Substrate processing apparatus and exhaust pipe cleaning method

Abstract

Provided are a substrate processing apparatus and an exhaust pipe cleaning method that make it possible to clean an exhaust pipe without interrupting substrate processing for a long period of time. This substrate processing apparatus comprises: a chamber that forms a processing space for processing a substrate; an exhaust pipe that is connected to the chamber and discharges the atmosphere in the processing space to the outside of the chamber; an upstream opening / closing valve installed in the exhaust pipe; a cleaning liquid pipe that is connected to a connection point downstream of the upstream opening / closing valve in the exhaust pipe and introduces a cleaning liquid to the exhaust pipe; a drain pipe that is connected to a branch point downstream of the connection point in the exhaust pipe and discharges the liquid in the exhaust pipe; and a downstream opening / closing valve that is installed downstream of the branch point in the exhaust pipe.

Description

Substrate processing apparatus and exhaust piping cleaning method

[0001] The present invention relates to an apparatus for processing substrates, and to a method for cleaning exhaust piping for evacuating a processing space in a chamber for processing substrates. Examples of substrates to be processed include semiconductor wafers, substrates for FPDs (Flat Panel Displays) such as liquid crystal displays and organic EL (Electroluminescence) displays, substrates for optical disks, substrates for magnetic disks, substrates for magneto-optical disks, substrates for photomasks, ceramic substrates, and substrates for solar cells.

[0002] Patent Document 1 discloses a heat treatment unit in which ozone gas is introduced into a heat treatment chamber containing a hot plate and supplied to a substrate heated by the hot plate. The heat treatment chamber is connected to an exhaust facility via an exhaust line, and is configured to prevent the ozone gas from leaking out.

[0003] Japanese Patent Application Laid-Open No. 2022-187165

[0004] The exhaust system to which the exhaust from the heat treatment chamber is directed is preferably equipped with an ozone detoxifier that decomposes ozone in the exhaust by, for example, passing the exhaust through a catalyst to decompose the ozone into oxygen and detoxify it.

[0005] Depending on the processing conditions in the heat treatment chamber, sublimates and by-products contained in the exhaust may solidify and precipitate in the exhaust piping, causing exhaust problems. Furthermore, if the exhaust gas flows back from the exhaust piping into the heat treatment chamber, the substrate may be contaminated. Furthermore, if the precipitates adhere to the catalyst of the ozone detoxifier, the detoxification performance may be reduced.

[0006] These problems can be avoided or ameliorated by periodically removing and cleaning the exhaust piping or by periodically replacing the exhaust piping, but this requires an extended interruption of substrate processing, resulting in a loss of productivity.

[0007] Therefore, one embodiment of the present invention provides a substrate processing apparatus and an exhaust pipe cleaning method that can clean the exhaust pipe without interrupting substrate processing for a long period of time.

[0008] One embodiment of the present invention provides a substrate processing apparatus and an exhaust pipe cleaning method having the following exemplary features.

[0009] One embodiment of the present invention provides a substrate processing apparatus including: a chamber forming a processing space for processing a substrate; an exhaust pipe connected to the chamber and exhausting an atmosphere in the processing space to the outside of the chamber; an upstream open / close valve interposed in the exhaust pipe; a cleaning liquid pipe connected to a connection point in the exhaust pipe downstream of the upstream open / close valve and introducing a cleaning liquid into the exhaust pipe; a drainage pipe connected to a branch point in the exhaust pipe downstream of the connection point and draining a liquid in the exhaust pipe; and a downstream open / close valve interposed in the exhaust pipe downstream of the branch point.

[0010] In one embodiment of the present invention, the exhaust pipe is connected to an ozone detoxifier downstream of the downstream open / close valve.

[0011] In one embodiment of the present invention, the exhaust pipe has a downstream connection portion extending upward from the branch point, and the downstream open / close valve is disposed at the downstream connection portion.

[0012] In one embodiment of the present invention, the exhaust pipe has an upstream connection part extending upward from the connection point, and the upstream opening / closing valve is disposed at the upstream connection part.

[0013] In one embodiment of the present invention, the branch point is disposed below the connection point.

[0014] In one embodiment of the present invention, the drainage pipe has a connection portion extending downward from the branch point.

[0015] In one embodiment of the present invention, the substrate processing apparatus further includes a downstream gas-liquid separation unit interposed in the exhaust piping at the branching point, separating the gas and liquid in the exhaust piping and discharging the separated liquid into the drainage piping.

[0016] In one embodiment of the present invention, the substrate processing apparatus further includes a downstream trap container interposed in the exhaust piping at the branch point and having an exhaust inlet connected to the exhaust piping upstream of the branch point, an exhaust outlet connected to the exhaust piping downstream of the branch point, and a drain outlet positioned below the exhaust inlet and the exhaust outlet and to which the drain piping is connected.

[0017] In one embodiment of the present invention, the exhaust pipe has a downstream connection portion extending upward from the exhaust outlet, and the downstream open / close valve is disposed at the downstream connection portion.

[0018] In one embodiment of the present invention, the substrate processing apparatus further includes an upstream trap container that is interposed in the exhaust piping at the connection point and that has an exhaust inlet that is connected to the exhaust piping upstream of the connection point, a cleaning liquid inlet that is connected to the cleaning liquid piping, and an exhaust outlet that is positioned below the exhaust inlet and the cleaning liquid inlet and that is connected to the exhaust piping downstream of the connection point.

[0019] In one embodiment of the present invention, the exhaust pipe has an upstream connecting portion extending upward from the exhaust inlet, and the upstream opening / closing valve is disposed at the upstream connecting portion.

[0020] In one embodiment of the present invention, the connection point and the branch point are arranged so as to include a section in between in which the exhaust gas discharged from the processing space of the chamber cools, causing substances in the exhaust gas to precipitate and adhere to the inner wall of the exhaust pipe.

[0021] In one embodiment of the present invention, the substrate processing apparatus further includes an upstream heater that heats the exhaust pipe upstream of the connection point.

[0022] In one embodiment of the present invention, the substrate processing apparatus further includes a narrow section heater that heats a narrow section in the exhaust pipe. The narrow section refers to a flow path portion in the exhaust pipe where the cross-sectional area is partially reduced. Typically, the narrow section corresponds to a flow path portion formed by a fluid component such as a valve. The narrow section heater may be a heater that heats a fluid component such as a valve that is interposed in the exhaust pipe.

[0023] In one embodiment of the present invention, the substrate processing apparatus further includes an exhaust cooler that cools the exhaust pipe between the connection point and the branch point.

[0024] In one embodiment of the present invention, the substrate processing apparatus further includes a controller that executes an exhaust pipe cleaning process for cleaning the exhaust pipe, the exhaust pipe cleaning process including a preparation step of closing the upstream on-off valve and the downstream on-off valve, a cleaning liquid introduction step of introducing a cleaning liquid from the cleaning liquid pipe to the exhaust pipe while maintaining the upstream on-off valve and the downstream on-off valve in the closed state, a drainage step of draining the cleaning liquid in the exhaust pipe through the drainage pipe while maintaining the upstream on-off valve and the downstream on-off valve in the closed state, and a recovery step of opening the upstream on-off valve and the downstream on-off valve after draining the cleaning liquid from the exhaust pipe is completed.

[0025] In one embodiment of the present invention, the cleaning liquid introducing step fills the exhaust pipe between the connection point and the branch point with the cleaning liquid.

[0026] In one embodiment of the present invention, the exhaust pipe cleaning process further includes a drying step between the draining step and the recovery step, in which a dry gas is introduced into the exhaust pipe between the connection point and the branch point to dry the exhaust pipe.

[0027] In one embodiment of the present invention, the drying step opens the upstream opening / closing valve and closes the downstream opening / closing valve, and introduces the dry gas into the exhaust pipe upstream of the upstream opening / closing valve.

[0028] In one embodiment of the present invention, the controller executes the exhaust pipe cleaning process when predetermined exhaust pipe cleaning conditions including operating status conditions related to the operating status of the chamber are satisfied.

[0029] In one embodiment of the present invention, the substrate processing apparatus further includes a contamination sensor that detects a contamination level inside the exhaust pipe between the connection point and the branch point, and the controller executes the exhaust pipe cleaning process when predetermined exhaust pipe cleaning conditions are satisfied, the predetermined exhaust pipe cleaning conditions including a contamination level condition that specifies that the contamination level detected by the contamination sensor has reached a predetermined threshold.

