Method for operating substrate processing device, substrate processing device, and program

Abstract

The present invention addresses the problem of providing a technique for satisfactorily cleaning the inside of a processing container in a substrate processing apparatus. A method according to the present disclosure for operating a substrate processing apparatus that is provided with a processing container in which an internally formed processing space is evacuated via an exhaust path, and a substrate placed on a stage provided in the processing space is processed, comprises a cleaning step for supplying a cleaning fluid, which is a gas or mist for cleaning the processing space in a state in which the substrate is not placed on the stage, from a first supply port that opens to the processing space, and varying the exhaust pressure of the exhaust path until the processing space is opened to the outside of the processing container.

Description

Method of operating substrate processing apparatus, substrate processing apparatus and program

[0001] The present disclosure relates to a method of operating a substrate processing apparatus, a substrate processing apparatus, and a program.

[0002] In a semiconductor device manufacturing process, photolithography is performed to form a pattern by forming a resist film on a semiconductor wafer (hereinafter referred to as a wafer), exposing the resist film, and developing the resist film. Patent Document 1 describes that this development is performed by supplying a gas to the resist film.

[0003] Japanese Unexamined Patent Publication No. 3-95559

[0004] The present disclosure provides a technique for satisfactorily cleaning the inside of a processing container in a substrate processing apparatus.

[0005] A method of operating a substrate processing apparatus, the substrate processing apparatus including a processing container in which a processing space formed inside the processing container is exhausted through an exhaust path, and processing is performed on a substrate placed on a stage provided in the processing space, the method comprising: a cleaning step of supplying a cleaning fluid, which is a gas or a mist for cleaning the processing space, from a first supply port opening into the processing space in a state where no substrate is placed on the stage, and changing an exhaust pressure in the exhaust path before the processing space is opened to the outside of the processing container.

[0006] According to the present disclosure, the inside of a processing container in a substrate processing apparatus can be satisfactorily cleaned.

[0007] This is a longitudinal cross-sectional side view of a developing apparatus according to one embodiment of the substrate processing apparatus of the present disclosure. This is a flow path configuration diagram showing the configuration of the gas supply mechanism and exhaust mechanism of the developing apparatus. This is a longitudinal cross-sectional side view of the developing apparatus for showing wafer processing. This is a longitudinal cross-sectional side view of the developing apparatus for showing cleaning processing. This is a longitudinal cross-sectional side view of the developing apparatus for showing cleaning processing. This is a longitudinal cross-sectional side view of the developing apparatus for showing cleaning processing. This is a chart diagram showing changes in exhaust pressure, etc., in the cleaning processing. This is a schematic diagram showing changes in deposits in the processing container in the cleaning processing. This is a schematic diagram showing changes in deposits in the processing container in the cleaning processing. This is a schematic diagram showing changes in deposits in the processing container in the cleaning processing. This is a schematic diagram showing changes in deposits in the processing container in the cleaning processing. This is a longitudinal cross-sectional side view of the developing apparatus for showing purging processing. This is a longitudinal cross-sectional side view of the developing apparatus for showing purging processing. This is a chart diagram showing changes in exhaust pressure, etc., in the purging processing. This is a chart diagram showing changes in exhaust pressure, etc., in other cleaning processing. This is a chart diagram showing changes in exhaust pressure, etc., in other cleaning processing. This is a chart diagram showing changes in exhaust pressure, etc., in other cleaning processing. This is a longitudinal cross-sectional side view of the developing apparatus for showing gas flow in the processing container. This is a longitudinal cross-sectional side view of a developing apparatus to show the gas flow in the processing container. This is a chart showing changes in exhaust pressure, etc., in other washing processes. This is a chart showing changes in exhaust pressure, etc., in other washing processes.

[0008] [Overview of the developing apparatus and the wafer to be processed] Figure 1 shows a longitudinal cross-sectional side view of a developing apparatus 1 according to one embodiment of the substrate processing apparatus of the present disclosure. In the developing apparatus 1, a wafer W in which an exposed resist film R has been formed on the surface (top surface) and which has undergone heat treatment after exposure is transported by a transport mechanism (not shown). The developing apparatus 1 stores the wafer W in a processing space 20 formed inside a closed processing container 21 (not shown in Figure 1 because the processing container 21 is open), and performs a developing process on the resist film R by supplying developing gas to the processing space 20.

[0009] Then, after the developed wafer W is removed from the processing container 21 by the support plate 12, which is a transport mechanism described later, a cleaning process is performed by supplying a cleaning fluid, which is a cleaning gas, to the processing space 20. This cleaning process removes any deposits P that have adhered to the walls and other surfaces that form the processing space 20 by sublimation from the resist film R during development, thereby cleaning the processing space 20. Although the wafer W is placed on the stage 34 in the processing space 20 for development, the cleaning process is performed with the wafer W not placed on the stage 34, as the wafer W is removed from the processing container 21 as described above.

[0010] The resist film R formed on the wafer W is composed of, for example, a metal-containing resist. This metal-containing resist contains metal as a component of the resist, and does not mean a resist that contains metal only as an impurity. During film formation on the wafer W, this metal-containing resist contains metal to which ligands are bound. The metal component of this resist may be any of the following, or a combination of several of these: tin (Sn), tungsten (W), hafnium (Hf), zirconium (Zr), indium (In), tellurium (Te), antimony (Sb), nickel (Ni), cobalt (Co), titanium (Ti), tungsten (W), tantalum (Ta), molybdenum (Mo), bismuth (Bi), iodine (I), germanium (Ge). Furthermore, it is not limited to the metals listed herein.

[0011] To illustrate the reaction of a metal-containing resist, after the bond between the metal and the ligand is broken (i.e., the ligand is removed), a condensation reaction occurs, and the metals bond to each other via oxygen atoms to form an oxide. This oxided metal is a stronger compound than the metal before it became an oxide. The removal of the ligand proceeds mainly by exposure, and the condensation reaction proceeds mainly by heating after exposure, resulting in the presence of the oxided metal in the resist film R. When developing gas is supplied in the developing apparatus 1, the unexposed areas where the amount of oxide formation is small dissolve, forming a pattern of irregularities on the surface of the wafer W.

[0012] As described above, since the resist film R contains metal, the deposits P in each part that form the processing space 20 after the development process also contain metal. The cleaning process for the processing space 20 described above prevents the metal constituting these deposits P from adhering to the wafer W that is newly transported into the processing container 21 after the development process, thereby preventing the wafer W from becoming contaminated with metal. Hereafter, the explanation will assume that this metal is Sn.

[0013] In this example, the developing gas and washing gas used contain a weak acid as a component that has a cleaning effect (washing component). In this disclosure, "weak acid" means an acid with an acid dissociation constant (pKa) of 4 or more (for example, about 5). The developing gas and washing gas may be, for example, a mixed solution consisting of the weak acid in liquid form and an organic solvent, which is vaporized and supplied into the processing container 21 together with a carrier gas. In other words, the developing gas and washing gas may each contain a carrier gas and an organic solvent other than the weak acid, in addition to the developing component and the weak acid which is the washing component. Note that the organic solvent is not required to be included in the gas of the weak acid and organic solvent.

[0014] The weak acid mentioned above is, for example, a carboxylic acid, and a more specific example is acetic acid. The organic solvent is, for example, propylene glycol monomethyl ether acetate (PGMEA). The carrier gas is, for example, nitrogen (N ２ ) is an inert gas such as argon (Ar). In the following, when describing the configuration of the developing apparatus 1, we will use acetic acid, an organic solvent, and a carrier gas called N. ２ An example is described in which a mixed gas is supplied to the processing container 21 as a developing gas and a cleaning gas. In this example, the developing gas, which is the processing gas used to treat the wafer W, and the cleaning gas, which acts on the processing container 21, are composed of the same compound and each contains a weak acid, acetic acid. Therefore, these developing gas and cleaning gas may not be distinguished and may be described as a weak acid-containing gas.

[0015] Each of the development and cleaning processes described above is performed without forming plasma in the processing space 20. As will be described in detail later, for the cleaning process, the exhaust pressure in the exhaust passage that exhausts the processing space 20 is controlled so that sufficient cleaning power is ensured even without generating plasma. In other words, the pressure in the processing space 20 fluctuates due to the exhaust. Since plasma is not used in this way, there is no need to maintain a relatively low pressure in the processing space 20 that is sufficient to generate and maintain plasma of sufficient strength. Therefore, as will be described later, the development and cleaning processes can be performed without excessively lowering the pressure in the processing space 20, and the processing container 21 can be opened quickly after the cleaning process to load the wafer W into the processing container 21.

[0016] [Configuration of the developing apparatus] To give a more detailed explanation of the configuration of the developing apparatus 1, the developing apparatus 1 is installed in an atmospheric environment and is equipped with a housing 10. A transport opening 11 is formed in the side wall of the housing 10, through which wafers W are loaded and unloaded by a transport mechanism. Inside the housing 10, the side with the transport opening 11 is considered the front side. A processing container 21 is provided at the back of the housing 10. The processing container 21 is circular in plan view and is equipped with a base portion 31 that forms the lower side of the processing container 21 and a lid portion 51 that forms the upper side of the processing container 21.

