Plasma processing method and plasma processing apparatus

Abstract

To provide a plasma processing method and a plasma processing apparatus for detecting moisture.SOLUTION: A plasma processing method for executing predetermined plasma processing in a processing chamber, comprises: a step of acquiring a first emission intensity by executing plasma processing for a preset number of times and setting a threshold value for determining an amount of moisture contained in the processing chamber based on an emission intensity; and a step of determining the amount of moisture based on a second emission intensity in subsequent plasma processing and the threshold value. The step of setting the threshold value includes: Step S102 of exciting plasma of a processing gas in the processing chamber; Step S104 of acquiring the first emission intensity by receiving light in a specific wavelength region correlated with the amount of moisture in the processing chamber in an emission spectrum; Step S105 of recording a value of the first emission intensity; Steps S106 to S108 of calculating the threshold value from the first emission intensity for the preset number of times; and Step S109 of recording the threshold value.SELECTED DRAWING: Figure 8

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a plasma processing method for performing a predetermined plasma processing in a processing chamber, characterized in that the plasma processing comprises the steps of reducing the pressure inside the processing chamber, introducing a predetermined gas while evacuating the processing chamber, and exciting plasma of the gas, and receiving light in a specific wavelength range that is correlated with the amount of moisture inside the processing chamber from the emission spectrum of the plasma that passes through a monitor window provided in the processing chamber, to obtain the emission intensity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-147052 Summary of the Invention [Problem to be solved by the invention]

[0004] In one aspect, the present disclosure provides a plasma processing method and a plasma processing apparatus that detect moisture. [Means for solving the problem]

[0005] In order to solve the above problem, according to one aspect, there can be provided a plasma processing method for performing a predetermined plasma processing in a processing chamber, the plasma processing including the steps of: performing a predetermined number of plasma processing operations to obtain a first emission intensity; and setting a threshold for determining a moisture content in the processing chamber based on the obtained first emission intensity; and determining the moisture content based on a second emission intensity in plasma processing operations after the predetermined number of operations and the threshold, wherein the step of setting the threshold includes: (a) exciting plasma of a processing gas in the processing chamber; (b) receiving light in a specific wavelength region of the emission spectrum of the plasma that is correlated with the moisture content in the processing chamber to obtain the first emission intensity; (c) recording the value of the first emission intensity; (d) calculating the threshold from the first emission intensity for the predetermined number of operations; and (e) recording the threshold. [Effects of the Invention]

[0006] According to one aspect, a plasma processing method and a plasma processing apparatus for detecting moisture can be provided. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a vertical cross-sectional view showing an example of a first plasma processing apparatus. [Figure 2] FIG. 10 is a vertical cross-sectional view showing an example of a second plasma processing apparatus. [Figure 3] 1 is a graph showing an example of a plasma emission spectrum. [Figure 4] 1 is a graph showing an example of a plasma emission spectrum. [Figure 5] 1 is a graph showing an example of a plasma emission spectrum. [Figure 6] 1 is a graph showing an example of a plasma emission spectrum. [Figure 7] 1 is a graph showing an example of a plasma emission spectrum. [Figure 8] 10 is a flowchart showing an example of a process performed by a plasma processing apparatus. [Figure 9] 10 is a flowchart showing an example of a process performed by a plasma processing apparatus. [Figure 10] 10 is a flowchart showing an example of a process performed by a plasma processing apparatus. [Figure 11] FIG. 10 is a diagram showing an example of the moisture content of a substrate. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant explanations may be omitted.

[0009] [First plasma processing apparatus] A first plasma processing apparatus 100 (substrate processing system) will be described with reference to Fig. 1. Fig. 1 is a vertical cross-sectional view showing an example of the first plasma processing apparatus 100.

[0010] The plasma processing apparatus 100 shown in FIG. 1 is an inductively coupled plasma (ICP) processing apparatus that performs various substrate processing methods on a rectangular substrate G (hereinafter simply referred to as "substrate") for a flat panel display (hereinafter referred to as "FPD") in a planar view. The substrate is primarily made of glass, although transparent synthetic resin may also be used depending on the application. Substrate processing includes film formation using a chemical vapor deposition (CVD) method, etching, and the like. Examples of FPDs include liquid crystal displays (LCDs), electroluminescence (EL), and plasma display panels (PDPs). The substrate may be a substrate having a circuit patterned on its surface, as well as a supporting substrate. Furthermore, the planar dimensions of FPD substrates have become larger with each generation, and the planar dimensions of the substrate G processed by the plasma processing apparatus 100 range at least from approximately 1500 mm × 1800 mm for the sixth generation to approximately 3000 mm × 3400 mm for the 10.5th generation. The thickness of the substrate G is approximately 0.2 mm to several mm.

