside. The hot plate (45) is formed in a donut shape or a disc shape. The hot plate (45) heats the substrate (W) with radiant heat. In addition, the hot plate (45) also heats the gas discharged from the gas discharge port (47) described later, thereby heating the substrate (W) through the gas. The temperature of the substrate (W) is measured by a non-contact temperature sensor (46). The temperature sensor (46) is equipped with a detection element that detects infrared rays emitted by the substrate (W).

[0054] A shaft (49) is installed on the lower surface of the spin base (41). The rotation mechanism (51) has an electric motor. The rotation mechanism (51) rotates the shaft (49) around the rotation axis (AX3). That is, the rotation mechanism (51) rotates the substrate (W), which is held by six holding pins (43) (specifically three holding pins (43A)) installed on the spin base (41), around the rotation axis (AX3).

[0055] Refer to FIG. 3 and FIG. 4(b). A gas discharge port (47) is opened on the upper surface of the spin base (41) and formed in the central part of the spin base (41). A flow path (53) is formed in the center of the spin base (41) with an upward opening. Additionally, a discharge member (57) is installed in the flow path (53) through a plurality of spacers (55). The gas discharge port (47) is composed of a ring-shaped opening formed by the gap between the discharge member (57) and the flow path (53).

[0056] The gas supply pipe (59) is installed to pass through the shaft (49) and the rotating mechanism (51) along the rotation axis (AX3). The gas pipe (61) sends gas (e.g., an inert gas such as nitrogen) from the gas supply source (63) to the gas supply pipe (59). An opening / closing valve (V1) is installed in the gas pipe (61). The opening / closing valve (V1) supplies and stops the gas. When the opening / closing valve (V1) is in an open state, gas is discharged from the gas discharge port (47). When the opening / closing valve (V1) is in a closed state, gas is not discharged from the gas discharge port (47). The gas discharge port (47) discharges gas so that gas flows from the center side of the substrate (W) to the outer edge of the substrate (W) in the gap between the substrate (W) and the spin base (41).

[0057] Next, a configuration for supplying a chemical solution, a rinse solution, and a gas is described. The polishing unit (22) is equipped with a first chemical solution nozzle (65), a second chemical solution nozzle (67), a first cleaning solution nozzle (69), a second cleaning solution nozzle (71), a rinse solution nozzle (73), and a gas nozzle (75).

[0058] A chemical pipe (78) for sending a first chemical solution from a first chemical supply source (77) is connected to the first chemical solution nozzle (65). The first chemical solution is, for example, hydrofluoric acid (HF). An opening / closing valve (V2) is installed in the chemical solution pipe (78). The opening / closing valve (V2) controls the supply and stopping of the first chemical solution. When the opening / closing valve (V2) is in an open state, the first chemical solution is supplied from the first chemical solution nozzle (65). Also, when the opening / closing valve (V2) is in a closed state, the supply of the first chemical solution from the first chemical solution nozzle (65) is stopped.

[0059] A second chemical solution nozzle (67) is connected to a chemical solution pipe (81) for sending a second chemical solution from a second chemical solution supply source (80). The second chemical solution is, for example, a mixture of hydrofluoric acid (HF) and nitric acid (HNO3), TMAH (Tetramethylammonium hydroxide), or diluted ammonia hot water (Hot-dNH4OH). An opening / closing valve (V3) is installed in the chemical solution pipe (81). The opening / closing valve (V3) supplies and stops the second chemical solution.

[0060] A cleaning solution pipe (84) for sending a first cleaning solution from a first cleaning solution supply source (83) is connected to the first cleaning solution nozzle (69). The first cleaning solution is, for example, SC2 or SPM. SC2 is a mixture of hydrochloric acid (HCl), hydrogen peroxide (H2O2), and water. SPM is a mixture of sulfuric acid (H2SO4) and hydrogen peroxide (H2O2). An opening / closing valve (V4) is installed in the cleaning solution pipe (84). The opening / closing valve (V4) supplies the first cleaning solution and stops it.

[0061] A cleaning solution pipe (87) for sending a second cleaning solution from a second cleaning solution supply source (86) is connected to the second cleaning solution nozzle (71). The second cleaning solution is, for example, SC1. SC1 is a mixture of ammonia, hydrogen peroxide (H2O2), and water. An opening / closing valve (V5) is installed in the cleaning solution pipe (87). The opening / closing valve (V5) supplies and stops the second cleaning solution.

[0062] A rinse liquid pipe (90) for sending rinse liquid from a rinse liquid supply source (89) is connected to the rinse liquid nozzle (73). The rinse liquid is, for example, pure water or carbonated water such as DIW (Deionized Water). An opening / closing valve (V6) is installed in the rinse liquid pipe (90). The opening / closing valve (V6) supplies and stops the rinse liquid.

[0063] A gas pipe (93) for supplying gas from a gas supply source (92) is connected to the gas nozzle (75). The gas is an inert gas such as nitrogen. An opening / closing valve (V7) is installed in the gas pipe (93). The opening / closing valve (V7) supplies and stops the gas.

[0064] The first liquid nozzle (65) is moved horizontally by a nozzle moving mechanism (95). The nozzle moving mechanism (95) is equipped with an electric motor. The nozzle moving mechanism (95) may rotate the first liquid nozzle (65) around a preset vertical axis (not shown). Additionally, the nozzle moving mechanism (95) may move the first liquid nozzle (65) in the X and Y directions. Additionally, the nozzle moving mechanism (95) may move the first liquid nozzle (65) in the up and down direction (Z direction). Like the first liquid nozzle (65), the five nozzles (67, 69, 71, 73, 75) may each be moved by a nozzle moving mechanism (not shown).

[0065] Next, the configuration of the polishing mechanism (37) will be described. The polishing mechanism (37) polishes the back surface of the substrate (W). FIG. 5 is a side view showing the polishing mechanism (37). The polishing mechanism (37) is equipped with a polishing tool (96) and a polishing tool moving mechanism (97). The polishing tool moving mechanism (97) is equipped with a mounting member (98), a shaft (100), and an arm (101).