[0030] According to an embodiment of the present invention, there is provided an exhaust pipe cleaning method for cleaning an exhaust pipe connected to a chamber that forms a processing space for processing a substrate and that exhausts an atmosphere in the processing space to the outside of the chamber, the method including: a preparation step of closing an upstream on-off valve and a downstream on-off valve provided in the exhaust pipe; a cleaning liquid introduction step of introducing a cleaning liquid into the exhaust pipe from a cleaning liquid pipe connected to a junction point in the exhaust pipe downstream of the upstream on-off valve and upstream of the downstream on-off valve while maintaining the upstream on-off valve and the downstream on-off valve in the closed state; a drainage step of draining the cleaning liquid from the exhaust pipe through a drainage pipe connected to a branch point in the exhaust pipe downstream of the junction point and upstream of the downstream on-off valve while maintaining the upstream on-off valve and the downstream on-off valve in the closed state; and a recovery step of opening the upstream on-off valve and the downstream on-off valve after the cleaning liquid has been drained from the exhaust pipe.

[0031] In a preferred embodiment of the present invention, the cleaning liquid introducing step fills the inside of the exhaust pipe between the connection point and the branch point with the cleaning liquid.

[0032] In one embodiment of the present invention, the method further includes a drying step between the draining step and the recovery step, in which a dry gas is introduced into the exhaust piping between the connection point and the branch point to dry the exhaust piping.

[0033] In one embodiment of the present invention, the drying step opens the upstream opening / closing valve and closes the downstream opening / closing valve, and introduces the dry gas into the exhaust pipe upstream of the upstream opening / closing valve.

[0034] In one embodiment of the present invention, the method executes the exhaust pipe cleaning method when predetermined exhaust pipe cleaning conditions including operating status conditions related to the operating status of the chamber are satisfied.

[0035] In one embodiment of the present invention, a contamination sensor is provided between the connection point and the branch point to detect the level of contamination inside the exhaust pipe, and the exhaust pipe cleaning method is executed when predetermined exhaust pipe cleaning conditions are satisfied, including a contamination level condition that specifies that the level of contamination detected by the contamination sensor has reached a predetermined threshold.

[0036] FIG. 1 is a schematic plan view showing the layout of a substrate processing apparatus according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing an example of the configuration of a wet processing unit. FIG. 3 is a schematic cross-sectional view for explaining an example of the configuration of a dry processing unit. FIG. 4 is a system diagram for explaining an example of the configuration of a gas supply system and an exhaust system for a heat processing unit. FIG. 5A is a schematic cross-sectional view showing an example of the configuration of an upstream trap container. FIG. 5B is a schematic cross-sectional view showing an example of the configuration of a downstream trap container. FIG. 6 is a block diagram for explaining an example of the configuration related to control of a substrate processing apparatus. FIG. 7 is a flowchart for explaining an example of processing by a controller related to cleaning of an exhaust pipe. FIG. 8A is a diagram showing the state of an exhaust system during substrate processing. FIG. 8B is a diagram showing the state of an exhaust system in a preparation step for exhaust pipe cleaning. FIG. 8C is a diagram showing the state of an exhaust system at the beginning of a cleaning liquid introduction step. FIG. 8D is a diagram showing the state of an exhaust system at an intermediate stage of a cleaning liquid introduction step. FIG. 8E is a diagram showing the state of an exhaust system when the exhaust pipe is filled with cleaning liquid at the end of the cleaning liquid introduction step. FIG. 8F is a diagram showing the state of an exhaust system in a liquid drainage step. Fig. 9A is a conceptual diagram showing an example of a configuration for detecting the contamination level of an exhaust pipe. Fig. 9B is a conceptual diagram showing an example of a configuration for detecting the contamination level of an exhaust pipe. Fig. 10 is a conceptual diagram showing an example of a configuration of an exhaust cooler for cooling the exhaust pipe.

[0037] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0038] FIG. 1 is a schematic plan view showing the layout of a substrate processing apparatus 1 (substrate processing system) according to one embodiment of the present invention.

[0039] The substrate processing apparatus 1 is a single-wafer processing apparatus that processes substrates W one by one. The substrates W are, for example, semiconductor wafers. The substrate processing apparatus 1 includes a plurality of load ports LP that respectively hold a plurality of carriers C that accommodate substrates W, and a plurality of processing units 2 that process the substrates W transported from the plurality of load ports LP with processing fluids such as processing liquids and processing gases.

[0040] The substrate processing apparatus 1 further includes transport units (IR, SH, CR) that transport the substrates W, and a controller (control device) 3 that controls the substrate processing apparatus 1. The controller 3 is typically a computer, and includes a memory 3m that stores information such as programs, and a processor 3p that controls the substrate processing apparatus 1 in accordance with the information stored in the memory 3m.

[0041] The transport units (IR, SH, CR) include an indexer robot IR, a shuttle SH, and a center robot CR, which are arranged on a transport path extending from a plurality of load ports LP to a plurality of processing units 2. The indexer robot IR transports substrates W between the plurality of load ports LP and the shuttle SH. The shuttle SH moves back and forth between the indexer robot IR and the center robot CR to transport substrates W. The center robot CR transports substrates W between the shuttle SH and a plurality of processing units 2. The center robot CR further transports substrates W between a plurality of processing units 2. The thick arrows in FIG. 1 indicate the movement directions of the indexer robot IR and the shuttle SH.

[0042] The multiple processing units 2 form four towers arranged at four horizontally spaced positions. Each tower includes multiple processing units 2 stacked vertically. Two of the four towers are arranged on each side of the transport path. The multiple processing units 2 include multiple wet processing units 2W (liquid processing units) that process substrates W with a processing liquid, and multiple dry processing units 2D (gas processing units) that process substrates W with a processing gas. The two towers on the load port LP side are formed by multiple dry processing units 2D, and the remaining two towers are formed by multiple wet processing units 2W.

[0043] FIG. 2 is a schematic cross-sectional view showing an example of the configuration of a wet processing unit 2W. The wet processing unit 2W is a single-wafer liquid processing unit that processes substrates W one by one. The wet processing unit 2W includes a box-shaped wet chamber 9 (see FIG. 1) that defines an internal space, a spin chuck 70 (substrate holding means, substrate holder) that holds a single substrate W in a horizontal position within the wet chamber 9 and rotates the substrate W about a vertical rotation axis A1 passing through the center of the substrate W, a processing liquid supply unit 80 that supplies a processing liquid to the substrate W held on the spin chuck 70, and a cylindrical cup 73 that surrounds the spin chuck 70. As shown in FIG. 1, the wet chamber 9 is formed with a loading / unloading port 9a through which the substrate W passes, and is provided with a shutter 10 for opening and closing the loading / unloading port 9a. The wet chamber 9 is an example of a liquid processing chamber in which substrate processing using a processing liquid is performed.

[0044] The spin chuck 70 includes a disk-shaped spin base 74 held in a horizontal position, a plurality of chuck pins 75 that hold the substrate W in a horizontal position above the spin base 74, a rotation shaft 76 extending downward from the center of the spin base 74, and a spin motor 77 that rotates the rotation shaft 76 to rotate the substrate W and the spin base 74 about a rotation axis A1. The spin chuck 70 is not limited to a clamping type chuck that brings the plurality of chuck pins 75 into contact with the peripheral edge surface of the substrate W, but may also be a vacuum type chuck that holds the substrate W horizontally by attracting the back surface (lower surface) of the substrate W, which is the non-device formation surface, to the upper surface of the spin base 74.

[0045] The cup 73 is disposed outward (in a direction away from the rotation axis A1) from the substrate W held on the spin chuck 70. The cup 73 surrounds the periphery of the spin base 74. The cup 73 receives the processing liquid that is discharged around the substrate W when the processing liquid is supplied to the substrate W while the spin chuck 70 is rotating the substrate W. The processing liquid received in the cup 73 is sent to a recovery device or a liquid drainage device (not shown).

