Apparatus for processing substrate and method for cleaning workbench

Abstract

This invention provides an apparatus for processing substrates and a method for cleaning a workbench. A substrate to be processed is placed on the workbench of the substrate processing apparatus. A liquid for temperature regulation of the substrate is supplied from a liquid supply unit, and the liquid flows through a flow path formed within the workbench. A control unit controls the process by replacing the fluid in the flow path with the liquid using gas supplied from a gas supply unit, and then heating the workbench to a temperature higher than the operating temperature of the liquid to remove any adhering substances. This invention cleans the workbench while avoiding any impact on the temperature-regulating liquid during the heating process.

Description

Technical Field

[0001] The present invention relates to an apparatus for processing a substrate and a method for cleaning a workbench. Background Art

[0002] In the manufacturing process of semiconductor devices, various processing gases are supplied to a semiconductor wafer (hereinafter referred to as a wafer) as a substrate while it is placed on a workbench, thereby performing various processes such as film formation and etching. On the other hand, during these processes, the processing gas used for film formation may react on the surface of the workbench to form deposits, or substances removed from the wafer by etching may adhere to the workbench. Therefore, by heating the workbench, cleaning is performed to remove the deposits.

[0003] Patent document 1 describes a technique for performing a flushing process while supplying a clean gas while heating the shower head to remove reaction byproducts attached to the shower head for supplying a film-forming gas. A refrigerant flow path is formed in the shower head, and cooling water is passed through it for cooling, thereby suppressing the reaction of the gas on its surface. On the other hand, during the flushing process, the supply of cooling water is stopped, and the cooling water remaining in the refrigerant flow path is heated and boiled by a heater, thereby discharging the cooling water and achieving efficient heating of the shower head.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-13504 Summary of the invention

[0007] Technical problem to be solved by the invention

[0008] The present invention provides a technology for cleaning a workbench while preventing the temperature regulating liquid from being affected by the heating of the workbench.

[0009] Technical solutions for solving technical problems

[0010] The present invention is an apparatus capable of processing a substrate, comprising:

[0011] A worktable capable of mounting a substrate to be processed;

[0012] a liquid supply unit configured to supply liquid for adjusting the temperature of the substrate to the workbench;

[0013] a flow path formed in the workbench, configured to allow the liquid supplied from the liquid supply unit to flow;

[0014] a liquid receiving portion configured to receive the liquid discharged from the flow path;

[0015] A heating unit configured to heat the workbench to a temperature higher than a use temperature of the liquid to remove attachments attached to the workbench;

[0016] a gas supply unit configured to supply gas to the flow path; and

[0017] Control Department,

[0018] The control unit is configured to control the following: switching the fluid in the flow path from the liquid supplied by the liquid supply unit to the gas supplied by the gas supply unit, replacing the flow path with the gas, and then heating the workbench with the heating unit.

[0019] Effects of the Invention

[0020] According to the present invention, the workbench can be cleaned while preventing the temperature adjustment liquid from being affected by heating of the workbench. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a longitudinal sectional side view of a substrate processing apparatus according to one embodiment.

[0022] Figure 2 It is an exploded perspective view of a workbench arranged in the above-mentioned substrate processing device.

[0023] Figure 3 It is a perspective view of the intermediate flow path portion constituting the above-mentioned workbench.

[0024] Figure 4 It is a longitudinal sectional side view of the upper side of the above-mentioned workbench.

[0025] Figure 5 It is a perspective view of the valve unit group.

[0026] Figure 6 It is a perspective view showing the configuration state of the above-mentioned substrate processing apparatus.

[0027] Figure 7 This is the first explanatory diagram of the function of the above-mentioned workbench.

[0028] Figure 8 This is a second explanatory diagram of the function of the above-mentioned workbench.

[0029] Fig. 9 This is the third explanatory diagram of the function of the above-mentioned workbench.

[0030] Fig.10 It is a top view of a workbench according to another embodiment.

[0031] Description of Reference Numerals

[0032] W1 substrate processing device

[0033] 100 Control Department

[0034] 2 Workbench

[0035] 220 Small room department

[0036] 231 First Tube

[0037] 232 Second Tube

[0038] 33 Heating lamp

[0039] 61 High temperature liquid supply unit

[0040] 62 Cryogenic liquid supply unit

[0041] 66 Nitrogen supply unit. DETAILED DESCRIPTION

[0042] Below, refer to Figure 1 to Figure 6 , the structure of the substrate processing apparatus 1 according to the embodiment will be described. Figure 1 It is a longitudinal sectional side view of the substrate processing apparatus 1 .

[0043] The substrate processing apparatus 1 of this example is configured as, for example, a capacitively coupled plasma processing apparatus. The substrate processing apparatus 1 has a substantially cylindrical chamber 11. Inside the chamber 11, a processing space 110 for processing a wafer W as a substrate is included. The chamber 11 is made of a metal such as aluminum and is electrically grounded. A plasma-resistant film such as aluminum oxide or yttrium oxide is formed on the inner surface constituting the processing space 110.

[0044] A carrying port 12 for carrying the wafer W into the processing space 110 and carrying the wafer W out of the processing space 110 is formed on the side wall of the chamber 11 . The carrying port 12 can be opened and closed by a gate valve 121 .

[0045] The stage 2 is disposed at the bottom of the chamber 11. The stage 2 is configured to be able to place a wafer W on a placement surface formed on the upper surface side thereof. The stage 2 includes an electrostatic chuck 21, a plate 22, and a manifold 23. The detailed structure of the stage 2 will be described later.

