Cleaning method and plasma processing apparatus

Abstract

To improve productivity by suppressing damage to the inside of a processing container caused by plasma cleaning.SOLUTION: In an identification step, the pressure inside a processing chamber during plasma cleaning is identified from the amount of damage to a protective film provided on the inner surface of the processing chamber and the cleaning rate for removing deposits deposited in the processing chamber, which are conditions for plasma cleaning. In a cleaning step, while cleaning gas is supplied into the processing chamber, the pressure in the processing chamber is adjusted to the pressure identified in the identification step; plasma is generated in the processing chamber by microwaves; and the inside of the processing chamber is plasma-cleaned.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] Patent Document 1 proposes a technology in which cleaning is performed by generating plasma while supplying a cleaning gas into a processing vessel, and cleaning the inside of the processing vessel at a first pressure and a second pressure higher than the first pressure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-211099 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique for suppressing damage to the inside of a processing vessel caused by plasma cleaning and improving productivity. [Means for solving the problem]

[0005] A cleaning method according to an embodiment of the present disclosure includes a specifying step and a cleaning step. In the specifying step, a pressure in the processing vessel during plasma cleaning is specified based on the amount of damage to a protective film provided on the inner surface of the processing vessel and a cleaning rate for removing deposits accumulated in the processing vessel, which are conditions for plasma cleaning. In the cleaning step, the pressure in the processing vessel is adjusted to the pressure specified in the specifying step while supplying a cleaning gas into the processing vessel, and plasma is generated in the processing vessel by microwaves to plasma clean the inside of the processing vessel. Effect of the Invention

[0006] According to the present disclosure, damage to the inside of a processing vessel caused by plasma cleaning can be suppressed, and productivity can be improved. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view that illustrates an example of a plasma processing apparatus according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing an example of the arrangement of antenna modules on a top wall according to the embodiment. [Diagram 3] FIG. 3 is a diagram illustrating an example in which a protective film of a processing container according to the embodiment is etched by plasma for plasma cleaning. [Figure 4] FIG. 4 is a graph showing an example of the relationship between the pressure inside the processing container and the amount of damage to the protective film in the plasma cleaning according to the embodiment. [Diagram 5] FIG. 5 is a graph showing an example of the relationship between the pressure inside the processing container and the cleaning rate in the plasma cleaning according to the embodiment. [Figure 6] FIG. 6 is a graph showing an example of identifying the overlapping range. [Figure 7] FIG. 7 is a diagram showing an example of a cleaning time of the plasma cleaning according to the embodiment. [Figure 8] FIG. 8 is a diagram showing an example of the cleaning time and the film thickness to be removed in the plasma cleaning according to the embodiment. [Figure 9] FIG. 9 is a diagram showing an example of a change in the amount of damage to a protective film depending on the cleaning time of plasma cleaning according to the embodiment. [Figure 10] FIG. 10 is a diagram showing an example of a change in the number of particles depending on the number of substrates on which films are formed according to the embodiment. [Figure 11] FIG. 11 is a flowchart showing an example of the flow of the pressure setting process according to this embodiment. [Figure 12] FIG. 12 is a flowchart showing an example of the flow of the cleaning process according to this embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, embodiments of the cleaning method and plasma processing apparatus disclosed in the present application will be described in detail with reference to the drawings. Note that the cleaning method and plasma processing apparatus disclosed in the present application are not limited to the embodiments.

[0009] In recent years, with the increasing density and miniaturization of semiconductor products, plasma processing apparatuses using microwaves for film formation processing are being used in the manufacturing process of semiconductor products. By using microwaves, the plasma processing apparatus can stably generate plasma even in a high vacuum state with a relatively low pressure. In addition, by using microwaves, the plasma processing apparatus can generate high-density plasma. When a film formation process is performed in the plasma processing apparatus, deposits are deposited on the surfaces of structures in the processing vessel, such as the inner wall surfaces of the processing vessel. For this reason, in the plasma processing apparatus, plasma cleaning is performed in which a cleaning gas is flowed into the processing vessel to remove deposits every time a predetermined number of substrates are formed or every time a film is formed to a predetermined cumulative thickness. For example, Patent Document 1 performs plasma cleaning by switching the pressure in the processing vessel between two states, a first pressure and a second pressure higher than the first pressure.

[0010] Incidentally, it is known that plasma processing apparatuses provide a protective film on the inner surface of a processing vessel to protect the inner surface of the processing vessel from damage caused by plasma. In a processing vessel provided with a protective film, for example, in a cleaning process such as that described in Patent Document 1, damage caused by plasma cleaning due to the first pressure (low pressure) is particularly large, and maintenance such as part replacement becomes more frequent. Higher frequency of maintenance has a significant impact on productivity. For this reason, technology is desired that suppresses damage to the inside of the processing vessel due to plasma cleaning and improves productivity.

[0011] [Embodiment] An embodiment will be described. First, an example of a plasma processing apparatus for carrying out the cleaning method of the present disclosure will be described. FIG. 1 is a cross-sectional view that shows a schematic diagram of an example of a plasma processing apparatus 100 according to an embodiment. The plasma processing apparatus 100 shown in FIG. 1 includes a processing vessel 101, a mounting table 102, a gas supply mechanism 103, an exhaust device 104, a microwave introduction device 105, and a control unit 200.

[0012] The processing vessel 101 accommodates a substrate W such as a semiconductor wafer. A mounting table 102 is provided inside the processing vessel 101. The substrate W is mounted on the mounting table 102. A gas supply mechanism 103 supplies gas into the processing vessel 101. An exhaust device 104 exhausts the inside of the processing vessel 101. A microwave introduction device 105 generates microwaves for generating plasma in the processing vessel 101, and introduces the microwaves into the processing vessel 101. A control unit 200 controls the operation of each unit of the plasma processing apparatus 100.

[0013] The processing vessel 101 is made of a metal material such as aluminum or its alloy, and has a substantially cylindrical shape. The processing vessel 101 has a plate-shaped top wall 111 and bottom wall 113, and a side wall 112 connecting them. The inner wall of the processing vessel 101 is coated with yttria (Y2O3) or the like to provide a protective film. The microwave introduction device 105 is provided on the upper part of the processing vessel 101, and introduces electromagnetic waves (microwaves) into the processing vessel 101 to generate plasma. The microwave introduction device 105 will be described in detail later.

[0014] The ceiling wall 111 has a plurality of openings into which a microwave radiation mechanism 143 and a gas introduction nozzle 123, described later, of the microwave introduction device 105 are fitted. The side wall 112 has a transfer port 114 for transferring the substrate W between the processing vessel 101 and a transfer chamber (not shown) adjacent to the processing vessel 101. The side wall 112 is also provided with a gas introduction nozzle 124 at a position above the mounting table 102. The transfer port 114 is opened and closed by a gate valve 115.