[0066] The grinding tool (96) grinds the back surface of the substrate (W) by a dry chemical mechanical grinding (CMG) method. The grinding tool (96) is formed in a cylindrical shape. The grinding tool (96) has a resin body in which abrasive particles are dispersed. In other words, the grinding tool (96) is formed by fixing abrasive particles (abrasive) with a resin binder. As abrasive particles, for example, oxides such as cerium oxide or silica are used. It is preferable that the average particle size of the abrasive particles be 10 μm or less. As the resin body and resin binder, thermosetting resins such as epoxy resin or phenolic resin are used, for example. Also, as the resin body and resin binder, thermoplastic resins such as ethyl cellulose may be used, for example. In this case, grinding is performed so that the thermoplastic resin does not soften.

[0067] Here, Chemical Mechanical Grinding (CMG) is described. It is believed that CMG grinds based on the following principle. That is, localized high temperature and high pressure near the abrasive grains, generated by the contact between abrasive grains such as cerium oxide and the workpiece, cause a solid-state reaction between the abrasive grains and the workpiece, thereby producing silicates. As a result, the surface layer of the workpiece becomes smooth, and the smoothed surface layer is mechanically removed by the abrasive grains. Additionally, there is a polishing method called Chemical Mechanical Polishing (CMP). This method involves supplying a slurry solution to a pad that contacts the workpiece, and chemical mechanical polishing is performed by maintaining the abrasive grains contained in the slurry solution on the irregularities of the pad's surface. The present invention adopts the CMG method.

[0068] The grinding member (96) is detachable from the mounting member (98), for example, by means of a screw. The mounting member (98) is fixed to the lower end of the shaft (100). A pulley (102) is fixed to the shaft (100). The upper end of the shaft (100) is received by the arm (101). That is, the grinding member (96) and the mounting member (98) are mounted to the arm (101) through the shaft (100).

[0069] An electric motor (104) and a pulley (106) are arranged within the arm (101). The pulley (106) is connected to the rotational output shaft of the electric motor (104). A belt (108) is placed over the two pulleys (102, 106). The pulley (106) is rotated by the electric motor (104). The rotation of the pulley (106) is transmitted to the pulley (102) and the shaft (100) by the belt (108). As a result, the grinding tool (96) rotates around the vertical axis (AX5).

[0070] Additionally, the grinding tool moving mechanism (97) is equipped with a lifting mechanism (110). The lifting mechanism (110) is equipped with a guide rail (111), an air cylinder (113), and an electric regulator (115). The base portion of the arm (101) is connected to the guide rail (111) so as to be vertically movable. The guide rail (111) guides the arm (101) in the vertical direction. The air cylinder (113) raises the arm (101). The electric regulator (115) supplies a gas, such as air, at a set pressure based on an electric signal from the main control unit (134) described later to the air cylinder (113). Additionally, the lifting mechanism (110) may be equipped with a linear actuator driven by an electric motor instead of the air cylinder (113).

[0071] Additionally, the grinding tool moving mechanism (97) is equipped with an arm rotation mechanism (117). The arm rotation mechanism (117) is equipped with an electric motor. The arm rotation mechanism (117) rotates the arm (101) and the lifting mechanism (110) around the vertical axis (AX6). That is, the arm rotation mechanism (117) rotates the grinding tool (96) around the vertical axis (AX6).

[0072] The polishing unit (22) is equipped with a substrate thickness measuring device (39). The substrate thickness measuring device (39) measures the thickness of the substrate (W) held in the holding rotating part (35). The substrate thickness measuring device (39) is configured to irradiate light from a light source to the mirror and the substrate (W) through an optical fiber, with light in a wavelength range (e.g., 1100 nm to 1900 nm) that is permeable to the substrate (W). Additionally, the substrate thickness measuring device (39) is configured to detect a return light by a light receiving element that interferes with the reflected light from the mirror, the reflected light reflected from the upper surface of the substrate (W), and the reflected light reflected from the lower surface of the substrate (W). Furthermore, the substrate thickness measuring device (39) is configured to generate a spectral interference waveform representing the relationship between the wavelength and light intensity of the return light, and to measure the thickness of the substrate (W) by analyzing this spectral interference waveform. The substrate thickness measuring device (39) is a known device. The substrate thickness measuring device (39) may be configured to move between a standby position outside the substrate and a measuring position above the substrate (W) by means of a moving mechanism not shown.

[0073] (1-3) Inspection unit (20)

[0074] FIG. 6 is a side view showing an inspection unit (20). The inspection unit (20) is equipped with a stage (121), an XY direction movement mechanism (122), a camera (124), a light (125), a laser scanning confocal microscope (127), a lifting mechanism (128), and an inspection control unit (130).

[0075] The stage (121) supports the substrate (W) in an upward and horizontal position on its back side. The stage (121) is equipped with a disc-shaped base member (131) and, for example, six support pins (132). The six support pins (132) are installed in a ring shape around the central axis (AX7) of the base member (131). Additionally, the six support pins (132) are arranged at equal intervals in the circumferential direction. With this configuration, the six support pins (132) can support the outer edge of the substrate (W) while keeping the substrate (W) separated from the base member (131). Additionally, the XY direction movement mechanism (122) moves the stage (121) in the XY direction (horizontal direction). The XY direction movement mechanism (122) is equipped with two linear actuators, for example, each driven by an electric motor.

[0076] The camera (124) photographs the back side of the substrate (W). The camera (124) is equipped with an image sensor such as a CCD (charge-coupled device) or CMOS (complementary metal-oxide semiconductor). The illumination (125) irradiates light onto the back side of the substrate (W). This makes it easier to observe, for example, scratches that occur on the back side of the substrate (W).

[0077] A laser scanning confocal microscope (127) is hereinafter referred to as "laser microscope (127)". The laser microscope (127) is equipped with a laser light source, an objective lens (127A), an imaging lens, a light sensor, and a confocal optical system having a confocal pinhole. The laser microscope (127) acquires a planar image by scanning the laser light source in the XY direction (horizontal direction). Additionally, the laser microscope (127) acquires a planar image while moving the objective lens (127A) in the Z direction (height direction) relative to the object being observed. As a result, the laser microscope (127) acquires a three-dimensional image (multiple planar images) containing a three-dimensional shape. Additionally, the laser microscope (127) is referred to as a three-dimensional shape measuring device.