[0011] 1 includes a processing vessel 10 having a rectangular box shape, a substrate mounting table 60 having a rectangular outer shape in a plan view that is disposed in the processing vessel 10 and on which a substrate G is mounted, and a control unit 90. The processing vessel 10 may have any other shape, such as a cylindrical box or an elliptical cylindrical box. In this case, the substrate mounting table 60 also has a circular or elliptical shape, and the substrate mounted on the substrate mounting table 60 also has a circular or elliptical shape.

[0012] Processing vessel 10 is divided into two spaces, upper and lower, by metal window 11, with the upper space, antenna chamber A, being formed by upper chamber 12, and the lower space, processing chamber S, being formed by lower chamber 13. In processing vessel 10, a rectangular ring-shaped support frame 14 is disposed at the boundary between upper chamber 12 and lower chamber 13 so as to protrude into the inside of processing vessel 10, and metal window 11 is attached to support frame 14.

[0013] The upper chamber 12 forming the antenna chamber A is entirely made of a metal such as aluminum or an aluminum alloy. The lower chamber 13 having the processing chamber S therein is entirely made of a metal such as aluminum or an aluminum alloy. The processing vessel 10 is also grounded by a ground wire 13e.

[0014] The support frame 14 is made of a metal such as conductive aluminum or an aluminum alloy, and can also be called a metal frame.

[0015] A rectangular annular (endless) seal groove is formed at the upper end of the side wall 13a of the lower chamber 13, and a seal member 15 such as an O-ring is fitted into the seal groove, and the seal member 15 is held by the abutting surface of the support frame 14, thereby forming a seal structure between the lower chamber 13 and the support frame 14.

[0016] A loading / unloading port (not shown) is provided in a side wall 13a of the lower chamber 13 for loading / unloading the substrate G into / from the lower chamber 13, and the loading / unloading port is configured to be freely opened and closed by a gate valve (not shown). A transfer chamber (neither of which is shown) containing a transfer mechanism is adjacent to the lower chamber 13, and the substrate G is loaded / unloaded by the transfer mechanism through the loading / unloading port by controlling the opening and closing of the gate valve.

[0017] Furthermore, a plurality of exhaust ports 13d are provided in the bottom plate 13c of the lower chamber 13. In the lower chamber 13, the sidewall 13a of the processing vessel 10 that accommodates the substrate mounting table 60 is formed in a rectangular cylindrical shape. In other words, the processing vessel 10 has a rectangular horizontal cross section at least at the position of the lower chamber 13 that accommodates the substrate mounting table 60. Furthermore, the substrate mounting table 60 has a rectangular horizontal cross section when viewed from above. In other words, the substrate mounting table 60 has a rectangular horizontal cross section. A plurality of exhaust ports 13d are arranged on the bottom plate 13c of the processing vessel 10, surrounding the substrate mounting table 60. In other words, the exhaust ports 13d are arranged outside the substrate mounting table 60 and inside the sidewall 13a of the processing vessel 10 (lower chamber 13) when viewed from above.

[0018] Each exhaust port 13d is connected to an exhaust device 50. A pressure gauge (not shown) is installed at an appropriate position in the lower chamber 13, and information monitored by the pressure gauge is sent to the control unit 90.

[0019] The substrate mounting table 60 has a base material 61. An electrostatic chuck (not shown) on which the substrate G is directly placed may be formed on the upper surface of the base material 61.

[0020] The base material 61 has a rectangular shape in a plan view, and has planar dimensions similar to those of the substrate G placed on the substrate mounting table 60. The length of the long side of the base material 61 can be set to about 1800 mm to 3400 mm, and the length of the short side can be set to about 1500 mm to 3000 mm. With respect to these planar dimensions, the thickness of the base material 61 can be, for example, about 50 mm to 100 mm.

[0021] The base material 61 is also provided with a meandering heating resistor (not shown) that covers the entire area of ​​the rectangular plane, and a temperature control medium flow path (not shown). The temperature control medium flow path may be provided on a temperature control plate that is a separate component separated from the base material 61. The heating resistor is also connected to a control unit and a power supply unit (neither of which are shown) that are installed outside the processing chamber 10 via a power supply line (not shown).

[0022] A box-shaped pedestal 62 made of an insulating material and having a step on the inside is fixed on the bottom plate 13c of the lower chamber 13, and the substrate mounting table 60 is placed on the step of the pedestal 62.