[0017] The lid 51 is connected to a lifting mechanism 22, and the processing container 21 is opened and closed by the lifting mechanism 22 moving up and down between the upper position shown in Figure 1 and the lower position (the position shown in Figure 2, which will be described later). The lid 51 has an upper side wall 52 that forms the upper part of the side wall of the processing container 21, and the base 31 has a lower side wall 32 that forms the lower part of the side wall of the processing container 21.

[0018] When the lid 51 is in the lower position and the processing container 21 is closed, the lower surface of the upper side wall 52 and the upper surface of the lower side wall 32 of the base 31 are in close contact with each other via a sealing member, which is an elastic material (not shown), thereby forming a sealed processing space 20 surrounded by the lid 51 and the base 31. As will be described later, the processing space 20 is exhausted, and this exhaust allows the air surrounding the processing container 21 to flow into the processing space 20 through a minute gap between the upper side wall 52 and the lower side wall 32. When the lid 51 moves from the lower position to the upper position from the state in which the processing space 20 has been formed, the processing container 21 separates and opens, and the processing space 20 is opened to the space outside the processing container 21.

[0019] Let's further explain the base 31. The lower side wall 32 is provided on the bottom wall of the housing 10. An annular heat insulating member 33 is provided on the inner circumferential surface of this lower side wall 32 in plan view. A stage 34 is provided, horizontally supported by the heat insulating member 33 and surrounded by the heat insulating member 33. The stage 34 is circular in plan view, and a plurality of protrusions 35 are provided on the upper surface of the stage 34. A heater 36 is embedded in the stage 34. The wafer W placed on the stage 34 is supported on its back surface by the protrusions 35, and is heated to the desired temperature by the heater 36 before development processing is performed.

[0020] Pins 38 are provided, each inserted through three holes 37 (only two shown in the illustration) that penetrate the stage 34 in the thickness direction. The lower end of each pin 38 is connected to a lifting mechanism 39 located below the stage 34 in an area enclosed by the lower side wall 32 and the bottom wall of the housing 10. A retractable cylindrical body 41 is provided that connects the lifting mechanism 39 to the stage 34 and surrounds the lower side of the pins 38. During the cleaning process, an inert gas such as N is used. ２ A gas supply unit 42 is provided that supplies gas to the hole 37 through the inside of the cylindrical body 41. ２ The gas is released upward from the hole 37, preventing the cleaning gas from flowing into the hole 37, and thus suppressing problems such as deterioration of the surrounding wall forming the hole 37 due to the cleaning gas.

[0021] Further, on the upper surface of the stage 34, there are provided holes 43 opened at positions facing the peripheral edge of the wafer W placed on the stage 34, and a large number of such holes 43 are formed along the circumference of the stage 34. During the development process, for example, N into each hole 43 as an inert gas ２ A gas supply unit 44 that supplies gas is provided, and the N ２ gas is discharged from the holes 43 toward the peripheral edge of the wafer W, thereby preventing the development gas from wrapping around to the back surface of the wafer W. The N supplied to each hole 43 by the gas supply unit 44 ２ gas supply is also performed during the cleaning process, which prevents the cleaning gas from flowing into each hole 43. Regarding the gas supply units 42 and 44 described above, N is supplied during a desired period ２ so that gas can be supplied to the target holes to be supplied, for example, N ２ is configured to include a fluid supply device (described later) interposed in a flow path connecting a gas supply source (not shown) and each hole.

[0022] Further, on the upper surface of the stage 34, for example, a supply port 45 is opened at the center of the upper surface of the stage 34. A second gas supply mechanism 4 for supplying each gas for performing a cleaning process to the supply port 45 is provided. Each gas supplied from the second gas supply mechanism 4 is discharged vertically upward from the supply port 45. The configuration of the second gas supply mechanism 4 will be described later.

[0023] Next, the lid part 51 will be described. The lid part 51 includes a shower head 53, and the shower head 53 is supported in a region surrounded by the upper side wall 52 by a support part (not shown). A diffusion space 54 for diffusing gas is formed inside the shower head 53. When the processing container 21 is closed and the processing space 20 is formed, the lower surface of the shower head 53 faces the upper surface of the stage 34 via the processing space 20.

[0024] Numerous supply ports 55 are provided at a distance from the underside of the shower head 53, and the upper side of each supply port 55 is connected to a diffusion space 54. Gas is supplied to the diffusion space 54 from the first gas supply mechanism 7, and this gas is discharged vertically downward from the supply ports 55 into the processing space 20. Therefore, the supply ports 55 open at a different position from the supply ports 45 of the stage 34 mentioned above, and the direction of gas discharge is also different, with the gas discharge directions being opposite between the supply ports 55 and 45. Thus, the supply ports 55 and the aforementioned supply ports 45, which each open into the processing space 20, are supplied with weak acid-containing gas and N by the first gas supply mechanism 7 and the second gas supply mechanism 4, respectively. ２ The gases are switched and discharged into the processing space 20. The configuration of the first gas supply mechanism 7 will be described later.

[0025] Later, an example of changing the flow rate of gas supplied from the supply port 55 of the showerhead 53 to the processing space 20 will be explained. The flow rate of gas supplied from the supply port 55 to the processing space 20 refers to the total flow rate of gas supplied from all supply ports 55 to the processing space 20, or in other words, the total flow rate of gas supplied from the first gas supply mechanism 7 to each supply port 55. Therefore, it does not refer to the flow rate of gas supplied from each individual supply port 55. An example of changing the flow rate of gas supplied from the supply port 55 to the processing space 20 will also be shown later. Multiple supply ports 45 may be provided in the stage 34, but even if multiple supply ports 45 are provided in this way, the flow rate of gas supplied from the supply ports 45 to the processing space 20 will refer to the total flow rate of gas supplied from all supply ports 45 to the processing space 20, similar to the flow rate of gas supplied from the supply ports 55 to the processing space 20. One of the supply ports 55 and 45 corresponds to the first supply port, and the other corresponds to the second supply port.

[0026] Returning to the description of the lid 51, an exhaust passage 58 is formed in the lid 51. This exhaust passage 58 is provided from between the side of the shower head 53 and the upper side wall 52, extending between the lower surface of the lid 51 and the upper surface of the shower head 53, and the upstream end (lower end) of the exhaust passage 58 opens into the processing space 20. The exhaust mechanism 9 constantly exhausts air from the exhaust passage 58. Therefore, the processing space 20 is constantly exhausted while it is being formed. The configuration of the exhaust mechanism 9 will be described later.

[0027] On the front side (transport port 11 side) of the lid 51 inside the housing 10, there is a horizontal support plate 12 for horizontally supporting the wafer W, and a moving mechanism 13 for horizontally moving the support plate 12 between a first transfer position on the front side of the processing container 21 and a second transfer position above the stage 34. The support plate 12 is equipped with a fluid channel (not shown), and the temperature of the supported wafer W is adjusted by heat exchange with the fluid.

[0028] The first transfer position is the position where the wafer W is transferred to the developing apparatus 1 by the lifting and lowering of the transport mechanism that transports the wafer W to the developing apparatus 1. The second transfer position is the position where the wafer W is transferred to the stage 34 by the pin 38. In this way, the wafer W is transferred between the transport mechanism and the stage 34 via the support plate 12. In order to enable the transfer of the wafer W at the second transfer position, the support plate 12 has a groove that penetrates the support plate 12 vertically and through which the pin 38 can pass, and the groove is formed from the end facing the processing container 21 side toward the transport opening 11 side.

[0029] [Gas Supply Mechanism Configuration] Figure 2 is a flow path configuration diagram showing the first gas supply mechanism 7, the second gas supply mechanism 4, and the exhaust mechanism 9 in the developing apparatus 1. First, the first gas supply mechanism 7 will be described. The first gas supply mechanism 7 includes gas supply passages 71, 83, valves V1 to V3, vaporizer 73, fluid supply passages 74, 75, fluid supply equipment 76, 78, 84, liquid storage section 79, heating mechanisms 81, 85, and exhaust passage 82. The downstream end of the gas supply passage 71 is connected to the upper side of the shower head 53. The gas supply passage 71 is connected to the vaporizer 73 via valve V1 and concentration sensor 72 in order toward the upstream side. The downstream ends of the fluid supply passages 74 and 75 are connected to the vaporizer 73, and the fluid supply passages 74 and 75 are connected to the gas supply passage 71 via flow paths provided in the vaporizer 73. The upstream end of the fluid supply passage 74 is connected to N via fluid supply equipment 76. ２ It is connected to a gas supply source 77. The upstream end of the fluid supply passage 75 is connected to the liquid storage section 79 via a fluid supply device 78.