[0078] A laser microscope (127) acquires a three-dimensional image of any scratch that occurs on the back surface of a substrate (W). For example, a control unit described later measures the depth of the scratch from the three-dimensional shape of the scratch in the acquired three-dimensional image. A lifting mechanism (128) raises and lowers the laser microscope (127) in the vertical direction (Z direction). The lifting mechanism (128) is composed of a linear actuator driven by an electric motor.

[0079] The inspection control unit (130) is equipped with one or more processors, such as a central processing unit (CPU), and a memory unit (not shown). The inspection control unit (130) controls each component of the inspection unit (20). The memory unit of the inspection control unit (130) is equipped with at least one of ROM (Read-only Memory), RAM (Random-Access Memory), and a hard disk. The memory unit of the inspection control unit (130) stores a computer program for operating the inspection unit (20), an observation image, a result of extracting a scratch, and a three-dimensional image.

[0080] Additionally, the substrate processing device (1) is equipped with a main control unit (134) and a memory unit (not shown) that are connected to communicate with the inspection control unit (130). The main control unit (134) is equipped with one or more processors, such as a central processing unit (CPU). The main control unit (134) controls each component of the substrate processing device (1). In addition, the memory unit of the main control unit (134) is equipped with at least one of ROM (Read-only Memory), RAM (Random-Access Memory), and a hard disk. The memory unit of the main control unit (134) stores computer programs, etc., for operating the substrate processing device (1).

[0081] (2) Operation of the substrate processing device (1)

[0082] Next, with reference to FIG. 7, the operation of the substrate processing device (1) will be explained.

[0083] [Step S01] Removal of substrate (W) from carrier (C)

[0084] A carrier (C) is placed on a predetermined carrier mounting stand (7). The indexer robot (9) extracts a substrate (W) from the carrier (C) and returns the extracted substrate (W) to an inversion unit (RV). At this time, the device surface of the substrate (W) is upward, and the back surface of the substrate (W) is downward.

[0085] [Step S02] Inversion of the substrate (W)

[0086] When one or two substrates (W) are placed on the placement members (28A, 28B) by the indexer robot (9), the inversion unit (RV) inverts the two substrates (W) as shown in FIG. 2 (a) to FIG. 2 (d). As a result, the back side of the substrate (W) becomes upward.

[0087] The substrate transport robot (CR) extracts the substrate (W) from the inversion unit (RV) and transports the substrate (W) to one of the two inspection units (20). On the stage (121) of the inspection unit (20) shown in FIG. 6, a substrate (W) with its back side facing upward is placed.

[0088] [Step S03] Scratch Observation

[0089] The inspection unit (20) inspects the back surface of the substrate (W). The inspection unit (20) detects scratches, particles, and other protrusions. In this embodiment, in particular, the case of detecting scratches formed on the back surface of the substrate (W) is described.

[0090] In the inspection unit (20) shown in FIG. 6, the illumination (125) irradiates light toward the back surface of the substrate (W). The camera (124) captures the back surface of the substrate (W) to which the light is irradiated and acquires an observation image. The shooting by the camera (124) may be performed while moving the stage (121) on which the substrate (W) is placed by the XY direction movement mechanism (122). Large and small scratches are imprinted on the acquired observation image. The inspection control unit (130) performs image processing on the observation image and extracts one or more scratches by making the part where the reflected light is relatively strong, that is, the part having a brightness greater than a preset threshold, the target for polishing. In addition, the inspection control unit (130) may extract the scratches to be polished based on the length of the scratches.

[0091] Additionally, the inspection unit (20) measures the depth of the scratch when it detects a scratch. For example, when multiple scratches are detected (extracted), the inspection unit (20) measures the depth of one or more representative scratches among them. The measurement of the scratch depth will be explained.

[0092] The lifting mechanism (128) (Fig. 6) lowers the laser microscope (127) to a preset height position. In addition, the XY direction movement mechanism (122) moves the stage (121) so that the scratch of the measurement target is positioned below the objective lens (127A) of the laser microscope (127). The movement of the stage (121) is performed based on the coordinates of the scratch extracted in the observation image. The laser microscope (127) irradiates laser light from the objective lens (127A) onto the scratch (whole or part) and its surroundings, and collects reflected light through the objective lens (127A). As a result, the laser microscope (127) acquires a three-dimensional image including a three-dimensional shape.

[0093] The inspection control unit (130) performs image processing on a three-dimensional image and measures the depth of the scratch. FIG. 8 (a) is a cross-sectional view to explain the state of the substrate (W) before the etching process. In FIG. 8 (a), for example, a thin film such as silicon oxide, silicon nitride, or polysilicon is formed on the back surface of the substrate (W). Also, the scratch (SH1) on the left side of FIG. 8 (a) is assumed to reach the bare silicon (BSi). In this case, the inspection control unit (130) measures the depth (value DP1) of the scratch (SH1) from the three-dimensional image obtained by the laser microscope (127).

[0094] After observing for scratches, etc., the substrate transport robot (CR) transports the substrate (W) from the stage (121) of the inspection unit (20) to one of the six polishing units (22) (U2~U4). The substrate (W), with its back side facing upward, is placed on the holding rotation part (35) of the polishing unit (22). Then, a magnet not shown rotates the three holding pins (43A) shown in FIG. 4 (a) around the rotation axis (AX4). As a result, the three holding pins (43A) hold the substrate (W). Here, the substrate (W) is held in a state separated from the spin base (41) and the hot plate (45).

[0095] Here, before the next wet etching process, the substrate thickness measuring device (39) measures the thickness of the substrate (W). The thickness (TK1) of the substrate (W) is obtained as shown in FIG. 8 (a).

[0096] [Step S04] Wet etching

[0097] If a thin film such as a silicon oxide film, a silicon nitride film, or a polysilicon film is formed on the back side of the substrate (W), the back side of the substrate (W) cannot be polished well by the polishing tool (96). These films may be films that are unintentionally formed during the manufacturing process of the device, or films that are intentionally formed to suppress warping of the substrate (W). Therefore, the polishing unit (22) removes the film (F1) formed on the back side of the substrate (W) by supplying a first chemical solution (etching solution) to the back side of the substrate (W).