[0015] An opening is provided in the bottom wall 113, and an exhaust device 104 is provided via an exhaust pipe 116 connected to the opening. The exhaust device 104 includes a vacuum pump and a pressure control valve. The inside of the processing vessel 101 is exhausted via the exhaust pipe 116 by the vacuum pump of the exhaust device 104. The pressure inside the processing vessel 101 is controlled by the pressure control valve of the exhaust device 104.

[0016] The mounting table 102 is formed in a disk shape. The mounting table 102 is made of a metal material, for example, aluminum whose surface has been anodized, or a ceramic material, for example, aluminum nitride (AlN). The substrate W is mounted on the upper surface of the mounting table 102. The mounting table 102 is supported by a cylindrical support member 120 and a base member 121 made of ceramics such as AlN, which extend upward from the center of the bottom of the processing vessel 101. A guide ring 181 for guiding the substrate W is provided on the outer edge of the mounting table 102. In addition, inside the mounting table 102, lift pins (not shown) for lifting and lowering the substrate W are provided so as to be able to protrude and retract from the upper surface of the mounting table 102.

[0017] Furthermore, a resistance heating type heater 182 is embedded in the mounting table 102. The heater 182 heats the substrate W placed on the mounting table 102 by receiving power from a heater power supply 183. A thermocouple (not shown) is inserted in the mounting table 102, and the heating temperature of the substrate W can be controlled based on a signal from the thermocouple. Furthermore, an electrode 184 having a size approximately equal to that of the substrate W is embedded in the mounting table 102 above the heater 182. A high frequency bias power supply 122 is electrically connected to the electrode 184. The high frequency bias power supply 122 applies a high frequency bias for attracting ions to the mounting table 102. The high frequency bias power supply 122 may not be provided depending on the characteristics of the plasma processing.

[0018] The gas supply mechanism 103 supplies various gases into the processing vessel 101. The gas supply mechanism 103 includes gas introduction nozzles 123 and 124, gas supply pipes 125 and 126, and a gas supply unit 127. The gas introduction nozzle 123 is fitted into an opening formed in a ceiling wall 111 of the processing vessel 101. The gas introduction nozzle 124 is fitted into an opening formed in a side wall 112 of the processing vessel 101. The gas supply unit 127 is connected to each gas introduction nozzle 123 via the gas supply pipe 125. The gas supply unit 127 is connected to each gas introduction nozzle 124 via the gas supply pipe 126. The gas supply unit 127 includes supply sources of various gases. The gas supply unit 127 includes an opening / closing valve for starting and stopping the supply of various gases and a flow rate adjustment unit for adjusting the flow rate of the gas. For example, when a film forming process is performed, the gas supply unit 127 supplies a process gas containing a film forming material, and when a plasma cleaning is performed, the gas supply unit 127 supplies a cleaning gas.

[0019] The microwave introduction device 105 is provided above the processing vessel 101. The microwave introduction device 105 introduces electromagnetic waves (microwaves) into the processing vessel 101 to generate plasma.

[0020] The microwave introduction device 105 has a top wall 111 of the processing container 101, a microwave output unit 130, and an antenna unit 140. The top wall 111 functions as a top plate of the processing container 101. The microwave output unit 130 generates microwaves and distributes the microwaves to a plurality of paths for output. The antenna unit 140 introduces the microwaves output from the microwave output unit 130 into the processing container 101.

[0021] The microwave output unit 130 has a microwave power supply, a microwave oscillator, an amplifier, and a distributor. The microwave oscillator is solid-state and oscillates (e.g., PLL oscillates) a microwave at, for example, 860 MHz. The microwave frequency is not limited to 860 MHz, and frequencies in the range of 700 MHz to 10 GHz, such as 2.45 GHz, 8.35 GHz, 5.8 GHz, and 1.98 GHz, can be used. The amplifier amplifies the microwave oscillated by the microwave oscillator. The distributor distributes the microwave amplified by the amplifier to multiple paths. The distributor distributes the microwave while matching the impedance of the input side and the output side.

[0022] The antenna unit 140 has a plurality of antenna modules. Three antenna modules of the antenna unit 140 are shown in FIG. 1. Each antenna module has an amplifier section 142 and a microwave radiation mechanism 143. The microwave output section 130 generates microwaves and distributes and outputs the microwaves to each antenna module. The amplifier section 142 of the antenna module mainly amplifies the distributed microwaves and outputs them to the microwave radiation mechanism 143. The microwave radiation mechanism 143 is provided on the ceiling wall section 111. The microwave radiation mechanism 143 radiates the microwaves output from the amplifier section 142 into the processing vessel 101.

[0023] The amplifier unit 142 has a phase shifter, a variable gain amplifier, a main amplifier, and an isolator. The phase shifter changes the phase of the microwave. The variable gain amplifier adjusts the power level of the microwave input to the main amplifier. The main amplifier is configured as a solid-state amplifier. The isolator separates the reflected microwave that is reflected by the antenna unit of the microwave radiation mechanism 143 (described later) and heads toward the main amplifier.

[0024] As shown in FIG. 1, the microwave radiation mechanisms 143 are provided on the top wall 111. The microwave radiation mechanisms 143 each have a cylindrical outer conductor and an inner conductor that is coaxially disposed within the outer conductor. The microwave radiation mechanisms 143 each have a coaxial tube having a microwave transmission line between the outer conductor and the inner conductor, and an antenna unit that radiates microwaves into the processing vessel 101. A microwave transmission plate 163 that is fitted into the top wall 111 is provided on the lower surface side of the antenna unit. A lower surface of the microwave transmission plate 163 is exposed to the internal space of the processing vessel 101. The microwaves that have passed through the microwave transmission plate 163 generate plasma in the space within the processing vessel 101.

[0025] FIG. 2 is a diagram showing an example of the arrangement of antenna modules on the top wall portion 111 according to the embodiment. As shown in FIG. 2, seven microwave radiation mechanisms 143 of the antenna modules are provided on the top wall portion 111. Six of the microwave radiation mechanisms 143 are arranged to be vertices of a regular hexagon, and one is arranged at the center of the regular hexagon. In addition, microwave transmission plates 163 are provided on the top wall portion 111 in correspondence with the seven microwave radiation mechanisms 143, respectively. These seven microwave transmission plates 163 are arranged so that adjacent microwave transmission plates 163 are equally spaced apart. In addition, a plurality of gas introduction nozzles 123 of the gas supply mechanism 103 are arranged to surround the periphery of the central microwave transmission plate. The number of antenna modules provided on the top wall portion 111 is not limited to seven.