[0046] The substrate processing device 1 includes an electrode plate 31 constituting an upper electrode. The electrode plate 31 is arranged above the workbench 2 across the space in the processing space 110. The electrode plate 31 is supported on the upper part of the chamber 11 by a support member 32. The electrode plate 31 is formed of a conductor or semiconductor with low Joule heat and low resistance, and is grounded via the support member 32 and the chamber 11. When the electrode plate 31 is connected to a high-frequency power supply as in the example described later, the support member 32 supporting the electrode plate 31 is made of an insulating material.

[0047] A gas release hole 311 is formed in the central portion of the electrode plate 31 when viewed from above. The gas release hole 311 opens on the upper surface side of the electrode plate 31 and is connected to the processing gas supply pipe 51. The processing gas supply pipe 51 is connected to the processing gas supply unit 54 via a valve 52 and a flow regulator 53. For example, the flow regulator 53 is composed of a mass flow controller or a pressure-controlled flow controller. The processing gas for processing the wafer W in the substrate processing device 1 is supplied from the processing gas supply unit 54. The processing gas supplied from the processing gas supply unit 54 is released into the processing space 110 via the processing gas supply pipe 51 and the gas release hole 311.

[0048] For example, when the wafer W is subjected to film forming processing, only a raw material gas containing a film raw material is supplied as the processing gas, or a raw material gas and a reaction gas reacting with the raw material gas are supplied alternately. In addition, in the case of etching processing, an etching gas is supplied as the processing gas.

[0049] An exhaust passage is formed between the side wall of the chamber 11 and the stage 2. A baffle plate 131 is provided in the middle of the exhaust passage. The baffle plate 131 has a plurality of holes penetrating the constituent material thereof in the plate thickness direction.

[0050] An exhaust port 132 is provided at the bottom of the chamber 11 below the baffle plate 131. The exhaust port 132 is connected to an exhaust device 133 via an exhaust pipe 13. The exhaust device 133 includes a pressure controller and a vacuum pump such as a turbomolecular pump.

[0051] The substrate processing apparatus 1 includes a first high-frequency power source 41 and a matching device 42 , and a second high-frequency power source 43 and a matching device 44 .

[0052] The first high-frequency power source 41 is a power source that outputs a high frequency for plasma generation. The frequency of the high frequency output by the first high-frequency power source 41 is a frequency of 27 MHz or more, for example, 40 MHz. The first high-frequency power source 41 is connected to the plate 22 via a matcher 42. The high frequency output by the first high-frequency power source 41 is supplied to the plate 22 via the matcher 42. The matcher 42 includes a matching circuit for matching the impedance of the load side of the first high-frequency power source 41 with the output impedance of the first high-frequency power source 41. The first high-frequency power source 41 may also be connected to the electrode plate 31 via the matcher 42.

[0053] The second high-frequency power source 43 is a power source that outputs a high frequency for attracting ions to the wafer W. The frequency of the high frequency output by the second high-frequency power source 43 is 13.56 MHz or less, for example, 3 MHz. The second high-frequency power source 43 is connected to the plate 22 via the matching device 44. The high frequency output by the second high-frequency power source 43 is supplied to the plate 22 via the matching device 44. The matching device 44 includes a matching circuit for matching the impedance of the load side of the second high-frequency power source 43 with the output impedance of the second high-frequency power source 43.

[0054] In addition to the above Figure 1 In addition, refer to Figure 2 to Figure 4 , describe the workbench 2 in detail. Figure 2 and Figure 3 It is an exploded perspective view of the workbench 2. Figure 4 It is a longitudinal sectional view which shows a part of the workbench 2 in an enlarged manner.

[0055] like Figure 1 As shown in FIG. 1 , the electrostatic chuck 21 is configured in a substantially disk shape, and a placement area capable of placing a wafer W is provided on its upper surface. The electrostatic chuck 21 is configured such that a chuck electrode 211 as a conductive film is sandwiched between a pair of insulating layers or insulating sheets made of, for example, ceramic. The chuck electrode 211 is connected to a DC power source 45, and can fix and hold the wafer W by utilizing electrostatic force such as Coulomb force generated by applying a DC voltage.

[0056] A plate 22 is provided below the electrostatic chuck 21. The plate 22 is formed in a substantially disk shape and supports the electrostatic chuck 21 from the lower surface side. Various metals and ceramics can be used as the constituent material of the plate 22. In this example, the plate 22 is formed of SiSiCTi (silicon-infiltrated titanium silicon carbide) having low thermal conductivity.

[0057] like Figure 2 As shown in FIG. 2 , the plate 22 of this embodiment has a disk-shaped main body 22a on the central side and an annular flange 22b on the peripheral side. Figure 2 and Figure 4 As shown, a plurality of through holes 221 extending in the plate thickness direction of the plate 22 are formed in the main body 22a. The plurality of through holes 221 are formed independently of each other and are arranged in a planar shape below the electrostatic chuck 21. The openings on the upper surface side of the plurality of through holes 221 are closed by the electrostatic chuck 21. The openings on the lower surface side of the plurality of through holes 221 are open.

[0058] like Figure 4As shown in the figure, the back side of the electrostatic chuck 21 is bonded to the main body 22a of the plate 22 via the bonding layer 213. That is, the region (upper surface of the wall portion 222) on the front side of the plate 22 opposite to the back side of the electrostatic chuck 21, where the plurality of through holes 221 are not formed, is bonded to the back side of the electrostatic chuck 21. On the other hand, the region 212 on the back side of the electrostatic chuck 21 that is not bonded to the plate 22 is exposed to each through hole 221.