[0098] FIG. 9 is a flowchart illustrating the details of the wet etching process of step S04. First, a removal process of the silicon oxide film and the silicon nitride film is performed (step S21).

[0099] Here, a gas discharge port (47) formed in the center of the spin base (41) discharges gas. That is, the gas discharge port (47) discharges gas so that gas flows from the center side of the substrate (W) to the outer edge of the substrate in the gap between the substrate (W) and the spin base (41). The device surface (surface) of the substrate (W) faces the spin base (41). When gas is discharged from the gas discharge port (47), gas is ejected outward from the gap between the outer edge of the substrate (W) and the spin base (41). For example, it prevents liquids such as polishing residue or the first chemical solution from adhering to the device surface of the substrate (W). That is, the device surface can be protected. In addition, due to the Bernoulli effect, a force acting to adsorb the substrate (W) to the spin base (41) is applied.

[0100] The nozzle moving mechanism (95) moves the first chemical solution nozzle (65) from a standby position outside the substrate to any processing position above the substrate (W). The holding rotating part (35) rotates the substrate (W) while maintaining the substrate (W) in a horizontal position. Then, the first chemical solution (e.g., hydrofluoric acid) is supplied from the first chemical solution nozzle (65) to the back surface of the rotating substrate (W). As a result, the silicon oxide film and silicon nitride film formed on the back surface of the substrate (W) can be removed.

[0101] Additionally, the first chemical solution may be supplied while moving the first chemical solution nozzle (65) horizontally. Also, after stopping the supply of the first chemical solution from the first chemical solution nozzle (65), the first chemical solution nozzle (65) is moved to a standby position outside the substrate.

[0102] After that, a rinsing treatment is performed (step S22). That is, a rinsing liquid (e.g., DIW or carbonated water) is supplied from the rinsing liquid nozzle (73) to the center of the rotating substrate (W). As a result, the first chemical solution remaining on the back surface of the substrate (W) is washed out of the substrate. After that, a drying treatment is performed (step S23). That is, the supply of rinsing liquid from the rinsing liquid nozzle (73) is stopped. Then, the holding rotating part (35) dries the substrate (W) by rotating the substrate (W) at high speed. At this time, gas may be supplied to the back surface of the substrate (W) from the gas nozzle (75) moved upward of the substrate (W). Additionally, the drying treatment may be performed by supplying gas from the gas nozzle (75) without rotating the substrate (W) at high speed.

[0103] After steps S21 to S23, a polysilicon film removal process is performed (step S24). The second chemical nozzle (67) is moved from a standby position outside the substrate to any processing position above the substrate (W). The holding rotation unit (35) rotates the substrate (W) at a preset rotation speed. Then, a second chemical solution (e.g., a mixture of hydrofluoric acid (HF) and nitric acid (HNO3)) is supplied from the second chemical nozzle (67) to the back surface of the rotating substrate (W). As a result, the polysilicon film formed on the back surface of the substrate (W) can be removed.

[0104] The second liquid may be supplied while moving the second liquid nozzle (67) in a horizontal direction. Also, after stopping the supply of the second liquid from the second liquid nozzle (67), the second liquid nozzle (67) is moved to a standby position outside the substrate.

[0105] After that, a rinsing treatment (step S25) is performed approximately the same as in the case of the first chemical solution (steps S22, S23), and then a drying treatment (step S26) is performed. The holding rotating part (35) stops the rotation of the substrate (W).

[0106] [Step S05] Backside polishing of the substrate (W)

[0107] After the etching process, the polishing unit (22) polishes the back side of the substrate (W). This polishing is performed when a scratch, in particular, is detected on the back side of the substrate (W) by the inspection unit (20). It will be explained in detail.

[0108] The holding rotation part (35) rotates the substrate (W) while maintaining it in a horizontal position. The arm rotation mechanism (117) (Fig. 5) of the polishing mechanism (37) rotates the polishing tool (96) and the arm (101) around the vertical axis (AX6). As a result, the polishing tool (96) is moved from a standby position outside the substrate to a preset position above the substrate (W). Additionally, the electric motor (104) of the polishing mechanism (37) rotates the polishing tool (96) around the vertical axis (AX5) (shaft (100)).

[0109] Additionally, the hot plate (45) generates heat through the application of electricity and heats the substrate (W). The temperature of the substrate (W) is monitored by a non-contact temperature sensor (46). The main control unit (134) adjusts the heat generated by the hot plate (45) based on the temperature of the substrate (W) detected by the temperature sensor (46). The heating temperature of the substrate (W) is adjusted to a temperature higher than room temperature (e.g., 25°C) to obtain a high polishing rate. However, it is preferable to adjust it to 100°C or lower to avoid thermal degradation of the polishing tool (96).

[0110] After that, the electric regulator (115) supplies gas at pressure based on an electric signal to the air cylinder (113). As a result, the air cylinder (113) lowers the polishing tool (96) and the arm (101) to bring the polishing tool (96) into contact with the back surface of the substrate (W). The polishing tool (96) is pressed against the back surface of the substrate (W) with a preset contact pressure. As a result, polishing is performed. When polishing is performed, the arm rotation mechanism (117) (Fig. 5) of the polishing mechanism (37) oscillates the polishing tool (96) and the arm (101) around the vertical axis (AX6). That is, the polishing tool (96) repeats a reciprocating motion between, for example, the center side position and the outer side position of the back surface of the substrate (W).

[0111] In addition, regarding the amount of polishing in the thickness direction (Z direction) of the substrate (W), it is thought that polishing is unnecessary if the substrate (W) satisfies a preset flatness even if scratches are present. However, there is a risk that the edges of the scratches may create new damage, for example, on the stage of the exposure machine. Therefore, polishing is performed until scratches of a preset size are removed.

