SUBSTRATE PROCESSING METHOD AND SUBSTRATE PROCESSING APPARATUS

Abstract

To reduce a damage on a back surface of a substrate at absorption of the substrate in substrate processing in which the substrate is adsorbed on a substrate table heated by a heater.SOLUTION: A substrate processing device includes a substrate table for adsorbing a substrate, a heater for heating the substrate table, and a processing liquid nozzle for supplying processing liquid to the substrate adsorbed on the substrate table. A substrate processing method is to perform liquid processing on the substrate in the substrate processing device and includes an adsorbing step of adsorbing the substrate with the substrate table when a temperature difference between the substrate and the substrate table is zero or within a predetermined range, and a processing liquid supplying step of, after the adsorbing step, supplying the processing liquid from the processing liquid nozzle to the substrate adsorbed on the substrate table heated by the heater.SELECTED DRAWING: Figure 12

Description

[Technical field]

[0001] The present disclosure relates to a substrate processing method and a substrate processing apparatus. [Background technology]

[0002] In the manufacture of semiconductor devices, a chemical solution whose temperature is controlled and heated is supplied to a substrate such as a semiconductor wafer, thereby performing a liquid treatment such as a chemical cleaning treatment or a wet etching treatment on the substrate. An example of a single-wafer type substrate treatment apparatus that performs such liquid treatment is described in Patent Document 1. The apparatus of Patent Document 1 includes a spin chuck that holds and rotates the wafer, and a non-rotating disk-shaped member (lower surface moving member) that can be brought into contact with and separated from the lower surface of the wafer W held by the spin chuck. A heater is embedded inside the lower surface moving member. A gap of about 0.5 to 3 mm is formed between the upper surface of the lower surface moving member and the lower surface of the wafer W, and this gap is filled with a chemical solution, which is heated by the heater of the non-rotating lower surface moving member. By rotating the substrate at a low speed of about 30 to 50 rpm by the spin chuck, it is possible to perform a chemical treatment on the lower surface of the substrate with a temperature-controlled chemical solution while preventing the chemical solution from stagnating in the gap. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3837026 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique for reducing scratches that occur on the back surface of a substrate when the substrate is adsorbed onto a substrate table heated by a heater for substrate processing. [Means for solving the problem]

[0005] According to one embodiment, in a substrate processing method for liquid processing a substrate in a substrate processing apparatus comprising a substrate table for adsorbing a substrate, a heater for heating the substrate table, and a processing liquid nozzle for supplying processing liquid to the substrate adsorbed to the substrate table, the substrate processing method comprises: an adsorption step of adsorbing the substrate by the substrate table when there is no temperature difference between the substrate and the substrate table or is within a predetermined range; and a processing liquid supply step of, after the adsorption step, supplying processing liquid from the processing liquid nozzle to the substrate adsorbed to the substrate table heated by the heater. Effect of the Invention

[0006] According to the present disclosure, when a substrate is processed by being attracted to a substrate table heated by a heater, scratches that occur on the rear surface of the substrate when the substrate is attracted can be reduced. [Brief description of the drawings]

[0007] [Figure 1] 1 is a schematic plan view showing an overall configuration of a substrate processing apparatus according to an embodiment; [Diagram 2] 2 is a schematic cross-sectional view showing an example of the configuration of a processing unit included in the substrate processing apparatus of FIG. 1. [Diagram 3] FIG. 4 is a schematic plan view for explaining an example of an arrangement of heaters of a hot plate provided in the processing unit. [Figure 4] FIG. 2 is a schematic plan view showing an example of the configuration of the upper surface of the hot plate. [Diagram 5] 4 is a schematic plan view showing an example of the configuration of the lower surface of the suction plate provided in the processing unit. FIG. [Figure 6] 4 is a schematic plan view showing an example of a configuration of the upper surface of the suction plate. FIG. [Figure 7] 4 is a schematic plan view showing an example of the configuration of a first electrode section provided in the processing unit. FIG. [Figure 8] 3 is a schematic cross-sectional view showing an enlarged view of the structure around the first electrode portion and the second electrode portion shown in FIG. 2. [Figure 9] FIG. 7 is a schematic cross-sectional view of the suction plate shown in FIGS. 5 and 6. [Figure 10] 10 is a schematic cross-sectional view of the suction plate taken along a cross section different from that of FIG. 9. [Figures 11A-11P] FIG. 1 is a diagram illustrating a procedure of chemical solution treatment. [Figure 12] 1A and 1B are schematic diagrams for explaining an example of a procedure for adsorbing and heating a wafer. [Figure 13] 13A and 13B are schematic diagrams illustrating another embodiment of the suction plate. [Figure 14] 13A and 13B are schematic diagrams illustrating still another embodiment of the suction plate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] An embodiment of a substrate processing apparatus (substrate processing system) will be described below with reference to the accompanying drawings.

[0009] 1 is a diagram showing a schematic configuration of a substrate processing system according to an embodiment of the present invention. In the following, to clarify the positional relationship, an X-axis, a Y-axis, and a Z-axis that are perpendicular to each other are defined, and the positive direction of the Z-axis is defined as the vertical upward direction.

[0010] 1, the substrate processing system 1 includes a loading / unloading station 2 and a processing station 3. The loading / unloading station 2 and the processing station 3 are provided adjacent to each other.

[0011] The carry-in / out station 2 includes a carrier placement section 11 and a transport section 12. On the carrier placement section 11, a plurality of carriers C are placed, each of which accommodates a plurality of substrates, in this embodiment, semiconductor wafers (hereinafter referred to as wafers W), in a horizontal state.

[0012] The transfer section 12 is provided adjacent to the carrier placement section 11, and includes therein a substrate transfer device 13 and a transfer section 14. The substrate transfer device 13 includes a wafer holding mechanism that holds the wafer W. The substrate transfer device 13 is capable of moving in the horizontal and vertical directions and rotating about a vertical axis, and transfers the wafer W between the carrier C and the transfer section 14 using the wafer holding mechanism.

[0013] The processing station 3 is provided adjacent to the transport section 12. The processing station 3 includes a transport section 15 and a plurality of processing units 16. The plurality of processing units 16 are provided side by side on both sides of the transport section 15.

[0014] The transfer section 15 includes a substrate transfer device 17 therein. The substrate transfer device 17 includes a wafer holding mechanism that holds the wafer W. The substrate transfer device 17 is capable of moving in the horizontal and vertical directions and rotating about a vertical axis, and transfers the wafer W between the delivery section 14 and the processing unit 16 using the wafer holding mechanism.

[0015] The processing unit 16 performs a predetermined substrate processing on the wafer W transferred by the substrate transfer device 17 .

[0016] The substrate processing system 1 also includes a control device 4. The control device 4 is, for example, a computer, and includes a control unit 18 and a storage unit 19. The storage unit 19 stores programs for controlling various processes executed in the substrate processing system 1. The control unit 18 controls the operation of the substrate processing system 1 by reading out and executing the programs stored in the storage unit 19.

[0017] Such a program may be recorded in a computer-readable storage medium and installed from that storage medium into the storage unit 19 of the control device 4. Examples of computer-readable storage media include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnet optical disk (MO), and a memory card.

[0018] In the substrate processing system 1 configured as described above, first, the substrate transfer device 13 in the loading / unloading station 2 removes the wafer W from the carrier C placed on the carrier placement section 11, and places the removed wafer W on the transfer section 14. The wafer W placed on the transfer section 14 is then removed from the transfer section 14 by the substrate transfer device 17 in the processing station 3, and carried into the processing unit 16.

[0019] The wafer W carried into the processing unit 16 is processed by the processing unit 16, and then carried out of the processing unit 16 by the substrate transfer device 17 and placed on the transfer section 14. Then, the processed wafer W placed on the transfer section 14 is returned to the carrier C of the carrier placement section 11 by the substrate transfer device 13.

[0020] Next, a description will be given of the configuration of one embodiment of the processing unit 16. The processing unit 16 is configured as a single-wafer liquid processing unit.

[0021] 2, the processing unit 16 includes a turntable (substrate table) 100, a processing liquid supply unit 700 that supplies a processing liquid to the wafer W, and a liquid receiving cup (processing cup) 800 that collects the processing liquid scattered from the rotated substrate. The turntable 100 can hold and rotate a circular substrate such as the wafer W in a horizontal position. The components of the processing unit 16, such as the turntable 100, the processing liquid supply unit 700, and the liquid receiving cup 800, are contained in a housing 1601 (also called a processing chamber).

[0022] Although Fig. 2 shows only the left half of the processing unit 16, the processing unit 16 has a configuration that is generally symmetrical with respect to the rotation axis Ax shown at the right end of Fig. 2. To ensure dynamic balance of the turntable 100 during rotation, one or more balance weights 178 may be attached to the turntable 100.

[0023] The turntable 100 has a suction plate 120, a hot plate 140, a support plate 170, a peripheral cover body 180, and a hollow rotation shaft 200. The suction plate 120 suctions the wafer W placed thereon in a horizontal position. The hot plate 140 is a base plate for the suction plate 120 that supports and heats the suction plate 120. The support plate 170 supports the suction plate 120 and the hot plate 140.

[0024] The rotating shaft 200 extends downward from the support plate 170. The rotating table 100 is rotated about a rotation axis Ax extending in the vertical direction by an electric drive unit (rotation drive mechanism) 102 disposed around the rotating shaft 200, thereby rotating the held wafer W about the rotation axis Ax. The electric drive unit 102 (details not shown) may transmit power generated by an electric motor to the rotating shaft 200 via a power transmission mechanism (e.g., a belt and a pulley) to rotate the rotating shaft 200. The electric drive unit 102 may also directly rotate the rotating shaft 200 by an electric motor.

[0025] The suction plate 120 is a disk-shaped member having a diameter slightly larger than that of the wafer W (or, depending on the configuration, it may be the same diameter), i.e., an area larger than or equal to that of the wafer W. The suction plate 120 has an upper surface (front surface) 120A that suctions the lower surface (the surface not to be processed) of the wafer W, and a lower surface (back surface) 120B that contacts the upper surface of the hot plate 140. The suction plate 120 can be made of a high thermal conductivity material such as thermally conductive ceramics, for example, SiC. The thermal conductivity of the material constituting the suction plate 120 is preferably 150 W / m·k or higher.

[0026] The hot plate 140 is a disk-shaped member having a diameter approximately equal to that of the suction plate 120. The hot plate 140 has a plate body 141 and an electric heater (electric heater) 142 provided on the plate body 141. The plate body 141 is made of a high thermal conductivity material such as thermally conductive ceramics, for example, SiC. The thermal conductivity of the material constituting the plate body 141 is preferably, for example, 150 W / m·k or more.

[0027] The heater 142 can be configured by a planar heater, for example, a polyimide heater, provided on the lower surface (rear surface) of the plate body 141. Preferably, the hot plate 140 is provided with a plurality (for example, 10) of heating zones 143-1 to 143-10 as shown in FIG. 3. The heater 142 is configured by a plurality of heater elements 142E respectively assigned to the heating zones 143-1 to 143-10. Each heater element 142E is formed of a conductor that extends in a serpentine manner within each heating zone 143-1 to 143-10. In FIG. 3, only the heater element 142E in the heating zone 143-1 is shown.

[0028] These heater elements 142E can be powered independently from one another by a power supply unit 300, which will be described later. Therefore, different heating zones of the wafer W can be heated under different conditions, and the temperature distribution of the wafer W can be controlled.