[0059] In addition, a covering film 214 may be formed on the workbench 2 to cover the outer edge of the bonding layer 213. The covering film 214 is, for example, a film of Al2O3 formed by thermal spraying. The covering film 214 protects the bonding layer 213 so that the bonding layer 213 is not degraded by plasma or free radicals generated in the processing space 110.

[0060] The collecting pipe part 23 is arranged below the plate 22. The collecting pipe part 23 has a substantially disk shape, and supports the back surface of the plate 22 on its upper surface.

[0061] The collecting pipe part 23 includes a disk-shaped main body part 23a on the central side and an annular flange part 23b on the peripheral side. Figure 4 As shown, the flange portion 23 b of the collecting pipe portion 23 is arranged to face the flange portion 22 b of the plate 22 .

[0062] like Figure 4 As shown, a plurality of first tubes 231, a plurality of second tubes 232 and a partition wall 230 are formed in the region of the collecting tube portion 23 corresponding to the main body portion 23a. Figure 4 As shown, when the plate 22 is arranged on the manifold 23, the upper end of each first tube 231 formed so as to protrude upward from the main body 23a of the plate 22 is inserted from the back side toward each through hole 221 formed on the side of the plate 22. In this state, a small chamber 220 is formed between the inner peripheral surface of the through hole 221, the outer peripheral surface of the first tube 231, and the lower surface of the electrostatic chuck 21. The small chamber 220 is a flow path for the fluid supplied from the first tube 231 to flow. The plurality of small chambers 220 are arranged in a planar manner on the lower surface side of the plate 22 so as to communicate with the spaces on the manifold 23 side divided by the partition wall 230.

[0063] As described above, one first tube 231 is inserted into each of the small chambers 220 , and each of the small chambers 220 is communicated with one second tube 232 through the partition wall 230 .

[0064] Each first tube 231 is a flow path having a first opening end 231a on the lower end side and a second opening end 231b on the upper end side. The second opening end 231b on the upper end side is opened so as to face the area 212 on the back side of the electrostatic chuck 21 exposed to the small chamber portion 220 through the through hole 221.

[0065] In each small chamber 220, the partition wall 230 surrounds the outer periphery of the first tube 231 so as to form a space around the outer peripheral surface of the first tube 231. In each small chamber 220, the partition wall 230 forms a second tube 232 that is a flow path between a first open end 232a connected to the lower end side and a second open end 232b connected to the partition wall 230 on the upper end side.

[0066] In addition, the first pipe 231 passes through the side wall surface of the partition wall 230 whose diameter gradually decreases from the second opening end 232 b toward the first opening end 232 a , and is led out to the outside of the space surrounded by the partition wall 230 .

[0067] Each first tube 231 functions as a nozzle for releasing the temperature regulating liquid (temperature regulating liquid) supplied from the high temperature liquid supply unit 61 and the low temperature liquid supply unit 62 described later to the small chamber 220. In addition, each second tube 232 functions as a tube for discharging the temperature regulating liquid released from the first tube 231 and passing through the small chamber 220 to the outside of the space.

[0068] Various metals, ceramics, resins, and composite materials thereof can be used as the constituent material of the manifold 23. In this example, the manifold 23 is made of aluminum. The manifold 23 can be formed using, for example, a 3D printer.

[0069] like Figure 1 and Figure 2 As shown, the workbench 2 may further include a shell 24 and a connecting flow path portion 25 .

[0070] The housing 24 is made of metal such as stainless steel. The housing 24 has a side wall 241 and a bottom wall 242, and defines a storage space 244 therein. The side wall 241 has a cylindrical shape, and the plate 22 is supported by an upper end surface 243 of the side wall 241.

[0071] like Figure 3 As shown, a supply pipe 247 and a recovery pipe 245 are formed on the side wall 241 of the housing 24. The supply pipe 247 is formed to extend radially outwardly along the side wall 241 and communicate with the storage space 244 via the first opening 248. The recovery pipe 245 is formed to extend radially outwardly along the side wall 241 and communicate with the storage space 244 via the second opening 246.

[0072] The collecting pipe section 23 and the connecting flow path section 25 can be accommodated in the accommodation space 244. An O-ring 243a extending in a ring shape along the upper end surface 243 of the side wall 241 may be provided.

[0073] Below, refer to Figure 3 , explaining the structure of the connecting flow path section 25. The connecting flow path section 25 is arranged below the manifold section 23 in the storage space 244, and has formed therein: a flow path (supply flow path 262) for supplying the temperature regulating liquid to the manifold section 23; and a flow path (recovery flow path 282) for recovering the temperature regulating liquid from the manifold section 23.

[0074] like Figure 3 As shown, the connecting flow path part 25 is a roughly cylindrical block having an upper surface 251 and a side surface 252. A plurality of supply flow paths 262 and a plurality of recovery flow paths 282 are formed inside the connecting flow path part 25. These supply flow paths 262 and recovery flow paths 282 are composed of elongated cavities that penetrate the interior of the connecting flow path part 25. Figure 3 In FIG. 1 , a portion of the supply flow path 262 and the recovery flow path 282 are shown by dotted lines.

[0075] Each of the plurality of supply flow paths 262 has a plurality of one end portions 261 open to the upper surface 251 and a single other end portion 263 open to the side surface 252. In the connection flow path portion 25, each supply flow path 262 branches and extends midway so as to be connected between a single other end portion 263 and the plurality of one end portions 261.

[0076] On the upper surface 251 of the connecting flow path portion 25, each one end portion 261 is formed at a position opposite to the first open end 231a formed on the lower end side of the first tube 231 formed on the side of the collecting tube portion 23. Each one end portion 261 is connected to the first open end 231a of the first tube 231 arranged oppositely.