[0030] The liquid storage section 79 stores the aforementioned mixed solution of acetic acid and organic solvent, and the liquid storage section 79 supplies this mixed solution toward the vaporizer 73. The liquid storage section 79 may be a bottle equipped with such a liquid supply mechanism, or it may be equipment in a factory where the developing device 1 is installed. The fluid supply devices 76 and 78 are equipped with mechanisms and valves to adjust the flow rate of the fluid supplied to the downstream side of the flow path, such as a mass flow controller. The fluid supply devices 76 and 78 then supply N to the downstream side of the fluid supply paths 74 and 75 according to the control signals from the control device 100 described later. ２ Switching between supplying and stopping the supply of gas and mixed solution, and supplying N to the downstream side. ２ The flow rates of the gas and the mixed solution can be changed separately. Furthermore, other fluid supply devices besides the fluid supply devices 76 and 78 described above and below may have a similar configuration to these fluid supply devices 76 and 78.

[0031] The vaporizer 73 is equipped with a heater and heats the mixed solution supplied from the fluid supply passage 75. In the vaporizer 73, the heated mixed solution and the carrier gas N supplied from the fluid supply passage 74 are used. ２When the gas and are mixed, the mixed solution vaporizes as described above, producing acetic acid gas, organic solvent gas and N ２ A weak acid-containing gas, which is a mixture of gas (carrier gas), is generated. This weak acid-containing gas flows downstream through the gas supply passage 71, is supplied to the shower head 53 when valve V1 is opened, and is discharged into the processing space 20 from the supply port 55.

[0032] A heating mechanism 81 is provided to heat the gas supply passage 71 so as to prevent the liquefaction of the weak acid-containing gas flowing through the gas supply passage 71. For example, the gas supply passage 71 is a flow path within a pipe, and the heating mechanism 81 is composed of, for example, a tape heater surrounding the pipe. The output of the heating mechanism 81 and the heater of the vaporizer 73 are controlled by a control signal from the control device 100. By changing the output of the heating mechanism 81 and the heater of the vaporizer 73, the temperature of the weak acid-containing gas supplied to the shower head 53 and the temperature of the weak acid-containing gas supplied from the shower head 53 to the processing space 20 can be changed.

[0033] Furthermore, an exhaust passage 82 with valve V2 interposed between valve V1 and concentration sensor 72 in the gas supply passage 71 is connected. In order to stabilize the acetic acid concentration in the weak acid-containing gas, the mixed fluid and N are supplied to the vaporizer 73 during the operation of the developing apparatus 1. ２ Gas is supplied continuously, and weak acid-containing gas is constantly generated. When it is not necessary to supply weak acid-containing gas to the shower head 53, valve V2 of valves V1 and V2 is opened. Therefore, the weak acid-containing gas flows to the exhaust passage 82 and is not supplied to the shower head 53. As described above, when valve V1 is opened and weak acid-containing gas is supplied to the shower head 53, valve V2 is closed.

[0034] As the components of the first gas supply unit 7 are configured as described above, the concentration of acetic acid contained in the weak acid-containing gas can be changed. Specifically, the N supplied to the vaporizer 73 by the fluid supply devices 76 and 78 ２The concentration of acetic acid can be changed by changing the ratio of the gas flow rate (let's call it A1) to the flow rate of the mixed solution (let's call it A2). To increase the concentration of acetic acid, the value of A2 / A1 should be increased. The value of A2 / A1 can be changed by changing either the flow rate A1 or the flow rate A2, or by changing both the flow rates A1 and A2. Based on the detection result from the concentration sensor 72, the control device 100 provides feedback control to the operation of the fluid supply device 78 to set the detected concentration of acetic acid to a predetermined value.

[0035] Also, N ２ By increasing both the gas flow rate A1 and the mixed solution flow rate A2, and raising the temperature of the heater in the vaporizer 73, it is also possible to increase the flow rate supplied to the weak acid-containing gas treatment container 21 while maintaining the concentration of acetic acid in the weak acid-containing gas. To decrease the concentration of acetic acid and increase the flow rate supplied to the weak acid-containing gas treatment container 21, N ２ It is sufficient to increase only the gas flow rate A1. As described above, the first gas supply unit 7 is configured to include a concentration changing unit for changing the concentration of the weak acid (acetic acid) in the weak acid-containing gas, a temperature changing unit for changing the temperature of the weak acid-containing gas, and a flow rate changing unit for changing the flow rate of the weak acid-containing gas.

[0036] Furthermore, the configuration of the vaporizer for generating the weak acid-containing gas is arbitrary and is not limited to a configuration that vaporizes a mixed solution that is constantly supplied from a location other than the vaporizer, as in the vaporizer 73 described above. For example, N supplied by the fluid supply device 76 ２ The system may also include a bubbling reservoir where the mixed solution is stored, and a heater that heats the reservoir to change its temperature, so that vaporization is carried out by bubbling using gas. In that case, N ２ The concentration of acetic acid in the weak acid-containing gas can be changed by altering the gas flow rate A1 and / or the temperature of the bubbling reservoir, thereby changing the vaporization efficiency of the mixed solution. Furthermore, in a configuration where bubbling is performed in this way, in order to increase the flow rate supplied to the weak acid-containing gas treatment container 21 while maintaining the concentration of acetic acid in the weak acid-containing gas, the temperature of the heater in the reservoir and N ２The gas flow rate A1 should be increased. Thus, the method for changing the concentration of acetic acid in the weak acid-containing gas and the flow rate of the weak acid-containing gas supplied to the processing container 21 should be appropriate to the configuration of the vaporizer.

[0037] Furthermore, the upstream end of the gas supply passage 83 is connected to the upstream side of the location where the fluid supply equipment 76 is installed in the fluid supply passage 74, and the downstream side of the gas supply passage 83 is connected to the downstream side of the valve V1 in the gas supply passage 71 via the fluid supply equipment 84, heating mechanism 85, and valve V3 in that order. The heating mechanism 85 is composed of a heater and heat exchanger that heat the gas supply passage. Therefore, when valve V3 is opened, N ２ Gas is supplied to the shower head 53 via the gas supply passage 71 when valve V3 is opened. The output of the heating mechanism 85 is controlled by the control device 100 in the same way as the heating mechanism 81, and N is supplied to the shower head 53 in this manner. ２ The gas temperature can be changed by the heating mechanisms 81 and 85.

[0038] In the following explanation, the vaporizer 73, fluid supply passages 74, 75, and fluid supply devices 76, 78, which are equipment related to the supply of weak acid-containing gas to the processing space 20, may be collectively referred to as the weak acid-containing gas supply section 7A. ２ The fluid supply equipment 84 and the heating mechanism 85, which are devices for supplying gas, are collectively referred to as N ２ It may sometimes be referred to as the gas supply unit 7B.

[0039] The second gas supply mechanism 4 will now be described as follows: This second gas supply mechanism 4 supplies each gas from the gas supply passage 71 to the supply port 45 of the stage 34, namely weak acid-containing gas and N ２ Except for the different gas supply destination, it has the same configuration as the first gas supply mechanism 7. To avoid confusion in the explanation, the weak acid-containing gas supply section of this second gas supply mechanism 4, N ２The gas supply sections are designated as 4A and 4B, respectively. The valves corresponding to valves V1 and V3 in the second gas supply mechanism 4 are designated as V11 and V13. Other components are indicated by the same symbols used in the first gas supply mechanism 7. The weak acid-containing gas supply sections 7A and 4A correspond to the cleaning fluid supply sections, and N ２ Gas supply units 7B and 4B correspond to inert gas supply units.

[0040] [Configuration of the Exhaust Mechanism] Next, the exhaust mechanism 9 will be described. The exhaust mechanism 9 includes exhaust passages 91 and 94, a pressure sensor 92, a damper 93, valves V4 and V5, an ejector 95, a supply passage 96, and a discharge passage 97. The exhaust passage 91 is a flow path formed by, for example, piping, and the upstream end of the exhaust passage 91 is connected to the exhaust passage 58 in the processing container 21 described above. A pressure sensor 92 is provided in the exhaust passage 91. Further downstream from the position where pressure detection by the pressure sensor 92 is performed, valves V4 and damper 93 are interposed in the exhaust passage 91 in that order. The downstream end of the exhaust passage 91 is connected to an exhaust source (not shown) which is said to have a relatively low pressure, and this exhaust source is, for example, an exhaust passage provided in a factory where the developing apparatus 1 is installed.

[0041] The upstream end of the exhaust passage 94 is connected between the location where the pressure sensor 92 is installed in the exhaust passage 91 and the location where the valve V5 is installed. The downstream end of the exhaust passage 94 is connected to the ejector 95. The ejector 95 is connected to an air supply passage 96 and an air discharge passage 97. For example, air is constantly supplied to the ejector 95 from a supply source (not shown) via the supply passage 96, and this air is discharged to the discharge passage 97. The airflow in the ejector 95 generates a relatively large suction force on the exhaust passage 94, which reduces the pressure in the exhaust passage 94.

[0042] For the sake of explanation, in the exhaust passage 91, the part upstream of the point where the exhaust passage 94 is connected will be referred to as the common exhaust passage 91A, and the part downstream of that point will be referred to as the low exhaust passage 91B. The exhaust passage 94 may also be referred to as the high exhaust passage 94. The valves V4 and V5 described above are controlled to open and close one at a time. The low exhaust passage 91B and the high exhaust passage 94 are both reduced to a pressure lower than atmospheric pressure by exhaust from the exhaust source connected to them and by the action of the ejector 95, so that the gas in the processing space 20 flows into either the low exhaust passage 91B or the high exhaust passage 94 and is exhausted.