[0046] In this example, the processing liquid supply unit 80 is configured to supply multiple types of processing liquid to the surface of the substrate W held on the spin chuck 70. Specifically, the processing liquid supply unit 80 includes a chemical liquid supply unit 81, a rinse liquid supply unit 82, an organic solvent supply unit 83, and a water repellent agent supply unit 84. The chemical liquid supply unit 81 includes a chemical liquid nozzle 81n that discharges the chemical liquid toward the surface of the substrate W, a chemical liquid pipe 81p that guides the chemical liquid from a chemical liquid supply source to the chemical liquid nozzle 81n, and a chemical liquid valve 81v that is an on-off valve provided in the chemical liquid pipe 81p. The rinse liquid supply unit 82 includes a rinse liquid nozzle 82n that discharges the rinse liquid toward the surface of the substrate W, a rinse liquid pipe 82p that guides the rinse liquid from a rinse liquid supply source to the rinse liquid nozzle 82n, and a rinse liquid valve 82v that is an on-off valve provided in the rinse liquid pipe 82p. The organic solvent supply unit 83 includes an organic solvent nozzle 83n that ejects an organic solvent toward the surface of the substrate W, an organic solvent pipe 83p that guides the organic solvent from an organic solvent supply source to the organic solvent nozzle 83n, and an organic solvent valve 83v that is an on-off valve provided in the organic solvent pipe 83p. The water repellent supply unit 84 includes a water repellent nozzle 84n that ejects a water repellent toward the surface of the substrate W, a water repellent pipe 84p that guides the water repellent from the water repellent supply source to the water repellent nozzle 84n, and a water repellent valve 84v that is an on-off valve provided in the water repellent pipe 84p.

[0047] The chemical liquid supplied from the chemical liquid supply source is, for example, hydrofluoric acid (hydrogen fluoride solution: HF). Of course, the chemical liquid is not limited to hydrofluoric acid, and may be a liquid containing at least one of sulfuric acid, acetic acid, nitric acid, hydrochloric acid, hydrofluoric acid, buffered hydrofluoric acid (BHF), dilute hydrofluoric acid (DHF), ammonia water, hydrogen peroxide solution, organic alkali (e.g., TMAH: tetramethylammonium hydroxide), surfactant, and corrosion inhibitor. Examples of chemical liquids that are mixtures of these include SPM (sulfuric acid-hydrogen peroxide solution mixture), SC1 (ammonia-hydrogen peroxide solution mixture), and SC2 (hydrochloric acid-hydrogen peroxide solution mixture).

[0048] The rinse liquid supplied from the rinse liquid supply source is, for example, DIW, but of course the rinse liquid is not limited to DIW and may be carbonated water, electrolytic ion water, ozone water, ammonia water, diluted hydrochloric acid water (for example, about 10 ppm to 100 ppm), or reduced water (hydrogen water).

[0049] The organic solvent supplied from the organic solvent supply source is, for example, IPA (isopropyl alcohol). Of course, the organic solvent is not limited to IPA, and may be an organic solvent other than IPA that does not chemically react (has poor reactivity) with the pattern (not shown) formed on the substrate W. More specifically, the organic solvent may be an organic solvent containing at least one of IPA, HFE (hydrofluoroether), methanol, ethanol, acetone, and trans-1,2-dichloroethylene.

[0050] The water repellent supplied from the water repellent supply source may be, for example, a silicon-based water repellent that hydrophobicizes silicon itself and silicon-containing compounds, or a metal-based water repellent that hydrophobicizes metal itself and metal-containing compounds. The metal-based water repellent may include, for example, an amine having a hydrophobic group and at least one of an organosilicon compound. The silicon-based water repellent may be, for example, a silane coupling agent. The silane coupling agent may include, for example, at least one of HMDS (hexamethyldisilazane), TMS (tetramethylsilane), fluorinated alkylchlorosilane, alkyldisilazane, and a non-chlorinated water repellent. The non-chlorinated water repellent may include, for example, at least one of dimethylsilyldimethylamine, dimethylsilyldiethylamine, hexamethyldisilazane, tetramethyldisilazane, bis(dimethylamino)dimethylsilane, N,N-dimethylaminotrimethylsilane, N-(trimethylsilyl)dimethylamine, and an organosilane compound.

[0051] In the substrate processing in the wet processing unit 2W, for example, chemical processing, rinsing processing, first organic solvent processing, water repellent agent processing, second organic solvent processing, and drying processing are performed in this order.

[0052] Specifically, the substrate W is carried from the carrier C into the wet processing unit 2W by the indexer robot IR, the shuttle SH, and the center robot CR, and then transferred to the spin chuck 70 (substrate carrying-in). Thereafter, the substrate W is held horizontally by the chuck pins 75 until it is carried out by the center robot CR (substrate holding step).

[0053] The spin motor 77 then rotates the spin base 74. As a result, the substrate W held horizontally on the spin chuck 70 rotates about the rotation axis A1 at a liquid processing rotation speed (for example, 50 rpm to 1200 rpm) (substrate rotation process). In this state, the chemical valve 81v is opened to start chemical processing. That is, a chemical (for example, hydrofluoric acid) is discharged from the chemical nozzle 81n and supplied to the surface of the rotating substrate W, and processing such as etching is performed on the upper surface of the substrate W.

[0054] After the chemical treatment for a certain period of time, the chemical valve 81v is closed, and instead the rinse liquid valve 82v is opened to perform a rinse treatment. A rinse liquid (e.g., DIW) is discharged from the rinse liquid nozzle 82n and supplied to the surface of the rotating substrate W, and the chemical liquid on the surface of the substrate W is replaced with the rinse liquid.

[0055] After the rinsing process for a certain period of time, the rinsing liquid valve 82v is closed, and instead the organic solvent valve 83v is opened to perform the first organic solvent process. In the first organic solvent process, an organic solvent (e.g., IPA) is discharged from the organic solvent nozzle 83n and supplied to the surface of the rotating substrate W, and the rinsing liquid on the substrate W is replaced with the organic solvent.

[0056] After the first organic solvent treatment for a certain period of time, the organic solvent valve 83v is closed, and instead the water repellent valve 84v is opened to perform the water repellent treatment. In the water repellent treatment, the water repellent is discharged from the water repellent nozzle 84n and supplied to the surface of the rotating substrate W, and the organic solvent on the substrate W is replaced with the water repellent.

[0057] After the water-repellent treatment for a certain period of time, the water-repellent agent valve 84v is closed, and instead, the organic solvent valve 83v is opened to perform a second organic solvent treatment. In the second organic solvent treatment, an organic solvent (e.g., IPA) is discharged from the organic solvent nozzle 83n and supplied to the surface of the rotating substrate W, and the water-repellent agent on the substrate W is replaced with the organic solvent.

[0058] After the second organic solvent treatment for a certain period of time, a drying treatment is performed to spin off the liquid components on the upper surface of the substrate W by centrifugal force. Specifically, after the organic solvent valve 83v is closed, the substrate W is rotated at a high speed at a drying rotation speed (for example, 2000 rpm). After a certain period of time, the spin motor 77 stops the rotation of the substrate W.

[0059] Thereafter, the center robot CR enters the wet processing unit 2W, scoops up the processed substrate W from the spin chuck 70, and carries it out of the wet processing unit 2W. The substrate W is then carried into, for example, the dry processing unit 2D.

[0060] After the surface of the substrate W is supplied with a water repellent agent to perform water repellent treatment, the water repellent agent is rinsed with an organic solvent having a surface tension lower than that of water, and then the substrate W is rotated at high speed to shake off the liquid, thereby drying the substrate W while suppressing collapse of the pattern on the substrate W.

[0061] However, rinsing with an organic solvent may not completely remove the water repellent agent, and the water repellent agent may remain on the surface of the substrate W. In particular, when the water repellent agent contains organic matter, the remaining water repellent agent may become organic contamination, so it is preferable to remove it before the next process.

[0062] Therefore, in this embodiment, substrate processing for removing organic contamination (residual water repellent agent) is performed in the dry processing unit 2D.

[0063] 3 is a schematic cross-sectional view for explaining an example of the configuration of a dry processing unit 2D. The dry processing unit 2D includes a dry chamber 4 having an inlet / outlet 4a through which substrates W pass, a shutter 5 for opening and closing the inlet / outlet 4a of the dry chamber 4, a heat treatment unit 8 for supplying a processing gas to the substrates W while heating them in the dry chamber 4, a cooling unit 7 for cooling the substrates W heated by the heat treatment unit 8 in the dry chamber 4, and an indoor transport mechanism 6 for transporting the substrates W in the dry chamber 4. The center robot CR (see FIG. 1) loads and unloads substrates W into and from the dry chamber 4 via the inlet / outlet 4a. The cooling unit 7 is arranged in the dry chamber 4 near the inlet / outlet 4a.

[0064] The cooling unit 7 includes a cool plate 20, lift pins 22 that move up and down while penetrating the cool plate 20, and a pin lifting / lowering drive mechanism 23 that moves the lift pins 22 up and down. The cool plate 20 has a cooling surface 20a on which a substrate W is placed. A coolant path (not shown) through which a coolant (typically, cooling water) circulates is formed inside the cool plate 20. The lift pins 22 move up and down between an upper position where they support the substrate W above the cooling surface 20a and a lower position where their tips are recessed below the cooling surface 20a.