[0077] On the other hand, the other ends 263 of the plurality of supply flow paths 262 are partially gathered at the side surface 252 of the connecting flow path section 25 to form a first opening collection section 253. When the connecting flow path section 25 is accommodated in the housing 24, the first opening collection section 253 is arranged at a position opposite to the first opening section 248 of the housing 24. Figure 3 Only a portion of the other end portion 263 constituting the first opening aggregate portion 253 is shown.

[0078] Each of the plurality of recovery flow paths 282 has: a plurality of one end portions 281 open to the upper surface 251; and one other end portion 283 open to the side surface 252. In the connecting flow path portion 25, each recovery flow path 282 branches and extends midway in a manner connected between one other end portion 283 and the plurality of one end portions 281.

[0079] On the upper surface 251 of the connecting flow path portion 25, each one end portion 281 is formed at a position facing the first open end 232a of the lower end side of the second tube 232 formed on the collecting tube portion 23 side. Each one end portion 281 is connected to the first open end 232a of the second tube 232 arranged oppositely.

[0080] On the other hand, the other ends 283 of the plurality of recovery flow paths 282 are partially gathered at the side surface 252 of the connecting flow path section 25 to form a second opening collection section 254. When the connecting flow path section 25 is accommodated in the housing 24, the second opening collection section 254 is arranged at a position opposite to the second opening section 246 of the housing 24. Figure 3 Only a portion of the other end portion 283 constituting the second opening aggregate portion 254 is shown.

[0081] The connecting flow path portion 25 having the above-described structure can be formed using a 3D printer.

[0082] Figure 1 , Figure 5 and Figure 6 One end of the first tube 64 and the second tube 65 are respectively connected to the supply tube 247 and the recovery tube 245 of the housing 24. The other ends of the first tube 64 and the second tube 65 are connected to the valve unit 63. Figure 1 and Figure 6 FIG. 6 shows a set of first tube 64, second tube 65 and valve unit 63, but in fact, Figure 5 As shown, a plurality of sets of first tubes 64, second tubes 65 and valve units 63 are provided. According to this structure, the main body 23a of the collecting tube part 23 can be divided into a plurality of regions, and the temperature control liquid can be independently supplied to the first tubes 231 arranged in each region, and the temperature control liquid can be independently recovered from the second tubes 232 arranged in each region.

[0083] In addition, for the sake of convenience, Figure 5 In the figure, regarding the supply flow path 262 and the recovery flow path 282 which are configured as the cavity in the connection flow path section 25 as described above, illustration of the connection flow path section 25 main body is omitted and they are shown as separate pipes.

[0084] Each valve unit 63 is connected to a cryogenic liquid supply flow path 621, which is connected to the supply port of the temperature regulating liquid of the cryogenic liquid supply unit 62 after merging in the middle. In addition, each valve unit 63 is connected to a cryogenic liquid recovery flow path 622, which is connected to the recovery port of the temperature regulating liquid of the cryogenic liquid supply unit 62 after merging in the middle. Figure 1 and Figure 6 In the figure, the confluence (branching) of the cryogenic liquid supply flow path 621 and the cryogenic liquid recovery flow path 622 is omitted.

[0085] The cryogenic liquid supply unit 62 is a device for circulating and supplying a temperature regulating liquid (hereinafter, also referred to as "cryogenic liquid") that has been adjusted to a first temperature. The cryogenic liquid supply unit 62 recovers the temperature regulating liquid returned from the plurality of valve units 63 via the cryogenic liquid recovery flow path 622, and adjusts the recovered temperature regulating liquid to the first temperature. Then, the temperature regulating liquid at the first temperature is respectively supplied to the plurality of valve units 63 via the cryogenic liquid supply flow path 621. The first temperature may be, for example, 30°C.

[0086] In addition, each valve unit 63 is connected to a high-temperature liquid supply flow path 611, which is connected to the supply port of the temperature-adjusting liquid of the high-temperature liquid supply unit 61 after merging in the middle. In addition, each valve unit 63 is connected to a high-temperature liquid recovery flow path 612, which is connected to the recovery port of the temperature-adjusting liquid of the high-temperature liquid supply unit 61 after merging in the middle. In addition, for the convenience of illustration, Figure 1 and Figure 6 In FIG. 6 , the confluence (branching) of the high-temperature liquid supply flow path 611 and the high-temperature liquid recovery flow path 612 is omitted from illustration.

[0087] The high temperature liquid supply unit 61 is a device for circulating and supplying a temperature control liquid (hereinafter, also referred to as "high temperature liquid") that has been adjusted to a second temperature higher than the first temperature. The high temperature liquid supply unit 61 recovers the temperature control liquid returned from the plurality of valve units 63 via the high temperature liquid recovery flow path 612, and adjusts the recovered temperature control liquid to the second temperature. Then, the temperature control liquid at the second temperature is supplied to the valve units 63 respectively via the high temperature liquid supply flow path 611. The second temperature is a temperature higher than the set temperature, and may be, for example, 120°C.

[0088] Each valve unit 63 is connected to the supply flow path 262 via the first tube 64. Furthermore, the valve unit 63 is connected to the recovery flow path 282 via the second tube 65. The valve unit 63 has a function of allowing or preventing the temperature control liquid from the high temperature liquid supply part 61 or the low temperature liquid supply part 62 to be supplied to the plurality of first tubes 231 arranged in each area by using a switching mechanism (not shown) formed inside. Furthermore, each valve unit 63 has a function of switching the low temperature liquid supplied via the low temperature liquid supply flow path 621 and the high temperature liquid supplied via the high temperature liquid supply flow path 611 in a pulse manner to adjust the average temperature of the temperature control liquid supplied to the plurality of first tubes 231 arranged in each area.