[0043] To describe the exhaust path in more detail, when valve V4 is opened, the gas in the processing space 20 flows from the common exhaust passage 91A to the low exhaust passage 91B and is exhausted. The pressure sensor 92 mentioned above detects the pressure in the common exhaust passage 91A and transmits the detected value data to the control device 100. When valve V4 is opened, the control device 100 feedback-controls the opening degree of the damper 93 so that this detected value becomes a predetermined value, and the amount of exhaust to the low exhaust passage 91B is adjusted. On the other hand, when valve V5 is opened, the gas in the processing space 20 flows from the common exhaust passage 91A to the ejector 95 via the high exhaust passage 94, and together with the air supplied from the supply passage 96, flows to the discharge passage 97 and is discharged.

[0044] As described above, when one of valves V4 or V5 is opened, exhaust is carried out to either the low exhaust passage 91B or the high exhaust passage 94, so the processing space 20 is constantly exhausted. This exhaust maintains a negative pressure in the processing space 20 relative to the pressure in the area surrounding the processing container 21, thus preventing the weak acid-containing gas from leaking outside the processing container 21. Therefore, this prevents the acetic acid-containing gas from causing problems in the processing carried out around the developing apparatus 1.

[0045] Then, due to the action of the ejector 95, the pressure in the high-pressure exhaust passage 94 is made lower than the pressure in the low-pressure exhaust passage 91B. Therefore, when valve V5 is open, the pressure in the common exhaust passage 91A (i.e., the exhaust pressure of the exhaust passage connected to the processing space 20) and the pressure in the processing space 20 are lower than when valve V4 is open, so the amount of gas exhausted per unit time from the processing container 21 increases. As described above, by switching the opening and closing of valves V4 and V5, the exhaust pressure, which is the pressure in the exhaust passage (specifically the common exhaust passage 91A) that exhausts the processing container 21, changes, and the amount of gas exhausted in the processing space 20 changes.

[0046] Hereafter, the state in which valve V4 is open and exhaust is carried out into the low exhaust passage 91B will be described as the low exhaust state, and the state in which valve V5 is open and exhaust is carried out into the low exhaust passage 91B will be described as the high exhaust state. Therefore, the exhaust pressure is high when in the low exhaust state and low when in the high exhaust state. In both the low and high exhaust states, the pressure in the processing space 20 is, for example, low vacuum (10 ５ Pa-10 ２ The pressure is maintained at Pa. The difference between the pressure in the processing space 20 in the low displacement state and the pressure in the processing space 20 in the high displacement state is, for example, within the range of 10 Pa to 10 kPa.

[0047] As will be detailed later in the explanation of the device's operation, during the purging and washing processes of the developing gas remaining in the processing space after the developing process, the system switches between a low-volume and a high-volume state to improve purging and washing efficiency. Since the processing space 20 is at a low vacuum in both the low-volume and high-volume states, the exhaust state can be switched quickly between the two states, thereby shortening the time required for purging the developing gas and the time required for washing. Furthermore, after switching the exhaust state, the processing container 21 can be opened and the processing space 20 can be opened to the outside without adjusting the pressure in the processing space 20. As described above, maintaining the processing space 20 at a low vacuum contributes to improving the throughput of the developing device 1.

[0048] [Configuration of the Control Device] The developing apparatus 1 described above is equipped with a control device 100, which is a control unit. The control device 100 is, for example, a computer and has a program storage unit (not shown). The program storage unit stores a program that controls the processing of wafers W in the developing apparatus 1. The program storage unit also stores a program that controls the operation of the drive systems of the various processing devices and transport devices mentioned above to realize wafer processing in the developing apparatus 1. The program is composed of a group of steps necessary to transport and process wafers W in the developing apparatus 1, and the control device 100 outputs control signals to each part of the developing apparatus 1 according to the program, and the transport and processing are carried out by controlling each part as described above. Specifically, the program controls the operation of each fluid supply device, the opening and closing of valves, the heating mechanism and heater output, etc. The control device 100 also determines whether or not there is an abnormality as described above, and if it determines that an abnormality has occurred, it outputs an alarm to that effect by voice or screen display.

[0049] The above program may be recorded on a computer-readable storage medium H and installed from the storage medium H to the control device 100. The storage medium H may include ROM, RAM, or a hard disk, but its structure and type are not limited, and it may be temporary or non-temporary. The control device 100 may include a part that stores, reads, and executes the program for realizing wafer processing and performs related communications, and the location of each part may be either inside or outside the developing apparatus 1. The control device 100 may be one or more circuits, and may be provided as a single unit or in parts.

[0050] [Development Process Example] Next, the wafer development process performed by the development apparatus 1 will be explained with reference to the longitudinal cross-sectional side view of the development apparatus 1 in Figure 3. In the figures showing the longitudinal cross-section of the development apparatus 1 from Figure 3 onward, the gas flow supplied by the first gas supply mechanism 7 and the second gas supply mechanism 4 is indicated by solid arrows, and the air flowing into the processing space 20 from outside the processing container 21 is indicated by dotted arrows. For the sake of illustration, the flow of this air on the wafer W is shown offset from the position where a gap is formed between the base 31 and the lid 51 of the processing container 21. In addition, the parts through which gas flows in the flow paths of the first gas supply mechanism 7, the second gas supply mechanism 4, and the exhaust mechanism 9 are shown with thicker lines than other parts.

[0051] As previously mentioned, during the developing gas treatment shown in Figure 3, N gas is released from the hole 43 of the stage 34 to the peripheral edge of the wafer W. ２ Gas is supplied, and during the cleaning process shown in Figures 4 to 6 below, N is released from holes 37 and 43 of stage 34. ２ Gas is supplied to prevent gas from flowing into each hole, but in each figure this N ２ The gas type is not indicated.

[0052] First, the wafer W, which has been transported to the developing apparatus 1 by the transport mechanism, is transferred from the transfer mechanism 13 to the pins 38 of the stage 34. The wafer W is then placed on the stage 34 and heated to a predetermined temperature, while the processing container 21 is closed to form the processing space 20. In the exhaust mechanism 9, valve V4 of valves V4 and V5 is opened, resulting in a low exhaust volume state where exhaust is carried out into the low exhaust passage 91B. As the processing space 20 becomes negative pressure relative to the outside of the processing container 21, air flows into the processing space 20 from outside the processing container 21. This inflow of air prevents the negative pressure from becoming excessively large (the pressure in the processing space 20 from becoming excessively low), and as described above, the pressure in the processing space 20 is maintained at a low vacuum.

[0053] Then, valve V1 is opened and developing gas (weak acid-containing gas) is supplied from the weak acid-containing gas supply unit 7A to the shower head 53 and discharged into the processing space 20 from the supply port 55. After being supplied to the wafer W, this developing gas flows through the exhaust passage 58 to the low exhaust passage 91B and is exhausted. As described above, the resist film R is developed by the action of the developing gas, and sublimation containing Sn is generated from the resist film R. This sublimation adheres to the wall surface that makes up the processing space 20 and solidifies, becoming deposits P. Specifically, for example, these deposits P adhere to the side wall surface of the processing container 21 and the lower surface of the shower head 53, which are the wall surfaces.

[0054] Subsequently, valve V1 is closed, stopping the discharge of developing gas from supply port 55, and processing container 21 is opened. Between the cessation of developing gas discharge and the opening of processing container 21, purging of developing gas from processing space 20 is performed, but the operation of the device during this purging process will be explained later. After processing container 21 is opened, the wafer W is moved away from stage 34 by the operation of pin 38 and transfer mechanism 13 and handed over to transport mechanism.

[0055] [Cleaning Process Example] The cleaning process performed after the wafer W is removed from the stage 34 will be explained below with reference to the longitudinal cross-sectional side view of the developing apparatus 1 in Figures 4 to 6, the time chart in Figure 7, and the schematic diagrams showing the changes in the deposits P in Figures 8 to 11. As the components constituting the deposits P volatilize, a gas phase region with a relatively high concentration of these volatile components is formed around the deposits P, and in Figures 8 to 11, this gas phase region is shown as the volatilization region P1. The dotted arrows indicate the components volatilizing from the deposits P. In addition, the airflow in the processing space 20 in the low-volume and high-volume states is schematically shown by solid and white arrows, respectively.

[0056] The time chart in Figure 7 shows the flow of cleaning gas (weak acid-containing gas) into the processing space 20 from the supply port 55 of the shower head 53 and the supply port 45 of the stage 34, N ２This chart shows the respective gas supply periods and the exhaust pressure of the common exhaust passage 91A. Therefore, this time chart also shows the opening and closing timings of valves V1 and V3 of the first gas supply mechanism 7, valves V11 and V13 of the second gas supply mechanism 4, and valves V4 and V4 of the exhaust mechanism 9. As mentioned above, the high displacement state is the state in which exhaust is performed by the ejector 95. In the chart, a high exhaust pressure state (exhaust pressure = α) indicates that a low displacement state has been formed, and a low exhaust pressure state (exhaust pressure = β) indicates that a high displacement state has been formed.