[0065] The thermal treatment unit 8 includes a hot plate 30, a thermal treatment chamber 34 that houses the hot plate 30, lift pins 38 that move up and down while passing through the hot plate 30, and a pin lifting drive mechanism 39 that moves up and down the lift pins 38. The hot plate 30 has a heating surface 30a on which the substrate W is placed, and has a built-in heater 33.

[0066] The heater 33 is configured to heat the substrate W placed on the heating surface 30a to a constant temperature higher than room temperature, and may be configured to heat the substrate W up to 250° C., for example. The heating surface 30a has a planar shape that follows the shape of the substrate W and is slightly larger than the substrate W. Specifically, if the substrate W is circular, the heating surface 30a is formed in a circular shape that is slightly larger than the substrate W.

[0067] The heat treatment chamber 34 includes a chamber body 35 and a lid 36 that moves up and down above the chamber body 35. The heat treatment unit 8 includes a lid lifting mechanism 37 that raises and lowers the lid 36. The chamber body 35 has an opening 35a that opens upward, and the lid 36 opens and closes this opening 35a. The lid 36 moves up and down between a closed position (lower position) where it closes the opening 35a of the chamber body 35 to form an airtight treatment space inside the heat treatment chamber 34, and an upper position where it is retracted upward to open the opening 35a. The lift pins 38 move up and down between an upper position where they support the substrate W above the heating surface 30a, and a lower position where their tips are recessed below the heating surface 30a.

[0068] Exhaust ports 41 are formed in the bottom of the chamber body 35. The exhaust ports 41 are preferably arranged at multiple locations (e.g., three locations) at circumferentially spaced intervals. The exhaust ports 41 are connected to an exhaust facility via exhaust piping 42.

[0069] The lid 36 includes a plate portion 45 extending parallel to the heating surface 30a and a tubular portion 46 extending downward from the periphery of the plate portion 45. Specifically, the plate portion 45 is substantially circular, and the tubular portion 46 has a cylindrical shape. The lower end of the tubular portion 46 faces the upper end of the chamber body 35. As a result, the opening 35a of the chamber body 35 can be opened and closed by moving the lid 36 up and down.

[0070] The lid 36 is provided with a gas nozzle 50 that introduces gas into the heat treatment chamber 34. A gas pipe 51 is connected to the gas nozzle 50. An inert gas (e.g., nitrogen gas) and / or ozone gas is supplied to the gas pipe 51. A shower plate 49 is disposed between the gas nozzle 50 and the substrate W on the hot plate 30. The gas ejected from the gas nozzle 50 diffuses in the space between the shower plate 49 and the lid 36 and passes through a plurality of holes that penetrate the shower plate 49. This allows the gas to be uniformly supplied to the upper surface of the substrate W on the hot plate 30. The gas supply system to the gas nozzle 50 will be described later.

[0071] The indoor transport mechanism 6 transports the substrate W inside the dry chamber 4. More specifically, the indoor transport mechanism 6 includes an indoor transport hand 6H that transports the substrate W between the cooling unit 7 and the heat treatment unit 8. The indoor transport hand 6H is configured to be able to transfer the substrate W to and from the lift pins 22 of the cooling unit 7, and to be able to transfer the substrate W to and from the lift pins 38 of the heat treatment unit 8. This allows the indoor transport hand 6H to operate to receive the substrate W from the lift pins 22 of the cooling unit 7 and transfer the substrate W to the lift pins 38 of the heat treatment unit 8. Furthermore, the indoor transport hand 6H can operate to receive the substrate W from the lift pins 38 of the heat treatment unit 8 and transfer the substrate W to the lift pins 22 of the cooling unit 7.

[0072] A typical operation of the dry processing unit 2D is roughly as follows.

[0073] When the center robot CR loads a substrate W into the dry chamber 4, the shutter 5 is controlled to an open position that opens the loading / unloading port 4a. In this state, the hand H of the center robot CR enters the dry chamber 4 and places the substrate W above the cool plate 20. The lift pins 22 then rise to their upper positions and receive the substrate W from the hand H of the center robot CR. The hand H of the center robot CR then retreats to the outside of the dry chamber 4. Next, the indoor transport hand 6H of the indoor transport mechanism 6 receives the substrate W from the lift pins 22 and transports it to the lift pins 38 of the thermal treatment unit 8. At this time, the lid 36 is in the open position (upper position), and the lift pins 38 support the received substrate W at their upper positions. After the indoor transport hand 6H retreats from the thermal treatment chamber 34, the lift pins 38 descend to their lower positions and place the substrate W on the heating surface 30a. Meanwhile, the lid 36 is lowered to the closed position (lower position), forming an airtight processing space containing the hot plate 30. In this state, heat processing is performed on the substrate W while a processing gas (inert gas and / or ozone gas) is introduced from the gas nozzle 50. For example, unnecessary substances on the substrate W can be decomposed and removed by heat processing performed while supplying ozone gas. One example of the substances to be removed is organic matter on the substrate W, and more specifically, it may be components of a water repellent agent remaining on the substrate W.

[0074] After the heat treatment is completed, the lid 36 rises to the open position (upper position) to open the heat treatment chamber 34. Furthermore, the lift pins 38 rise to the upper position to push the substrate W above the heating surface 30a. In this state, the indoor transport hand 6H of the indoor transport mechanism 6 receives the substrate W from the lift pins 38 and transports the substrate W to the lift pins 22 of the cooling unit 7. The lift pins 22 support the received substrate W at the upper position. After the indoor transport hand 6H has retracted, the lift pins 22 descend to the lower position, thereby placing the substrate W on the cooling surface 20a of the cool plate 20. This causes the substrate W to be cooled.

[0075] When cooling of the substrate W is completed, the lift pins 22 rise to the upper position, thereby pushing the substrate W above the cooling surface 20a. In this state, the shutter 5 is opened, and the hand H of the center robot CR (see FIG. 1) enters the dry chamber 4 and is positioned below the substrate W supported by the lift pins 22 (see FIG. 3) at the upper position. In this state, the lift pins 22 are lowered, thereby transferring the substrate W to the hand H of the center robot CR. The hand H holding the substrate W retreats to the outside of the dry chamber 4, after which the shutter 5 closes the loading / unloading opening 4a.

[0076] FIG. 4 is a system diagram for explaining an example of the configuration of a gas supply system and an exhaust system for the heat treatment unit 8. As shown in FIG.

[0077] An ozone gas pipe 52 and an inert gas pipe 56 are connected to a gas pipe 51 connected to a gas nozzle 50. The ozone gas pipe 52 is connected to an ozone gas generator 53 (ozone gas supply source). The ozone gas pipe 52 is equipped with an ozone gas valve 54 for opening and closing the flow path and an ozone gas filter 55 for removing foreign matter from the ozone gas. The inert gas pipe 56 is connected to an inert gas supply source 57 for supplying an inert gas (e.g., nitrogen gas). The inert gas pipe 56 is equipped with an inert gas valve 58 for opening and closing the flow path and an inert gas filter 59 for removing foreign matter from the inert gas. The ozone gas pipe 52, the ozone gas valve 54, etc. constitute an example of an ozone gas supply unit. Similarly, the inert gas pipe 56, the inert gas valve 58, etc. constitute an example of an inert gas supply unit.

[0078] The ozone gas generator 53 generates ozone and supplies this ozone-containing gas (hereinafter also referred to as "ozone gas") to the gas pipe 51 via the ozone gas pipe 52. The temperature of the ozone gas when supplied to the gas pipe 51 is, for example, less than 150°C, preferably less than 100°C, and typically approximately room temperature. A flow rate control device (mass flow controller) may be installed in the ozone gas pipe 52 as necessary.

[0079] The inert gas supply source 57 supplies an inert gas at, for example, room temperature. The inert gas is a chemically inert gas such as nitrogen gas or argon gas. The inert gas pipe 56 may be provided with a flow control valve for adjusting the flow rate of the inert gas, a flow meter for measuring the flow rate of the inert gas, or the like, as necessary.

[0080] The heat treatment chamber 34 forms a processing space for processing a substrate W. An exhaust pipe 42 is connected to an exhaust port 41 of the heat treatment chamber 34. The exhaust pipe 42 constitutes an exhaust line for exhausting the atmosphere in the processing space of the heat treatment chamber 34 to the outside of the heat treatment chamber 34, and extends from the exhaust port 41 to an exhaust facility 95. The exhaust pipe 42 is connected to the exhaust facility 95 via an ozone detoxifier 94. An ejector 43 is provided midway along the exhaust pipe 42. By operating the ejector 43, the atmosphere in the processing space of the heat treatment chamber 34 can be strongly sucked and exhausted.