[0029] 4, the upper surface (front surface) of the plate body 141 has one or more (two in the illustrated example) plate suction ports 144P, one or more (one in the center in the illustrated example) substrate suction ports 144W, and one or more (two on the outside in the illustrated example) purge gas supply ports 144G. The plate suction port 144P is used to transmit a suction force for adsorbing the suction plate 120 to the hot plate 140. The substrate suction port 144W is used to transmit a suction force for adsorbing the wafer W to the suction plate 120.

[0030] Furthermore, the plate body 141 is formed with a plurality of (three in the illustrated example) lift pin holes 145L through which lift pins 211, which will be described later, pass, and a plurality of (six in the illustrated example) service holes 145S for accessing screws for assembling the rotary table 100. During normal operation, the service holes 145S are closed with caps 145C.

[0031] The heater element 142E is disposed so as to avoid the plate suction port 144P, the substrate suction port 144W, the purge gas supply port 144G, the lift pin hole 145L, and the service hole 145S. Also, the service hole can be eliminated by connecting the rotating shaft 200 with an electromagnet.

[0032] 5, the lower surface 120B of the suction plate 120 is formed with a lower surface suction flow groove 121P for a plate, a lower surface suction flow groove 121W for a substrate, and a lower surface purge flow groove 121G. When the suction plate 120 is placed on the hot plate 140 in an appropriate positional relationship, at least a part of the lower surface suction flow groove 121P for a plate communicates with a suction port 144P for a plate. Similarly, at least a part of the lower surface suction flow groove 121W for a substrate communicates with a suction port 144W for a substrate, and at least a part of the lower surface purge flow groove 121G communicates with a purge gas supply port 144G. The lower surface suction flow groove 121P for a plate, the lower surface suction flow groove 122W for a substrate, and the lower surface purge flow groove 121G are separated from each other (not communicated with each other).

[0033] FIG. 10 shows a schematic state in which the suction port 144P (or 144W, 144G) of the hot plate 140 and the flow channel 121P (or 121W, 121G) of the suction plate 120 overlap and communicate with each other.

[0034] 6 and 9, a plurality of (five in the illustrated example) thick annular partition walls 124 are formed on the upper surface 120A of the suction plate 120. The thick partition walls 124 define a plurality of mutually separated recessed regions 125W, 125G (four outer annular regions and an innermost circular region) on the upper surface 120A.

[0035] A plurality of through holes (129W) penetrating the suction plate 120 in the thickness direction are formed at multiple locations in the lower surface suction flow groove 121W for the substrate, and each through hole connects the lower surface suction flow groove 121W for the substrate to any one of the multiple (four in the illustrated example) recessed areas 125W.

[0036] Further, through holes (129G) penetrating the suction plate 120 in the thickness direction are formed at a plurality of locations in the lower surface purge flow groove 121G, and each through hole connects the lower surface purge flow groove 121G to the outermost recessed region 125G. The outermost recessed region 125G becomes a single annular upper surface purge flow groove.

[0037] Each of the four inner recessed regions 125W is provided with a plurality of thin, generally annular, separation walls 127 arranged concentrically. The thin separation walls 127 form at least one upper surface suction flow channel 125WG that meanders through each recessed region 125W. In other words, the thin separation walls 127 distribute the suction force evenly within each recessed region 125W.

[0038] 2, a suction / purge unit 150 is provided near the rotation axis Ax. The suction / purge unit 150 has a rotary joint 151 provided inside a hollow rotation shaft 200. An upper piece 151A of the rotary joint 151 is connected to a suction pipe 152W communicating with the plate suction port 144P and the substrate suction port 144W of the hot plate 140, and a purge gas supply pipe 152G communicating with the purge gas supply port 144G.

[0039] Although not shown, the suction pipe 152W may be branched and the branched suction pipe may be connected to the plate body 141 of the hot plate 140 immediately below the plate suction port 144P and the substrate suction port 144W. In this case, through holes extending vertically through the plate body 141 may be formed in the plate body 141, and the branched suction pipe may be connected to each through hole. Similarly, the purge gas supply pipe 152G may be branched and the branched purge gas supply pipe may be connected to the plate body 141 of the hot plate 140 immediately below the purge gas supply port 144G. In this case, through holes extending vertically through the plate body 141 may be formed in the plate body 141, and the purge gas supply pipe may be connected to each through hole. The above-mentioned branched suction pipe or branched purge gas pipe is shown in FIG. 10 (reference symbols 152WB and 152GB are attached).

[0040] Alternatively, the suction pipe 152W and the purge gas supply pipe 152G may be connected to the center of the plate body 141 of the hot plate 140. In this case, inside the plate body 141, there are provided flow paths that respectively connect the suction pipe 152W to the plate suction port 144P and the substrate suction port 144W, and a flow path that connects the purge gas supply pipe 152G to the purge gas supply port 144G.

[0041] A suction pipe 153W communicating with the suction pipe 152W and a purge gas supply pipe 153G communicating with the purge gas supply pipe 151G are connected to the lower piece 151B of the rotary joint 151. The rotary joint 151 is configured so that the upper piece 151A and the lower piece 151B can rotate relative to each other while maintaining communication between the suction pipes 152W and 153W and between the purge gas supply pipes 152G and 153G. The rotary joint 151 itself having such a function is known.

[0042] The suction pipe 153W is connected to a suction device 154 such as a vacuum pump. The purge gas supply pipe 153G is connected to a purge gas supply device 155. The suction pipe 153W is also connected to the purge gas supply device 155. In addition, a switching device 156 (e.g., a three-way valve) that switches the connection destination of the suction pipe 153W between the suction device 154 and the purge gas supply device 155 is provided.

[0043] A plurality of temperature sensors 146 for detecting the temperature of the plate body 141 of the hot plate 140 are embedded in the hot plate 140. For example, one temperature sensor 146 can be provided for each of the ten heating zones 143-1 to 143-10. Based on the deviation between the detection value of the temperature sensor 146 and a target value (target temperature), for example, a control function provided in the power supply unit 300 controls the power supplied to the heater element 142e of each heating zone (143-1 to 143-10), thereby maintaining the temperature of each heating zone at the target value. In addition, at least one thermoswitch 147 for detecting overheating of the heater 142 is provided at a position close to the heater 142 of the hot plate 140.

[0044] In the space S between the hot plate 140 and the support plate 170, in addition to the above-mentioned temperature sensor 146 and thermoswitch 147, there are provided control signal wiring (first conductive lines) 148A, 148B for transmitting detection signals from the temperature sensor 146 and thermoswitch 147, and power supply wiring (first conductive line) 149 for supplying power to each heater element 142E of the heater 142.

[0045] As shown in FIG. 2, a switch mechanism 160 is provided around the rotary joint 151. The switch mechanism 160 has a first electrode portion 161A fixed in the direction of the rotation axis Ax, a second electrode portion 161B movable in the direction of the rotation axis Ax, and an electrode movement mechanism 162 (lifting mechanism) that moves (lifts) the second electrode portion 161B in the direction of the rotation axis Ax. Note that it is only necessary that the first electrode portion 161A and the second electrode portion 161B are relatively movable in the direction of the rotation axis Ax. In other words, an electrode movement mechanism (not shown) may move the first electrode portion 161A in the direction of the rotation axis Ax, and the second electrode portion 161B may be fixed in the direction of the rotation axis Ax.

[0046] 7, the first electrode portion 161A has a first electrode support 163A and a plurality of first electrodes 164A supported by the first electrode support 163A. The plurality of first electrodes 164A include a first electrode 164AC (indicated by a small "o" in FIG. 7) for control signal communication connected to the control signal wirings 148A and 148B, and a first electrode 164AP (indicated by a large "o" in FIG. 7) for heater power supply connected to the power supply wiring 149.

[0047] The first electrode carrier 163A is a generally disk-shaped member having a generally circular shape when viewed from the direction of the rotation axis Ax. A circular hole 167 is formed in the center of the first electrode carrier 163A, into which the upper piece 151A of the rotary joint 151 is inserted. The upper piece 151A of the rotary joint 151 may be fixed to the first electrode carrier 163A. The peripheral portion of the first electrode carrier 163A can be screwed to the support plate 170 using the screw holes 171.

[0048] As shown in Fig. 2, the second electrode section 161B has a second electrode support 163B and a plurality of second electrodes 164B supported by the second electrode support 163B. The second electrode support 163B is a generally disk-shaped member having approximately the same diameter as the first electrode support 163A shown in Fig. 7. A circular hole of a size that allows the lower piece 151B of the rotary joint 151 to pass through is formed in the center of the second electrode support 163B.

[0049] The second electrode 164B, which moves up and down relative to the first electrode 164A to come into contact with and separate from the first electrode 164A, has the same planar arrangement as the first electrode 164A. Hereinafter, the second electrode 164B (power supply electrode) in contact with the first electrode 164AP (power receiving electrode) for heater power supply is also called the "second electrode 164BP." The second electrode 164B in contact with the first electrode 164AC for control signal communication is also called the "second electrode 164BC." The second electrode 164BP is connected to a power output terminal of the power supply device (power supply section) 300. The second electrode 164BC is connected to a control input / output terminal of the power supply section 300.

[0050] 7, a first electrode 164AP for supplying power to the heater is provided in the central region of the first electrode support 163A, and a first electrode 164AC for communicating a control signal is provided in an outer region outside the central region. The first electrodes 164AP are also referred to as a first electrode group of the first electrodes 164A. The first electrodes 164AC are also referred to as a second electrode group of the first electrodes 164A.

[0051] It is self-evident that the second electrode 164B (164BP, 164BC) is arranged at a position (horizontal position, vertical position) that is compatible with the paired first electrode 164A (164AP, 164AC), and therefore an explanation of the arrangement of the second electrode 164B is omitted.

[0052] The conductive paths (second conductive lines) 168A, 168B, 169 (see FIG. 2) connecting each second electrode 164B to the power output terminal and the control input / output terminal of the power supply unit 300 are at least partially formed of flexible electric wires. The flexible electric wires allow the entire second electrode unit 161B to rotate around the rotation axis Ax from the neutral position in the forward and reverse directions by a predetermined angle range (in other words, a limited angle range) while maintaining the conduction between the second electrode 164B and the power supply unit 300. This angle range is, for example, 180 degrees, but is not limited to this angle. This means that the turntable 100 can be rotated by approximately ±180 degrees while maintaining the connection between the first electrode 164A and the second electrode 164B.

[0053] One of the pair of first electrode 164A and second electrode 164B may be configured as a pogo pin. In FIG. 2, all of the second electrodes 164B are formed as pogo pins. The term "pogo pin" is widely used to mean an expandable rod-shaped electrode with a built-in spring. Instead of a pogo pin, an outlet, a magnet electrode, an induction electrode, or the like may be used as the electrode.

[0054] It is preferable to provide a locking mechanism 165 that locks the first electrode support 163A and the second electrode support 163B so that they cannot rotate relative to each other when the pair of the first electrode 164A and the second electrode 164B are in appropriate contact with each other. The locking mechanism 165 can be composed of a hole 165A provided in the first electrode support 163A and a pin 165B provided in the second electrode support and fitted into the hole, for example, as shown in Figures 2 and 8.