[0026] The antenna unit 140 according to the embodiment is capable of adjusting the power of microwave plasma radiated from the microwave radiating mechanism 143 of each antenna module by controlling the amplifier section 142 of each antenna module. The antenna unit 140 is capable of controlling the power ratio of microwave plasma radiated from the microwave radiating mechanism 143 in the central portion and the peripheral portion. For example, the antenna unit 140 is capable of controlling the microwave power ratio between the central portion and the peripheral portion within a range of 0:550 to 500:550.

[0027] Note that, as long as the power density of the microwave can be appropriately controlled, a microwave plasma source having a single microwave introduction part having a size corresponding to the substrate W may be used.

[0028] The operation of the plasma processing apparatus 100 configured as above is generally controlled by a control unit 200. To the control unit 200, a user interface 210 and a storage unit 220 are connected.

[0029] The user interface 210 is composed of an operation unit such as a keyboard through which a process manager inputs commands to manage the plasma processing apparatus 100, and a display unit such as a display that visualizes and displays the operating status of the plasma processing apparatus 100. The user interface 210 accepts various operations. For example, the user interface 210 accepts a predetermined operation to instruct the start of plasma processing.

[0030] The storage unit 220 is a storage device that stores various data. For example, the storage unit 220 is a storage device such as a hard disk, a solid state drive (SSD), an optical disk, etc. Note that the storage unit 220 may be a semiconductor memory in which data can be rewritten, such as a random access memory (RAM), a flash memory, or a non-volatile static random access memory (NVSRAM).

[0031] The storage unit 220 stores an OS (Operating System) and various recipes executed by the control unit 200. For example, the storage unit 220 stores various recipes including recipes for executing each process of a cleaning method described later. Furthermore, the storage unit 220 stores various data used in the recipes. For example, the storage unit 220 stores first relationship data 221, second relationship data 222, and cleaning setting data 223. The first relationship data 221 and the second relationship data 222 will be described in detail later. The cleaning setting data 223 is data that stores various settings for plasma cleaning. Note that the programs and data may be stored in a computer-readable computer recording medium (e.g., a hard disk, a CD, a flexible disk, a semiconductor memory, etc.). Alternatively, the programs and data may be transmitted from another device via, for example, a dedicated line at any time and used online.

[0032] The control unit 200 is a device that controls the plasma processing apparatus 100. The control unit 200 may be an electronic circuit such as a central processing unit (CPU) or a micro processing unit (MPU), or an integrated circuit such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA). The control unit 200 has an internal memory for storing programs that define various processing procedures and control data, and executes various processes using these. The control unit 200 functions as various processing units by the operation of various programs. For example, the control unit 200 has a reception unit 201, a specification unit 202, and a cleaning control unit 203.

[0033] The control unit 200 controls each part of the plasma processing apparatus 100. For example, the control unit 200 controls each part of the plasma processing apparatus 100 to perform a film forming process according to a recipe of the recipe data stored in the storage unit 220. In the plasma processing apparatus 100, a substrate W is placed on a mounting table 102. In the plasma processing apparatus 100, a film forming process is performed on the substrate W placed on the mounting table 102. For example, the plasma processing apparatus 100 applies a bias power from a high frequency bias power supply 122 to the mounting table 102. In addition, the plasma processing apparatus 100 supplies a processing gas containing, for example, a silicon-containing gas and a nitrogen-containing gas from a gas supply unit 127 into the processing vessel 101, while introducing microwaves from a microwave introduction device 105 into the processing vessel 101 to generate plasma and form a silicon-containing film on the substrate W.

[0034] Examples of the silicon-containing gas include silane-based hydrogen gas such as SiH4, Si2H6, and SiH2Cl2, or silane-based halogen gas. Examples of the nitrogen-containing gas include hydrogen nitride gas such as NH3, N2H4, and N3H5, such as ammonia, hydrazine, and triazane, and nitrogen gas N2 alone. The gas supply unit 127 may further supply other gases such as rare gases and carbon-containing gases as the process gas.

[0035] In this embodiment, for example, the silicon-containing gas is SiH4 gas, the nitrogen-containing gas is NH3 gas, and a SiN film is formed as the silicon-containing film on the substrate W.

[0036] The control unit 200 controls the power of microwave plasma radiated from the microwave radiation mechanism 143 of each antenna module by controlling the amplifier unit 142 of each antenna module during the film formation process. For example, the control unit 200 controls the microwave power ratio between the central part at the top of the processing vessel 101 and the peripheral part surrounding the central part within a range of 0:550 to 500:550 as necessary.

[0037] As described above, when the plasma processing apparatus 100 performs a film formation process, deposits are deposited on the surface of the structure in the processing vessel 101. For example, when a silicon-containing film is formed on the substrate W, silicon-containing materials are deposited as deposits on the surface of the structure in the processing vessel 101. Examples of the deposited silicon-containing materials include SiN, SiCN, SiON, SiOCN, SiC, and amorphous silicon (a-Si). Note that amorphous carbon (aC) may also be deposited as deposits.

[0038] Therefore, the plasma processing apparatus 100 performs plasma cleaning to remove deposits by generating plasma while flowing a cleaning gas into the processing vessel 101 every time a predetermined number of substrates W are formed or every time a film with a predetermined cumulative thickness is formed. For example, as in the conventional technology, the plasma cleaning is performed by switching the pressure inside the processing vessel 101 between two states during cleaning.

[0039] When plasma cleaning is performed, the protective film provided on the inner surface of the processing vessel 101 is damaged by the plasma of the plasma cleaning. In the plasma processing apparatus 100, when plasma cleaning is performed repeatedly, the protective film on the inner surface of the processing vessel 101 is gradually etched by the plasma of the plasma cleaning, and the inner surface of the processing vessel 101 is exposed.

[0040] FIG. 3 is a diagram illustrating an example in which the protective film of the processing vessel 101 according to the embodiment is etched by plasma in plasma cleaning. The upper side (a) of FIG. 3 shows a schematic view of an upper part of the processing vessel 101 in an initial state. The lower side (b) of FIG. 3 shows a schematic view of an upper part of the processing vessel 101 after repeatedly performing plasma cleaning. Three microwave transmission plates 163 are provided in correspondence with the microwave radiation mechanism 143 on the ceiling wall 111 of the processing vessel 101. A protective film 101a is provided on the inner surface of the processing vessel 101. The protective film 101a is, for example, an yttria (Y2O3) film. In the plasma cleaning, microwaves radiated from the microwave radiation mechanism 143 and transmitted through the microwave transmission plate 163 generate plasma in the space within the processing vessel 101. When the plasma cleaning is periodically and repeatedly performed in the plasma processing apparatus 100, the protective film 101a on the inner surface of the processing vessel 101 is etched by the plasma, exposing the inner surface of the processing vessel 101. In the lower side (b) of FIG. 3, a part of protective film 101a around microwave transmitting plate 163 is removed, and the inner surface of processing vessel 101 is partially exposed.