[0081] An upstream open / close valve 61 is provided in the exhaust pipe 42. One end of a cleaning liquid pipe 62 for introducing a cleaning liquid into the exhaust pipe 42 is connected to a connection point 60 located downstream of the upstream open / close valve 61 in the exhaust pipe 42. In this example, the connection point 60 is located upstream of the ejector 43 in the exhaust pipe 42. The other end of the cleaning liquid pipe 62 is connected to a cleaning liquid tank 63. A cleaning liquid valve 64 (open / close valve) is provided in the cleaning liquid pipe 62. Furthermore, a branch point 90 located downstream of the connection point 60 in the exhaust pipe 42 is connected to a drainage pipe 92 for draining liquid (mainly cleaning liquid) from the exhaust pipe 42. In this example, the branch point 90 is located downstream of the ejector 43 in the exhaust pipe 42. A downstream open / close valve 91 is provided downstream of the branch point 90 in the exhaust pipe 42. The exhaust pipe 42 is connected to an ozone decommissioner 94 downstream of the downstream open / close valve 91.

[0082] The branch point 90 is disposed below the connection point 60. The drainage pipe 92 has a connection part 92a extending downward from the branch point 90. This allows the cleaning liquid introduced from the connection point 60 into the exhaust pipe 42 to flow by gravity to the branch point 90 and then to be discharged through the drainage pipe 92. A drainage valve 93 (open / close valve) is provided in the drainage pipe 92.

[0083] An upstream trap vessel 100 is attached to the exhaust pipe 42 at the connection point 60. Furthermore, a downstream trap vessel 110 is attached to the exhaust pipe 42 at the branch point 90. The downstream trap vessel 110 functions as a downstream gas-liquid separator that separates the gas and liquid in the exhaust pipe 42 at the branch point 90 and allows the separated liquid to flow into the drain pipe 92.

[0084] The connection point 60 and the branch point 90 are arranged so as to include a section between the connection point 60 and the branch point 90 where the exhaust gas discharged from the processing space of the heat treatment chamber 34 cools as it flows through the exhaust pipe 42, causing substances in the exhaust gas to precipitate and adhere to the inner wall of the exhaust pipe 42. The precipitated substances are mainly sublimates and by-products generated in the heat treatment chamber 34 that solidify as they cool. For example, organic substances in a water repellent agent remaining on the surface of the substrate W may solidify and precipitate. Since the ozone decomposer 94 is configured to decompose ozone using, for example, a catalyst, it is preferable that the precipitates can be suppressed or prevented from reaching the ozone decomposer 94.

[0085] The substrate processing apparatus 1 may include a fluid box 65, located outside the heat treatment chamber 34 (more specifically, outside the dry chamber 4), that houses a collection of pipes and valves. Solidification and precipitation of exhaust substances may begin on the inner wall of the exhaust pipe 42 in the section passing through the fluid box 65. Therefore, the connection point 60 and the branch point 90 are preferably arranged to include at least a portion of the section passing through the fluid box 65. In the illustrated example, the connection point 60 is located near the inlet to the fluid box 65 on the exhaust pipe 42 (inside the fluid box 65 in this example), and the upstream opening / closing valve 61 is located close to the connection point 60. In the illustrated example, the branch point 90 is located downstream of the outlet from the fluid box 65 on the exhaust pipe 42 (i.e., outside the fluid box 65), and the downstream opening / closing valve 91 is located close to the branch point 90.

[0086] The cleaning liquid introduced from the cleaning liquid tank 63 through the cleaning liquid pipe 62 into the exhaust pipe 42 is a cleaning processing liquid capable of washing away deposits that solidify and deposit within the exhaust pipe 42. For example, the cleaning liquid preferably contains a liquid capable of dissolving the deposits. More specifically, when decomposing and removing unwanted substances (substances to be removed) on the substrate W in the heat treatment chamber 34, the solvent of the processing liquid (e.g., processing liquid containing a water repellent) that is the source of the unwanted substances can be used as the cleaning liquid. For example, when the substance to be removed is organic, it is appropriate to use an organic solvent (e.g., IPA) as the cleaning liquid.

[0087] 5A is a schematic cross-sectional view showing an example of the configuration of the upstream trap vessel 100. The upstream trap vessel 100 includes a box-shaped (e.g., rectangular or cylindrical) sealed vessel 101 that is attached to the exhaust pipe 42 at the connection point 60. The upstream trap vessel 100 has an exhaust inlet 102 that is connected to the exhaust pipe 42 upstream of the connection point 60, a cleaning liquid inlet 103 that is connected to the cleaning liquid pipe 62, and an exhaust outlet 104 that is connected to the exhaust pipe 42 downstream of the connection point 60. The exhaust outlet 104 is located below the exhaust inlet 102 and the cleaning liquid inlet 103. In this example, the exhaust inlet 102 and the cleaning liquid inlet 103 are provided in the ceiling of the sealed vessel 101. The exhaust outlet 104 is located in the bottom of the sealed vessel 101.

[0088] The exhaust pipe 42 has an upstream connection part 42a that extends upward from the exhaust inlet 102 (i.e., extends upward from the connection point 60). An upstream opening / closing valve 61 is disposed at this upstream connection part 42a. Therefore, the section in the exhaust pipe 42 from the upstream opening / closing valve 61 to the space within the sealed container 101 forms a downward (vertically downward in this example) flow path.

[0089] A degassing pipe 105 for connecting the space inside the sealed container 101 to an atmospheric pressure space is connected to the upstream trap container 100 above the exhaust outlet 104, more specifically, to the ceiling of the sealed container 101. A degassing valve 106 (open / close valve) is installed in the degassing pipe 105.

[0090] A liquid level sensor 107, which is formed of, for example, a photosensor, is provided to detect the liquid level in the sealed container 101. The liquid level sensor 107 detects whether the liquid level has reached a predetermined liquid level 108 (liquid level height) and outputs a detection signal. The predetermined liquid level 108 is set to the height between the ceiling and bottom of the sealed container 101, i.e., the height between the exhaust inlet 102 and the exhaust outlet 104, and in this example, it is set near the ceiling of the sealed container 101.

[0091] 5B is a schematic cross-sectional view showing an example of the configuration of the downstream trap container 110. The downstream trap container 110 includes a box-shaped (e.g., rectangular or cylindrical) sealed container 111 interposed in the exhaust pipe 42 at the branch point 90. The downstream trap container 110 has an exhaust inlet 112 connected to the exhaust pipe 42 upstream of the branch point 90, an exhaust outlet 113 connected to the exhaust pipe 42 downstream of the branch point 90, and a drain port 114 connected to the drain pipe 92. The drain port 114 is located below the exhaust inlet 112 and the exhaust outlet 113. In this example, the exhaust inlet 112 and the exhaust outlet 113 are provided in the ceiling of the sealed container 111. The drain port 114 is provided in the bottom of the sealed container 111. The drain pipe 92 has a connection portion 92a extending downward from the bottom of the sealed container 111 (i.e., extending downward from the branch point 90). As described above, the drainage valve 93 is provided in the drainage pipe 92 .

[0092] The exhaust pipe 42 has a downstream connection part 42b that extends upward from the exhaust outlet 113 (i.e., extends upward from the branch point 90). A downstream opening / closing valve 91 is disposed in this downstream connection part 42b. Therefore, the section in the exhaust pipe 42 from the sealed container 111 to the downstream opening / closing valve 91 forms an upward (vertically upward in this example) flow path.

[0093] FIG. 6 is a block diagram illustrating an example of a configuration for controlling the substrate processing apparatus 1. The controller 3 is configured, for example, by a microcomputer. The controller 3 includes a memory 3m for storing information such as programs, and a processor 3p (CPU) for controlling the substrate processing apparatus 1 in accordance with the information stored in the memory 3m. Recipes indicating the processing procedures and processing steps for substrates W are stored in the memory 3m. The controller 3 is programmed to control the substrate processing apparatus 1 based on the recipes stored in the memory 3m, thereby performing processing on substrates W. An input device 11 for receiving operations by an operator is connected to the controller 3, allowing the operator to set operation settings and input various commands. Additionally, the controller 3 may communicate with a host computer (not shown) and perform processing in response to commands from the host computer.