[0055] It is also preferable to provide a sensor 172 (schematically shown in FIG. 2) for detecting that the pair of the first electrode 164A and the second electrode 164B are in proper contact with each other. As such a sensor, an angular position sensor (not shown) for detecting that the angular positional relationship between the first electrode carrier 163A and the second electrode carrier 163B is in a proper state may be provided. As such a sensor, a distance sensor (not shown) for detecting that the distance between the first electrode carrier 163A and the second electrode carrier 163B in the direction of the rotation axis Ax is in a proper state may be provided. Furthermore, a contact type sensor (see FIG. 8) for detecting that the pin 165B is properly fitted in the hole 165A of the lock mechanism 165 may be provided.

[0056] In order to realize the contact-type sensor shown in FIG. 8, two holes 165A and two pins 165B are provided. Preferably, the pins 165B are made of a conductive material, and the first electrode carrier 163A is made of an insulating material. The first electrode carrier 163A is provided with a conductive member consisting of two electrodes 175A and a conductive member 175B that electrically connects the two electrodes 175A. The two electrodes 175A are provided at positions corresponding to the two holes 165A, respectively. The two pins 165B are connected to a continuity sensor 175D via a conductive member 175C. When each pin 165B is properly inserted into the corresponding hole 165A, the tip of the pin 165B comes into contact with the electrode 175A, which is detected by the continuity sensor 175D.

[0057] It is preferable to provide the power supply unit 300 with a control function that enables power supply to the electric heater 142 only when the continuity sensor 175D confirms that the hole 165A and the pin 165B are properly fitted together. This makes it possible to prevent, for example, discharge from occurring between the first electrode 164AP and the second electrode 164BP for supplying power to the heater, which would cause damage to the electrodes or the electric circuit.

[0058] The electrode movement mechanism 162, which is shown in FIG. 2, can be configured to include a push rod 162A for pushing up the second electrode carrier 163B, and a lifting mechanism 162B (air cylinder, ball screw, etc.) for lifting the push rod 162A, as shown in FIG. 8. At least one permanent magnet 173A can be provided on the first electrode carrier 163A, and at least one electromagnet 173B can be provided on the second electrode carrier 163B. The permanent magnet 173A and the electromagnet 173B form a part of the lock mechanism 165. As a result, the first electrode portion 161A and the second electrode portion 161B can be coupled by electromagnetic attraction so as to be immovable relative to each other in the vertical direction, and the first electrode portion 161A and the second electrode portion 161B can be separated by electromagnetic repulsion, as necessary. Preferably, a plurality of permanent magnets 173A and the same number of electromagnets 173B as the number of permanent magnets are provided and are disposed at equal intervals in the circumferential direction centered on the rotation axis Ax.

[0059] If the first electrode portion 161A and the second electrode portion 161B are coupled and separated at the same angular position of the turntable 100, the second electrode portion 161B does not need to be supported rotatably around the rotation axis Ax. That is, when the first electrode portion 161A and the second electrode portion 161B are separated, a member (e.g., the above-mentioned push rod 162A or another support table) that supports the second electrode portion 161B may be provided. When the first electrode portion 161A and the second electrode portion 161B are coupled by, for example, electromagnetic force, the second electrode portion 161B may be separated from the member (e.g., the push rod 162A or another support table) that supports the second electrode portion 161B.

[0060] The electric drive unit 102 of the turntable 100 has a positioning function for stopping the turntable 100 at an arbitrary rotation angle position. The positioning function can be realized by rotating the motor of the electric drive unit 102 based on the detection value of a rotary encoder attached to the turntable 100 (or a member rotated by the turntable 100). With the turntable 100 stopped at a predetermined rotation angle position, the second electrode unit 161B is raised by the electrode moving mechanism 162, so that the corresponding electrodes of the first and second electrode units 161A and 161B can be appropriately brought into contact with each other. When the second electrode unit 161B is separated from the first electrode unit 161A, it is also preferable to separate the turntable 100 with the turntable 100 stopped at the above-mentioned predetermined rotation angle position.

[0061] As described above, a plurality of electrical components (heaters, wiring, sensors, etc.) are disposed in the space S between the suction plate 120 and the support plate 170 and at positions facing the space S. The peripheral cover body 180 prevents the processing liquid, particularly the corrosive chemical liquid, supplied to the wafer W from entering the space S, and protects the electrical components. A purge gas (N2 gas) may be supplied to the space S through a pipe (not shown) branched from the purge gas supply pipe 152G. This prevents the corrosive gas derived from the chemical liquid from entering the space S from the outside of the space S, and the space S can be maintained in a noncorrosive atmosphere.

[0062] In particular, it is preferable to provide an inert gas supply mechanism for supplying an inert gas (N2 gas) to the space SE between the first electrode support 163A and the second electrode support 163B where the first electrode of the first electrode unit and the second electrode of the second electrode unit are in contact with each other. This inert gas supply mechanism can be composed of a purge gas supply device 155 and an inert gas supply pipe 176 for supplying N2 gas as an inert gas from the purge gas supply device 155 to the space SE. That is, the purge gas supply device 155 for supplying N2 gas as a purge gas into the space S is also used as an inert gas supply device for supplying N2 gas as an inert gas to the space SE. It is preferable to constantly supply an inert gas to the space SE during the operation of the processing unit 16. This maintains the surface of the electrode in a good condition, thereby improving the operational reliability of the processing unit 16.

[0063] In order to supply an inert gas (N2 gas) to the space SE, a dedicated inert gas supply source independent of the purge gas supply device 155 may be used. Also, if the space SE is filled with N2 gas by supplying N2 gas as a purge gas into the space S, it is not necessary to provide an inert gas supply mechanism dedicated to the space SE.

[0064] 2, the peripheral cover body 180 has an upper portion 181, a peripheral side portion 182, and a lower portion 183. The upper portion 181 protrudes above the suction plate 120 and is connected to the suction plate 120. The lower portion 183 of the peripheral cover body 180 is connected to the support plate 170.

[0065] The inner peripheral edge of the upper part 181 of the peripheral cover body 180 is located radially inward from the outer peripheral edge of the suction plate 120. The upper part 181 has an annular lower surface 184 that contacts the upper surface of the suction plate 120, an inclined annular inner peripheral surface 185 rising from the inner peripheral edge of the lower surface 184, and an annular outer peripheral surface 186 that extends radially outward generally horizontally from the outer peripheral edge of the inner peripheral surface 185. The inner peripheral surface 185 is inclined so as to become lower as it approaches the center of the suction plate 120.

[0066] A seal is preferably provided between upper surface 120A of suction plate 120 and lower surface 184 of upper portion 181 of peripheral cover body 180 to prevent liquid infiltration. The seal may be an O-ring 192 (see FIG. 9) disposed between upper surface 120A and lower surface 184.

[0067] As shown in FIG. 5, a part of the lower surface suction flow groove 121P for the plate extends in the circumferential direction in the outermost peripheral portion of the suction plate 120. Also, as shown in FIG. 6, a recessed groove 193 extends continuously in the circumferential direction in the outermost peripheral portion of the upper surface 120A of the suction plate 120. As shown in FIG. 9, the outermost peripheral lower surface suction flow groove 121P and the recessed groove 193 communicate with each other through a plurality of through holes 129P that are provided at intervals in the circumferential direction and penetrate the suction plate 120 in the thickness direction. The lower surface 184 of the upper portion 181 of the peripheral cover body 180 is placed on the recessed groove 193. Therefore, the lower surface 184 of the upper portion 181 of the peripheral cover body 180 is sucked to the upper surface 120A of the suction plate 120 by the negative pressure acting on the lower surface suction flow groove 121P for the plate. This suction causes the O-ring 192 to collapse, thereby achieving a reliable seal.

[0068] The height of the outer circumferential surface 186, i.e., the top of the peripheral cover body 180, is higher than the height of the upper surface of the wafer W held by the suction plate 120. Therefore, when a processing liquid is supplied to the upper surface of the wafer W while the wafer W is held by the suction plate 120, a liquid pool in which the wafer W can be immersed can be formed so that the upper surface of the wafer W is located below the liquid level LS (see FIG. 2). That is, the upper portion 181 of the peripheral cover body 180 forms a dam surrounding the periphery of the wafer W held by the suction plate 120, and the upper portion 181 of the peripheral cover body 180 and the suction plate 120 form a recess in which the processing liquid can be stored. Using this configuration, it is also possible to perform an immersion process of the wafer W.

[0069] The inclination of the inner peripheral surface 185 of the upper part 181 of the peripheral cover body 180 facilitates smooth outward scattering of the processing liquid in the tank when the turntable 100 is rotated at high speed. In other words, this inclination makes it possible to prevent the liquid from remaining on the inner peripheral surface of the upper part 181 of the peripheral cover body 180 when the turntable 100 is rotated at high speed.

[0070] In the chemical liquid processing disclosed in the present specification (described in detail later), the wafer W is not immersed in a bath of the processing liquid, but a liquid puddle processing is performed to form a puddle on the surface of the wafer W. If the wafer W is not immersed in the processing liquid, the height of the upper portion 181 of the peripheral cover body 180 may be lower than in the illustrated example, and the inclination of the inner peripheral surface 185 may be gentler than in the illustrated example.

[0071] A rotating cup 188 (rotating liquid receiving member) that rotates together with the peripheral cover body 180 is provided on the radially outer side of the peripheral cover body 180. The rotating cup 188 is connected to a component of the turntable 100, in the illustrated example, the peripheral cover body 180, via a plurality of connecting members 189 that are provided at intervals in the circumferential direction. The upper end of the rotating cup 188 is located at a height that allows it to receive the processing liquid splashed from the wafer W. A passage 190 through which the processing liquid splashed from the wafer W flows down is formed between the outer circumferential surface of the side periphery 182 of the peripheral cover body 180 and the inner circumferential surface of the rotating cup 188.

[0072] The liquid receiving cup 800 surrounds the periphery of the rotary table 100 and collects the processing liquid splashed from the wafer W. In the illustrated embodiment, the liquid receiving cup 800 has a fixed outer cup element 801, a fixed inner cup element 804, a first movable cup element 802 and a second movable cup element 803 that can be raised and lowered, and a fixed inner cup element 804. A first discharge passage 806, a second discharge passage 807, and a third discharge passage 808 are formed between two adjacent cup elements (between 801 and 802, between 802 and 803, and between 803 and 804), respectively. By changing the positions of the first and second movable cup elements 802 and 803, the processing liquid flowing out from the passage 190 between the peripheral cover body 180 and the rotary cup 188 can be guided to any one selected from the three discharge passages 806, 807, and 808. The first discharge passage 806, the second discharge passage 807, and the third discharge passage 808 are each connected to one of an acid-based drainage passage, an alkali-based drainage passage, and an organic-based drainage passage (none of which are shown) installed in a semiconductor manufacturing factory. A gas-liquid separation structure (not shown) is provided in the first discharge passage 806, the second discharge passage 807, and the third discharge passage 808. The first discharge passage 806, the second discharge passage 807, and the third discharge passage 808 are connected to a factory exhaust system via an exhaust device (not shown) such as an ejector, and are sucked. Such a liquid receiving cup 800 is known from Japanese Patent Publication No. 2012-129462, Japanese Patent Publication No. 2014-123713, etc., which are related to patent applications filed by the applicant of the present application, and these publications should be referred to for details.

[0073] The suction plate 120 and the support plate 170 are also formed with three lift pin holes 128L, 171L, respectively, so as to be aligned with the three lift pin holes 145L of the hot plate 140 in relation to the direction of the rotation axis Ax.

[0074] A plurality of lift pins 211 (three in the illustrated example) are provided on the turntable 100, penetrating the lift pin holes 145L, 128L, and 171L. Each lift pin 211 is movable between a transfer position (raised position) where the upper end of the lift pin 211 protrudes upward from the upper surface 120A of the suction plate 120 and a processing position (lowered position) where the upper end of the lift pin 211 is positioned below the upper surface 120A of the suction plate 120.