[0041] In plasma cleaning, if the pressure inside the processing vessel 101 during cleaning is low, the protective film 101a is significantly damaged, the protective film 101a is etched, and the inner surface of the processing vessel 101 is exposed. On the other hand, if the pressure inside the processing vessel 101 during cleaning is high, the damage to the protective film 101a is small and etching of the protective film 101a is suppressed, but the cleaning time becomes long, which adversely affects productivity.

[0042] The damage in the processing vessel 101 and the amount of removal (cleaning rate) of deposits deposited in the processing vessel 101 will be further described. FIG. 4 is a graph showing an example of the relationship between the pressure in the processing vessel 101 and the amount of damage to the protective film 101a in the plasma cleaning according to the embodiment. When the protective film 101a is etched, the components of the protective film 101a scatter inside the processing vessel 101. The vertical axis of the graph in FIG. 4 is the amount of damage Y to the protective film 101a, and the amount of damage Y increases toward the upper side. The horizontal axis of the graph is the pressure in the processing vessel 101 in the plasma cleaning, and the pressure increases toward the right side. The amount of damage to the protective film 101a was obtained by removing the substrate W after performing plasma cleaning with the substrate W placed on the upper surface of the mounting table 102 and then determining the amount of protective film components attached to the substrate W. In this embodiment, the area density per unit area of ​​Y (yttrium), which is a component of yttria (Y2O3) coated as the protective film 101a, is shown as the amount of damage Y.

[0043] 4, the damage amount Y decreases as the pressure inside the processing vessel 101 increases. The decreasing tendency of the damage amount Y is exponential up to a certain pressure. That is, when the pressure inside the processing vessel 101 is low, the damage amount Y is large, and as the pressure inside the processing vessel 101 increases, the damage amount Y decreases.

[0044] 5 is a graph showing an example of the relationship between the pressure inside the processing vessel 101 and the cleaning rate in plasma cleaning according to the embodiment. The vertical axis of the graph in FIG. 5 is the cleaning rate of plasma cleaning, with the cleaning rate increasing toward the top. The horizontal axis of the graph is the pressure inside the processing vessel 101 in plasma cleaning, with the pressure increasing toward the right. The cleaning rate is the amount of reduction in the film thickness of the deposit inside the processing vessel 101 by plasma cleaning per unit time. In this embodiment, an optical sensor installed in the processing vessel 101 measures the emission spectrum when the deposit is removed by plasma cleaning, and the cleaning rate is calculated from the change in the spectrum of a specific element.

[0045] As shown in FIG. 5, the cleaning rate decreases as the pressure inside the processing vessel 101 increases.

[0046] Returning to Fig. 1, as described above, the storage unit 220 stores the first relationship data 221 and the second relationship data 222 regarding the relationship between the amount of damage, the cleaning rate, and the pressure.

[0047] The first relationship data 221 is data indicating a relationship between the pressure in the processing vessel 101 and the amount of damage to the protective film 101a during plasma cleaning. The first relationship data 221 may be, for example, an equation indicating the correlation between the pressure in the processing vessel 101 and the amount of damage, as shown in Fig. 4. The first relationship data 221 may also be table data storing the pressure in the processing vessel 101 for each amount of damage.

[0048] The second relationship data 222 is data indicating a relationship between the pressure in the processing vessel 101 and the cleaning rate during plasma cleaning. The second relationship data 222 may be, for example, an equation indicating the correlation between the pressure in the processing vessel 101 and the cleaning rate as shown in Fig. 5. The second relationship data 222 may also be table data storing the pressure in the processing vessel 101 for each cleaning rate.

[0049] The reception unit 201 displays various operation screens on the user interface 210 and receives various inputs. For example, the reception unit 201 receives input of the amount of damage to the protective film 101a and the cleaning rate, which are conditions for plasma cleaning. In this embodiment, the reception unit 201 receives input of the amount of damage to the protective film 101a and the cleaning rate, but is not limited to this. The amount of damage to the protective film 101a and the cleaning rate, which are conditions for plasma cleaning, may be included in plasma cleaning recipe data or may be received from another device.

[0050] The specifying unit 202 specifies the pressure inside the processing vessel 101 during plasma cleaning from the amount of damage to the protective film 101a and the cleaning rate, which are the conditions for the plasma cleaning. For example, the specifying unit 202 specifies a first pressure range that is equal to or less than the amount of damage, which is the condition for the plasma cleaning, from the first relationship data 221. The specifying unit 202 also specifies a second pressure range that is equal to or greater than the cleaning rate, which is the condition for the plasma cleaning, from the second relationship data 222. Then, the specifying unit 202 specifies an overlapping range in which the specified first pressure range and second pressure range overlap.

[0051] 6 is a graph showing an example of identifying the overlapping range. For example, the damage amount and cleaning rate of the protective film 101a, which are conditions for plasma cleaning, are set as a shown in FIG. 4, where the damage amount is a, and the cleaning rate is b shown in FIG. 5. The damage amount a is, for example, 20×10^12 atoms / cm 2 and if the cleaning rate is equal to or less than a, damage to the protective film 101a in the processing vessel 101 can be suppressed. The cleaning rate b is, for example, 200 nm / min, and if the cleaning rate is equal to or more than b, deposits in the processing vessel can be quickly removed (etched). The identifying unit 202 identifies, from the first relationship data 221, the pressure at which the amount of damage to the protective film 101a is equal to or less than the dashed line a. The identifying unit 202 also identifies, from the second relationship data 222, the pressure at which the cleaning rate of the deposits is equal to or more than the dashed line b. The identifying unit 202 then identifies, as an overlapping range, the pressure within the range AR surrounded by the dashed line a indicating the amount of damage and the dashed line b indicating the cleaning rate, from the pressure approximation curve obtained from the relationship between the amount of damage and the cleaning rate, as shown in FIG. 6.

[0052] The specifying unit 202 specifies the pressure in the processing vessel 101 during plasma cleaning from within the specified overlap range. For example, the specifying unit 202 specifies the pressure at the center of the overlap range as the pressure in the processing vessel 101 during plasma cleaning. The specifying unit 202 may specify any pressure in the overlap range as the pressure in the processing vessel 101 during plasma cleaning. In addition, when a setting is made to emphasize suppressing the amount of damage to the protective film 101a, the specifying unit 202 may specify a pressure in the overlap range that is higher than the center of the overlap range as the pressure in the processing vessel 101 during plasma cleaning. For example, the specifying unit 202 may specify the highest pressure in the overlap range as the pressure in the processing vessel 101 during plasma cleaning. In addition, when a setting is made to emphasize increasing the cleaning rate, the specifying unit 202 may specify a pressure in the overlap range that is lower than the center of the overlap range as the pressure in the processing vessel 101 during plasma cleaning. For example, the identifying unit 202 may identify the lowest pressure in the overlapping range as the pressure in the processing vessel 101 during plasma cleaning.