[0057] After the development process described above, the wafer W is moved away from the stage 34, and then the processing container 21 is closed to form the processing space 20. In the exhaust mechanism 9, valve V4 of valves V4 and V5 is opened, resulting in a low exhaust volume state where exhaust is carried out into the low exhaust passage 91B. As the processing space 20 becomes negative pressure relative to the outside of the processing container 21, air flows into the processing space 20 from outside the processing container 21, similar to the development process, and the processing space 20 is maintained at a low vacuum.

[0058] Then, valves V1 and V11 are opened (time t1 in the chart), and cleaning gas (weak acid-containing gas) is supplied from the weak acid-containing gas supply units 7 and 7A to the supply port 55 of the shower head 53 and the supply port 45 of the stage 34, respectively, and discharged into the processing space 20 from these supply ports as shown in Figure 4. The cleaning process is started when the cleaning gas is supplied to the processing space 20 in this way. The acetic acid contained in the cleaning gas acts on the deposits P at various points on the wall surface P2 of the processing space 20, and the dissolution of the deposits P proceeds. This cleaning gas is supplied to the processing space 20 at a high temperature, for example, higher than the ambient temperature of the processing container 21, in order to promote the reaction with the deposits P.

[0059] Subsequently, valves V1 and V11 are closed and valves V3 and V13 are opened (at time t2), and as shown in Figure 5, N is supplied from supply ports 55 and 45 instead of cleaning gas. ２ The gases are each discharged into the processing space 20. ２Regarding the gas, it is supplied to the processing space 20 in a heated state, such as to a temperature higher than the ambient temperature of the processing container 21, in order to increase the activity of the cleaning gas remaining in the processing space 20 and promote its reaction with the adhering substances P. ２ The gas flow presses against the deposit P, whose adhesion to the wall surface P2 has been weakened by acetic acid, and a portion of the deposit P peels off from the wall surface P2 and is removed from the processing space 20. In addition, the volatile components released from the deposit P are N ２ The gas current pushes the components away, promoting volatilization from the deposits P so that the concentration of the components in the volatile region P1 is compensated for. As a result, the amount and size of the deposits P decrease (Figure 8).

[0060] Subsequently, valve V4 of the exhaust mechanism 9 is closed and valve V5 is opened, changing the state from low exhaust to high exhaust (time t3). As the exhaust volume of the processing space 20 increases, the direction of the airflow toward the remaining deposits P changes, as shown in Figure 9, and the flow velocity of this airflow increases. This airflow pushes away more volatile components from the deposits P than in the low exhaust state, reducing the thickness of the volatile region P1. To compensate for the concentration of components in the volatile region P1, volatilization of components from the deposits P progresses further. As a result, the amount and size of the deposits P decrease further (Figure 10). In addition, the deposits P are pressed by the airflow from a different direction than in the low exhaust state, and since this pressing force is greater than in the low exhaust state, the detachment of the deposits P from the walls of the processing space 20 progresses further. Furthermore, this high-volume exhaust state increases the amount of air flowing into the processing container 21 from outside, and the processing space 20 remains under vacuum pressure.

[0061] Subsequently, valve V5 is closed and valve V4 is opened, and the operation of the device returns from the high-displacement state to the low-displacement state shown in Figure 5 (time t4). Due to the change in the displacement of the processing space 20, the direction of the airflow toward the deposit P changes. Consequently, the direction of pressure on the deposit P by the airflow changes, and the detachment of the deposit P from the wall surface progresses. Then, as in the case of the formation of the low-displacement state (times t2-t3), N ２The gas flow acts on the attached substance P.

[0062] Next, valve V4 is closed and valve V5 is opened, and the operation of the device returns from the low-displacement state to the high-displacement state shown in Figure 6 (time t5). The resulting change in the displacement of the processing space 20 changes the direction of the airflow toward the deposits P again. Consequently, the direction of pressure applied to the deposits P by the airflow changes, and this pressure increases again. As a result, similar to when the high-displacement state was formed earlier (times t3-t4), the detachment of the deposits P from the wall surface and the volatilization of components from the deposits P proceed further.

[0063] This period of low displacement and high displacement is repeated periodically, for example. During this repetition process, the deposits P are removed from the wall surface P2 by peeling and / or volatilization of the components, as shown in Figure 11. Meanwhile, the weak acid-containing gas supplied to the processing space 20 at times t1 to t2 is N ２ The gas is used to purge and remove the material from the processing space 20. After exhausting in a low-volume state and a high-volume state is performed a predetermined number of times, the processing container 21 is opened when the low-volume state is reached, and the cleaning process is completed. Subsequently, the wafer W is brought into the processing container 21 for the developing process.

[0064] [Example of purging process after development] Next, we will explain the processing operation of the apparatus when the developed wafer W is removed from the processing container 21. Specifically, this process is a purging process to remove the developing gas (which is also a cleaning gas as mentioned above) from the processing space 20. Figures 12 and 13 are longitudinal cross-sectional side views of the developing apparatus 1 during this purging process, and Figure 14 is a time chart showing the changes in the flow rate of the gas supplied to the processing space 20 and the exhaust pressure, similar to Figure 7, for the operation during this purging process. In the time chart of Figure 14, the flow rate of the gas supplied to the processing space 20 from the supply ports 45 and 55 is shown. ２ This indicates the gas flow rate.

[0065] As explained in Figure 3, after the developing gas is supplied, valve V1 is closed and valves V3 and V13 are opened (at time t11 in the chart), and the low-displacement state is maintained, and as shown in Figure 12, N is supplied from the supply port 55 instead of developing gas. ２ Gas is coming from the supply port 45. ２ The gases are each discharged into the processing space 20. ２ The gas is used to purge and remove any developing gas remaining in the processing space 20.

[0066] Next, valve V4 of the exhaust mechanism 9 is closed and valve V5 is opened, changing from a low exhaust volume state to a high exhaust volume state as shown in Figure 13 (time t12). As the exhaust volume of the processing space 20 increases, the direction of the airflow in the processing space 20 changes, and the flow velocity of this airflow increases. Due to the change in the direction of the airflow, N is released into each part of the processing space 20. ２ The gas spreads throughout the area. And because the airflow velocity is high, the purging of the developing gas proceeds quickly.

[0067] Subsequently, valve V5 is closed and valve V4 is opened, returning from the high-displacement state to the low-displacement state shown in Figure 11 (time t13). Due to the change in the displacement of the processing space 20, the direction of the airflow toward the deposits P changes again, allowing sufficient N to flow into each part of the processing space 20. ２ The gas is spreading, and the purging is progressing.

[0068] Next, valve V4 is closed and valve V5 is opened, returning from the low-displacement state to the high-displacement state shown in Figure 12 (time t14). Similar to when the state was changed to the high-displacement state at time t12, the purging of the developing gas progresses further due to the change in the direction of the airflow and the increase in the airflow velocity. As with the washing process, this period of low-displacement state and high-displacement state is repeated periodically. When exhaust in the low-displacement state and exhaust in the high-displacement state are performed a predetermined number of times, the state returns to the low-displacement state, the processing container 21 is opened, the purging process is completed, and the wafer W is moved away from the stage 34.

[0069] Furthermore, the cleaning gas supplied to the processing space 20 during the cleaning process described in Figures 4 to 7 is also treated in the same way as during the purging process in Figures 12 to 14, with N at various points in the processing space 20. ２ The gas will be removed once it has spread sufficiently.

[0070] As described above, during the washing process and the purging process of the washing gas after the developing process, the exhaust mechanism 9 operates in such a way that the exhaust pressure changes, causing the amount of exhaust gas in the processing space 20 to fluctuate. This allows for increased washing power during the washing process, enabling efficient cleaning of the processing space 20. Furthermore, because the used washing gas is discharged from the processing space 20 relatively quickly and reliably, the washing process can be completed in a relatively short time. Similarly, during the purging process, because the used developing gas is discharged from the processing space 20 relatively quickly and reliably, the purging process can be completed in a relatively short time. In this way, the time required for both the washing and purging processes can be shortened, thereby increasing the throughput of the developing apparatus 1 during operation.

[0071] [Second Cleaning Process Example] The cleaning process example described so far is considered the first cleaning process example, and other cleaning process examples are described below. In the first cleaning process example, the same type of gas was supplied to the processing space 20 from supply ports 45 and 55, but it is not limited to the supply of the same type of gas. Figure 15 shows a time chart illustrating an example of other gas supply during the cleaning process as the second cleaning process example. The difference from the first cleaning process example in Figure 7 is that in this second cleaning process example, during the low exhaust volume state at times t1 to t2, the cleaning gas is supplied from supply port 55 and N is supplied from supply port 45. ２ The gas supply and the process are performed simultaneously. In this way, N is supplied from the supply port 45. ２ The supply of gas prevents cleaning gas from flowing into the supply port 45.