[0112] As shown in FIG. 8(a), the depth of the scratch (SH1) (value DP1) is obtained by a laser microscope (127). Accordingly, the polishing unit (22) polishes the back surface of the substrate (W) until the thickness corresponding to the depth of the scratch (SH1) (value DP1) measured by the laser microscope (127) is removed. The thickness corresponding to the depth of the scratch (SH1) is value DP1. Polishing is performed until the thickness of the substrate (W) becomes value TK2 (=TK1-DP1). The thickness of the substrate (W) is periodically measured by a substrate thickness measuring device (39). The main control unit (134) compares the measured value of the substrate thickness with the target value (e.g., value TK2), and if the measured value has not reached the target value, controls the polishing to continue.

[0113] Additionally, FIG. 8(b) is a diagram showing the state after the etching process (step S04). When the film (FL) is removed by the etching process, the depth of the scratch (SH1) becomes shallow. Consequently, the amount of polishing in the vertical direction is reduced, but the thickness of the substrate (W) is polished to a value TK2, which remains unchanged. FIG. 8(c) is a diagram showing the state after the polishing process (step S05). Additionally, the scratch (SH2) shown in FIG. 8(a) does not reach the bare silicon. Such scratches are removed along with the removal of the film (FL), such as a silicon oxide film.

[0114] The substrate (W) is heated by a hot plate (45). FIG. 10 is a diagram showing the relationship between the heating temperature of the substrate (W) and the polishing rate. The contact pressure of the polishing tool (96) and the rotational speed of the substrate (W) are constant. Here, for example, compared to the case where the temperature of the substrate (W) is room temperature (e.g. 25°C), if the temperature TM2 of the substrate (W) is increased, the polishing rate increases. Therefore, by heating the substrate (W) by the hot plate (45), the polishing rate can be increased. Therefore, the time for the polishing process can be shortened.

[0115] The polishing unit (22) may adjust the polishing rate by controlling the heating temperature of the substrate (W) by the hot plate (45) when performing polishing. The polishing rate may be adjusted by raising and lowering the heating temperature of the substrate (W). The polishing rate may be adjusted before polishing or during polishing. For example, the polishing rate may be different between the center side of the substrate (W) and the outer side of the substrate (W) by changing the temperature of the substrate (W) between the center side of the substrate (W) and the outer side of the substrate (W). Additionally, the polishing tool (96) is moved to the standby position of the substrate (W).

[0116] [Step S06] Cleaning of the substrate (W)

[0117] After polishing the back side of the substrate (W), the back side of the substrate (W) is cleaned. This removes polishing residue remaining on the back side of the substrate (W), as well as metal, organic matter, and particles. FIG. 11 is a flowchart showing the details of the cleaning process of step S06.

[0118] First, a first cleaning solution is supplied to the back surface of the substrate (W) (step S31). This will be explained in detail. The holding rotating part (35) continues to hold the substrate (W). Additionally, the holding rotating part (35) continues to protect the device surface of the substrate (W) by discharging gas from the gas discharge port (47). The first cleaning solution nozzle (69) is moved from a standby position outside the substrate to any processing position above the substrate (W). The holding rotating part (35) rotates the substrate (W). After that, the first cleaning solution (e.g. SC2 or SPM) is supplied from the first cleaning solution nozzle (69) to the back surface of the rotating substrate (W). The first cleaning solution may be supplied while moving the first cleaning solution nozzle (69) in a horizontal direction.

[0119] After the first cleaning solution is supplied and the cleaning treatment is performed, a rinsing treatment is performed (step S32). That is, a rinsing solution (DIW or carbonated water) is supplied from the rinsing solution nozzle (73) to the center of the rotating substrate (W). As a result, the first cleaning solution remaining on the back surface of the substrate (W) is washed away. After that, a drying treatment is performed (step S33). That is, the supply of rinsing solution from the rinsing solution nozzle (73) is stopped. Then, the holding rotating part (35) dries the substrate (W) by rotating the substrate (W) at high speed. At this time, gas may be supplied to the back surface of the substrate (W) from the gas nozzle (75) moved upward of the substrate (W). Additionally, the drying treatment may be performed by supplying gas from the gas nozzle (73) without rotating the substrate (W) at high speed.

[0120] After steps S31 to S33, a second cleaning solution is supplied (step S34). That is, the second cleaning solution nozzle (71) is moved from a standby position outside the substrate to any processing position above the substrate (W). The holding rotation unit (35) rotates the substrate (W) at a preset rotational speed. Then, the second cleaning solution (e.g., SC1) is supplied from the second cleaning solution nozzle (71) to the back surface of the rotating substrate (W).

[0121] The second cleaning solution may be supplied while moving the second cleaning solution nozzle (71) in a horizontal direction. After stopping the supply of the second cleaning solution from the second cleaning solution nozzle (71), the second cleaning solution nozzle (71) is moved to a standby position outside the substrate.

[0122] After that, a rinsing treatment (step S35) is performed approximately the same way as in the case of the first cleaning solution (steps S32, S33), and then a drying treatment (step S36) is performed. The holding rotating part (35) stops the rotation of the substrate (W). Since the polishing unit (22) of this embodiment has a cleaning function, the substrate (W) from which polishing residue has been cleaned can be removed from the polishing unit (22).

[0123] [Step S07] Inversion of the substrate (W)

[0124] The substrate transport robot (CR) takes out the substrate (W) from the polishing unit (22) and transports the substrate (W) to the inversion unit (RV). At this time, the back side of the substrate (W) is upward, and the device side of the substrate (W) is downward. When one or two substrates (W) are placed on the placement member (28A, 28B) by the substrate transport robot (CR), the inversion unit (RV) inverts the two substrates (W), as shown in FIG. 2 (a) to FIG. 2 (d). As a result, the back side of the substrate (W) becomes downward.

[0125] [Step S08] Storage of the substrate (W) into the carrier (C)

[0126] The indexer robot (9) extracts the substrate (W) from the inversion unit (RV) and returns the substrate (W) to the carrier (C).

[0127] According to the present embodiment, the polishing unit (22) comprises a holding rotating part (35), a hot plate (45) (heating means), and a polishing tool (96). The polishing tool (96) contacts the back surface of a rotating substrate (W) and polishes the back surface of the substrate (W) by a chemical mechanical grinding (CMG) method. When this polishing is performed, the substrate (W) is heated by the hot plate (45). When the substrate (W) is heated, the polishing rate can be increased (see FIG. 10). Therefore, the time for the polishing process can be shortened.