[0089] As the temperature regulating liquid supplied from the high temperature liquid supply unit 61 and the low temperature liquid supply unit 62, a fluorine-based liquid having a boiling point of 100°C or higher can be used. A connecting flow path 60 can also be provided between the high temperature liquid supply unit 61 and the low temperature liquid supply unit 62, and the connecting flow path 60 is used to adjust the holding amount ( Figure 1 ). The high temperature liquid supply part 61 and the low temperature liquid supply part 62 correspond to the liquid supply part of this example.

[0090] In the substrate processing apparatus 1 having the above-described structure, as the wafer W is processed using the processing gas, deposits may be attached to the surface of the worktable 2. For example, in addition to the peripheral portion of the placement area of ​​the wafer W formed on the upper surface of the worktable 2, the processing gas for film formation may also enter the back side (placement area) of the wafer W to form deposits. In addition, substances removed from the wafer by the processing gas for etching may also be attached to the peripheral portion of the placement area.

[0091] When these deposits are peeled off from the stage 2 after being deposited, they may become particles and become a source of contamination that is attached to the wafer W. Therefore, in the substrate processing apparatus 1 of this embodiment, a heating unit for heating the stage 2 to remove the deposits is provided.

[0092] exist Figure 1 In the example shown, the heating unit is configured as a heating lamp 33 which is a heating light source for heating the table 2 with radiant heat.

[0093] like Figure 1 As shown, in the substrate processing device 1 of this example, the heating lamp 33 is housed in a lampshade 342, and the lampshade 342 is provided on the electrode plate 31 located above the workbench 2. When power is supplied to each heating lamp 33 from the power supply unit 35, light of a predetermined wavelength such as infrared rays is released from the heating lamp 33. A window 341 is provided on the bottom surface of the lampshade 342, through which the light released from the heating lamp 33 can pass. The light passing through the window 341 is irradiated to the upper surface of the workbench 2 via the opening 312 formed in the electrode plate 31, and the temperature of the workbench 2 that absorbs the light rises.

[0094] Here, in order to remove the deposits attached to the workbench 2, for example, the surface temperature of the workbench 2 may need to be heated to about 300° C. There is also a method of, for example, supplying a remote plasma of a processing gas for etching processing to promote the removal of the deposits, thereby reducing the heating temperature of the workbench 2. In this case, the workbench 2 may need to be heated to about 200° C.

[0095] On the other hand, as described above, the temperature control liquid with a set temperature of about 120° C. may boil and decompose when heated to about 200° C. When a fluorine-based liquid is used as the temperature control liquid, fluorine gas is generated during decomposition. Therefore, it may be difficult to clean the workbench 2 that uses the temperature control liquid to control the temperature of the wafer W.

[0096] Therefore, the substrate processing apparatus 1 of this example includes a gas supply unit for replacing the temperature control liquid with gas from inside the workbench 2 during the cleaning of the workbench 2. Figure 1 and Figure 6 As shown, the gas supply unit of this example is configured to supply nitrogen as a gas to, for example, the high-temperature liquid supply flow path 611 located downstream of the supply port of the high-temperature liquid supply unit 61 and before the branch. The supply position of the nitrogen gas is not limited to this example, and for example, it can also be directly introduced into the first pipe 64 connected to each valve unit 63.

[0097] A nitrogen supply pipe 661 having a valve 662 for supplying and shutting off nitrogen is connected to the high-temperature liquid supply flow path 611, and a nitrogen supply unit 66 is provided on the upstream side of the nitrogen supply pipe 661. The nitrogen supply unit 66 includes a nitrogen supply source, a nitrogen flow rate regulating mechanism, etc. As a nitrogen supply source, a nitrogen bottle can be used, or nitrogen can be received from a facility system of a factory where the substrate processing apparatus 1 is installed. The nitrogen supply unit 66 and the nitrogen supply pipe 661 constitute a gas supply unit of this example.

[0098] like Figure 1 As shown, in the substrate processing apparatus 1 having the above structure, a control unit 100 composed of a computer is provided, and a program is stored. The program is compiled into a step group, and the step group is used to send a control signal to each part of the substrate processing apparatus 1 to control the operation of each part to perform various processes on the wafer W. Based on the program, the control of the processing of the wafer W using the processing gas and the control of the cleaning operation of the workbench 2 are performed. The program is installed in the control unit 100 from a storage medium such as a hard disk, an optical disk, a magneto-optical disk, a memory card, etc.

[0099] Below, taking film forming as an example, refer to Figure 7 to Figure 9 , the function of the substrate processing device 1 of the present invention is explained. Figure 7 to Figure 9The internal state of the workbench 2 at each time when the wafer W is being processed, when the workbench 2 is being prepared for cleaning, and when cleaning is being performed is schematically shown. In each figure, the flow of the temperature control liquid is indicated by a solid arrow, and the flow of nitrogen gas is indicated by a dotted arrow. In addition, the area where the temperature control liquid exists in the flow path of the workbench 2 is indicated in gray. In addition, in order to avoid complicating the drawings, Figure 8 and Fig. 9 The illustration of unused flow paths (low-temperature liquid supply flow path 621 and high-temperature liquid recovery flow path 612) is omitted.

[0100] When processing the wafer W, after the wafer W is carried into the chamber 11 through the carrying port 12 and placed on the stage 2 , the pressure in the processing space 110 is adjusted and the temperature of the wafer W is adjusted.