[0072] In this second cleaning process example, cleaning gas and N are supplied from supply port 55 and supply port 45, respectively. ２At time t3, after time t2 when the gas supply is stopped, the system switches from a low displacement state to a high displacement state. Thereafter, the cleaning process is carried out by repeatedly switching between the low displacement state and the high displacement state, similar to the first cleaning process example described in Figure 7. N from the supply port 45 ２ The airflow in the processing space 20 after the gas supply is stopped will be formed by the atmosphere flowing into the processing space 20 from outside the processing container 21. As shown in this second cleaning process example, after the supply of cleaning gas to the processing space 20 is terminated, N into the processing space 20 ２ It is not limited to supplying gas. However, N ２ Supplying gas allows the cleaning gas to be quickly flushed out of the processing space 20 and removed, which is preferable.

[0073] By the way, in order to perform the cleaning process, it is sufficient for the cleaning gas to be supplied to the processing space 20, so it is sufficient for the cleaning gas to be supplied from at least one of the supply port 55 and the supply port 45. Therefore, contrary to the example explained in Figure 15, N ２ Gas may be supplied, and cleaning gas may be supplied from the supply port 45. In the cleaning process examples shown below, if different types of gas are discharged from the supply ports 45 and 55, the types of gas discharged from the supply ports 45 and 55 are not limited to those exemplified, and can be appropriately swapped between the supply ports 45 and 55.

[0074] [Third Cleaning Process Example] The cleaning gas is not limited to simply switching between a state where the supply is stopped and a state where it is supplied at a specific flow rate, but may be supplied to the processing space 20 in such a way that the flow rate changes in stages. Furthermore, the cleaning gas is not limited to being supplied to the processing space 20 when a low displacement state is formed. Figure 16 shows a third cleaning process example in which the flow rate of the cleaning gas is changed in stages and supplied to the processing space 20 in both the low displacement state and the high displacement state.

[0075] In this third cleaning process example, when the cleaning gas is supplied to the processing space 20, the supply amount is periodically switched between a flow rate C1 and a flow rate C2 that is greater than flow rate C1. At the same time, a low exhaust volume state and a high exhaust volume state are periodically switched. As shown in the first and second cleaning process examples, the cleaning gas may be supplied from at least one of the supply ports 45 and 55.

[0076] In the first and second cleaning process examples, we showed cases where switching between low and high exhaust volume states was not performed during the supply of cleaning gas. However, as shown in this third cleaning process example, this exhaust state switching may be performed during the supply of cleaning gas. Although the flow rate C1 was explained as being greater than 0, it may also be 0. In other words, the supply of cleaning gas may be stopped during the period indicated as flow rate C1 in the chart. Accordingly, the flow rate of the cleaning gas may be changed during the period when it is continuously supplied to the processing space 20, or it may be supplied to the processing space 20 intermittently.

[0077] In the illustrated example, the length of one cycle for switching the flow rate of the cleaning gas is different from the length of one cycle for switching the exhaust state. Therefore, when the supply amount of cleaning gas becomes flow rate C1, and when the supply amount of cleaning gas becomes flow rate C2, a switch occurs between the low exhaust state and the high exhaust state. However, the timing of the exhaust state switch is arbitrary and is not limited to being staggered with the timing of the cleaning gas flow rate switch.

[0078] The time chart for this third washing process example does not show the operation of the developing device 1 after the supply of washing gas has ended, but after the supply has ended, the washing gas can be removed by exhausting the processing space 20, and then the processing space 20 can be opened. The exhaust of this processing space 20 is N ２ Gas may or may not be supplied. Furthermore, exhaust may be performed under high-volume or low-volume conditions. In the other cleaning process examples described later, similar to this third cleaning process example, the cleaning gas can be removed by exhausting the processing space 20 after the cleaning gas supply is stopped, and then the processing space 20 can be opened.

[0079] [Supplementary Information on Processing Examples and Apparatus Configuration] The cleaning processing examples and apparatus configuration of the developing apparatus 1 described above will be explained in more detail below. In each of the cleaning processing examples described above, a low-volume state and a high-volume state are repeatedly formed, but such repetition is not required. Furthermore, when opening the processing space 20 to the outside of the processing container 21, it is preferable to set the processing space to a low-volume state in order to more reliably suppress the impact on the surroundings of the processing container 21. However, in this example, even in the high-volume state, the processing space 20 is at a low vacuum, so even if the processing space 20 is opened to the outside of the processing container 21 in the high-volume state, the impact on the surroundings of the processing container 21 is small. For this reason, the processing space 20 may be opened to the outside of the processing container 21 in the high-volume state.

[0080] Therefore, from the start of supplying cleaning gas to the processing space 20 until the processing space 20 is opened and the cleaning process is completed, the change between the low displacement state and the high displacement state may be made only once. When the change is made only once, it may be a change from the low displacement state to the high displacement state, or a change from the high displacement state to the low displacement state. Furthermore, this change between the high displacement state and the low displacement state may be made during the period when cleaning gas is supplied to the processing space 20, or during the period when cleaning gas is not supplied to the processing space 20.

[0081] Furthermore, when switching between the low-displacement and high-displacement states multiple times, the changes are not necessarily performed periodically. Therefore, the length of the period during the nth (where n is a positive integer) instance of the low-displacement state may be different from the length of the period during the (n+1)th instance of the low-displacement state. Similarly, the length of the period during the nth instance of the high-displacement state may be different from the length of the period during the (n+1)th instance of the high-displacement state. Note that in other cleaning process examples described later, the change between the low-displacement and high-displacement states is illustrated in the time chart diagrams illustrating these cleaning process examples, but the examples are not limited to these. As explained above, the low-displacement and high-displacement states can be switched at any timing and formed any number of times in any order.

[0082] Furthermore, in the second and third cleaning process examples and the cleaning process examples described thereafter, in order to improve the cleaning performance of the processing space 20, similar to the first cleaning process example, N ２ It is preferable that the gas is heated before being supplied to the processing space 20, but it is not limited to being heated before being supplied. Therefore, the N ２ A heating mechanism 85 for heating the gas does not need to be provided. Also, N is used as the inert gas supplied to the processing space 20 in this manner. ２ Although gas is used as an example, other inert gases such as Ar gas may also be used, in which case N ２ The gas supply mechanism 4 and 7 may be configured to receive gas from another inert gas source instead of the gas supply source 77.

[0083] [Fourth example of cleaning process] During the cleaning process, N ２ The gas flow rate may be changed. Figure 17 shows this. ２ This is a time chart showing a fourth washing process example in which the gas flow rate is changed. Figures 18 and 19 are longitudinal cross-sectional side views showing the developing apparatus 1 before and after the change in the gas flow rate. In this example as well as in the second washing process example, different types of gas are discharged from the supply ports 45 and 55, so the chart shows the gas flow rates from each gas supply port.

[0084] In this fourth cleaning process example, at time t21, the supply of cleaning gas from the supply port 55 of the shower head 53 begins, and the flow rate of the cleaning gas is set to C3. Meanwhile, at time t21, N is supplied from the supply port 45 of the stage 34. ２ The gas is supplied at flow rate D1. Then the cleaning gas and N ２ The gas supply continues, and at time t22, a predetermined time has elapsed from time t21, the N ２ The gas flow rate increases to a flow rate D2 which is greater than flow rate D1. The flow rate of the cleaning gas remains C3. Therefore, the flow rate of the cleaning gas supplied to the processing space 20 from different supply ports and the N supplied to the processing space 20 are... ２ The ratio to the gas flow rate changes.

[0085] Figures 18 and 19 show the cleaning gas and N in the processing space 20. ２The gas flow is schematically shown by solid arrows and dashed-dot arrows, respectively, and the region where a relatively large cleaning force can be obtained by the cleaning gas flow is enclosed by a dashed-dot line. At times t21 to t22, the N ratio to the flow rate of the cleaning gas is shown. ２ Because the gas flow rate (= D1 / C3) is relatively small, the airflow of the cleaning gas formed in the processing space 20 is N ２ It is less affected by the gas. Therefore, as shown in Figure 18, the airflow of the cleaning gas acts relatively strongly on the area relatively close to the second gas supply port 46, and the cleaning power in these areas is increased. Specifically, the cleaning power is relatively increased on the center of the lower surface of the shower head 53 and its vicinity, and on the lower side of the side wall of the processing container 21.

[0086] Then, from time t22 onward, N is relative to the flow rate of the cleaning gas. ２ Because the gas flow rate (= D2 / C3) is relatively large, the airflow of the cleaning gas formed in the processing space 20 is N ２ The system is susceptible to the effects of the gas. Therefore, as shown in Figure 19, the airflow of the cleaning gas acts relatively strongly on areas relatively far from the second gas supply port 46, resulting in a relatively greater cleaning force in these areas. Specifically, the cleaning force is relatively greater on the peripheral edges of the lower surface of the shower head 53 and its vicinity, and on the upper side of the side wall of the processing container 21.

[0087] When a predetermined time has elapsed from time t22 to time t23, the supply of cleaning gas to the processing space 20 is stopped. Then, as in the other cleaning process examples described so far, the cleaning gas can be exhausted and removed from the processing space 20. By changing the ratio of the gas flow rates supplied from the supply ports 55 and 45, which open at different locations in the processing space 20, the distribution and flow velocity of the cleaning gas in each part of the processing space 20 can be changed, allowing each part of the processing space 20 to be thoroughly cleaned in a relatively short time.