[0075] A push rod 212 is provided below each lift pin 211. The push rod 212 can be raised and lowered by a lifting mechanism 213, for example an air cylinder. The lift pin 211 can be raised to a delivery position by pushing up the lower end of the lift pin 211 with the push rod 212. The multiple push rods 212 may be provided on a ring-shaped support (not shown) centered on the rotation axis Ax, and the multiple push rods 212 may be raised and lowered by raising and lowering the ring-shaped support with a common lifting mechanism.

[0076] The wafer W placed on the lift pins 211 at the transfer position is located at a height position higher than the upper end 809 of the fixed outer cup element 801, allowing the wafer W to be transferred between the arm of the substrate transport device 17 (see Figure 1) that has entered the interior of the processing unit 16.

[0077] When the lift pin 211 leaves the push rod 212, the lift pin 211 descends to a processing position by the elastic force of the return spring 214 and is held at the processing position. In Fig. 1, reference numeral 215 denotes a guide member that guides the lift pin 211 to ascend and descend, and reference numeral 216 denotes a spring receiver that receives the return spring 214. The fixed inner cup element 804 is formed with an annular recess 810 for enabling the spring receiver 216 to rotate around the rotation axis Ax.

[0078] The processing liquid supply unit 700 includes a plurality of nozzles. The plurality of nozzles include a chemical liquid nozzle 701, a rinse nozzle 702, and a drying promotion liquid nozzle 703. A chemical liquid is supplied to the chemical liquid nozzle 701 from a chemical liquid supply source 701A through a chemical liquid supply mechanism 701B including a flow control device (not shown) such as an on-off valve and a flow control valve provided in a chemical liquid supply line (piping) 701C. A rinse liquid is supplied from a rinse liquid supply source 702A through a rinse liquid supply mechanism 702B including a flow control device (not shown) such as an on-off valve and a flow control valve provided in a rinse liquid supply line (piping) 702C. A drying promotion liquid, for example, IPA (isopropyl alcohol), is supplied from a drying promotion liquid supply source 703A through a drying promotion liquid supply mechanism 703B including a flow control device (not shown) such as an on-off valve and a flow control valve provided in a drying promotion liquid supply line (piping) 703C.

[0079] A heater 701D may be provided in the chemical supply line 701C as a temperature control mechanism for controlling the temperature of the chemical. Furthermore, a tape heater (not shown) for controlling the temperature of the chemical may be provided in the pipe constituting the chemical supply line 701C. Such a heater may also be provided in the rinsing liquid supply line 702C.

[0080] The chemical liquid nozzle 701, the rinse nozzle 702, and the drying promotion liquid nozzle 703 are supported by the tip of a nozzle arm 704. The base end of the nozzle arm 704 is supported by a nozzle arm drive mechanism 705 that raises, lowers, and rotates the nozzle arm 704. The nozzle arm drive mechanism 705 makes it possible to position the chemical liquid nozzle 701, the rinse nozzle 702, and the drying promotion liquid nozzle 703 at any radial position above the wafer W (positions related to the radial direction of the wafer W).

[0081] A wafer sensor 860 for detecting whether or not a wafer W is present on the turntable 100, and one or more infrared thermometers 870 (only one is shown) for detecting the temperature of the wafer W (or the temperature of the processing liquid on the wafer W) are provided on the ceiling of the housing 1601. When multiple infrared thermometers 870 are provided, it is preferable that each infrared thermometer 870 detects the temperature of an area of ​​the wafer W corresponding to each of the heating zones 143-1 to 143-10.

[0082] Next, referring to Figs. 11A to 11P, the operation of the substrate processing apparatus will be described by taking as an example a case where a chemical liquid process is performed on a wafer W. The chemical liquid can be, for example, a chemical liquid for wet etching or a chemical liquid for cleaning. In Figs. 11A to 11P, the number of arrows extending downward from the FFU roughly corresponds to the flow rate of gas supplied from the FFU into the processing chamber 1601. Reference character CA means clean air, and reference character DA means dry air. The exhaust flow rate from the liquid receiving cup 800 roughly corresponds to the number of arrows with reference character EXH. In Figs. 11A to 11P, S1 to S16 written on the left side of the FFU mean that the figures correspond to steps 1 to 16.

[0083] In the following description, for the sake of simplicity, the processing parameters will be indicated as follows: The item "PLATE HEATING SWITCH" indicates the state of switch mechanism 160. "ON" indicates a state in which second electrode portion 161B of switch mechanism 160 is raised and in electrical contact with first electrode portion 161A, and power is being supplied to hot plate 140. "OFF" indicates a state in which second electrode portion 161B of switch mechanism 160 is lowered and separated from first electrode portion 161A (open state). The item "plate temperature" represents the temperature of the suction plate 120 of the turntable 100 on which the wafer W is placed. The temperature of the suction plate 120 increases as a result of being heated by the hot plate 140. After a certain amount of time has passed since the wafer W is sucked and integrated onto the suction plate 120, the temperature of the wafer W may be considered to be approximately equal to the temperature of the suction plate 120. The item "wafer rotation" indicates the number of rotations of the wafer W rotated by the turntable 100. In the case of continuous rotation in the same direction, the number of rotations is simply recorded, and in the case of oscillating rotation (alternate forward and reverse rotation), that fact is recorded. The item "liquid chemical nozzle" indicates whether or not liquid chemical is being discharged from the liquid chemical nozzle 701, and the position of the liquid chemical nozzle 701 (described only when liquid chemical is being discharged). The item "rinse nozzle" indicates whether or not a rinse liquid (here, DIW) is being discharged from the rinse nozzle 702, and the position of the rinse nozzle 702 (only the position during discharge is indicated). The item "IPA nozzle" indicates whether or not IPA is ejected from the drying acceleration liquid nozzle 703 as the drying acceleration liquid, and the position of the drying acceleration liquid nozzle 703 (described only when ejecting). 11A to 11P, the air supply from the FFU (fan filter unit (see also FIG. 2)) into the housing (processing chamber) 1610 is indicated by arrows, and the greater the number of arrows, the greater the supply air flow rate. CA means clean air, and DA means dry air. Additionally, the exhaust (EXH) from the liquid receiving cup 800 is indicated by arrows, and the greater the number of arrows, the greater the exhaust flow rate.

[0084] [Step 1 (wafer holding process)] The arm (see FIG. 1) of the substrate transfer device 17 holding the wafer W at room temperature (for example, about 24° C.) enters the processing unit 16 and is positioned directly above the suction plate 120 at room temperature (for example, about 24° C.). The lift pins 211 are positioned at the transfer position. In this state, the arm of the substrate transfer device 17 descends, whereby the wafer W is placed on the upper ends of the lift pins 211, and the wafer W is separated from the arm. Next, the arm of the substrate transfer device 17 retracts from the processing unit 16. Next, the suction device 154 is operated, the suction plate 120 is suctioned to the hot plate 140, and a suction force starts to act on the surface of the suction plate 120. In this state, the lift pins 211 descend to the processing position, and in the process, the wafer W is placed on the upper surface 120A of the suction plate 120, and the wafer W is immediately suctioned to the suction plate 120.

[0085] Thereafter, the wafer sensor 860 inspects whether the wafer W is properly adsorbed to the suction plate 120. When the wafer W is adsorbed to the suction plate 120, heat is transferred from the hot plate 140 to the wafer W via the suction plate 120. This allows the wafer W to be heated efficiently, and also allows precise temperature control for each heating zone.

[0086] A purge gas (e.g., N2 gas) is constantly supplied from the purge gas supply device 155 to the outermost recessed area 125G of the upper surface of the suction plate 120. As a result, even if there is a gap in the contact surface between the peripheral edge of the lower surface of the wafer W and the peripheral edge of the suction plate 120, the processing liquid does not seep into between the peripheral edge of the wafer W and the peripheral edge of the suction plate 120 through the gap.

[0087] The process conditions for step 1 are as follows. In the following, even if there is no special mention in the description of other steps, the chamber supply air flow rate may be slightly larger than the cup exhaust flow rate in order to maintain a slightly positive pressure inside the processing chamber 1610. Plate heating switch: OFF Plate temperature: 24℃ (23~27℃) Wafer rotation speed: 0 rpm Chemical nozzle: No discharge Rinse nozzle: No discharge IPA nozzle: No discharge

[0088] [Step 2 (preheating process)] Next, the switch mechanism 160 is turned ON to supply power to the hot plate 140 to generate heat, thereby heating the suction plate 120 and the wafer W suctioned thereto to 60° C., which is the same as the chemical processing temperature described below. At this time, the wafer W may be heated to a temperature slightly higher than the chemical processing temperature (for example, about 65° C.). By doing so, the temperatures of the suction plate 120 and the wafer W at the start of step 5 described below (which decreases due to heat dissipation) can be made approximately equal to the chemical processing temperature, and hunting, overshoot, and the like can be prevented from occurring immediately after the start of temperature control. During the pre-heating step, a dummy dispense of the chemical may be performed from the chemical nozzle 701 toward a dummy dispense port (schematically shown only in FIG. 11B with reference number 710).

[0089] The process conditions for step 2 are as follows: Plate heating switch: ON Plate temperature: 60℃ Wafer rotation speed: 0 rpm Chemical nozzle: No discharge or dummy dispense Rinse nozzle: No discharge IPA nozzle: No discharge

[0090] [Step 3] 11C, the switch mechanism 160 is turned OFF. This gradually reduces the temperatures of the suction plate 120 and the wafer W. In addition, the chemical liquid nozzle 701 is moved to directly above the center of the wafer W. The process conditions for step 3 are as follows: Plate heating switch: OFF Plate temperature: Uncontrolled (gradually decreases due to heat dissipation) Wafer rotation speed: 0 rpm Chemical nozzle: No discharge (moved directly above the center of the wafer W) Rinse nozzle: No discharge IPA nozzle: No discharge

[0091] [Step 4 (Liquid film formation process and film thickness adjustment process)] Next, as shown in FIG. 11D, while the wafer W is rotated at a high speed (e.g., 500 rpm or more, specifically, for example, about 1000 rpm), a chemical liquid having a temperature of, for example, about 60° C. is supplied to the center of the wafer W from the chemical liquid nozzle 701, and then, while continuing to supply the chemical liquid to the center of the wafer W from the chemical liquid nozzle 701, the rotation speed of the wafer W is reduced to a low speed of about 10 rpm.

[0092] The chemical liquid supplied to the center of the wafer W rotating at high speed is instantly (for example, in less than one second) spread over the entire surface of the wafer W due to centrifugal force. As a result, the entire surface of the wafer W is covered with a thin film of the chemical liquid. This stage can be considered as a pre-wetting stage that is performed prior to the chemical liquid puddle formation stage described below. By instantly spreading the chemical liquid over the entire surface of the wafer W, the in-plane uniformity of the contact time between the surface of the wafer W and the chemical liquid is increased, which results in increased in-plane uniformity of the chemical liquid processing.

[0093] After spreading the chemical liquid over the entire surface of the wafer W rotating at high speed (e.g., 500 rpm or more), the rotation speed of the wafer W is reduced (e.g., to less than half the rotation speed of the high speed rotation, specifically, for example, about 10 rpm) while continuing to supply the chemical liquid to the center of the wafer W, thereby forming a liquid film of the chemical liquid (also called a "puddle of the chemical liquid") of the desired thickness on the surface of the wafer W.