[0094] Specific objects controlled by the controller 3 include the indexer robot IR, shuttle SH, center robot CR, spin motor 77, chemical liquid valve 81v, rinse liquid valve 82v, organic solvent valve 83v, water repellent valve 84v, indoor transfer mechanism 6, pin lifting / lowering drive mechanisms 23 and 39, heater 33, lid lifting / lowering drive mechanism 37, ozone gas generator 53, ozone gas valve 54, and inert gas valve 58. Objects controlled by the controller 3 further include an upstream opening / closing valve 61, a downstream opening / closing valve 91, a cleaning liquid valve 64, a degassing valve 106, a drain valve 93, and an ejector 43. The controller 3 also receives an output signal from a liquid level sensor 107.

[0095] Fig. 7 is a flowchart illustrating an example of processing by the controller 3 regarding cleaning of the exhaust pipe 42. Figs. 8A to 8F are diagrams illustrating various states of the exhaust system. In Figs. 8A to 8F, valves in an open state are represented by solid valve symbols, and valves in a closed state are represented by unsolid valve symbols.

[0096] 8A shows a state during processing (normal operation) in which processing is being performed on a substrate W in the heat treatment chamber 34. The controller 3 controls the upstream on-off valve 61 and the downstream on-off valve 91 to an open state, and controls the cleaning liquid valve 64, the degassing valve 106, and the drain valve 93 to a closed state. The controller 3 also controls the ejector 43 (not shown in FIGS. 8A to 8F ) to an operating state. Therefore, the atmosphere in the processing space of the heat treatment chamber 34 is sucked into the exhaust pipe 42 and guided to the ozone detoxifier 94, where it is subjected to an ozone removal process and then guided to the exhaust equipment 95. Sublimates and by-products contained in the exhaust gas passing through the exhaust pipe 42 are cooled as they pass through the exhaust pipe 42, solidify, and precipitate, adhering to the inner wall of the exhaust pipe 42.

[0097] When the predetermined exhaust pipe cleaning condition is satisfied (step S1: YES), the controller 3 executes the exhaust pipe cleaning process during a period (step S2: YES) when the heat treatment chamber 34 is not being used for processing substrates W. The period when the heat treatment chamber 34 is not being used may be a period (between lots) between processing of substrates W for each lot (for example, one lot is composed of 25 substrates W).

[0098] The exhaust pipe cleaning condition may include an operating status condition related to the operating status of the heat treatment chamber 34. The operating status condition may include the cumulative processing time during which the heat treatment chamber 34 has been used for substrate processing reaching a predetermined threshold. The operating status condition may also include the cumulative number of substrates W processed in the heat treatment chamber 34 reaching a predetermined threshold. The operating status condition may also include the cumulative number of lots of substrates W processed by the substrate processing apparatus 1 reaching a predetermined threshold.

[0099] Furthermore, the exhaust pipe cleaning condition may include a contamination level condition regarding the contamination level of the exhaust pipe 42, instead of or in addition to the operating status condition. For example, as shown in FIG. 4 , a contamination sensor 96 is provided between the connection point 60 and the branch point 90 to detect the contamination level inside the exhaust pipe 42. More specifically, as shown in FIG. 9A , a transparent tube section 42T is provided midway through the exhaust pipe 42, and the contamination sensor 96 can be a photosensor with a light emitter 961 and a light receiver 962 arranged across the transparent tube section 42T. As shown in FIG. 9B , when contaminants in the exhaust solidify and deposits 420 of contaminants adhere to the inner wall of the transparent tube section 42T, the amount of light received by the light receiver 962 decreases. Therefore, the contamination level of the exhaust pipe 42 can be monitored by monitoring the output signal of the light receiver 962 (detection signal from the contamination sensor 96) with the controller 3. Therefore, the contamination level condition may be a condition that specifies that the contamination level detected by the contamination sensor 96 has reached a predetermined threshold.

[0100] When the exhaust pipe cleaning conditions include both the operating status conditions and the contamination level conditions, the controller 3 may determine that the exhaust pipe cleaning conditions are satisfied when only one of them is satisfied (OR condition), or may determine that the exhaust pipe cleaning conditions are satisfied when both of them are satisfied (AND condition).

[0101] If the exhaust pipe cleaning condition is satisfied (step S1: YES), the controller 3 executes, for example, exhaust pipe cleaning processing between lots (step S2: YES). When substrate processing is not being performed in the heat treatment chamber 34, the controller 3 closes the ozone gas valve 54 (see FIG. 4). Therefore, ozone gas is not supplied to the heat treatment chamber 34, and the controller 3 stops the ejector 43.

[0102] 8B , when performing the exhaust pipe cleaning process, the controller 3 controls the upstream open / close valve 61 and the downstream open / close valve 91 to a closed state (step S3: preparation step). This prevents the cleaning liquid from flowing into the heat treatment chamber 34 and the ozone detoxifier 94. The controller 3 also controls the drain valve 93 to a closed state so that the cleaning liquid can be stored in the section to be cleaned between the connection point 60 and the branch point 90. The controller 3 also controls the degassing valve 106 to an open state so that the cleaning liquid can be introduced into the section to be cleaned.

[0103] Next, as shown in FIG. 8C , the controller 3 opens the cleaning liquid valve 64 to introduce cleaning liquid into the exhaust pipe 42 of the section to be cleaned (step S4: cleaning liquid introduction step). At this time, the controller 3 maintains the upstream open / close valve 61 and the downstream open / close valve 91 in a closed state. The controller 3 also controls the drain valve 93 to a closed state and the degassing valve 106 to an open state. This introduces cleaning liquid into the cleaning section between the connection point 60 and the branch point 90. Then, the exhaust pipe 42 between the connection point 60 and the branch point 90 is filled with cleaning liquid.

[0104] More specifically, cleaning liquid flows from the cleaning liquid piping 62 into the upstream trap vessel 100, exits through the exhaust outlet 104, passes through the exhaust piping 42, and is introduced into the downstream trap vessel 110 through the exhaust inlet 112 of the downstream trap vessel 110. The cleaning liquid then begins to be stored in the downstream trap vessel 110. When the downstream trap vessel 110 is filled with cleaning liquid, as shown in FIG. 8D , the cleaning liquid begins to be stored in the exhaust piping 42 in the section between the upstream trap vessel 100 and the downstream trap vessel 110. When the storage of cleaning liquid in this section is completed, the cleaning liquid then begins to be stored in the upstream trap vessel 100. When the level of the cleaning liquid in the upstream trap vessel 100 reaches a predetermined level 108, the liquid level sensor 107 detects the level of the cleaning liquid and notifies the controller 3 that the storage of the cleaning liquid is complete.

[0105] Upon receiving the notification that the cleaning liquid storage is complete (step S5: YES), the controller 3 closes the cleaning liquid valve 64 and stops the supply of the cleaning liquid (step S6), as shown in FIG. 8E . The controller 3 then drains the cleaning liquid (step S7: draining step). The controller 3 may wait a certain period of time necessary and sufficient for cleaning with the cleaning liquid from the completion of the storage of the cleaning liquid until draining begins. The controller 3 opens the drain valve 93 while keeping the upstream opening / closing valve 61 and the downstream opening / closing valve 91 closed. The controller 3 also keeps the degassing valve 106 open to promote drainage. By opening the drain valve 93, the cleaning liquid in the downstream trap container 110 flows under its own weight into the drain pipe 92 and is drained. Then, the cleaning liquid in the exhaust pipe 42 upstream of the downstream trap container 110 flows into the downstream trap container 110 and is guided to the exhaust pipe 42. As a result, the cleaning liquid in the upstream trap vessel 100 is also guided to the downstream trap vessel 110 via the exhaust pipe 42 and drained from the drain pipe 92 .

[0106] The controller 3 waits for a predetermined time to elapse, which is required for all of the cleaning liquid to be guided to the exhaust pipe 42 downstream of the drain valve 93 and for the cleaning liquid to be completely drained from the exhaust pipe 42. Thereafter, as shown in FIG. 8F , the controller 3 executes a drying step (step S8) in which dry gas is introduced into the exhaust pipe 42 between the connection point 60 and the branch point 90 to dry the exhaust pipe 42. Specifically, the controller 3 opens the upstream open-close valve 61 and closes the downstream open-close valve 91, thereby introducing dry gas into the exhaust pipe 42 upstream of the upstream open-close valve 61.