[0088] [Variation of the fourth cleaning process example] N in relation to the flow rate of the cleaning gas described above ２Regarding the gas flow rate, in the example explained in the chart in Figure 17, the value for time t22-t23 (= D2 / C3), which is a later period during the cleaning process, is greater than the value for time t21-t22 (= D1 / C3), which is an earlier period during the cleaning process. In other words, the proportion of cleaning gas in the gas supplied to the processing space 20 is lower during the later period, time t22-t23.

[0089] By making the proportion of cleaning gas in the later period less than the proportion of cleaning gas in the earlier period, it is preferable to shorten the time required to remove the cleaning gas after the time t23 when the supply of cleaning gas is stopped. However, contrary to the example shown in Figure 17, N as a percentage of the flow rate of the cleaning gas ２ The gas flow rate may be set so that the value for the later period, from time t22 to t23, is smaller than the value for the earlier period, from time t21 to t22.

[0090] Furthermore, the N2 ratio to the flow rate of the cleaning gas mentioned above. ２ Regarding the gas flow rate value, N from supply port 45 ２ An example was shown where the gas flow rate is changed from D1 to D2, but in this way N ２ The value is not limited to being changed by changing the gas flow rate. The value may also be changed by changing the flow rate of the cleaning gas from the supply port 55, or by changing the N from the supply port 45. ２ The value may also be changed by changing both the gas flow rate and the flow rate of the cleaning gas from the supply port 55.

[0091] Furthermore, in order to improve the cleaning power at various points in the processing space 20 by changing the distribution and velocity of the airflow at those points as described above, it is sufficient to change the ratio of the flow rates of the gas supplied from each of the supply ports 45 and 55 that open at different locations in the processing space 20. Therefore, if cleaning gas is discharged from one of the supply ports 45 and 55, the type of gas supplied from the other will be N ２ It is not limited to being a gas, but can be any gas. Specifically, this any gas may be, for example, a washing gas, or a gas consisting only of organic solvents that do not contain acetic acid. Therefore, in the chart of Figure 17, the gas whose flow rate is changed by D1 and D2 is N ２Although it is shown as a gas, this N ２ The gas can be replaced with other gases, such as the cleaning gas mentioned above, as appropriate.

[0092] As described above, the flow rate of the cleaning gas supplied from the first gas supply port 45 and the N supplied from the second gas supply port 55 ２ While we have explained that the ratio of gas flow rate is changed, the combination of gas types supplied from each supply port is not limited to this example. The ratio of the flow rate of the gas supplied from the first gas supply port 45 (referred to as the first gas) and the flow rate of the gas supplied from the second gas supply port 55 (referred to as the second gas) is changed, and at least one of the first gas and the second gas is a cleaning gas.

[0093] Furthermore, in order to change this ratio, when changing the flow rate of one of the first gas and the second gas, assuming the other is a cleaning gas, the flow rate of this one gas may be changed to a flow rate between 0 and a non-zero value. In other words, for one of the gases, while the other gas, the cleaning gas, is being supplied to the processing space 20, the supply to the processing space 20 may be switched on and off, thereby changing the airflow distribution and flow velocity in the processing space 20 and obtaining the effects described above.

[0094] By the way, the supply ports 45 and 55 can be located in different positions from each other, so the arrangement is not limited to that shown in Figure 1, etc. Specifically, the supply ports 55 and / or supply ports 45 may be configured to open into the side wall of the processing container 21. When other washing process examples are implemented, the arrangement of the supply ports 55 and supply ports 45 is not limited to the examples shown in Figure 1, etc. However, since the supply ports 45 and 55 are in a positional relationship where they discharge gas in opposite directions, the gas discharged from one supply port interferes relatively significantly with the gas discharged from the other supply port, making it easier to create changes in the airflow in the processing space 20. Therefore, the positional relationship of the supply ports 45 and 55 is preferable because the effects of changing the airflow distribution and flow velocity described above can be obtained more reliably. There are no restrictions on the number of supply ports 45 and supply ports 55, and any number can be used.

[0095] [Fifth Cleaning Process Example] In this fifth cleaning process example, the concentration of the cleaning component (acetic acid in this example) contained in the cleaning gas is changed while the cleaning gas is being supplied during the cleaning process. As described in the second cleaning process example, when performing the cleaning process, the cleaning gas is supplied from at least one of the supply ports 45 and 55. When the cleaning process is performed by discharging the cleaning gas from only one of the supply ports 45 and 55, the concentration of the cleaning component contained in the cleaning gas discharged from that gas supply port is changed. When the cleaning process is performed by discharging the cleaning gas from both of the supply ports 45 and 55, the concentration of the cleaning component contained in the cleaning gas discharged from one or both gas supply ports is changed.

[0096] Figure 20 is a time chart showing the fifth cleaning treatment example. At time t31, the supply of cleaning gas with a cleaning component concentration of E1% is started, and at time t32, the concentration of the cleaning component is reduced to E2%, which is lower than E1%, and the supply of cleaning gas is continued until time t33, when the supply of cleaning gas is stopped. The reason for changing the concentration in this way is to ensure that the cleaning component concentration is relatively high at E1% during the earlier period (times t31 to t32) when there is a large amount of deposits P in the treatment space 20, thereby increasing the cleaning power and allowing the removal of deposits P to proceed quickly. Then, during the later period (times t32 to t33) when the removal of deposits P has progressed relatively well, the cleaning component concentration is relatively low at E2% to ensure appropriate cleaning power while allowing acetic acid to be quickly removed from the treatment space 20 after time t33.

[0097] The concentration of the cleaning component is not limited to the timings shown in the time chart in Figure 20. For example, the concentration may be changed in response to changes in the exhaust state. Specifically, the concentration of the cleaning component may be set to a relatively high E1% during the period when a high exhaust state is formed, and to a lower E2% during the period when a low exhaust state is formed. As mentioned above, the switching between the high and low exhaust states is not limited to the method shown in Figure 20.

[0098] The reason for increasing the concentration of cleaning components in the cleaning gas during high-displacement conditions compared to low-displacement conditions is explained below. When high-displacement conditions are formed, the cleaning gas can be efficiently discharged from the processing space 20, so even if the time between stopping the supply of the cleaning gas and opening the processing space 20 is relatively short, the cleaning components can be sufficiently removed. Furthermore, as mentioned above, the purpose of high-displacement conditions is to increase the airflow velocity in the processing space 20 to obtain high cleaning power, and this purpose can be achieved more reliably by using a cleaning gas with a high concentration of cleaning components.

[0099] On the other hand, in a low displacement state, the cleaning gas is less likely to be discharged from the processing space 20 compared to a high displacement state. Therefore, by keeping the concentration of the cleaning component relatively low, even if the time from stopping the supply of cleaning gas under a low displacement state to opening the processing space 20 is relatively short, the concentration of the cleaning component in the processing space 20 can be sufficiently reduced. For these reasons, it is preferable to have a higher concentration of the cleaning component in a high displacement state than in a low displacement state.

[0100] [Variation of the Fifth Washing Treatment Example] Incidentally, when changing the concentration of the cleaning component in the washing gas between E1% and E2%, which is lower than E1%, there are no particular restrictions on E1% and E2%. Therefore, E2% may be 0%. The washing gas contains N, which is necessary for the vaporization of the cleaning component. ２ Since it will contain gas, the E1% can be set to the highest possible value within a range lower than 100%.

[0101] Furthermore, the cleaning gas discharged from the supply port 45 and / or supply port 55 may contain a relatively large amount of cleaning components so that condensation forms on the walls of the processing space 20 after discharge. Subsequently, the condensed cleaning gas may be vaporized again and removed from the walls due to the pressure change in the processing space 20 when transitioning from a low exhaust volume state to a high exhaust volume state during the cleaning process. To promote vaporization, the temperature of the heater 36 in the stage 34 may be adjusted, or a heater for vaporization may be provided in the processing container 21 and its temperature may be adjusted.

[0102] Furthermore, as long as the cleaning components can be discharged from the processing space 20 as a gas, there may be a period during which they remain liquid in the processing space 20. Therefore, the cleaning fluid containing the cleaning components supplied to the processing space 20 is not limited to being a gas, but may also be a liquid mist. When discharging mist into the processing space 20 in this manner, a mist supply port opening to the processing space 20 may be provided separately from the supply ports 55 and 45. This mist supply port can be, for example, a supply port formed by a nozzle provided on the processing container 21.

[0103] Then, a channel for supplying liquid acetic acid to this mist supply port, N ２ Each gas supply channel is connected, including a channel for acetic acid, and N ２ These acetic acid and N are respectively connected to the gas flow channels. ２ The apparatus should be configured so that a fluid supply device is provided to adjust the flow rate to the gas supply port. Then, acetic acid, N ２ The acetic acid should be mixed with gas so that it is atomized and discharged into the processing space 20 from the mist supply port. ２ The concentration of acetic acid in the mist can be changed by altering the flow rate of acetic acid supplied to the mist inlet relative to the gas flow rate. Therefore, when supplying a cleaning fluid as a mist in this manner, the concentration of the cleaning components can be changed in the same way as when supplying a cleaning gas as a cleaning fluid.