[0094] The liquid film of the chemical liquid (designated by the reference symbol "CHM") may have a thickness that does not cause problems in the processing results due to evaporation of the chemical liquid. In this step 4, the total amount of the chemical liquid supplied from the chemical liquid nozzle 701 to the wafer W is, for example, 100 ml or less. Also, in this step 4, the temperature of the chemical liquid supplied from the chemical liquid nozzle 701 to the wafer W can be set to an appropriate temperature, for example, above room temperature and below the chemical liquid processing temperature Tc, so long as the temperature of the chemical liquid present on the wafer W can be maintained at approximately 60°C.

[0095] The process conditions for step 4 are as follows: Plate heating switch: OFF Plate temperature: Uncontrolled (gradually decreases due to heat dissipation) Wafer rotation speed: 1000rpm → 10rpm Chemical nozzle: Chemical is discharged from directly above the center of the wafer W. Rinse nozzle: No discharge IPA nozzle: No discharge

[0096] The chemical liquid supplied to the wafer W is entirely that supplied in step 4. The total amount of the chemical liquid supplied in step 4 to form the puddle of the chemical liquid is about 1 / 5 to 1 / 10 of the total amount of the chemical liquid used in a conventional chemical processing step, which is performed by continuously supplying a temperature-controlled chemical liquid to the rotating wafer W.

[0097] [Step 5 (liquid film heating process)] Next, the rotation of the wafer W is stopped, the switch mechanism 160 is turned ON, and power is supplied to the hot plate 140 to generate heat, thereby maintaining the temperature of the suction plate 120, the wafer W suctioned thereto, and the chemical on the wafer W at 60° C., which is the above-mentioned chemical processing temperature Tc. As shown in FIG. 11E, the turntable 100 (the suction plate 120 and the wafer W) is oscillated and rotated to agitate the chemical forming a liquid film on the wafer W, promoting the reaction between the chemical and the surface of the wafer W and improving the uniformity of the reaction. The oscillating rotation may be, for example, a 45° forward rotation and a 45° reverse rotation alternately repeated. The oscillating angle may be changed according to the physical properties (e.g., viscosity) of the chemical. From the viewpoint of uniformity of processing, it is preferable to perform the oscillating rotation, but the rotation may simply be stopped without performing the oscillating rotation.

[0098] At this time, the chemical nozzle 701 may be returned to its home position. However, when the chemical nozzle 701 and the rinse nozzle 702 are disposed at the tip of the same nozzle arm 704 as shown in Fig. 2, the chemical nozzle 701 (i.e., the rinse nozzle 702) may continue to be positioned directly above the center of the wafer W. The same applies to the relationship between the rinse nozzle 702 and the drying promotion liquid nozzle 703.

[0099] The process conditions for step 5 are as follows: Plate heating switch: ON Plate temperature: 60℃ Wafer rotation speed: Swing rotation Chemical nozzle: No discharge Rinse nozzle: No discharge IPA nozzle: No discharge

[0100] [STEP 6] Next, as shown in Fig. 11F, the switch mechanism 160 is turned OFF. This gradually reduces the temperatures of the suction plate 120 and the wafer W. Also, the rinse nozzle 702 (not shown in Fig. 11F) is positioned directly above the center of the wafer W or moved toward directly above the center.

[0101] The process conditions for step 6 are as follows: Plate heating switch: OFF Plate temperature: Uncontrolled (gradually decreases due to heat dissipation) Wafer rotation speed: 0 rpm Chemical nozzle: No discharge Rinse nozzle: No discharge (moved directly above the center of the wafer W) IPA nozzle: No discharge

[0102] [STEP 7] 11G, while the wafer W is being rotated at a relatively low speed (for example, 100 rpm or less, specifically, about 30 rpm), a rinsing liquid (here, DIW (pure water)) at room temperature is supplied to the center of the wafer W from the rinsing nozzle 702. This causes the chemical liquid on the surface of the wafer W to be washed away, and the reaction between the chemical liquid and the surface of the wafer W is stopped.

[0103] The process conditions for step 7 are as follows: Plate heating switch: OFF Plate temperature: Uncontrolled (gradually decreases due to heat dissipation and DIW) Wafer rotation speed: 10 rpm Chemical nozzle: No discharge Rinse nozzle: DIW is discharged from directly above the center of the wafer W. IPA nozzle: No discharge

[0104] [STEP 8] Next, as shown in FIG. 11H, while continuing to supply DIW from the rinse nozzle 702 to the center of the wafer W, the rotation speed of the wafer W is increased to a high speed of about 1000 rpm. The DIW supplied to the center of the wafer W rotating at high speed flows while spreading toward the periphery of the wafer W and scatters outside the periphery. As a result, the chemicals and reaction products remaining on the surface of the wafer W are washed away by the DIW. In addition, in this step 7, the wafer W and the suction plate 120 lose heat by the DIW at room temperature, and the temperature drops to approximately room temperature. In this step 7, in order to uniformly lower the temperature of the wafer W and the suction plate 120, the rinse nozzle 702 is reciprocated between a position directly above the center of the wafer W and a position directly above the periphery of the wafer W. In addition, when the rinse nozzle 702 is reciprocated, the amount of DIW discharged from the rinse nozzle 702 may be changed depending on the discharge position, thereby achieving a more uniform temperature drop.

[0105] The process conditions for step 8 are as follows: Plate heating switch: OFF Plate temperature: Uncontrolled (cooled down to room temperature by heat dissipation and DIW) Wafer rotation speed: 1000 rpm Chemical nozzle: No discharge Rinse nozzle: Discharges DIW while reciprocating between the center and the periphery of the wafer W IPA nozzle: No discharge

[0106] [STEP 9] 11I, while maintaining the rotation speed of the wafer W, the discharge of DIW from the rinse nozzle 702 is stopped, and IPA at room temperature is discharged onto the center of the wafer W from the drying promotion liquid nozzle 703 located directly above the center of the wafer W. In step 9, the rinse liquid on the wafer W is replaced with the IPA discharged onto the center of the wafer W, and the surface of the wafer W is covered with a liquid film of IPA.

[0107] The process conditions for step 9 are as follows: Plate heating switch: OFF Plate temperature: Uncontrolled (almost room temperature) Wafer rotation speed: 1000 rpm Chemical nozzle: No discharge Rinse nozzle: No discharge IPA nozzle: IPA is discharged from directly above the center of the wafer W.

[0108] [STEP 10] 11J, while continuing to supply IPA at room temperature to the center of the wafer W from the drying acceleration liquid nozzle 703, the rotation speed of the wafer W is reduced to a low speed of about 10 rpm. By reducing the rotation speed of the wafer W while continuing to supply IPA to the center of the wafer W, a liquid film of IPA (also called an "IPA puddle") with a desired thickness can be formed on the surface of the wafer W. The liquid film of IPA should be thick enough that evaporation of IPA does not cause problems in the processing results.

[0109] In steps 9 and 10, IPA is supplied at room temperature, which substantially increases the filtering efficiency of the filter provided in the IPA supply line, thereby increasing the cleanliness of the IPA supplied to the wafer W. At high temperatures, impurities that should be filtered by the filter dissolve in the IPA, which may substantially decrease the filtering efficiency. After step 10 is completed, the drying promotion liquid nozzle 703 may be retreated to the home position.

[0110] The process conditions for step 10 are as follows: Plate heating switch: OFF Plate temperature: Uncontrolled (approximately room temperature) Wafer rotation speed: 10 rpm Chemical nozzle: No discharge Rinse nozzle: No discharge IPA nozzle: IPA is discharged from directly above the center of the wafer W.

[0111] [STEP 11] Next, as shown in FIG. 11K, the rotation of the wafer W is stopped, the switch mechanism 160 is turned on, and the hot plate 140 is energized to generate heat, thereby raising the temperature of the suction plate 120, the wafer W suctioned thereto, and the IPA on the wafer W to, for example, about 60° C. (or a higher temperature). At this time, the turntable 100 (the suction plate 120 and the wafer W) may be oscillated and rotated, or the turntable 100 may be stationary. At this time, the chamber supply air flow rate and the cup exhaust flow rate are still maintained at low flow rates to suppress the evaporation or volatilization of the IPA forming the liquid film. This makes it possible to prevent partial disappearance of the liquid film at undesirable positions on the wafer W. By increasing the temperature of the IPA, the surface tension of the IPA is reduced, and the effect of suppressing pattern collapse is increased in step 13 described later. In addition, by increasing the temperature of the IPA, substances that can dissolve in the IPA are dissolved in the IPA, so that the generation of particles can also be suppressed.

[0112] The process conditions for step 11 are as follows: Plate heating switch: ON Plate temperature: 60℃ Wafer rotation speed: 0 rpm (or oscillating rotation) Chemical nozzle: No discharge Rinse nozzle: No discharge IPA nozzle: No discharge

[0113] [STEP 12] 11L, the switch mechanism 160 is turned OFF, whereby the temperatures of the chucking plate 120 and the wafer W gradually decrease. The process conditions for step 12 are as follows: Plate heating switch: OFF Plate temperature: Uncontrolled (gradually decreases due to heat dissipation) Wafer rotation speed: 0 rpm Chemical nozzle: No discharge Rinse nozzle: No discharge IPA nozzle: No discharge

[0114] [STEP 13] 11M, the wafer W is rotated at a high speed of about 1000 to 1500 rpm, thereby shaking off and removing the IPA from the surface of the wafer W. The process conditions for step 8 are as follows. Plate heating switch: OFF Plate temperature: Uncontrolled (gradually decreases due to heat dissipation) Wafer rotation speed: 1000 rpm Chemical nozzle: No discharge Rinse nozzle: No discharge IPA nozzle: No discharge

[0115] [Step 14 (wafer removal process)] Once the wafer W is dried, the rotation of the wafer W is stopped, and the wafer W is removed from the processing unit 16 by the arm of the substrate transfer device 17 .

[0116] The process conditions for step 14 are as follows: Plate heating switch: OFF Plate temperature: Uncontrolled (gradually decreases due to heat dissipation) Wafer rotation speed: 0 rpm Chemical nozzle: No discharge Rinse nozzle: No discharge IPA nozzle: No discharge

[0117] Details of the wafer unloading process will be described with reference to Fig. 2. First, the switching device (three-way valve) 156 is switched to change the connection destination of the suction pipe 155W from the suction device 157W to the purge gas supply device 159. As a result, purge gas is supplied to the lower surface suction flow groove 121P for plates, and also supplied to the recessed area 125W of the upper surface 120A of the suction plate 120 via the lower surface suction flow groove 122W for substrates. As a result, the suction of the wafer W to the suction plate 120 is released.

[0118] In accordance with the above operation, the suction of the suction plate 120 to the hot plate 140 is also released. Since it is not necessary to release the suction of the suction plate 120 to the hot plate 140 every time the processing of one wafer W is completed, the piping system may be changed to one that does not cause this release of suction.

[0119] Next, the lift pins 211 are raised to the delivery position. Since the suction of the wafer W to the suction plate 120 has been released by the above-mentioned purging, the wafer W can be easily separated from the suction plate 120. This makes it possible to prevent the wafer W from being scratched.

[0120] Next, the wafer W placed on the lift pins 211 is lifted by an arm of the substrate transfer device 17 (see FIGS. 1 and 11N) and carried out to the outside of the processing unit 16. Thereafter, the wafer sensor 860 confirms that the wafer W is not present on the suction plate 120.