[0053] The specifying unit 202 stores the specified pressure inside the processing vessel 101 during the plasma cleaning in the cleaning setting data 223 as a set pressure for the plasma cleaning.

[0054] The cleaning control unit 203 adjusts the pressure inside the processing vessel 101 to the pressure specified by the specifying unit 202 while supplying the cleaning gas into the processing vessel 101, and generates plasma in the processing vessel 101 by microwaves to perform plasma cleaning inside the processing vessel 101. For example, the cleaning control unit 203 reads out the set pressure of the plasma cleaning from the cleaning setting data 223. The cleaning control unit 203 controls the exhaust device 104 to adjust the pressure inside the processing vessel 101 to the set pressure of the plasma cleaning. In addition, the cleaning control unit 203 controls the gas supply unit 127 to supply the cleaning gas from the gas supply unit 127 into the processing vessel 101. In addition, the cleaning control unit 203 controls the microwave introduction device 105 to radiate microwaves from the microwave introduction device 105 into the processing vessel 101. As a result, plasma of the cleaning gas is generated in the processing vessel 101, and plasma cleaning is performed.

[0055] The cleaning gas contains a halogen-based gas. For example, the cleaning gas contains any one of NF3, ClF3, SF6, and CF4. The cleaning gas may contain an inert gas. For example, the cleaning gas may contain at least one of N2, Ar, and He as an inert gas. The flow rate ratio of the cleaning gas to the inert gas is preferably 10:1 to 10:15.

[0056] The cleaning gas may be separately supplied from the gas introduction nozzles 123 and 124. For example, the cleaning control unit 203 controls the gas supply unit 127 to supply a halogen-based gas from the gas supply unit 127 to the gas supply pipe 125 and to supply an inert gas from the gas supply unit 127 to the gas supply pipe 126. Thus, the halogen-based gas is supplied from the gas introduction nozzle 123 at the upper part of the processing vessel 101 through the gas supply pipe 125 into the processing vessel 101. The inert gas is supplied from the gas introduction nozzle 124 at the side of the processing vessel 101 through the gas supply pipe 126 into the processing vessel 101. Note that the inert gas may be supplied from the gas supply unit 127 to the gas supply pipe 125 and then supplied from the gas introduction nozzle 123 at the upper part of the processing vessel 101 into the processing vessel 101. Alternatively, the halogen-based gas may be supplied from a gas supply unit 127 to a gas supply pipe 126 and then supplied into the processing vessel 101 through a gas introduction nozzle 124 on the side surface of the processing vessel 101 .

[0057] Furthermore, the cleaning control unit 203 may control the power of the microwave plasma radiated from the microwave radiation mechanism 143 of each antenna module by controlling the amplifier unit 142 of each antenna module during plasma cleaning. For example, the control unit 200 may control the microwave power ratio between the central part at the top of the processing vessel 101 and the peripheral part surrounding the central part within a range of 0:550 to 500:550, as necessary.

[0058] Next, a comparison result between the plasma cleaning of the embodiment in which the pressure inside the processing vessel 101 is set to the overlapping range pressure identified by the identification unit 202, for example, 60 Pa, and the plasma cleaning of the comparative example will be described. The plasma cleaning of the comparative example is a plasma cleaning in which the pressure inside the processing vessel 101 is alternately switched between two states, 20 Pa and 100 Pa.

[0059] FIG. 7 is a diagram showing an example of the cleaning time of the plasma cleaning according to the embodiment. FIG. 7 shows the cleaning time in one plasma cleaning and the change in the emission intensity of the plasma during the cleaning. The vertical axis of the graph in FIG. 7 is the emission intensity of the plasma, and the emission intensity increases toward the upper side. The horizontal axis of the graph is the cleaning time, which shows the time axis of the cleaning. The emission intensity of the plasma is detected by an optical sensor. The optical sensor may be disposed in the processing vessel 101 to detect the emission of the plasma. The optical sensor may be disposed outside the processing vessel 101 to detect the emission of the plasma through a transparent window provided in the processing vessel 101. FIG. 7 shows the change in the emission intensity of the plasma in the plasma cleaning of the embodiment in which the pressure in the processing vessel 101 is set to 60 Pa as "Example". FIG. 7 also shows the change in the emission intensity of the plasma in the plasma cleaning of the comparative example as "Comparative Example". In the comparative example, the emission intensity of the plasma shifts when the pressure in the processing vessel 101 is switched between 20 Pa and 100 Pa. In plasma cleaning, F (fluorine) contained in the plasma reacts with the SiN of the deposit to remove the deposit. When there are no more deposits in the processing vessel 101, F is no longer consumed, so F saturates and the emission intensity of the plasma also saturates. In plasma cleaning, the time until the emission intensity of the plasma saturates can be considered as the cleaning time. In both the example and the comparative example, the emission intensity of the plasma saturates around timing T1, so the cleaning times are about the same.

[0060] FIG. 8 is a diagram showing an example of the cleaning time and the thickness of the film removed in the plasma cleaning according to the embodiment. The vertical axis of the graph in FIG. 8 is the cleaning time, and the cleaning time is longer toward the top. The horizontal axis of the graph is the film thickness of the deposit removed during the cleaning time, and the film thickness is thicker toward the right. In FIG. 8, the change in the film thickness of the deposit removed when the cleaning time of the plasma cleaning according to the embodiment in which the pressure in the processing vessel 101 is set to 60 Pa is changed is shown as "Example". Also, in FIG. 8, the change in the film thickness of the deposit removed when the cleaning time of the plasma cleaning according to the comparative example is changed is shown as "Comparative Example". The example and the comparative example have the same change in the film thickness of the deposit removed with respect to the cleaning time. The example and the comparative example have the same slope of the change in the film thickness, and therefore have the same cleaning rate.

[0061] FIG. 9 is a diagram showing an example of the change in the amount of damage to the protective film 101a depending on the cleaning time of the plasma cleaning according to the embodiment. The vertical axis of the graph in FIG. 9 is the cumulative amount of damage Y to the protective film 101a, and the amount of damage Y increases toward the upper side. The horizontal axis of the graph is the cleaning time, and the cleaning time increases toward the right side. In FIG. 9, the amount of damage Y to the protective film 101a for each cleaning time of the plasma cleaning according to the embodiment in which the pressure inside the processing container 101 is set to 60 Pa is plotted, and a line connecting the plotted points is shown as "Example". In addition, in FIG. 9, the amount of damage Y to the protective film 101a for each cleaning time of the plasma cleaning according to the comparative example is plotted, and a line connecting the plotted points is shown as "Comparative Example". The amount of damage to the protective film 101a was determined by performing plasma cleaning with the substrate W placed on the upper surface of the mounting table 102, removing the substrate W at each cleaning time, and determining the amount of protective film components attached to the substrate W. In the embodiment, the amount of damage Y of the protective film 101a is smaller than that in the comparative example regardless of the cleaning time, and damage to the protective film 101a is suppressed.