[0101] When adjusting the temperature, the valve unit 63 is used to switch the low-temperature liquid (for example, 30°C) supplied from the low-temperature liquid supply unit 62 and the high-temperature liquid (for example, 120°C) supplied from the high-temperature liquid supply unit 61 in a pulsed manner, thereby controlling the supply ratio of the low-temperature liquid / high-temperature liquid. Through this action, the average temperature of the temperature-regulating liquid supplied to the first tube 231 arranged in each area of ​​the workbench 2 can be adjusted. In addition, it is difficult to show how the low-temperature liquid and the high-temperature liquid are switched in a pulsed manner in one figure, so for convenience, Figure 7 The figure shows a state where the high temperature liquid and the low temperature liquid are supplied together.

[0102] For example, in the case of film forming processing, in the prior art, the chip W is heated to a high temperature of about 200 to 300°C. However, from the perspective of reducing damage to the semiconductor device formed on the chip W, the heating temperature of the chip W needs to be lowered to about 80 to 150°C.

[0103] On the other hand, in the worktable of the conventional structure, the mainstream method is to use a heater electrode for resistance heating to heat the wafer W. In this case, a structure is adopted in which the heater electrode arranged on the upper surface side of the worktable is covered with thermally sprayed ceramics, or a structure is adopted in which the heater electrode is buried in a ceramic body and the ceramic body is bonded and fixed to the upper surface of the worktable body.

[0104] However, when the power supplied to the heater electrode is low, it is difficult to perform stable temperature control. Therefore, in the case of low-temperature heating, a refrigerant flow path is provided in the workbench below the heater electrode, and refrigerant is passed through the refrigerant flow path, and power capable of performing heating higher than the target temperature is supplied to the heater. According to this configuration, stable low-temperature heating is achieved by forcibly discharging a portion of the generated heat to the refrigerant side.

[0105] In contrast, Figure 7The worktable 2 of the present example shown adjusts the temperature of the wafer W by bringing the temperature-regulating liquid adjusted to a temperature substantially equal to the heating temperature of the wafer W into direct contact with the back surface of the electrostatic chuck 21. Therefore, compared with the conventional method using a heater electrode, there is no need to forcibly discharge heat to the refrigerant, and the thermal efficiency is good.

[0106] In particular, Figure 7 In the embodiment, as indicated by the arrow in the small chamber 220, the temperature control liquid released from the second open end 231b on the upper end side of the first tube 231 changes its flow direction after hitting the back side of the electrostatic chuck 21 exposed to the through hole 221 arranged above the release position. By forming such a flow, it is possible to suppress the formation of a boundary layer of the temperature control liquid on the back side of the electrostatic chuck 21, and realize efficient heat conduction.

[0107] Furthermore, since the electrostatic chuck 21 is bonded to the plate 22 (the upper surface of the wall portion 222) by the bonding layer 213 in the region other than the portion exposed to the through hole 221, the heat of the temperature control liquid is directly supplied to the electrostatic chuck 21 without passing through the bonding layer 213. In this regard, efficient heating using the temperature control liquid is also possible.

[0108] By the above method, the temperature of the wafer W placed on the workbench 2 is adjusted to a range of 80 to 150° C., for example, 100° C. Furthermore, after the pressure adjustment of the processing space 110 performed together with the temperature adjustment of the wafer W is completed, high-frequency power is applied to the workbench 2 from the first high-frequency power supply 41 and the matching device 42. Furthermore, the process gas for film formation is supplied to the control unit 100 from the gas release hole 311.

[0109] As a result, the film forming gas becomes plasma and reacts to form a film on the surface of the heated wafer W. After film forming for a predetermined time, the supply of the processing gas and the application of the high frequency power are stopped, the pressure in the processing space 110 is adjusted, and the wafer W is sent out in the reverse process of the sending-in process.

[0110] After the chip W is sent out, the supply of temperature regulating liquid to the workbench 2 is not stopped, and the workbench 2 can be maintained at the temperature during film formation (near 100°C in the above example). The temperature of the workbench 2 can also be lowered by using the valve unit 63 to change the supply ratio of high-temperature liquid and low-temperature liquid.

[0111] When the wafers W are processed sequentially according to the above process, deposits generated by the reaction of the processing gas adhere to the surface of the workbench 2. Therefore, for example, the workbench 2 is cleaned when a predetermined number of wafers W have been processed or a predetermined time has passed since the previous cleaning.

[0112] In the workbench of the conventional structure, the workbench can be heated to the temperature for cleaning by using the heater electrode for heating the wafer W. On the other hand, in the workbench 2 of this example, the temperature regulating liquid for heating the wafer W cannot heat the workbench 2 to the level of 200 to 300° C. required for cleaning. Therefore, as described above, the substrate processing apparatus 1 of this example heats the workbench 2 using the heating lamp 33 to perform cleaning.

[0113] However, when the workbench 2 is heated while the temperature control liquid remains in the flow path (the small chamber 220, the first tube 231, and the second tube 232), the temperature control liquid boils and decomposes to generate fluorine. In order to avoid such a situation, the substrate processing apparatus 1 of this example switches the fluid supplied to the workbench 2 from the temperature control liquid supplied by the high-temperature liquid supply unit 61 and the low-temperature liquid supply unit 62 to nitrogen supplied by the nitrogen supply unit 66, and replaces the flow path with nitrogen.

[0114] exist Figure 8 The valve 662 is opened to supply nitrogen from the nitrogen supply unit 66 to the workbench 2, and the nitrogen is released from each first tube 231 to push the temperature control liquid in the small chamber 220 and the second tube 232 to the downstream side, thereby replacing the temperature control liquid. The temperature control liquid discharged from the workbench 2 is recovered to the cryogenic liquid supply unit 62 via the cryogenic liquid recovery flow path 622.