[0121] [STEP 15] 11O, while maintaining the chamber supply air flow rate and the cup exhaust flow rate, the rinse nozzle 702 is moved to directly above the center of the suction plate 120 of the turntable 100. The turntable 100 is rotated at a rotation speed of about 1000 rpm or less. In this state, DIW is supplied as a rinse liquid from the rinse nozzle 702 to the center of the suction plate 120 to clean the front surface of the suction plate 120. By performing this cleaning, it is possible to prevent the rear surface of the wafer W to be processed next from being contaminated.

[0122] In step 15, the suction plate 120 loses heat by the room temperature DIW, and the temperature drops to approximately room temperature. Suction plate 120 In this way, the entire surface of the suction plate 120 can be uniformly cleaned, and the temperature of the suction plate 120 can be uniformly reduced.

[0123] The process conditions for step 15 are as follows: Plate heating switch: OFF Plate temperature: Uncontrolled (gradually decreases due to heat dissipation and DIW) Wafer rotation speed: ~1000 rpm Chemical nozzle: No discharge Rinse nozzle: Discharge ( Suction plate 120 Fixed in the center of the Suction plate 120 (moving between the center and periphery of IPA nozzle: No discharge

[0124] [STEP 16] 11P, the discharge of DIW from the rinse nozzle 702 is stopped, and the turntable 100 is rotated at a high speed of about 1000 to 1500 rpm, thereby shaking off and drying the surface of the suction plate 120. This completes one cycle (steps 1 to 16) of operation in the processing unit 16. If there is another wafer to be processed, the process returns to step 1.

[0125] The process conditions for step 16 are as follows: Plate heating switch: OFF Plate temperature: Uncontrolled (room temperature) Wafer rotation speed: 1000~1500rpm Chemical nozzle: No discharge Rinse nozzle: No discharge IPA nozzle: No discharge

[0126] Problems that may occur in step 1 (holding step) and step 2 (preheating step) and countermeasures therefor will be described in detail below. In step 1 (holding step), the lift pins 211 holding the wafer W are lowered to place the wafer W on the upper surface 120A of the suction plate 120 (wafer placement stage 1-1), and the wafer W placed on the suction plate 120 is adsorbed to the suction plate 120 (wafer adsorption stage 1-2). In the above-described embodiment, in step 1 (holding step), the wafer W at room temperature is placed on the suction plate 120 at room temperature, and is immediately adsorbed to the suction plate 120. Then, immediately thereafter, step 2 (preheating step) is performed.

[0127] The wafer W and the suction plate 120 expand or contract with a change in temperature. If the temperature of the wafer W and / or the suction plate 120 changes after the wafer W is suctioned to the suction plate 120, the wafer W shifts relative to the suction plate 120 while being pressed against the suction plate 120 due to the difference in the amount of expansion or contraction between the two. If the amount of shift becomes large, scratches of a depth or height that cannot be ignored may occur on the rear surface of the wafer W. These scratches may cause defocusing in the exposure process of photolithography. A method for preventing or suppressing scratches on the rear surface of the wafer W will be described below.

[0128] [First method: Uniform temperature of wafer / chuck plate during chucking] Before describing the first method, let us consider the difference in the amount of thermal expansion caused by temperature change between the wafer W and the chucking plate 120. The parameters used in the consideration are defined as follows. αp: Linear expansion coefficient of the suction plate 120 αw: Linear expansion coefficient of wafer W (However, the linear expansion coefficients αp and αw are within the temperature range to which the wafer W is exposed in the apparatus according to the above embodiment (for example, about 24° C. to 80° C.). Tpi: the temperature of the suction plate 120 at the time (time t0) immediately before the wafer W is suctioned onto the suction plate 120 Twi: The temperature of the wafer W immediately before it is attracted to the attraction plate 120 Tt: the temperature of the wafer W and the suction plate 120 at a time (time t2) when the temperatures of the wafer W and the suction plate 120 become substantially the same after a certain amount of time has elapsed since the moment of suction (time t1) (for example, the temperature of the wafer W and the suction plate 120 in a preheating process or a processing process).

[0129] The amount of change in length ΔLp per unit length of the suction plate 120 from time t1 to time t2 can be expressed as ΔLp = αp (Tt - Tpi). Also, the amount of change in length ΔLp per unit length of the wafer W from time t1 to time t2 can be expressed as ΔLw = αw (Tt - Twi). In other words, the difference in the amount of change in length ΔLp - ΔLw per unit length of the suction plate 120 and the wafer W is ΔLp-ΔLw=αp(Tt-Tpi)-αw(Tt-Twi) (Formula 1) It can be expressed as:

[0130] The characteristics required for the suction plate 120 include high thermal conductivity (to efficiently heat the wafer W) and a relatively small difference in linear expansion coefficient from the wafer W (to suppress the occurrence of scratches as described above). Examples of materials having such characteristics include silicon nitride (SiC) and aluminum nitride (AlN). Furthermore, if it is necessary to further reduce the surface resistivity as a countermeasure against static electricity, the suction plate 120 is preferably made of anti-static grade SiC.

[0131] The linear expansion coefficient of SiC (αp) is 4.5×10 -6 / K, and the linear expansion coefficient (αw) of silicon Si, the material of the wafer W, is 3.9×10 -6 / K. However, the linear expansion coefficient of the material varies slightly depending on the manufacturer that provides the material. If the processing temperature of the wafer W is assumed to be 60° C., the above formula 1 can be rewritten as follows: ΔLp-ΔLw=(4.5×10 -6 / K)×(60-Tpi)-(3.9×10 -6 / K)×(60-Twi)

[0132] Here, if Tpi = Twi, ΔLp - ΔLw = (4.5 × 10 -6 / K-3.9×10 -6 / K) × (60-Tpi). In other words, ΔLp-ΔLw is determined according to the difference between the adsorption temperature and the treatment temperature. When Tpi=Twi=24° C. (room temperature), ΔLp−ΔLw is 0.0000216, and when the wafer W is a 12-inch wafer (radius 150 mm), the difference in the amount of thermal expansion across the wafer radius is 150 mm×1000×0.0000216=3.24 μm. When Tpi=Twi=60° C. (processing temperature), ΔLp−ΔLw is zero, and the difference in thermal expansion across the wafer radius is zero.

[0133] If Tpi and Twi are not equal, for example, Tpi = 60°C and Twi = 24°C, ΔLp-ΔLw = (4.5×10 -6 / K)×(60-60)-(3.9×10-6 / K)×(60−24)=0.0001404, and if the wafer W is a 12-inch wafer, the difference in the amount of thermal expansion over the radius of the wafer W is 150 mm×1000×0.0001404=21.06 μm.

[0134] As is clear from the above calculations, it is preferable that the temperature Tpi of the suction plate 120 and the temperature Twi of the wafer W when the wafer W is suctioned to the suction plate 120 are equal to each other. Note that Tpi and Twi do not necessarily need to be completely the same, and |Tpi-Twi| may be, for example, 5° C. or less. In order to reduce the difference in the amount of thermal expansion caused by heating, it is more preferable to suction the wafer W after raising the temperature of the wafer W to a high temperature (for example, a processing temperature). This can further prevent or suppress the occurrence of scratches on the back surface of the wafer W due to the difference in the amount of thermal expansion.

[0135] In order to adsorb the wafer W after raising the temperature of the wafer W to a high temperature (e.g., 60° C.), the following steps V1 to V4 can be executed instead of the above-mentioned step 1 (holding step) and step 2 (preheating step).

[0136] Step V1: The suction plate 120 is preheated to 60° C. The temperature of the suction plate 120 can be considered to be substantially the same as the temperature of the hot plate 140, and therefore can be monitored by the temperature sensor 146 described above. (FIG. 12(A))

[0137] Step V2 (Placement step): The lift pins 211 are lowered from a state where the wafer W is supported by the raised lift pins 211, so that the wafer W is placed on the surface of the suction plate 120 (without suction). The wafer W and the suction plate 120 are not in close contact with each other, but are in contact with each other or are close to each other with a minute gap of up to about several tens of microns. Therefore, the wafer W is heated by direct heat conduction from the suction plate 120, indirect heat conduction through the air, heat radiation from the suction plate 120, etc. (FIG. 12(B)). It was confirmed by an experiment that the temperature rise rate is reduced to 1 / 10 by simply separating the wafer W from the suction plate 120 by about 0.5 mm using the lift pins 211. In other words, it was confirmed that it is preferable to heat the wafer W while it is placed on the suction plate 120.

[0138] Step V3 (heating waiting step): Wait until the temperature of the wafer W reaches 60° C. or stabilizes at 60° C. At this time, the temperature of the wafer W is monitored by the infrared thermometer 870 (see FIG. 2) described above (FIG. 12(C)).

[0139] Step V4 (adsorption step): When the temperature of the wafer W reaches 60° C. or is stabilized at 60° C., the wafer W is adsorbed onto the adsorption plate 120. At this time, it may be confirmed whether the adsorption plate 120 is at 60° C. (FIG. 12(D)).

[0140] When step V4 is completed, the chucking plate 120 and the wafer W have already reached 60° C., so that the process can proceed to step 3 described above.

[0141] Strictly speaking, (4.5×10 -6 / K)×(60-Tpi)=(3.9×10 -6 / K)×(60−Twi), so in this case, for example, it may be possible to set (Tpi, Twi)=(52.2° C., 51.0° C.) or (56.1° C., 55.5° C.). However, doing so means that adsorption is performed when the temperature is transiently changing, making it difficult to perform steps 1 to 4 above while reliably managing the temperature. In actual operation, it is preferable to perform adsorption when the temperature of the wafer W and the temperature of the adsorption plate 120 are stable at the same temperature (e.g., 80° C.).

[0142] Incidentally, for example, when Tpi=Twi=60° C., if the temperature of the suction plate 120 and the wafer W are lowered to room temperature (for example, 24° C.) while the wafer W is suctioned to the suction plate 120 after the wafer W processing, the difference in the amount of thermal contraction over the radius of the wafer W due to thermal contraction is 3.24 μm, similar to the estimated calculation of Tpi=Twi=24° C. If it is desired to prevent the rear surface of the wafer W from being scratched due to the difference in the amount of thermal contraction, the suction of the wafer W may be released when the temperature of the wafer W is relatively high. At this time, for example, by supplying the wafer W with DIW having a temperature higher than room temperature and IPA having a temperature higher than room temperature after the chemical processing, the temperature of the wafer W at the time when the series of processing for the wafer W is completed can be made higher than room temperature.

[0143] Although it depends on the allowable size (length, height, depth) of the scratch, it is preferable that the difference in the amount of thermal expansion (amount of contraction) over the radius of the wafer W due to temperature fluctuations between the wafer W and the suction plate 120 is smaller than, for example, 5 μm. It is preferable to select a material for the suction plate 120 having an appropriate linear expansion coefficient based on the allowable difference in the amount of thermal expansion (amount of contraction) and the temperature fluctuation width (which depends on the process conditions) of the wafer W and the suction plate 120. It is preferable that the linear expansion coefficient of the material constituting the suction plate 120 is as close as possible to the linear expansion coefficient of the wafer W.