[0128] Additionally, the inspection unit (20) that inspects the substrate (W) detects a scratch formed on the back surface of the substrate (W) before polishing the back surface of the substrate (W). Additionally, the inspection unit (20) polishes the back surface of the substrate (W) when a scratch is detected. As a result, the detected scratch, i.e., the selected scratch, can be removed.

[0129] Additionally, the inspection unit (20) measures the depth of the scratch when a scratch is detected. The polishing unit (22) polishes the back surface of the substrate (W) until a thickness corresponding to the depth of the scratch measured by the inspection unit (20) is removed. As a result, the depth of the scratch is recognized, so the amount of polishing in the thickness direction of the substrate (W) can be appropriately adjusted.

[0130] (1-4) Grinding head (201)

[0131] Here, with reference to FIG. 12, a preferred configuration of the polishing mechanism (37) described above will be explained. FIG. 12 is a drawing showing a preferred configuration of the polishing mechanism of a polishing unit.

[0132] This polishing mechanism (37A) is different in configuration from the polishing mechanism (37) described above in the following respects.

[0133] A polishing head (201) is mounted on the mounting member (98). The polishing head (201) is equipped with a polishing tool (96).

[0134] The shaft (100) on which the mounting member (98) is mounted has a gas supply pipe (203) and a suction pipe (205) inside. The gas supply pipe (203) and the suction pipe (205) are installed side by side within the shaft (100). The gas supply pipe (203) and the suction pipe (205) are inserted and pass through the shaft (100). The gas supply pipe (203) and the suction pipe (205) are connected in communication with a rotary joint (207). The rotary joint (207) has a fixed side body (209) and a rotating side body (211). The fixed side body (209) is fixed to the arm (101). The rotating side body (211) is mounted on the shaft (100). The rotary joint (207) can allow at least two fluids to flow between a fixed side body (209) fixed to an arm (101) and a rotating side body (211) that rotates together with a shaft (100).

[0135] A gas supply pipe (203) extending from a rotary joint (207) has one end connected to a gas supply source (213). The gas supply source (213) supplies gas. The gas is preferably an inert gas. The inert gas is, for example, nitrogen gas. The gas supply pipe (203) is equipped with a flow control valve (215) and an opening / closing valve (217). The flow control valve (215) controls the flow rate of the gas flowing through the gas supply pipe (203). The opening / closing valve (217) allows or blocks the flow of gas in the gas supply pipe (203).

[0136] A suction pipe (205) extending from a rotary joint (207) has one end connected to a suction source (219). The suction source (219) sucks into the interior of the suction pipe (205). The suction source (219) sucks in gas. The suction source (219) is, for example, a suction pump or a utility for suction installed in a clean room. The suction pipe (205) is equipped with an opening / closing valve (221). The opening / closing valve (221) allows or blocks the flow of gas in the suction pipe (205).

[0137] The above-described opening / closing valves (217, 221) and the flow control valve (215) are operated by the main control unit (134).

[0138] Here, refer to FIGS. 13 and FIGS. 14. FIG. 13 is a longitudinal cross-sectional view of a polishing head according to Example 1. FIG. 14 is a bottom cross-sectional view of a polishing head according to Example 1.

[0139] The polishing head (201) is equipped with a polishing tool (96), a head body (223), and a cover (225). The polishing tool (96) is mounted on the lower surface of the head body (223). The head body (223) forms a first fluid path (227) and a second fluid path (229). The first fluid path (227) and the second fluid path (229) are not connected to each other. The first fluid path (227) and the second fluid path (229) are connected to the upper surface and the outer surface of the head body (223). For example, the first fluid path (227) has openings (231) formed at three locations on the outer surface of the head body (223). For example, the second fluid path (229) has openings (233) formed at three locations on the outer surface of the head body (223). It is preferable that the first Euro (227) and the second Euro (229) be formed to be symmetric with respect to a straight line passing through the vertical axis (AX5) when viewed in a plane.

[0140] The cover (225) is mounted on the head body (223). The cover (225) is mounted on the outer surface of the head body (223). The cover (225) has a shape that slopes outward from a horizontally extended portion, for example. In other words, the cover (225) has a trapezoidal shape. The bottom of the cover (225) is positioned higher than the bottom surface of the polishing tool (96). This is to prevent the cover (225) from interfering with the substrate (W) even if the polishing tool (96) is worn out. The cover (225) is provided with a first cover (225a) and a second cover (225b). The first cover (225a) and the second cover (225b) are formed to be symmetrical with respect to a straight line passing through the vertical axis (AX5) when viewed from a plane.

[0141] The first cover (225a) covers the side of the opening (231). The second cover (225b) covers the side of the opening (233). The lower part of the first cover (225a) forms a nozzle (235). The lower part of the second cover (225b) forms a suction port (237). The nozzle (235) is formed along half a turn of the outer surface of the grinding port (96). The suction port (237) is formed along half a turn of the outer surface of the grinding port (96). The suction port (237) is formed so as to be symmetrical with respect to the nozzle (235) with respect to a straight line passing through the vertical axis (AX5) when viewed from a plane.

[0142] The polishing head (201) has a first flow path (227) connected to the other end of the gas supply pipe (203). The polishing head (201) has a second flow path (229) connected to the other end of the suction pipe (205). In other words, the nozzle (235) is connected to the gas supply source (213). The suction port (237) is connected to the suction source (219).

[0143] The polishing unit (22) configured as described above performs polishing of the substrate (W) as follows, for example. In addition, the operation of the arm (101), etc., is as described above.

[0144] The main control unit (134) performs operations for the supply and suction of gas. Specifically, the main control unit (134) sets the flow rate control valve (215) to a predetermined supply flow rate. It is preferable that this predetermined supply flow rate be set within a range that does not exceed the flow rate sucked from the suction pipe (205). The main control unit (134) opens the opening / closing valves (217, 221) at the timing when the polishing process begins, or at a slightly earlier timing. As a result, nitrogen gas is supplied to the gas supply pipe (203) at a predetermined supply flow rate, and gas is sucked from the suction pipe (205).