[0115] Figure 8 The temperature control liquid in the workbench 2 is shown to be uniformly discharged in each area, but in reality, depending on the area of ​​the area and the flow rate of the nitrogen gas, the temperature control liquid in each flow path is sometimes unevenly discharged. In this case, the gas-liquid mixed flow of the temperature control liquid and the nitrogen gas flows into the cryogenic liquid supply part 62. The temperature control liquid and the nitrogen gas are separated into gas and liquid in a tank (not shown) in the cryogenic liquid supply part 62, and the nitrogen gas is discharged to the outside.

[0116] In addition, as the temperature control liquid is recovered only to the low temperature liquid supply unit 62, the imbalance of the storage amount of the temperature control liquid between the high temperature liquid supply unit 61 and the low temperature liquid supply unit 62 may become larger. In this case, a part of the temperature control liquid can be transferred from the low temperature liquid supply unit 62 to the high temperature liquid supply unit 61 via the connecting flow path 60.

[0117] In this way, after the fluid in the stage 2 is replaced from the temperature control liquid to the nitrogen gas, the high temperature liquid supply unit 61 and the low temperature liquid supply unit 62 adjust the temperature of the temperature control liquid and stand by.

[0118] Then, the power source 35 supplies power to the heating lamp 33, irradiates the entire upper surface of the workbench 2 on which the wafer W is not mounted, and heats the workbench 2 to a temperature in the range of, for example, 200 to 300° C. by radiant heat. As a result, the attached matter attached to the workbench 2 is decomposed and removed. In addition, during cleaning, remote plasma of the etching process gas may be supplied into the processing space 110 to promote cleaning.

[0119] In addition, if Fig. 9 As shown, during the above cleaning period, nitrogen gas may continue to be supplied to the flow path (small chamber 220, first tube 231, second tube 232) in the temperature control liquid flow path 20. For example, nitrogen gas is supplied to the flow path at a temperature close to room temperature. Therefore, the nitrogen gas can also be used as a refrigerant to prevent the temperature of the components of the plate 22 and the shell 24 from excessively rising and to protect these components.

[0120] When the fluid flowing through the above-mentioned flow path is switched to nitrogen as a gas, the following effects can also be obtained: (i) the nitrogen released from the first tube 231 collides with the back side of the electrostatic suction cup 21, thereby improving the heat conduction efficiency; (ii) the nitrogen is directly supplied to the back side of the electrostatic suction cup 21 without passing through the first tube 231, thereby improving the cooling efficiency.

[0121] Furthermore, in order to reduce the influence of continuous supply of nitrogen gas on cleaning, the flow rate of nitrogen gas may be reduced during the cleaning period compared to the period of replacement from the temperature control liquid to the nitrogen gas.

[0122] In this way, after the cleaning is performed for a preset time, the power supply to the heating lamp 33 is stopped, and the heating of the workbench 2 is terminated. In the case of using remote plasma, the supply of plasma is also stopped. On the other hand, nitrogen gas may continue to be supplied to the workbench 2 to promote the cooling of the workbench 2 until the temperature at which boiling and decomposition do not occur even if the temperature regulating liquid is supplied.

[0123] When the temperature of the worktable 2 drops to a preset temperature, the temperature control liquid is supplied from the high temperature liquid supply unit 61 and the low temperature liquid supply unit 62 to control the temperature of the worktable 2. Then, the processing of the wafer W is resumed.

[0124] According to the substrate processing apparatus 1 of the embodiment described above, the stage 2 can be cleaned while avoiding the generation of decomposition products due to boiling and decomposition of the temperature control liquid accompanying the heating of the stage 2 .

[0125] Here, the cleaning of the workbench 2 is not limited to the case where the method of heating the workbench 2 by the heating lamp 33 is used. For example, when removing the attachment formed in a ring shape on the peripheral portion of the placement area of ​​the wafer W, it is not necessary to heat the entire upper surface of the workbench 2. In this case, the following structure can also be adopted: a cylindrical member is arranged to surround the workbench 2 from the side peripheral surface, a heater electrode for resistance heating of the cylindrical member is buried, and the upper end of the cylindrical member is bent inwardly to be in contact with the peripheral area of ​​the electrostatic chuck 21. In this way, the peripheral area of ​​the electrostatic chuck 21 can also be heated and cleaned by heat conduction from the above-mentioned cylindrical member.

[0126] In the example using the above-mentioned cylindrical member, in order to prevent the temperature control liquid from boiling and decomposing, the workbench 2 is replaced with nitrogen when cleaning is performed. At this time, for example, the above-mentioned area division may be performed in a manner that separates the central part side and the peripheral part side of the manifold 23, and only the area on the peripheral part side where the temperature control liquid boils and reaches the decomposition temperature may be replaced with nitrogen to perform cleaning.

[0127] In addition, as in the case of heating using a cylindrical member as described above, when a heater is provided on the workbench 2 side (when the heating lamp 33 is not used), it is also possible to replace Figure 1 The electrode plate 31 shown is provided with a shower head having a large number of gas release holes.

[0128] In addition, the technology of the present invention is not limited to application to Figure 4 The working table 2 of the flow path of the chamber part 220, the first tube 231 and the second tube 232 is shown. Fig.10 In the example shown in the top view, the present technology can also be applied to a workbench 2a in which a temperature control liquid flow path 20 of the temperature control liquid is spirally formed along the mounting surface of the wafer W. In this workbench 2a, when cleaning is performed, the temperature control liquid supplied from the temperature control liquid supply unit 6a is switched to nitrogen gas, and the temperature control liquid flow path 20 is replaced.