[0144] Next, the results of an experiment investigating the relationship between the temperature during suction and scratches on the back surface of the wafer will be described. In Example 1, as in the above-described embodiment, in step 1 (wafer holding step), the wafer W at room temperature (24° C.) was adsorbed onto the suction plate 120 at room temperature (24° C.), and immediately thereafter, power was applied to the heater 142 to execute step 2 (preheating step). After 30 seconds had elapsed since the wafer W was adsorbed onto the suction plate 120 (i.e., since the preheating step had started), the adsorption was released. In Example 2, the above-mentioned steps V1 to V4 were executed instead of the above-mentioned step 1 (wafer holding step) and step 2 (preheating step). The temperature of the suction plate 120 was set to 60° C., and the transition from step V3 (heat-up waiting step) to step V4 (suction step) was performed when the temperature of the wafer W reached 60° C. The suction was released 30 seconds after the start of step V4. In the comparative example, in the above-mentioned step 1 (wafer holding step), the wafer W at room temperature (24° C.) is adsorbed onto the suction plate 120 at 40° C., which is higher than the room temperature, and then immediately thereafter, the heater 142 is energized to execute step 2 (preheating step). The adsorption is released 30 seconds after the wafer W is adsorbed onto the suction plate 120 (i.e., after the preheating step is started). If the execution time of the above-mentioned step 15 is short, the temperature of the suction plate 120 may not drop completely to room temperature, and this comparative example assumes this case. In all of Examples 1 and 2 and the comparative example, the vacuum suction force was the same (-80 kPa), and after suction, the wafer W was not rotated, and no processing liquid was supplied to the wafer.

[0145] After the suction was released, the back surface of the wafer W was scrubbed, and then a test was conducted to check the number of defects of 100 nm or more in size using a particle inspection device. Since real particles can be largely removed by scrubbing, most of the defects detected are scratches (irregularities). For simplicity, the above test will be referred to as the "scratch formation test" below, and the number of defects of 100 nm or more in size detected in the "scratch formation test" after scrubbing will be referred to as the "number of scratches."

[0146] In the comparative examples, the numbers of scratches were 16,305, 16,771, and 15,866. In contrast, the numbers of scratches were 3,476, 3,748, and 3,717 in the example 1, and the numbers of scratches were 3,218, 3,951, and 3,702 in the example 2. In other words, the number of scratches was significantly reduced in the examples 1 and 2 compared to the comparative examples. ), both stripe-like scratches (drag marks) and spot-like scratches were found in the comparative example, whereas most of the scratches were spot-like in Examples 1 and 2. This shows that the occurrence of scratches due to differences in the amount of thermal expansion can be significantly suppressed by performing adsorption at the same temperature.

[0147] As reference data, after performing only the above-mentioned step V1 and step V2, the back surface of the wafer W was scrubbed and the amount of foreign matter of 100 nm or more was detected by a particle inspection device, and the amount of foreign matter was 325, 359, and 339. From this, it is understood that the number of scratches caused by only landing the wafer W at room temperature (24° C.) on the suction plate 120 at 60° C. without suction is small, and most of the scratches caused in Example 2 occurred after suction.

[0148] There is no significant difference in the amount of damage caused between Example 1 and Example 2. However, when the procedure of Example 1 is performed, the temperature of the suction plate 120, which has risen to 60° C. or more in Step 11, must be lowered to room temperature at the start of Step 1. This requires a relatively long time. For example, Step 15 must be performed for a relatively long time. Also, if only the cleanliness of the suction plate 120 is considered, Step 15 (cleaning of the suction plate 120) does not necessarily need to be performed every time the processing of one wafer W is completed, but if cooling of the suction plate 120 is essential, Step 15 must be performed every time the processing of one wafer W is completed. These factors reduce the throughput per processing unit.

[0149] In contrast, when the procedure of the first embodiment is performed, it is possible to start temperature adjustment of the suction plate 120 immediately after unloading the wafer W that was just processed. Also, if step 15 is performed using HOT-DIW at about 60° C., for example, it is possible to prevent the temperature of the suction plate 120 from dropping, and almost no time is required to raise the temperature of the suction plate 120 to about 60° C. after the end of step 15. The same can be said when step 15 is not performed, because the temperature of the suction plate 120 at the end of step 14 is relatively high.

[0150] As an example, when the temperature of the suction plate 120 at the end of step 14 is 35° C., the time required for one cycle of the process is 301 seconds in Example 2 and 361 seconds in Example 1. In Example 1, it took about 70 seconds to cool the suction plate 120 to room temperature (24° C.). Instead, in Example 2, the suction plate 120 is heated to 60° C., and then the wafer W is heated to 60° C. before suction is performed. This results in a low efficiency in heating (heating) the wafer W, and Example 2 required about 10 seconds extra time for heating compared to Example 1.

[0151] Therefore, if the above-mentioned steps 1 to 15 are to be performed for each wafer W, then Example 2, which has a higher throughput, is more preferable than Example 1. However, depending on the series of steps performed for one wafer W, there may be cases where the temperature of the wafer W just before it is unloaded from the turntable 100 has dropped to near room temperature. In this case, it may be preferable to employ Example 1.

[0152] [Second method: Reducing the contact area between the suction plate and the wafer W] In the second method, a suction plate 120A according to a modified embodiment is used. Instead of the surface structure of the suction plate 120 shown in Fig. 6 and Fig. 9, the suction plate 120A uses a surface structure in which a plurality of microsupport members 123 are arranged at intervals on the surface of the suction plate 120 as shown in Fig. 13.

[0153] The configuration of the peripheral region of the suction plate 120A is the same as that of the peripheral region of the suction plate 120 shown in FIG. OUT The circular central region of the suction plate 120A may have the same configuration as the central region of the suction plate 120 shown in FIG. IN 13, has a large number of (only three are shown in FIG. 13) micro-support members 123 protruding from a flat surface. The circular central region of the suction plate 120A has a diameter slightly smaller than that of the wafer W.

[0154] As shown in Fig. 13, the central circular region of the suction plate 120A where the micro-support member 123 is disposed has through holes similar to the suction through hole 129W and the purge gas supply through hole 129G described above with reference to Fig. 6 and Fig. 9. The lift pin hole 128L penetrating the suction plate 120A is surrounded by a cylindrical wall 123A having the same height as the micro-support member 123. This prevents the suction force acting through the suction through hole 129 from leaking through the lift pin hole 128L.

[0155] In one embodiment, the micro-support members 123 have a flattened cylindrical shape, a bottom surface (top surface) with a diameter of 500 μm, a height of 50 μm, the micro-support members 123 are spaced apart by 6 mm, and one suction plate 120A has 1520 micro-support members 123 evenly arranged in a circular central area. The diameter of the top surface of the micro-support members 123 may be any size of 1 mm or less. The size and spacing of the micro-support members 123 are not limited to those described above, but are preferably set to satisfy the following conditions. (Condition 1) When the wafer W is suctioned to the suction plate 120A, a gap is reliably present between the back surface of the wafer W and the top surface of the suction plate 120A in the entire area except for the area where the micro-support members 123 are present. (Condition 2) The total contact area between the bottom surface of the wafer W and the top surface of the micro-support members 123 is as small as possible.

[0156] Hereinafter, the configuration of the suction plate 120A will also be referred to as configuration example 1.

[0157] If the warp of the wafer W is small and the wafer W is sufficiently flat, a suction plate 120B according to another modified embodiment shown in Fig. 14 can be used. The suction plate 120B is configured to suction only the peripheral region of the wafer W, and the region inside the peripheral region is simply supported by the micro support members 123. Specifically, the configuration of the peripheral region of the suction plate 120B is the same as that of the suction plate 120 shown in Fig. 9 (region II in Fig. 9). OUT 9. The circular central region of the suction plate 120B (region II in FIG. 9) may have the same structure as the suction plate 120B. IN 13. Similarly to suction plate 120A, suction plate 120B has a number of micro-support members 123 (only three are shown in FIG. 13) protruding from a flat surface. The circular central region of suction plate 120B has a diameter slightly smaller than that of wafer W.

[0158] The suction plate 120B suctions only the peripheral region of the wafer W by sucking the annular region between the partition wall 124 closest to the through hole 129G and the second closest partition wall 124. Since the circular central region of the suction plate 120B is not sucked, there is no need to provide through holes corresponding to the suction through hole 129W and the through hole 129G for supplying purge gas, and there is no need to provide the cylindrical wall 123A as shown in FIG. 13 around the lift pin hole 128L. In the suction plate 120B, the micro support members 123 are hardly loaded, so the number of the micro support members 123 may be small. The number of the micro support members 123 can be, for example, about 15.

[0159] Hereinafter, the configuration of the suction plate 120B will also be referred to as Configuration Example 2. Moreover, the configuration of the suction plate 120 shown in FIGS.

[0160] The above-mentioned scratch formation test was carried out under the same conditions (the same conditions as in Example 1) for each of Configuration Examples 1 to 3 to check the number of scratches formed on the back surface of the wafer W. The number of scratches was 3478 in Configuration Example 1, 937 in Configuration Example 2, and 5071 in Configuration Example 3. From this test, it was confirmed that the number of scratches can be reduced by reducing the contact area between the suction plate 120 and the wafer W.

[0161] The total surface area of ​​the suction plate 120 receiving the vacuum suction force is in the order of Configuration Example 3>Configuration Example 1>Configuration Example 2. For example, when comparing Configuration Example 1 and Configuration Example 3, the contact surface pressure during suction is in the order of Configuration Example 1>>Configuration Example 3. For this reason, it is considered that the back surface of the wafer W is more susceptible to scratches in Configuration Example 1 compared to Configuration Example 3. However, test results showed that the number of scratches was smaller in Configuration Example 1 compared to Configuration Example 3.

[0162] The inventors consider the reason why the number of scratches is small in Configuration Example 1 as follows. Scratches on the back surface of the wafer W are caused by the relative movement of the suction plate 120 and the wafer W with minute protrusions formed on the surface of the suction plate 120 biting into the back surface of the wafer W. The total contact area between the back surface of the wafer W and the top surface of the cylindrical body is reduced, which reduces the probability of the existence of minute protrusions of a problematic size, and therefore reduces the probability of scratches of a problematic size occurring.

[0163] The micro-supports 123 can be formed by blasting a hard masked flat surface, where the blasting material removes the area around the masked area, leaving the micro-supports 123 beneath the masked area.

[0164] By sufficiently smoothing the surface of the suction plate before applying the hard mask (for example, to about Ra<0.01) by polishing or lapping, the probability of micro-protrusions being present on the top surface of the micro-support member 123 can be significantly reduced, and even if micro-protrusions are present, their height can be reduced. This makes it possible to prevent or suppress the occurrence of scratches on the back surface of the wafer W. After blasting and removal of the hard mask, polishing or lapping may be applied to the top surface of the micro-support member 123. After polishing or lapping, hard particles remaining on the surface may be removed by ultrasonic cleaning.

[0165] It is also preferable to perform R-chamfering on the peripheral portion of the top surface of the micro-support member 123 by polishing (brush polishing, lapping polishing) or the like. This makes it possible to prevent or suppress the peripheral portion of the top surface from biting into the back surface of the wafer W, thereby causing damage to the back surface of the wafer W. Note that, if a prismatic micro-protrusion is used instead of the cylindrical micro-support member 123, there is a risk that the corners of the top surface will be bitten into the back surface of the wafer W, so it is preferable to use a cylindrical micro-protrusion. Note that, in configuration example 3 as well, it is preferable to polish the wafer contact surface and its corners of the suction plate 120.