[0062] Next, a change in damage to the protective film 101a when the plasma processing apparatus 100 periodically performs plasma cleaning will be described.

[0063] FIG. 10 is a diagram showing an example of a change in the number of particles depending on the number of substrates W on which films are formed according to the embodiment. The vertical axis of the graph in FIG. 10 is the number (number) of particles attached to the substrate W, and the number of particles increases toward the upper side. The horizontal axis of the graph is the number (number of substrates W on which films are formed) on which films are formed. In FIG. 10, the number of particles attached to the substrate W when the plasma cleaning according to the embodiment is periodically performed with the pressure in the processing vessel 101 set to 60 Pa is plotted, and a line connecting the plotted points is shown as "Example". In addition, in FIG. 10, the number of particles attached to the substrate W when the plasma cleaning according to the comparative example is periodically performed is plotted, and a line connecting the plotted points is shown as "Comparative Example". In the plasma processing apparatus 100, when the protective film 101a of the processing vessel 101 is damaged and worn away, and the inner surface of the processing vessel 101 is exposed, the number of particles attached to the substrate W increases. In the comparative example, the number of particles increases as the number of substrates W on which films are formed increases, and it can be inferred that damage to the protective film 101a gradually increases due to repeated plasma cleaning. On the other hand, in the example, the increase in the number of particles is suppressed compared to the comparative example, and it can be inferred that damage to the protective film 101a is suppressed even if plasma cleaning is repeated. The plasma processing apparatus 100 needs to perform maintenance such as part replacement before the number of particles adhering to the substrate W exceeds a predetermined allowable value. In the example, the increase in the number of particles is suppressed even if the number of substrates W increases compared to the comparative example, so that the number of substrates W on which films can be formed before maintenance can be increased, and productivity can be improved.

[0064] Next, a process performed by the plasma processing apparatus 100, including each step of the cleaning method according to the embodiment, will be described. First, a flow of a pressure setting process for setting the pressure of the plasma cleaning will be described. Fig. 11 is a flowchart showing an example of the flow of the pressure setting process according to the embodiment.

[0065] For example, the reception unit 201 displays an operation screen on the user interface 210 and receives input of the amount of damage to the protective film 101a and the cleaning rate, which are conditions for the plasma cleaning (S10). As described above, the amount of damage to the protective film 101a and the cleaning rate, which are conditions for the plasma cleaning, are not limited to this, and may be included in the recipe data for the plasma cleaning or may be received from another device.

[0066] The specifying unit 202 specifies the pressure in the processing vessel 101 during plasma cleaning from the amount of damage to the protective film 101a and the cleaning rate, which are the conditions for plasma cleaning (S11). For example, the specifying unit 202 specifies a first pressure range that is equal to or less than the amount of damage, which is the condition for plasma cleaning, from the first relation data 221. The specifying unit 202 also specifies a second pressure range that is equal to or more than the cleaning rate, which is the condition for plasma cleaning, from the second relation data 222. The specifying unit 202 specifies an overlapping range in which the specified first pressure range and the specified second pressure range overlap. The specifying unit 202 specifies the pressure in the processing vessel 101 during plasma cleaning from within the specified overlapping range. For example, the specifying unit 202 specifies the pressure in the middle of the overlapping range as the pressure in the processing vessel 101 during plasma cleaning.

[0067] The reception unit 201 determines whether the pressure for plasma cleaning has been identified by the identification unit 202 (S12). For example, if there is no overlapping range between the first pressure range and the second pressure range, it is determined that the pressure for plasma cleaning has not been identified. If the pressure for plasma cleaning cannot be identified (S12: No), the reception unit 201 displays on the user interface 210 that there is no pressure that satisfies the conditions for plasma cleaning (S13), and ends the process.

[0068] On the other hand, if the pressure for plasma cleaning can be identified (S12: Yes), the identification unit 202 stores the identified pressure inside the processing vessel 101 during the plasma cleaning as the set pressure for plasma cleaning in the cleaning setting data 223 (S14), and ends the process.

[0069] Next, the flow of the plasma cleaning process will be described. Fig. 12 is a flow chart showing an example of the flow of the cleaning process according to the embodiment. The cleaning process in Fig. 12 is performed at a timing when the plasma cleaning is performed periodically, such as every time a predetermined number of substrates W are formed with films or every time a film with a predetermined cumulative thickness is formed with films.

[0070] The cleaning control unit 203 determines whether it is time to perform plasma cleaning, such as every time a predetermined number of substrates W are formed or every time a film is formed to a predetermined cumulative thickness (S20). If it is time to perform plasma cleaning (S20: Yes), the cleaning control unit 203 adjusts the pressure inside the processing vessel 101 to the pressure specified by the specifying unit 202 while supplying cleaning gas into the processing vessel 101, generates plasma in the processing vessel 101 by microwaves, and performs plasma cleaning inside the processing vessel 101 (S21), and ends the process. For example, the cleaning control unit 203 reads the set pressure of plasma cleaning from the cleaning setting data 223. The cleaning control unit 203 controls the exhaust device 104 to adjust the pressure inside the processing vessel 101 to the set pressure of plasma cleaning. The cleaning control unit 203 also controls the gas supply unit 127 to supply cleaning gas from the gas supply unit 127 into the processing vessel 101. Furthermore, the cleaning control unit 203 controls the microwave introduction device 105 to radiate microwaves from the microwave introduction device 105 into the processing vessel 101. This generates plasma of the cleaning gas in the processing vessel 101, and plasma cleaning is performed. If it is not the timing to perform plasma cleaning (S20: No), the processing ends and the film formation process continues.

[0071] The cleaning time of the plasma cleaning may be set in advance. Alternatively, an optical sensor may be provided in the plasma processing apparatus 100, and the cleaning control unit 203 may detect the emission of plasma by the optical sensor and perform the plasma cleaning until the saturation of the emission intensity of the plasma is detected. The optical sensor may be disposed inside the processing vessel 101 and detect the emission of plasma. Alternatively, the optical sensor may be disposed outside the processing vessel 101 and detect the emission of plasma through a transparent window provided in the processing vessel 101.

[0072] As a result, the plasma processing apparatus 100 according to this embodiment can reduce damage to the inside of the processing container 101 caused by plasma cleaning, and can improve productivity.