[0107] More specifically, the controller 3 opens the inert gas valve 58 (see FIG. 4 ) to introduce inert gas as a drying gas into the heat treatment chamber 34. This inert gas flows from the heat treatment chamber 34 into the exhaust pipe 42. The controller 3 controls the cleaning liquid valve 64 and the degassing valve 106 to a closed state and the drain valve 93 to an open state. As a result, the inert gas flows into the upstream trap vessel 100 from the exhaust inlet 102 and exits the exhaust pipe 42 from the exhaust outlet 104. The inert gas then passes through the exhaust pipe 42, flows into the downstream trap vessel 110 from the exhaust inlet 112, and exits into the drain pipe 92. In this way, liquid in the downstream trap vessel 110 and the exhaust path upstream thereof can be removed. The liquid in the exhaust pipe 42 from the exhaust outlet 113 of the downstream trap vessel 110 to the downstream open / close valve 91 falls by gravity into the downstream trap vessel 110 and is removed, and is also removed by evaporating into the inert gas (dry gas) introduced into the downstream trap vessel 110. After performing this exhaust pipe drying process for a predetermined time, the controller 3 closes the inert gas valve 58 to end the drying step.

[0108] Next, the controller 3 opens the upstream on-off valve 61 and the downstream on-off valve 91 to restore the exhaust pipe 42 to its normal state (see FIG. 8A ) (step S9: restoration step). The controller 3 controls the drain valve 93 to a closed state, and further controls the cleaning liquid valve 64 and the degassing valve 106 to a closed state.

[0109] In this example, the process of automatically cleaning the exhaust pipe is shown when the exhaust pipe cleaning conditions are satisfied, but the operator may input an exhaust pipe cleaning command from the input device 11 to the controller 3, and the controller 3 may execute the exhaust pipe cleaning process in response to the input of the command.

[0110] As described above, according to this embodiment, by closing the upstream on-off valve 61, the cleaning liquid can be prevented from flowing into the heat treatment chamber 34, and by closing the downstream on-off valve 91, the cleaning liquid can be prevented from flowing into the ozone decontaminator 94. The cleaning liquid is introduced into the exhaust pipe 42 from the connection point 60 between the upstream on-off valve 61 and the downstream on-off valve 91, and the cleaning liquid can remove deposits attached to the inner wall of the exhaust pipe 42. Furthermore, the used cleaning liquid can be drained into the drain pipe 92 from the branch point 90 between the connection point 60 and the downstream on-off valve 91. In this way, the inside of the exhaust pipe 42 can be cleaned without removing the exhaust pipe 42, and therefore the exhaust pipe 42 can be cleaned without interrupting substrate processing for a long period of time.

[0111] The exhaust pipe 42 has a downstream connection part 42b extending upward from the downstream trap container 110 arranged at the branch point 90, and a downstream on-off valve 91 is arranged at the downstream connection part 42b, which effectively prevents the cleaning liquid from flowing past the downstream on-off valve 91 into the ozone detoxifier 94. The exhaust pipe 42 also has an upstream connection part 42a extending upward from the upstream trap container 100 arranged at the connection point 60, and an upstream on-off valve 61 is arranged at the upstream connection part 42a, which effectively prevents the cleaning liquid from flowing past the upstream on-off valve 61 into the heat treatment chamber 34.

[0112] Furthermore, since the branch point 90 to which the drainage pipe 92 is connected is located below the connection point 60, gravity can be used to drain the cleaning liquid introduced into the drainage pipe 92. Furthermore, since the drainage pipe 92 has a connection part 92a extending downward from the downstream trap container 110 located at the branch point 90, gravity can also be used to discharge the cleaning liquid into the drainage pipe 92. In this way, efficient drainage is possible, and the cleaning liquid can be prevented from remaining in the exhaust pipe 42.

[0113] The downstream trap container 110 disposed at the branch point 90 functions as a gas-liquid separator that separates the gas and liquid in the exhaust pipe 42 and causes the separated liquid (cleaning liquid) to flow into the drain pipe 92. More specifically, the drain port 114 is disposed lower than the exhaust inlet 112 and the exhaust outlet 113, thereby making it difficult for the cleaning liquid to flow toward the exhaust outlet 113. This allows the cleaning liquid to be drained while preventing it from flowing into the ozone detoxifier 94.

[0114] In the exhaust pipe cleaning process, both the upstream on-off valve 61 and the downstream on-off valve 91 are closed, and cleaning liquid is introduced into and stored in the exhaust pipe 42 between the connection point 60 and the branch point 90. The stored cleaning liquid is then discharged via the drainage pipe 92. Therefore, the exhaust pipe 42 can be cleaned while preventing the cleaning liquid from flowing into the heat treatment chamber 34 and the ozone detoxifier 94. Then, while the downstream on-off valve 91 remains closed, the upstream on-off valve 61 is opened, and an inert gas serving as a drying gas is introduced into the exhaust pipe 42 from upstream (specifically, from the heat treatment chamber 34), thereby drying the inside of the exhaust pipe 42. Therefore, when the downstream on-off valve 91 is subsequently opened, almost no liquid remains in the exhaust pipe 42, and therefore no liquid reaches the ozone detoxifier 94 in an amount that would impair its function.

[0115] Furthermore, the exhaust pipe cleaning process is automatically planned and executed when predetermined exhaust pipe cleaning conditions are met, which can eliminate or reduce the need for manual work planning for maintenance of the exhaust pipe 42. By including the operating status conditions and / or contamination level conditions as described above in the exhaust pipe cleaning conditions, the exhaust pipe 42 can be automatically cleaned at an appropriate time.

[0116] Although the embodiment of the present invention has been described above, the present invention can also be embodied in other forms as exemplified below.

[0117] 4, an upstream heater 97 may be provided to heat the exhaust pipe 42 upstream of the connection point 60. This prevents sublimates and by-products from cooling during exhaust inside the exhaust pipe 42 upstream of the connection point 60, thereby suppressing adhesion of solid matter to the inner wall of the exhaust pipe 42.

[0118] Furthermore, fluidic devices such as valves and the ejector 43 provided in the exhaust pipe 42 are narrow passages where the cross-sectional area of ​​the exhaust flow path is partially reduced, and in addition, the flow path structure is complex, making them difficult to clean with a cleaning liquid. Therefore, a narrow passage heater 98 may be provided to heat such narrow passages (more specifically, fluidic devices). This can prevent sublimates and by-products from solidifying and precipitating in the narrow passages.

[0119] An exhaust cooler 99 for cooling the exhaust pipe 42 may be provided between the connection point 60 and the branch point 90, more preferably between the connection point 60 and the ejector 43 as shown in FIG. 4 . The exhaust cooler 99 may be configured, for example, by wrapping the exhaust pipe 42 around a cooling water pipe 99C through which cooling water flows, as shown in FIG. 10 . For example, cooling efficiency can be improved by constructing the exhaust pipe 42 and the cooling water pipe 99C from a material with high thermal conductivity (e.g., a metal material such as SUS (Steel Use Stainless Steel)). In the section cooled by the exhaust cooler 99, the exhaust gas in the exhaust pipe 42 is cooled, promoting solidification and precipitation of sublimates and by-products in the exhaust. This allows sublimates and other substances to be actively precipitated and captured between the connection point 60 and the branch point 90, more preferably between the branch point 90 and the ejector 43. The trapped precipitates can be removed by exhaust pipe cleaning. In this way, it is possible to effectively suppress or prevent the sublimates and precipitates of by-products from reaching the ozone detoxifier 94 .

[0120] In the above-described embodiment, the upstream trap vessel 100 is disposed at the connection point 60 and the downstream trap vessel 110 is disposed at the branch point 90, but the upstream trap vessel 100 may be omitted, the downstream trap vessel 110 may be omitted, or both may be omitted.

[0121] Furthermore, in the above embodiment, an exhaust system from the heat treatment chamber 34 in which ozone gas is used to remove organic matter has been described as an example, but the present invention may also be applied to an exhaust system of a processing chamber in which other substrate processing (particularly substrate processing using a processing gas, such as dry etching or vapor phase etching) is performed.

[0122] In addition, various design modifications can be made within the scope of the claims.