[0145] In addition, the aforementioned grinding tool moving mechanism (97) corresponds to the "head driving mechanism" in the present invention. The aforementioned grinding unit (22) corresponds to the "grinding device" in the present invention. The aforementioned flow rate adjustment valve (215) and opening / closing valve (217) correspond to the "control valve" in the present invention. The aforementioned main control unit (134) corresponds to the "control unit" in the present invention.

[0146] According to the present embodiment, dust generated on the back surface of the substrate (W) by polishing with a polishing tool (96) rotating around a vertical axis (AX5) is pushed out to the outer periphery of the polishing tool (96) by centrifugal force. Nitrogen gas is sprayed there from the nozzle (235). As a result, dust attached to the back surface of the substrate (W) is removed from the back surface of the substrate (W). The dust is sucked in by the suction port (237). Therefore, it becomes difficult for dust to remain on the back surface of the substrate (W), so the dust removal rate resulting from polishing can be increased.

[0147] In addition, in this embodiment, the outer surface of the grinding tool (96) is divided symmetrically when viewed from a planar perspective, and each is designated as a nozzle (235) and a suction port (237). Therefore, the balance between the supply and suction of nitrogen gas on the outer surface of the grinding tool (96) can be maintained well. Consequently, dust can be effectively removed.

[0148] In addition, according to the present embodiment, the flow rate of nitrogen gas from the nozzle (235) is set so as not to exceed the flow rate by suction. Because of this, dust is not sucked in from the suction port (237) due to the injection of nitrogen gas from the nozzle (235), and can be prevented from scattering to the surroundings.

[0149] Additionally, the main control unit (134) preferably operates the flow rate adjustment valve (215) to vary the flow rate of nitrogen gas over time. In this case, the flow rate includes a flow rate of 0, where no nitrogen gas is supplied. As a result, the flow rate of nitrogen gas sprayed from the nozzle (235) becomes inconsistent. In other words, the supply of nitrogen gas is not constant and becomes discontinuous or intermittent. Also, the main control unit (134) may operate the opening and closing of the shut-off valve (217) while keeping the flow rate constant without operating the flow rate adjustment valve (215). As a result, the injection of nitrogen gas from the nozzle (235) is performed discontinuously or intermittently.

[0150] If nitrogen gas is continuously injected, dust may be compressed against the back surface of the substrate (W), making it difficult to smoothly suction and remove it. Therefore, the main control unit (134) operates the flow control valve (215) or the opening / closing valve (217) to inject nitrogen gas from the polishing head (201) intermittently. When nitrogen gas is injected intermittently, a state occurs in which the pressure exerted by the nitrogen gas is temporarily weakened, making it easier to remove the dust.

[0151] Example 2

[0152] Hereinafter, Embodiment 2 of the present invention will be described with reference to the drawings. In addition, the configuration excluding the polishing head (201A) is the same as the embodiment described above.

[0153] Refer to FIGS. 15 and FIGS. 16. FIG. 15 is a longitudinal cross-sectional view of a polishing head according to Example 2. FIG. 16 is a bottom cross-sectional view of a polishing head according to Example 2.

[0154] The polishing head (201A) is equipped with a polishing tool (96A), a head body (223A), and a cover (225A). The polishing tool (96A) is mounted on the lower surface of the head body (223A). The head body (223A) has a first fluid passage (241) and a second fluid passage (243) formed therein. The first fluid passage (241) and the second fluid passage (243) are not in communication with each other. An opening (245) is formed on the lower surface of the head body (223A) in the first fluid passage (241). The first fluid passage (241) is nearly aligned with the vertical axis (AX5). The second fluid passage (243) is in communication with the upper surface and the outer surface of the head body (223A). The second flow path (243) has, for example, four openings (247) formed on the outer surface of the head body (223A). The second flow path (243) is also connected at four locations on the upper surface of the head body (223A), for example. It is preferable that the positional relationship of the openings (247) in the second flow path (243) be equal when viewed from a plane. This allows for even suction.

[0155] The cover (225A) is mounted on the head body (223A). The cover (225A) is mounted on the outer surface of the head body (223A). The cover (225A) has a shape that hangs downward from, for example, a horizontally extended portion. The bottom of the cover (225A) is located higher than the bottom surface of the grinding hole (96A). The bottom of the cover (225A) forms a suction port (248).

[0156] The grinding hole (96A) has a through hole (249) formed in the center. The grinding hole (96A) appears circular when viewed from a plane. When viewed from a plane, the through hole (249) overlaps almost with the vertical axis (AX5). When viewed from a plane, the through hole (249) overlaps with the first flow path (241). The through hole (249) communicates with the first flow path (241). Among the through holes (249), the opening communicating with the lower surface of the grinding hole (96A) is the nozzle (251).

[0157] The polishing head (201A) has a first flow path (241) connected to the other end of the gas supply pipe (203). The polishing head (201A) has a second flow path (243) connected to the other end of the suction pipe (205). In other words, the nozzle (251) is connected to the gas supply source (213). The suction port (248) is connected to the suction source (219).

[0158] According to the present embodiment, nitrogen gas sprayed from the center of the polishing hole (96A) is directed toward the outer circumference of the polishing hole (96A) from the back side of the substrate (W). Thus, nitrogen gas containing dust can be efficiently sucked in through the suction port (248).

[0159] Example 3

[0160] Hereinafter, Embodiment 3 of the present invention will be described with reference to the drawings. In addition, the configuration excluding the polishing head (201B) is the same as the embodiment described above.

[0161] Refer to FIGS. 17 and FIGS. 18. FIG. 17 is a longitudinal cross-sectional view of a polishing head according to Example 3. FIG. 18 is a bottom cross-sectional view of a polishing head according to Example 3.

[0162] The polishing head (201B) is equipped with a polishing member (96B), a head body (223B), and a cover (225A). The head body (223B) has a polishing member (96B) mounted on its lower surface. The head body (223B) has a first fluid path (241) and a second fluid path (243) formed therein. The first fluid path (241) and the second fluid path (243) are the same as those in Example 2 described above. The head body (223B) has an edge portion (253) formed therein. The edge portion (253) is formed such that the edge portion of the lower surface of the head body (223B) protrudes downward. The polishing member (96B) is mounted on this edge portion (253).