[0166] [Third method: Use of less aggressive materials] The material of the suction plate 120 can be a SiC surface (wafer support surface) coated with a soft material, such as a resin material. For example, PEEK (polyether ether ketone) containing carbon filler can be used as the resin material. By using such a resin material, the risk of scratches occurring on the back surface of the wafer W due to the above mechanism can be eliminated. In addition, by using a conductive filler such as carbon that has low wafer attack, it is possible to prevent the wafer W from being charged. Since the thermal conductivity of resin materials such as PEEK is low, it is preferable to make the coating thin (for example, about 0.5 mm). PFA (a copolymer of tetrafluoroethylene and perfluoroalkoxyethylene) can also be used as the resin material for coating.

[0167] The above-mentioned scratch formation test (the test conditions were the same as those of the above-mentioned Example 1, except that the vacuum suction force was slightly lowered to -60 kPa) was performed using an adsorption plate in which the surface of SiC was coated with PEEK containing carbon filler, and no scratches were observed on the back surface of the wafer. Carbon-based foreign matter was observed adhering to almost the entire surface of the back surface of the wafer, but this foreign matter could be removed by scrubbing. If scratches on the back surface of the wafer W cannot be tolerated at all, the use of the carbon filler-containing PEEK coating is very beneficial. In this case, it is also beneficial to use the above-mentioned first method in combination. This is because it is possible to prevent carbon from falling off the coating and the coating from wearing away due to relative sliding (due to the difference in thermal expansion) between the back surface of the wafer W and the coating surface.

[0168] The suction plate 120 may be made of a material in which the surface (wafer support surface) of SiC is coated with DLC (diamond-like carbon), which has a lower coefficient of friction than SiC itself.

[0169] The surface of the SiC (wafer support surface) may be smoothed by forming a SiC layer on the surface of the SiC by CVD or by subjecting the SiC to a recrystallization annealing treatment. In the firing process of the SiC, the sintering aid disappears, causing voids to be exposed on the surface of the SiC surface, and SiC particles may fall off around the voids, which may cause scratches on the back surface of the wafer W. The smoothing treatment described above can prevent such an event from occurring.

[0170] [Fifth method: cleaning the suction plate surface] As in step 15 described above, the surface of the suction plate 120 may be cleaned every time processing of one wafer W is completed or periodically. The cleaning can be performed by, for example, spraying gas (e.g., N2 gas) onto the surface of the suction plate 120 from a gas nozzle, discharging a cleaning chemical (e.g., DHF, SC1, etc.), a rinse liquid (e.g., DIW) or a two-fluid (e.g., a mixed fluid of DIW mist and N2 gas) onto the surface of the suction plate 120 from a cleaning liquid nozzle, or scrubbing with a brush. Note that cleaning is preferably performed in a state in which purge gas is discharged from the gas suction hole for suction and the hole for supplying purge gas. This can prevent liquid from entering the holes. By periodically performing cleaning as described above, for example, hard particles that have fallen off the surface of the suction plate 120 can be prevented from being bitten into the back surface of the wafer W, and scratches can be prevented from occurring on the back surface of the wafer.

[0171] [Other methods] By reducing the lifting and lowering speed of the lift pins 211 to, for example, about 2 mm / sec, it is possible to prevent or suppress scratches on the back surface of the wafer when the wafer W lands on the suction plate 120 or when the wafer W leaves the suction plate 120.

[0172] The various techniques described above (techniques for preventing or suppressing the occurrence of scratches on the back surface of the wafer W) can be used in appropriate combination while taking into consideration the allowable level of scratches.

[0173] The embodiments disclosed herein should be considered as illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims.

[0174] The substrate to be processed is not limited to a semiconductor wafer, but may be any other type of substrate used in the manufacture of semiconductor devices, such as a glass substrate or a ceramic substrate. [Explanation of symbols]

[0175] W substrate (wafer) 100 Substrate table (rotary table) 142 Heater 701 Processing liquid nozzle (chemical liquid nozzle)

Claims

1. A substrate processing method for liquid processing a substrate in a substrate processing apparatus including a substrate table for adsorbing a substrate, a rotary drive mechanism for rotating the substrate table, a heater for heating the substrate table, a processing liquid nozzle for supplying a processing liquid to the substrate adsorbed to the substrate table, and a rinse nozzle for supplying a rinse liquid to the substrate adsorbed to the substrate table, comprising: a suction step of suctioning the substrate by the substrate table when there is no temperature difference between the substrate and the substrate table or when the temperature difference is within a predetermined range; a processing liquid supplying step of supplying a processing liquid from the processing liquid nozzle to the substrate adsorbed on the substrate table heated by the heater after the adsorption step; a heating stopping step of stopping heating of the substrate table by the heater after the processing liquid supply step; a rinsing liquid supplying step of supplying a rinsing liquid from the rinsing nozzle to the substrate attracted to the substrate table after the heating stopping step, the rinse liquid supply step comprises supplying the rinse liquid while moving the rinse nozzle so that a supply position of the rinse liquid moves between a center portion and a peripheral portion of the substrate; The substrate processing method includes providing the substrate table with the following requirements: the surface of the substrate table in contact with the substrate is formed by the circular top surfaces of a plurality of spaced apart flattened cylindrical support members; - the diameter of the circular top surface of the support member is less than or equal to 1 mm; the height of the support member is such that, when the substrate is attracted to the substrate table, there is ensured to be a gap between the underside of the substrate and the surface of the substrate table over the entire surface of the substrate table except for the area where the support member is present; - the support members are evenly distributed over a central area of ​​the surface of the substrate table; the top surface of the support member has an arithmetic mean roughness Ra<0.01; - the peripheral edge of the top surface of the support member is rounded; A substrate processing method performed using a substrate table satisfying the above.

2. a temperature measuring step of measuring a temperature of the substrate by a substrate temperature sensor and a temperature of the substrate table before the adsorption step; a determining step of determining whether or not there is no temperature difference between the substrate and the substrate table or whether the temperature difference is within the predetermined range based on the temperatures of the substrate and the substrate table measured in the temperature measuring step; Further equipped with 2. The substrate processing method according to claim 1, wherein the adsorption step is performed after it is determined in the determination step that there is no temperature difference between the substrate and the substrate table or that the temperature difference is within the predetermined range.

3. a step of placing the substrate on the substrate table having a temperature higher than that of the substrate without adsorption; a temperature rise waiting step of waiting for the temperature of the substrate heated by the substrate table to rise until the temperature difference between the substrate and the substrate table disappears or falls within the predetermined range; Further equipped with 3. The substrate processing method according to claim 1, wherein the adsorption step is performed after a temperature rise waiting step has been performed in which a temperature difference between the substrate and the substrate table has disappeared or has fallen within the predetermined range.

4. a cooling step of cooling the temperature of the substrate table before the adsorption step to a temperature at which a temperature difference between the substrate and the substrate table is eliminated or falls within the predetermined range; a heating step of heating the substrate table and the substrate attracted thereto by the heater after the adsorption step; 3. The substrate processing method according to claim 1, further comprising:

5. 5. The substrate processing method according to claim 1, wherein the temperature of the substrate at the start of the adsorption step is room temperature.

6. A substrate processing method according to claim 1 , wherein the temperature difference between the substrate and the substrate table being within the predetermined range means that the temperature difference between the substrate and the substrate table is ±5 degrees or less.

7. 7. The substrate processing method according to claim 1, further comprising a cleaning step of cleaning an attraction surface of the substrate table to which the substrate is attracted each time processing of one substrate is completed or periodically, the cleaning step being performed by at least one of blowing gas onto the attraction surface from a gas nozzle, ejecting a cleaning liquid onto the attraction surface from a cleaning liquid nozzle, and scrubbing the attraction surface.

8. 8. The substrate processing method according to claim 1, wherein the substrate processing apparatus further comprises a rotation drive mechanism that rotates the substrate table, and the rinsing liquid supply process is performed while rotating the substrate adsorbed to the substrate table.

9. a drying liquid application step of supplying a drying promotion liquid from a drying promotion liquid nozzle to a center portion of the substrate while rotating the substrate attracted to the substrate table in a state in which heating of the substrate table by the heater is stopped after the rinsing liquid supply step; a heating step of heating the substrate table by the heater after the drying liquid applying step, and a heating stopping step of stopping heating of the substrate table by the heater thereafter; The method of claim 1 , further comprising:

10. a suction releasing step of releasing suction of the substrate by the substrate table after liquid processing on the substrate is completed; a substrate unloading step of removing the substrate from above the substrate table after the suction releasing step; a substrate table cleaning step of supplying a rinse liquid from the rinse nozzle to a surface of the substrate table to clean the surface of the substrate table after the substrate unloading step; The method of claim 1 , further comprising:

11. 11. The substrate processing method according to claim 10, further comprising, after the substrate table cleaning step, a substrate table drying step of drying the substrate table by rotating the substrate table with the supply of the rinsing liquid stopped.

12. A substrate processing apparatus, comprising: a substrate table for adsorbing a substrate; a heater for heating the substrate adsorbed on the substrate table; lift pins capable of raising and lowering a substrate placed on an attraction surface of the substrate table to which the substrate is attracted; A power supply unit that supplies power to the heater; a suction unit that applies a suction force for suction to the substrate table; a processing liquid nozzle for supplying a processing liquid to the substrate attracted to the substrate table; a rinse nozzle that supplies a rinse liquid to the substrate attracted to the substrate table; a table temperature sensor for measuring a temperature of the substrate table; a substrate temperature sensor for measuring a temperature of the substrate; A control unit for controlling an operation of the substrate processing apparatus; Equipped with a surface of the substrate table in contact with the substrate is formed by circular top surfaces of a plurality of spaced apart flattened cylindrical support members; The diameter of the circular top surface of the support member is 1 mm or less; the height of the support member is such that, when the substrate is adsorbed to the substrate table, a gap is reliably present between the rear surface of the substrate and the surface of the substrate table in the entire area of ​​the surface of the substrate table excluding the area in which the support member is present, the support members are evenly distributed over a central region of a surface of the substrate table; The arithmetic mean roughness Ra of the top surface of the support member is less than 0.01; The peripheral edge of the top surface of the support member is R-chamfered, The control unit controls the substrate processing apparatus to a suction step of suctioning the substrate by the substrate table when there is no temperature difference or is within a predetermined range between the temperature of the substrate measured by the substrate temperature sensor and the temperature of the substrate table measured by the table temperature sensor; a processing liquid supplying step of supplying a processing liquid from the processing liquid nozzle to the substrate adsorbed on the substrate table heated by the heater after the adsorption step; a heating stopping step of stopping heating of the substrate table by the heater after the processing liquid supply step; a rinsing liquid supplying step of supplying the rinsing liquid to the substrate adsorbed on the substrate table while moving the rinsing nozzle so that a supply position of the rinsing liquid moves between a center portion and a peripheral portion of the substrate after the heating stopping step; The substrate processing apparatus executes the above.

13. The control unit is lowering the lift pins supporting the substrate above the substrate table, so that the substrate is placed on the substrate table, the temperature of which is higher than the temperature of the substrate, while preventing a suction force from being applied to the substrate by the suction unit; Thereafter, the temperature of the substrate table and the temperature of the substrate are monitored by the table temperature sensor and the substrate temperature sensor; executing the suction step of suctioning the substrate onto the substrate table by the suction unit after there is no temperature difference between the substrate and the substrate table or the temperature difference falls within the predetermined range; The substrate processing apparatus of claim 12 .

14. 14. The substrate processing apparatus according to claim 12, wherein a surface of the substrate table that comes into contact with the substrate when the substrate table adsorbs the substrate is made of PEEK containing a carbon filler or SiC.

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