[0123] 1: Substrate processing apparatus 2: Processing unit 2D: Dry processing unit 3: Controller 8: Heat processing unit 30: Hot plate 34: Heat processing chamber 41: Exhaust port 42: Exhaust piping 42T: Transparent tube portion 42a: Upstream connection portion 42b: Downstream connection portion 43: Ejector 50: Gas nozzle 51: Gas piping 52: Ozone gas piping 53: Ozone gas generator 54: Ozone gas valve 56: Inert gas piping 57: Inert gas supply source 58: Inert gas valve 60: Connection point 61: Upstream opening / closing valve 62: Cleaning liquid piping 63: Cleaning liquid tank 64: Cleaning liquid valve 65: Fluid box 90: Branch point 91: Downstream opening / closing valve 92: Drainage piping 92a: Connection portion 93 : Drain valve 94 : Ozone detoxifier 96 : Contamination sensor 97 : Upstream heater 98 : Narrow path heater 99 : Exhaust cooler 100 : Upstream trap container 102 : Exhaust inlet 103 : Cleaning liquid inlet 104 : Exhaust outlet 105 : Degassing piping 110 : Downstream trap container 112 : Exhaust inlet 113 : Exhaust outlet 114 : Drain port W : Substrate

Claims

1. A substrate processing apparatus comprising: a chamber forming a processing space for processing a substrate; an exhaust pipe connected to the chamber and exhausting the atmosphere of the processing space to the outside of the chamber; an upstream open / close valve interposed in the exhaust pipe; a cleaning liquid pipe connected to a connection point on the exhaust pipe downstream of the upstream open / close valve and introducing a cleaning liquid into the exhaust pipe; a drainage pipe connected to a branch point on the exhaust pipe downstream of the connection point and draining a liquid in the exhaust pipe; and a downstream open / close valve interposed in the exhaust pipe downstream of the branch point.

2. The substrate processing apparatus according to claim 1, wherein the exhaust pipe is connected to an ozone detoxifier downstream of the downstream open / close valve.

3. The substrate processing apparatus according to claim 1 or 2, wherein the exhaust pipe has a downstream connection portion extending upward from the branch point, and the downstream opening / closing valve is disposed at the downstream connection portion.

4. A substrate processing apparatus according to any one of claims 1 to 3, wherein the exhaust pipe has an upstream connection portion extending upward from the connection point, and the upstream opening / closing valve is disposed at the upstream connection portion.

5. The substrate processing apparatus according to any one of claims 1 to 4, wherein the branch point is located below the connection point.

6. The substrate processing apparatus according to any one of claims 1 to 5, wherein the drainage pipe has a connection portion extending downward from the branch point.

7. A substrate processing apparatus according to any one of claims 1 to 6, further comprising a downstream gas-liquid separation unit interposed in the exhaust piping at the branch point, separating the gas and liquid in the exhaust piping and discharging the separated liquid into the drainage piping.

8. A substrate processing apparatus according to any one of claims 1 to 7, further comprising a downstream trap container interposed in the exhaust piping at the branch point and having an exhaust inlet connected to the exhaust piping upstream of the branch point, an exhaust outlet connected to the exhaust piping downstream of the branch point, and a drain outlet positioned below the exhaust inlet and the exhaust outlet and to which the drain piping is connected.

9. The substrate processing apparatus according to claim 8, wherein the exhaust pipe has a downstream connection portion extending upward from the exhaust outlet, and the downstream opening / closing valve is disposed at the downstream connection portion.

10. A substrate processing apparatus according to any one of claims 1 to 9, further comprising an upstream trap container interposed in the exhaust piping at the connection point and having an exhaust inlet connected to the exhaust piping upstream of the connection point, a cleaning liquid inlet connected to the cleaning liquid piping, and an exhaust outlet positioned below the exhaust inlet and the cleaning liquid inlet and connected to the exhaust piping downstream of the connection point.

11. The substrate processing apparatus according to claim 10, wherein the exhaust pipe has an upstream connecting portion extending upward from the exhaust inlet, and the upstream opening / closing valve is disposed at the upstream connecting portion.

12. A substrate processing apparatus according to any one of claims 1 to 11, wherein the connection point and the branch point are arranged so as to include a section in between in which the exhaust gas discharged from the processing space of the chamber cools, causing substances in the exhaust gas to precipitate and adhere to the inner wall of the exhaust pipe.

13. The substrate processing apparatus according to any one of claims 1 to 12, further comprising an upstream heater that heats the exhaust pipe upstream of the connection point.

14. The substrate processing apparatus according to any one of claims 1 to 13, further comprising a narrow passage heater for heating a narrow passage in the middle of the exhaust pipe.

15. The substrate processing apparatus according to any one of claims 1 to 14, further comprising an exhaust cooler that cools the exhaust pipe between the connection point and the branch point.

16. A substrate processing apparatus according to any one of claims 1 to 15, further comprising a controller that executes an exhaust pipe cleaning process for cleaning the exhaust pipe, the exhaust pipe cleaning process comprising: a preparation step of closing the upstream on-off valve and the downstream on-off valve; a cleaning liquid introduction step of introducing a cleaning liquid from the cleaning liquid pipe to the exhaust pipe while maintaining the upstream on-off valve and the downstream on-off valve in a closed state; a drainage step of draining the cleaning liquid in the exhaust pipe through the drainage pipe while maintaining the upstream on-off valve and the downstream on-off valve in a closed state; and a recovery step of opening the upstream on-off valve and the downstream on-off valve after drainage of the cleaning liquid from the exhaust pipe is complete.

17. The substrate processing apparatus according to claim 16, wherein the cleaning liquid introducing step fills the exhaust pipe between the connection point and the branch point with the cleaning liquid.

18. A substrate processing apparatus according to claim 16 or 17, wherein the exhaust pipe cleaning process further includes a drying step between the draining step and the recovery step, in which a dry gas is introduced into the exhaust pipe between the connection point and the branch point to dry the exhaust pipe.

19. The substrate processing apparatus according to claim 18, wherein the drying step opens the upstream opening / closing valve and closes the downstream opening / closing valve, and introduces the dry gas into the exhaust piping upstream of the upstream opening / closing valve.

20. A substrate processing apparatus according to any one of claims 16 to 19, wherein the controller executes the exhaust pipe cleaning process when predetermined exhaust pipe cleaning conditions, including operating status conditions relating to the operating status of the chamber, are satisfied.

21. A substrate processing apparatus according to any one of claims 16 to 20, further comprising a contamination sensor that detects the level of contamination inside the exhaust pipe between the connection point and the branch point, wherein the controller executes the exhaust pipe cleaning process when predetermined exhaust pipe cleaning conditions are satisfied, including a contamination level condition that specifies that the level of contamination detected by the contamination sensor has reached a predetermined threshold.

22. An exhaust pipe cleaning method for cleaning an exhaust pipe connected to a chamber that forms a processing space for processing a substrate and that exhausts the atmosphere of the processing space to the outside of the chamber, comprising: a preparation step of closing an upstream open / close valve and a downstream open / close valve that are interposed in the exhaust pipe; a cleaning liquid introduction step of introducing a cleaning liquid into the exhaust pipe from a cleaning liquid pipe that is connected to a connection point in the exhaust pipe downstream of the upstream open / close valve and upstream of the downstream open / close valve, while maintaining the upstream open / close valve and the downstream open / close valve in a closed state; a drainage step of draining the cleaning liquid in the exhaust pipe through a drainage pipe that is connected to a branch point in the exhaust pipe downstream of the connection point and upstream of the downstream open / close valve, while maintaining the upstream open / close valve and the downstream open / close valve in a closed state; and a recovery step of opening the upstream open / close valve and the downstream open / close valve after drainage of the cleaning liquid from the exhaust pipe is complete.

23. The exhaust pipe cleaning method according to claim 22, wherein the cleaning liquid introducing step fills the inside of the exhaust pipe between the connection point and the branch point with the cleaning liquid.

24. The exhaust piping cleaning method according to claim 22 or 23, further comprising a drying step between the draining step and the recovery step, in which a dry gas is introduced into the exhaust piping between the connection point and the branch point to dry the exhaust piping.

25. An exhaust piping cleaning method according to claim 24, wherein the drying step involves opening the upstream opening / closing valve and closing the downstream opening / closing valve, and introducing the dry gas into the exhaust piping upstream of the upstream opening / closing valve.

26. An exhaust pipe cleaning method according to any one of claims 22 to 25, wherein the exhaust pipe cleaning method is executed when predetermined exhaust pipe cleaning conditions, including operating status conditions relating to the operating status of the chamber, are satisfied.

27. An exhaust pipe cleaning method according to any one of claims 22 to 26, wherein a contamination sensor is provided between the connection point and the branch point to detect the level of contamination inside the exhaust pipe, and the exhaust pipe cleaning method is executed when predetermined exhaust pipe cleaning conditions are satisfied, including a contamination level condition that specifies that the level of contamination detected by the contamination sensor has reached a predetermined threshold.

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