[0023] A power supply line 71 is connected to the base of the substrate mounting table 60, and the power supply line 71 is connected to a high-frequency power supply 73, which serves as a bias power supply, via a matcher 72 that performs impedance matching. When high-frequency power, for example, 3.2 MHz, is applied to the substrate mounting table 60 from the high-frequency power supply 73, an RF bias is generated. Ions generated by the high-frequency power supply 44, which serves as a plasma generation source (described below), are attracted to the substrate G, allowing, for example, film formation processing to be performed on the substrate G. In this manner, the substrate mounting table 60 forms a bias electrode that supports the substrate G and generates an RF bias. At this time, a portion of the lower chamber 13 that is at ground potential functions as a counter electrode to the bias electrode and constitutes a return circuit for the high-frequency power. The metal window 11 may also be configured as part of the return circuit for the high-frequency power.

[0024] The metal window 11 is formed by a plurality of divided metal windows 20. The number of divided metal windows 20 that form the metal window 11 can be set to various numbers, such as 12 or 24.

[0025] The divided metal window 20 also serves as a process gas outlet that discharges process gas into the process chamber S. The divided metal window 20 is made of a non-magnetic, electrically conductive, corrosion-resistant metal or a metal that has been subjected to a corrosion-resistant surface treatment, such as aluminum, an aluminum alloy, or stainless steel. Examples of the corrosion-resistant surface treatment include anodizing and ceramic spraying. The exposed surface of the divided metal window 20 facing the process chamber S may also be subjected to a plasma-resistant coating by anodizing or ceramic spraying. The divided metal window 20 is grounded via a ground wire (not shown).

[0026] Each divided metal window 20 constituting the metal window 11 is suspended from the top plate of the upper chamber 12 by a plurality of suspenders (not shown). A spacer (not shown) made of an insulating material is disposed above each divided metal window 20, and a radio-frequency antenna (inductively coupled antenna) 41 is disposed at a distance from the divided metal window 20 by the spacer. The radio-frequency antenna 41 contributes to plasma generation and is formed by winding an antenna wire made of a highly conductive metal such as copper in a circular or spiral shape. For example, multiple circular antenna wires may be disposed. The radio-frequency antenna 41 is disposed on the top surface of the divided metal window 20, and is therefore suspended from the top plate of the processing vessel 10 via the divided metal window 20. The radio-frequency antenna 41 is disposed in an antenna chamber A of the upper chamber 12, above the processing vessel 10.

[0027] The divided metal window 20 has a gas diffusion groove 21 formed therein, and a through-hole that connects the gas diffusion groove 21 to the upper end surface is provided therein. A gas introduction pipe 35 is embedded in this through-hole. The divided metal window 20 has a plurality of gas discharge holes 22 that connect the gas diffusion groove 21 to the processing chamber S.

[0028] Each divided metal window 20 is electrically insulated from the support frame 14 and the adjacent divided metal window 20 by an insulating member 25. Here, the insulating member 25 is made of a fluororesin such as PTFE (Polytetrafluoroethylene). A ceramic cover member (not shown) may be provided to cover the end face of the insulating member 25 on the processing chamber S side. This protects the insulating member 25 from plasma.

[0029] A power feeder 42 is connected to the high frequency antenna 41, and the power feeder 42 is connected to a high frequency power supply 44 via a matching box 43 that performs impedance matching.

[0030] When high frequency power, for example, 13.56 MHz, is applied to the high frequency antenna 41 from the high frequency power supply 44, an inductive electric field is formed in the lower chamber 13. This inductive electric field converts the processing gas supplied to the processing chamber S through the divided metal window 20 into plasma, generating inductively coupled plasma, and ions in the plasma are supplied to the substrate G.

[0031] The high frequency power supply 44 is a source for generating plasma, and the high frequency power supply 73 connected to the substrate mounting table 60 is a bias source that attracts the generated ions and imparts kinetic energy to them. In this way, the ion source generates plasma using inductive coupling, and a bias source, which is a separate power supply, is connected to the substrate mounting table 60 to control the ion energy, thereby independently generating plasma and controlling the ion energy, thereby increasing the degree of freedom in the process.

[0032] As shown in Figure 1, the gas introduction pipes 35 of each divided metal window 20 are connected to process gas supply sources 31, 32, and 33 via gas supply pipes 34 that are airtightly joined. The process gas supply source 31 supplies a cleaning gas as the process gas. The process gas supply source 32 supplies a seasoning gas as the process gas. The process gas supply source 33 supplies process gases as the process gas and pre-coating gas.

[0033] In plasma processing, processing gas is supplied from the processing gas supply unit 30 via the gas supply pipe 34 and the gas introduction pipe 35 to the gas diffusion grooves 21 of each divided metal window 20. Then, the processing gas is discharged from each gas diffusion groove 21 through the gas discharge holes 22 into the processing chamber S.