[0163] The polishing member (96B) is composed of a porous material. The polishing member (96B) has a plurality of small holes formed therein. The plurality of holes in the polishing member (96B) are interconnected. Nitrogen gas supplied from the first flow path (241) is sprayed from the lower surface to the back surface of the substrate (W) through the plurality of small holes of the polishing member (96B). In other words, the lower surface of the polishing member (96B) forms a spray nozzle (255).

[0164] The cover (225A) has the same configuration as the above-described embodiment 2, and its lower part forms a suction port (248).

[0165] According to the present embodiment, nitrogen gas can be supplied to a grinding tool (96B) made of a porous material, and nitrogen gas can be sprayed onto dust from a nozzle (255) corresponding to almost the entire surface of the lower surface. Thus, dust can be efficiently pushed outward.

[0166] The present invention is not limited to the above embodiments and can be modified as follows.

[0167] (1) In each of the above embodiments, suction is performed from a suction port (237, 248) having a wide opening formed in a cover (225, 225A). However, the present invention is not limited to this configuration. For example, a pipe structure may be adopted in which one end of the pipe is connected to the opening (233, 247) of the head body (223) (223A, 223B) and the other end of the pipe is directed toward the polished surface.

[0168] (2) In each of the embodiments described above, nitrogen gas is injected from the nozzle. However, the present invention is not limited to nitrogen gas. For example, argon gas may be used as the gas.

[0169] (3) In each of the embodiments described above, the gas supply pipe (203) and the suction pipe (205) are arranged in parallel. However, the present invention is not limited to this configuration. For example, a configuration may be adopted in which a double pipe is inserted and passed through the shaft (100) to be used for gas supply and suction.

[0170] (4) In each of the above-described embodiments, the main control unit (134) operates the flow control valve (215) to change the flow rate of nitrogen gas over time, but the present invention does not require such operation. That is, the flow rate of nitrogen gas may be kept constant throughout the polishing process.

[0171] (5) In each of the above embodiments, the polishing head (201, 201A, 201B) is configured to be detachably mounted to the mounting member (98). However, the polishing head (201, 201A, 201B) may be semi-fixed to the mounting member (98), and only the polishing tool (96, 96A, 96B) may be detachably and easily replaceable.

[0172] (6) In each of the embodiments described above, the holding rotation part (35) holds the substrate (W) with its back side facing upward in a horizontal position. Also, the spin base (41) of the holding rotation part (35) is positioned below the substrate (W). In this regard, the holding rotation part (35) may be positioned upside down. That is, the spin base (41) of the holding rotation part (35) is positioned above the substrate (W). Also, the holding rotation part (35) holds the substrate (W) with its back side facing downward in a horizontal position. In this case, the polishing tool (96) is brought into contact with the substrate (W) with its back side facing downward from the lower side of the substrate (W). Industrial applicability

[0173] As described above, the present invention is suitable for a polishing head for polishing the back surface of a substrate, a polishing device equipped with the same, and a substrate processing device. Explanation of the symbols

[0174] 1: Substrate processing device W: Substrate 22: Grinding unit 35: Holding rotating part 37, 37A: Grinding device 96, 96A, 96B: Grinding tool 100: Shaft 201, 201A, 201B: Grinded head 203: Gas supply piping 205: Suction piping 207: Rotary joint 209: Fixed side body 211: Rotating body 213: Gas source 215: Flow control valve 217: Open / close valve 219: Suction source 221: Opening / closing valve 223, 223A, 223B: Head body 225, 225A: Cover 227, 241: 1st Euro 229, 243: 2nd Euro 235, 251, 255: Nozzle 237, 248: Suction port

Claims

Claim 1 A polishing head for polishing a substrate, comprising a polishing tool having a resin body in which abrasive particles are dispersed, a nozzle for spraying gas onto dust generated by polishing with the polishing tool, and a suction nozzle for sucking up dust generated by polishing with the polishing tool, wherein the nozzle is formed along the outer surface of the polishing tool and the suction nozzle is formed along the outer surface of the polishing tool, and furthermore, when viewed in a planar view, is formed in a line-symmetric manner with respect to the nozzle. Claim 2 A polishing head for polishing a substrate, comprising: a polishing tool having a resin body in which abrasive particles are dispersed; a nozzle for spraying gas onto dust generated by polishing with said polishing tool; and a suction port for sucking up dust generated by polishing with said polishing tool, wherein said polishing tool is installed in an annular shape when viewed from a planar view, said nozzle is formed in the center of said polishing tool, and said suction port is formed over the entire circumference of the outer surface of said polishing tool. Claim 3 A polishing head for polishing a substrate, comprising: a polishing member having a resin body in which abrasive particles are dispersed; a nozzle for spraying gas onto dust generated by polishing with said polishing member; and a suction member for sucking up dust generated by polishing with said polishing member. The polishing member is composed of a porous member having a hole connected thereto, the nozzle is formed on the lower surface of said polishing member, and the suction member is formed over the entire circumference of the outer side of said polishing member. Claim 4 A grinding head according to any one of claims 1 to 3, wherein the nozzle sprays gas discontinuously. Claim 5 A polishing device for polishing a substrate, characterized by comprising: a polishing head as described in any one of claims 1 to 3; a head driving mechanism for rotating the polishing head around a vertical axis; a holding rotating part for rotating the substrate while maintaining the substrate in a horizontal position; a gas supply pipe for supplying gas to a nozzle of the polishing head; and a suction pipe for performing suction from a suction port of the polishing head. Claim 6 A polishing device according to claim 5, further comprising a control valve for controlling the flow of gas in the gas supply pipe and a control unit for operating the control valve, wherein the control unit operates the control valve so that the injection of gas from the polishing head is performed intermittently. Claim 7 A polishing device according to claim 6, wherein the control unit operates the control valve so that the flow rate of gas sprayed from the nozzle does not exceed the flow rate sucked from the suction pipe. Claim 8 A substrate processing apparatus characterized by having a polishing device as described in claim 5. Claim 9 delete

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