[0104] [Sixth Cleaning Process Example] In the sixth cleaning process example, the temperature of the cleaning gas is changed while it is being supplied during the cleaning process. If the cleaning process is performed by discharging the cleaning gas from only one of the supply ports 45 and 55, the temperature of the cleaning gas discharged from that one gas supply port is changed. If the cleaning process is performed by discharging the cleaning gas from both of the supply ports 45 and 55, the temperature of the cleaning gas discharged from one or both gas supply ports is changed.

[0105] FIG. 21 is a time chart showing a sixth cleaning process example. Supply of the cleaning gas is started at time t41 with the temperature of the cleaning gas set to F1°C, then supply of the cleaning gas is continued at subsequent time t42 with the temperature of the cleaning gas set to F2°C, which is higher than F1°C, and supply of the cleaning gas is stopped at time t43. The reason for controlling the temperature of the cleaning component as shown in this time chart is to accelerate the formation of cracks in the deposit P by rapidly increasing the temperature of the deposit P, thereby promoting the collapse and peeling of the deposit P and improving cleaning efficiency. F1°C is 180°C to 200°C as an example, F2°C is, for example, 50°C or more higher than F1°C, and specifically is 400°C, for example.

[0106] It is not limited to making the temperature of the cleaning gas in the later period (time t42 to t43) of the period in which the cleaning process is performed higher than the temperature of the cleaning gas in the earlier period (time t41 to t42). The temperature of the cleaning gas in the earlier period may be lower than the temperature of the cleaning gas in the later period.

[0107] [Other Matters] In the third to sixth cleaning process examples, the flow rates of the cleaning gas are C1 and C2, the flow rate of the cleaning gas and N ２ N for changing the ratio of the gas flow rate ２ the gas flow rate is set to D1 and D2, the concentration of the cleaning component in the cleaning gas is set to E1 and E2, and the temperature of the cleaning gas is set to F1 and F2, each of which is changed in two steps. However, each of these parameters (the flow rates of the cleaning gas and N ２ gas flow rate, concentration of the cleaning component, temperature of the cleaning gas) is not limited to such a two-step change, and may be changed in three or more steps. Further, in the third to sixth cleaning process examples, these parameters are changed only once during the cleaning process, but the number of changes is not limited to one, and may be a plurality of times.

[0108] Although it was stated that supply ports for independently supplying cleaning gas are provided at different locations, such as the supply port 55 of the showerhead 53 and the supply port 45 of the stage 34, it is also possible to supply cleaning gas from only one of the supply ports 45 and 55. In that case, the fifth and sixth cleaning treatment examples, which were shown to change the concentration of cleaning components in the cleaning gas and the temperature of the cleaning gas, respectively, can be changed by changing the concentration and temperature of the cleaning components in the cleaning gas supplied from the gas supply port that can supply the cleaning gas. As mentioned above, the location of the supply ports for supplying cleaning gas or cleaning mist to the processing space 20 is not limited to the showerhead 53 and the stage 34.

[0109] In this example, the processing gas used to treat the wafer W before cleaning is the same weak acid-containing gas as the cleaning gas. The gas used as the processing gas is arbitrary. For example, when developing in this manner, a gas containing a strong acid, such as HBr gas, may be used. When using a strong acid, it is necessary to ensure safety by providing a structure that strictly prevents leakage in the flow channels forming the exhaust mechanism 9 and the flow channels for introducing the strong acid gas into the processing space 20, and by forming a coating to prevent corrosion of the walls. In other words, the apparatus becomes large-scale. Therefore, the developing apparatus 1 in which both the processing gas and the cleaning gas are weak acid-containing gases has the advantage of being able to simplify the apparatus.

[0110] We have so far described examples of changing various parameters such as exhaust pressure, gas concentration, and gas flow rate. However, these parameter changes do not mean that they are unavoidable fluctuations due to the limitations of control by the control device 100, but rather that they are intentional changes. In other words, they are changes based on the control operation of the control device 100.

[0111] Furthermore, while an example of developing a resist film R made of a metal-containing resist was given as a process performed on the wafer W before cleaning the processing space 20, the developing process may also be performed on a resist film R made of a resist other than a metal-containing resist. Also, the process performed on the wafer W before cleaning is not limited to developing, but may also be a film deposition process by supplying a film deposition gas, or an annealing apparatus that heats the wafer W in an inert gas atmosphere to anneal it. The above developing and film deposition processes are not limited to being performed using gas, but can be performed using a mist containing developing components or a mist containing film deposition components. Therefore, the substrate processing apparatus is not limited to developing apparatus 1, nor is it limited to being a gas processing apparatus.

[0112] In the example above, the exhaust pressure in the exhaust passage 91 is changed by switching the exhaust path, but this is not limited to such switching of the exhaust path. For example, it may also be done by changing the opening degree of the damper 93. Therefore, a configuration without an ejector 95 is also possible. However, in order to rapidly change the exhaust pressure and alter the airflow in the processing space 20 to obtain a high cleaning effect, it is preferable to provide an ejector 95 and switch the exhaust path as described in Figures 5 and 6.

[0113] In each embodiment, the substrate to be processed is not limited to a wafer, but may be, for example, a substrate for manufacturing a flat panel display or a mask substrate for manufacturing a mask for exposure. Therefore, a rectangular substrate may also be processed. The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The above embodiments may be omitted, replaced, modified and combined in various ways without departing from the scope and spirit of the appended claims.

[0114] P2 Wall W Wafer 1 Developing device 20 Processing space 21 Processing container 45, 55 Supply port 91A Common exhaust passage

Claims

1. A method for operating a substrate processing apparatus, comprising a processing container in which a processing space formed inside is exhausted through an exhaust passage, wherein processing is performed on a substrate placed on a stage provided in the processing space, the method comprising: a cleaning step in which a cleaning fluid, which is a gas or mist, for cleaning the processing space is supplied from a first supply port opening into the processing space while no substrate is placed on the stage, and the exhaust pressure of the exhaust passage is varied until the processing space is opened to the outside of the processing container.

2. The method for operating a substrate processing apparatus according to claim 1, wherein the cleaning step is performed without generating plasma in the processing space.

3. A method for operating a substrate processing apparatus according to claim 1 or 2, comprising the step of supplying heated inert gas to the processing space from a second supply port provided at a different location from the first supply port and opening to the processing space.

4. The method for operating a substrate processing apparatus according to claim 1 or 2, wherein the fluctuation of the exhaust pressure is performed within a range in which the pressure in the processing space is maintained at a low vacuum.

5. A method for operating a substrate processing apparatus according to claim 1 or 2, comprising the steps of: supplying a cleaning gas as the cleaning fluid to the processing space from the first supply port; supplying the gas to the processing space from a second supply port located at a position different from the first supply port and opening to the processing space; and changing the ratio of the flow rate of the cleaning gas supplied to the processing space from the first supply port and the flow rate of the gas supplied to the processing space from the second supply port during the cleaning process.

6. A method for operating a substrate processing apparatus according to claim 1 or 2, comprising the steps of: during the execution of the cleaning step, varying the concentration of a component having a cleaning action in the cleaning fluid supplied from the first supply port, or supplying cleaning fluid to the processing space from a second supply port provided at a different location from the first supply port and opening to the processing space; and varying the concentration of a component having a cleaning action in the cleaning fluid supplied from the second supply port.

7. A method for operating a substrate processing apparatus according to claim 1 or 2, comprising the steps of: supplying a cleaning gas as the cleaning fluid to the processing space from the first supply port during the cleaning process; changing the temperature of the cleaning gas supplied to the processing space from the first supply port; or supplying the cleaning gas to the processing space from a second supply port located at a different position from the first supply port and opening to the processing space; and changing the temperature of the cleaning gas supplied from the second supply port.

8. A substrate processing apparatus comprising: a processing container having a processing space formed inside; an exhaust passage for exhausting the processing space; a stage provided in the processing space for placing and processing the substrate; a cleaning fluid supply unit for supplying a cleaning fluid, which is a gas or mist, for cleaning the processing space to a first supply port opening into the processing space when no substrate is placed on the stage; and an exhaust mechanism for exhausting the processing space to which the cleaning fluid has been supplied via the exhaust passage, and for varying the exhaust pressure of the exhaust passage until the processing space is opened to the outside of the processing container.

9. The substrate processing apparatus according to claim 8, further comprising: a second supply port provided at a position different from the first supply port and opening into the processing space; and an inert gas supply unit for supplying heated inert gas to the second supply port.

10. The substrate processing apparatus according to claim 8 or 9, wherein the fluctuation of the exhaust pressure is performed within a range in which the pressure in the processing space is maintained at a low vacuum.

11. A computer program used in a substrate processing apparatus, wherein the computer program is a program in which a group of steps is arranged to execute the substrate processing method described in claim 1 or 2.

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