[0073] In the above embodiment, the case where the specifying unit 202 specifies one pressure within the overlapping range, and the pressure in the processing vessel 101 is adjusted to the specified pressure in each plasma cleaning is described as an example. However, the present invention is not limited to this. The pressure in the processing vessel 101 may be changed within the overlapping range in each plasma cleaning. The specifying unit 202 may specify the pressure in the processing vessel 101 at the time of plasma cleaning to be high according to an increase in the number of times plasma cleaning has been performed. For example, the pressure in the processing vessel 101 at the time of plasma cleaning is gradually or stepwise increased according to an increase in the number of times plasma cleaning has been performed. The protective film 101a in the initial state is not damaged. Therefore, by setting the pressure in the processing vessel 101 at the time of plasma cleaning to a low pressure within the overlapping range, the cleaning time can be shortened. In addition, damage to the protective film 101a accumulates every time plasma cleaning is performed. Therefore, by gradually or stepwise increasing the pressure inside the processing vessel 101 during plasma cleaning within the overlap range as the number of times plasma cleaning is performed increases, the increase in damage accumulated in the protective film 101a can be suppressed and the generation of particles can be suppressed.

[0074] The cleaning control unit 203 may also monitor the cleaning amount during plasma cleaning and control the plasma cleaning according to the cleaning amount. For example, the cleaning control unit 203 detects plasma emission by an optical sensor and monitors the cleaning amount from the plasma emission intensity. Based on the change in the cleaning amount, the cleaning control unit 203 may control the microwave plasma power, the microwave plasma power ratio, the cleaning gas flow rate, and the cleaning gas flow rate ratio while maintaining the pressure inside the processing vessel 101 at a specific pressure.

[0075] In the above embodiment, the overlapping range is specified using the first relational data 221 and the second relational data 222, and the pressure in the processing vessel 101 during plasma cleaning is specified from the overlapping range. However, the present invention is not limited to this. For example, the specifying unit 202 may specify a pressure range of the processing vessel 101 in which plasma cleaning can be performed below the damage amount and above the cleaning rate by calculation or the like from the damage amount and cleaning rate that are the conditions of plasma cleaning. Also, for example, data that stores the pressure range of the processing vessel 101 in which plasma cleaning can be performed below the damage amount and above the cleaning rate for each damage amount and cleaning rate is stored in the storage unit 220. The specifying unit 202 may specify a pressure range corresponding to the damage amount and cleaning rate that are the conditions of plasma cleaning by referring to the data stored in the storage unit 220, and specify the pressure in the processing vessel 101 during plasma cleaning from the specified pressure range.

[0076] As described above, the cleaning method according to the embodiment includes a specifying step (S11) and a cleaning step (S20). In the specifying step, the pressure in the processing vessel 101 during the plasma cleaning is specified based on the amount of damage to the protective film 101a provided on the inner surface of the processing vessel 101 and the cleaning rate for removing deposits accumulated in the processing vessel 101, which are the conditions for the plasma cleaning. In the cleaning step, the pressure in the processing vessel 101 is adjusted to the pressure specified in the specifying step while supplying a cleaning gas into the processing vessel 101, and plasma is generated in the processing vessel 101 by microwaves to plasma clean the inside of the processing vessel 101. As a result, the cleaning method according to the embodiment can suppress damage to the inside of the processing vessel 101 due to the plasma cleaning and improve productivity.

[0077] The specifying step specifies a first pressure range that is equal to or less than the amount of damage set as a condition for plasma cleaning, from first relational data 221 indicating the relationship between the pressure in the processing vessel 101 during plasma cleaning and the amount of damage to the protective film 101a. The specifying step specifies a second pressure range that is equal to or more than the cleaning rate set as a condition for plasma cleaning, from second relational data 222 indicating the relationship between the pressure in the processing vessel 101 during plasma cleaning and the cleaning rate. The specifying step specifies the pressure in the processing vessel 101 during plasma cleaning from within an overlapping range where the specified first pressure range and second pressure range overlap. In this way, the cleaning method according to the embodiment can specify the pressure in the processing vessel 101 during plasma cleaning that satisfies the amount of damage and the cleaning rate set as the conditions for plasma cleaning.

[0078] Moreover, the specifying step specifies the pressure inside the processing vessel 101 within a range of 30 Pa to 60 Pa. As a result, the cleaning method according to the embodiment can reduce damage to the protective film 101a caused by plasma cleaning, compared to the plasma cleaning of the comparative example.

[0079] The cleaning gas includes a halogen-based gas. The cleaning gas includes any one of NF3, ClF3, SF6, and CF4. This allows the cleaning method according to the embodiment to remove silicon-containing deposits such as SiN.

[0080] The cleaning gas contains an inert gas. The inert gas contains at least one of N2, Ar, and He. The flow rate ratio of the cleaning gas to the inert gas is 10:1 to 10:15. As a result, the cleaning method according to the embodiment can stably generate plasma even in a high vacuum state with a relatively low pressure.

[0081] The processing vessel 101 further includes a plurality of microwave radiation mechanisms 143 in the central portion and in the peripheral portion surrounding the central portion, and the power ratio of the microwave plasma radiated from the microwave radiation mechanisms 143 in the central portion and the peripheral portion can be controlled. The plurality of microwave radiation mechanisms 143 can control the power ratio of the microwave plasma in the central portion and the peripheral portion in a range of 0:550 to 500:550. As a result, the cleaning method according to the embodiment can change the state of plasma in the central portion and the peripheral portion.

[0082] The cleaning gas includes a halogen-based gas and an inert gas. The processing vessel 101 has gas inlet holes (gas inlet nozzles 123, 124) in the upper portion and the sidewall portion, and the halogen-based gas is supplied from the gas inlet hole in the upper portion, and the inert gas is supplied from the gas inlet hole in the upper portion and / or the sidewall portion. In this way, the cleaning method according to the embodiment can change the region to be cleaned.

[0083] Moreover, the plasma processing apparatus 100 according to the embodiment includes a processing vessel 101, a gas supply unit (gas supply mechanism 103), an adjustment unit (exhaust device 104), an emission unit (microwave introduction device 105), a specifying unit 202, and a cleaning control unit 203. The processing vessel 101 has a protective film 101a on its inner surface. The gas supply unit supplies a cleaning gas into the processing vessel 101. The adjustment unit adjusts the pressure inside the processing vessel 101. The emission unit emits microwaves for generating plasma into the processing vessel 101. The specifying unit 202 specifies the pressure inside the processing vessel 101 during plasma cleaning based on the amount of damage to the protective film 101a and the cleaning rate for removing deposits accumulated inside the processing vessel 101, which are conditions for the plasma cleaning. The cleaning control unit 203 controls the adjustment unit to adjust the pressure in the processing vessel 101 to the pressure specified by the specification unit 202 while supplying a cleaning gas from the gas supply unit into the processing vessel 101, and controls the emission unit to emit microwaves to generate plasma in the processing vessel 101 and plasma clean the inside of the processing vessel 101. In this way, the plasma processing apparatus 100 according to the embodiment can specify the pressure in the processing vessel 101 during plasma cleaning that satisfies the amount of damage and cleaning rate that are set as the conditions for plasma cleaning.