[0129] In addition, the temperature regulating liquid that can be used for temperature regulation of the workbenches 2 and 2a is not limited to fluorine-based liquids that are heated to a temperature higher than the use temperature and boil, decompose, and may produce fluorine gas. For example, the technology of the present invention can also be applied when pressurized water, lubricating oil or hydraulic oil is used as the temperature regulating liquid. When pressurized water is heated to a high temperature higher than the use temperature and contacts with metal, hydrogen may be produced due to catalysis. In addition, with respect to lubricating oil and hydraulic oil, heating at a high temperature higher than the use temperature is not preferred. In the above case, when cleaning is performed, by replacing the temperature regulating liquid in the flow path (the small chamber 220 of the workbench 2, the first tube 231, the second tube 232, and the temperature regulating liquid flow path 20 of the workbench 2a) with a gas such as nitrogen, the generation of the above-mentioned hydrogen gas and the situation where the lubricating oil and hydraulic oil become a high-temperature state can also be suppressed.

[0130] In addition, the purpose of using the temperature control liquid is not limited to heating the wafer W, and may also be cooling.

[0131] The gas for replacing the temperature control liquid is not limited to the example of nitrogen, and argon gas or clean air may be used.

[0132] Furthermore, the processing of the wafer W performed by the substrate processing apparatus 1 provided with the worktables 2 and 2a may include, in addition to the above-mentioned film forming processing and etching processing, an ashing processing for removing the resist using plasma.

[0133] The embodiments disclosed herein are to be considered in all respects as illustrative and non-restrictive. The above embodiments may be omitted, replaced or modified in various ways without departing from the scope and spirit of the appended claims.

Claims

1. A device for processing a substrate, characterized in that: include: A worktable capable of mounting a substrate to be processed; a liquid supply unit configured to supply liquid for adjusting the temperature of the substrate to the workbench; a flow path formed in the workbench, the flow path being configured to allow the liquid supplied from the liquid supply unit to flow; a liquid receiving portion configured to receive the liquid discharged from the flow path; a heating unit configured to heat the workbench to a cleaning temperature higher than a use temperature of the liquid when cleaning the workbench, so as to remove attachments attached to the workbench; a gas supply unit configured to supply gas to the flow path; and Control Department, The control unit is configured to be able to perform the following control: when cleaning the workbench, in order to avoid the generation of decomposition products due to boiling or decomposition of the liquid accompanying the heating of the workbench, the fluid in the flow path is switched from the liquid supplied by the liquid supply unit to the gas supplied by the gas supply unit, the gas is used to replace the gas in the flow path, and then the workbench is heated to the temperature during cleaning by the heating unit.

2. The device according to claim 1, characterized in that The workbench comprises: a plate having a front surface arranged opposite to the substrate and a back surface on the opposite side of the front surface; a plurality of first tubes constituting a part of the flow path, which are arranged in a planar manner below the plate, extend upward, and have opening ends opening to the back side of the plate; partition walls respectively surrounding the plurality of first tubes to form a plurality of spaces as a part of the flow path; and a plurality of second tubes constituting a part of the flow path, connected to the partition wall so as to communicate with the plurality of spaces, respectively; The flow path is configured such that the fluid flowing through the flow path is released from the open ends of each of the plurality of first tubes to the back surface of the plate, flows into the second tubes through the plurality of spaces around each of the plurality of first tubes, and is discharged.

3. The device according to claim 1 or 2, characterized in that: The heating unit is a heating light source configured to heat the table with radiant heat.

4. The device according to claim 1 or 2, characterized in that: The liquid receiving portion is configured to receive the liquid and the gas discharged from the flow path by the replacement, and to perform gas-liquid separation of the liquid and the gas.

5. The device according to claim 1 or 2, characterized in that: A temperature above the use temperature of the liquid is a temperature at which the liquid decomposes.

6. The device according to claim 1 or 2, characterized in that: The liquid is used to adjust the temperature of the substrate placed on the stage to a temperature within a range of 80° C. to 150° C. inclusive.

7. A method for cleaning a workbench capable of carrying a substrate to be processed, characterized in that: The method comprises: A step of switching a fluid supplied to a flow path formed in the stage from a liquid for adjusting the temperature of the substrate to a gas, and replacing the flow path with the gas; and Next, in order to avoid the generation of decomposition products due to boiling or decomposition of the liquid accompanying the heating of the workbench, the workbench is heated to a cleaning temperature higher than the operating temperature of the liquid while the flow path is replaced with the gas, and the attachments attached to the workbench are removed.

8. The method according to claim 7, characterized in that: The workbench used includes: a plate having a front surface arranged opposite to the substrate and a back surface on the opposite side of the front surface; a plurality of first tubes constituting a part of the flow path, which are arranged in a planar manner below the plate, extend upward, and have opening ends opening to the back side of the plate; partition walls respectively surrounding the plurality of first tubes to form a plurality of spaces as a part of the flow path; and a plurality of second tubes constituting a part of the flow path, connected to the partition wall so as to communicate with the plurality of spaces, respectively; The flow path is configured such that the fluid flowing through the flow path is released from the open ends of the first tubes toward the back surface of the plate, flows into the second tubes through the spaces around the first tubes, and is discharged.

9. The method according to claim 7 or 8, characterized in that: In the step of removing the attached matter, a heating light source is used to heat the worktable using radiant heat.

10. The method according to claim 7 or 8, characterized in that: A temperature above the use temperature of the liquid is a temperature at which the liquid decomposes.

11. The method according to claim 7 or 8, characterized in that: The liquid is used to adjust the temperature of the substrate placed on the stage to a temperature within a range of 80° C. to 150° C. inclusive.

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