[0084] Although the embodiments have been described above, the disclosed embodiments should be considered to be illustrative and not restrictive in all respects. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the claims.

[0085] For example, in the above embodiment, the substrate W is a semiconductor wafer, but the present invention is not limited to this. The substrate W may be any type.

[0086] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0087] 100 Plasma treatment device 101 Processing vessel 101a Protective film 102 Placement table 103 Gas supply mechanism 104 Exhaust system 105 Microwave introduction device 123, 124 Gas introduction nozzle 125, 126 Gas supply pipe 127 Gas Supply Section 130 Microwave output section 140 Antenna unit 142 Amplifier section 143 Microwave Radiation Mechanism 200 Control section 201 Reception 202 Specific section 203 Cleaning control section 210 User Interface 220 Storage section 221 First Related Data 222 Second Related Data 223 Cleaning setting data W substrate

Claims

1. a determining step of determining a pressure in the processing vessel during plasma cleaning based on a damage amount to a protective film provided on an inner surface of the processing vessel and a cleaning rate for removing deposits accumulated in the processing vessel, the conditions being set as plasma cleaning conditions; a cleaning process in which a pressure in the processing vessel is adjusted to the pressure specified in the specifying process while a cleaning gas is supplied into the processing vessel, and plasma is generated in the processing vessel by microwaves to perform plasma cleaning inside the processing vessel; having The specifying step specifies a first pressure range that is equal to or less than the amount of damage that is a condition for the plasma cleaning from first relationship data that indicates a relationship between the pressure in the processing vessel during plasma cleaning and the amount of damage to the protective film, specifies a second pressure range that is equal to or more than the cleaning rate that is a condition for the plasma cleaning from second relationship data that indicates a relationship between the pressure in the processing vessel during plasma cleaning and a cleaning rate, and specifies the pressure in the processing vessel during plasma cleaning from within an overlapping range in which the specified first pressure range and second pressure range overlap. Cleaning method:

2. A process for determining a pressure in the processing vessel during plasma cleaning based on a damage amount to a protective film provided on an inner surface of the processing vessel and a cleaning rate for removing deposits accumulated in the processing vessel, the conditions being set as conditions for plasma cleaning; a cleaning process in which a pressure in the processing vessel is adjusted to the pressure specified in the specifying process while a cleaning gas is supplied into the processing vessel, and plasma is generated in the processing vessel by microwaves to perform plasma cleaning inside the processing vessel; having The cleaning step includes monitoring the cleaning amount during plasma cleaning using a monitoring unit that monitors the cleaning amount, and based on a change in the cleaning amount, controlling the microwave plasma power, the microwave plasma power ratio, the cleaning gas flow rate, and the cleaning gas flow rate ratio while maintaining the pressure in the processing vessel at the pressure specified in the specifying step.

3. The specifying step specifies the pressure in the processing vessel within a range of 30 Pa to 60 Pa. The cleaning method according to claim 1 or 2.

4. The processing vessel includes a processing chamber in which a film formation process is performed on a substrate, The cleaning step is carried out every time a predetermined number of substrates are formed or every time a film having a predetermined cumulative thickness is formed; The specifying step specifies a pressure in the processing vessel during plasma cleaning to be high in accordance with an increase in the number of times the cleaning step has been performed. The cleaning method according to any one of claims 1 to 3.

5. The cleaning gas includes a halogen-based gas. The cleaning method according to any one of claims 1 to 4.

6. The cleaning gas is NF ３ , ClF ３ , S.F. ６ , C.F. ４ Contains any of the following The cleaning method according to any one of claims 1 to 5.

7. The cleaning gas comprises an inert gas, The inert gas includes at least one of N2, Ar, and He. The cleaning method according to any one of claims 1 to 6.

8. The flow rate ratio of the cleaning gas to the inert gas is 10:1 to 10:

15. The cleaning method according to claim 7.

9. The processing vessel is provided with a plurality of microwave radiation mechanisms in a central portion of the upper portion and in a peripheral portion surrounding the central portion, and the power ratio of the microwave plasma radiated from the microwave radiation mechanisms in the central portion and the peripheral portion can be controlled. The cleaning method according to any one of claims 1 to 8.

10. The microwave radiation mechanisms are capable of controlling the power ratio of the microwave plasma in the central portion and the peripheral portion in a range of 0:550 to 500:

550. The cleaning method according to claim 9.

11. The cleaning gas includes a halogen-based gas and an inert gas, The processing vessel has gas inlet holes in an upper portion and a sidewall portion, the halogen-based gas is supplied from the gas inlet hole in the upper portion, and the inert gas is supplied from the gas inlet hole in the upper portion and / or the sidewall portion. The cleaning method according to any one of claims 1 to 10.

12. The deposit is a silicon-containing material that is deposited in a processing vessel by performing a film formation process of a silicon-containing material on a substrate in the processing vessel. The cleaning method according to any one of claims 1 to 11.

13. The silicon-containing material is SiN, SiCN, SiON, SiOCN, SiC, or amorphous silicon. The cleaning method according to claim 12.

14. The protective film is Y ２ O ３ It is a membrane of The cleaning method according to any one of claims 1 to 13.

15. A processing vessel having a protective film provided on its inner surface; a gas supply unit for supplying a cleaning gas into the processing vessel; an adjusting unit for adjusting a pressure inside the processing vessel; a radiation unit that radiates microwaves for generating plasma into the processing vessel; a determination unit that determines a pressure in the processing vessel during plasma cleaning based on an amount of damage to the protective film and a cleaning rate for removing deposits deposited in the processing vessel, the conditions being set as plasma cleaning conditions; and a cleaning control unit that controls the pressure in the processing vessel to be adjusted to the pressure specified by the specifying unit by the adjusting unit while supplying a cleaning gas from the gas supply unit into the processing vessel, and controls the pressure in the processing vessel to be plasma cleaned by radiating microwaves from the radiating unit to generate plasma in the processing vessel; and having The specifying unit specifies a first pressure range that is equal to or less than the amount of damage that is a condition for the plasma cleaning from first relationship data that indicates a relationship between the pressure in the processing vessel during plasma cleaning and the amount of damage to the protective film, specifies a second pressure range that is equal to or greater than the cleaning rate that is a condition for the plasma cleaning from second relationship data that indicates a relationship between the pressure in the processing vessel during plasma cleaning and a cleaning rate, and specifies the pressure in the processing vessel during plasma cleaning from within an overlapping range in which the specified first pressure range and second pressure range overlap. Plasma processing equipment.

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