[0034] As described above, the plasma processing apparatus 100 includes a plasma generating unit that generates processing plasma for performing substrate processing (film formation processing, etching processing, etc.) on the substrate G. The plasma generating unit includes at least a metal window 11 and a high-frequency antenna 41. A high-frequency power supply 44 supplies high-frequency power to the high-frequency antenna 41, and a processing gas supply unit 30 supplies processing gas to the processing chamber S through the divided metal window 20 (processing gas discharge unit). The plasma generating unit forms an induction electric field within the processing chamber S, and generates plasma of the processing gas supplied into the processing chamber S by this induction electric field.

[0035] The control unit 90 controls the operation of each component of the plasma processing apparatus 100. The control unit 90 also has user interfaces such as input devices such as a keyboard and a mouse for inputting commands, a display device such as a display for visualizing and displaying the operating status of the plasma processing apparatus 100, and an output device such as a printer.

[0036] In addition, the control unit 90 is connected to a memory unit 91 that stores programs for realizing various processes performed in the plasma processing device 100 under the control of the control unit 90, as well as recipe data required to execute the programs.

[0037] The storage unit 91 stores, for example, a plurality of process recipes for executing process processing of substrates or wafers. The recipes contain control information for the plasma processing apparatus 100 relative to process conditions. The control information includes, for example, the gas flow rate, the pressure inside the processing vessel 10, the temperature inside the processing vessel 10, the temperature of the substrate 61, and the process time. The storage unit 91 also stores, for example, the emission intensity, the maximum emission intensity value, and a threshold value, which will be described later.

[0038] Here, moisture in the processing chamber S may affect the quality of the film formed on the substrate G by the plasma processing apparatus 100. In particular, when a semiconductor device using an oxide semiconductor is formed on the substrate G, the transistor characteristics vary significantly due to the influence of hydrogen and trace amounts of moisture in the film. The plasma processing apparatus 100 is equipped with a moisture detection unit that detects moisture in the processing chamber S. The moisture detection unit has a light receiving unit 200, an optical fiber 210, and a plasma emission monitor 220.

[0039] A transmission window 13b is provided on the side wall 13a of the lower chamber 13 to keep the processing chamber S of the processing vessel 10 airtight and to allow light of plasma generated in the processing chamber S to pass through. The transmission window 13b is made of a material such as quartz. A light receiving unit 200 that detects the plasma light is provided on the outside of the transmission window 13b. The light receiving unit 200 is installed so as to capture an image of the substrate G placed on the substrate mounting table 60 from the side in a horizontal direction through the transmission window 13b.

[0040] The plasma light incident on light receiving unit 200 is input to plasma emission monitor 220 via optical fiber 210. Plasma emission monitor 220 acquires an emission spectrum in a wavelength range of, for example, 200 nm to 800 nm. Plasma emission monitor 220 then detects the emission intensity for each wavelength (resolution of the wavelength range).

[0041] Here, if there are water molecules in the processing chamber S of the processing vessel 10, the water molecules are dissociated into H radicals and OH radicals by the plasma generated in the processing chamber S. The greater the amount of moisture in the processing chamber S, the more OH radicals are dissociated, and the intensity (emission intensity) of the emission spectrum at a wavelength corresponding to the OH radicals (for example, around 306 nm) becomes higher. In this way, the plasma emission monitor 220 can detect the amount of moisture in the processing chamber S based on the emission intensity at a wavelength corresponding to the OH radicals (specifically, a wavelength between 305 nm and 310 nm).

[0042] The inflow of water molecules into the processing chamber S includes water that flows into the processing chamber S from the outside (atmosphere) due to a leak in the processing chamber S, water that remains in the processing chamber S after the processing chamber S is opened to the atmosphere for maintenance, water that is adsorbed onto the substrate G transported into the processing chamber S, etc.

[0043] An example of the occurrence of leaks will now be described. The seal members may thermally expand and deform due to heat input from plasma during processing or radiant heat input from the substrate mounting table 60, causing the seal members to become misaligned or the amount of sealing to be insufficient, resulting in leaks. The seal members include a seal member 15 between the side wall 13a of the lower chamber 13 and the support frame 14, a seal member (not shown) between the metal window 11 and the insulating member 25, a seal member (not shown) between the bottom surface of the substrate mounting table 60 and the step portion of the pedestal 62, and a seal member 16 between the bottom surface of the pedestal 62 and the bottom plate 13c of the lower chamber 13.

[0044] In addition, a plurality of lift pins 80 are arranged on the substrate mounting table 60, which rise from the mounting surface to lift up the substrate G. The lift pins 80 are connected to pin holders 81, which are guided by pin guides 82. The pin holders 81 are connected to a drive unit (not shown), and are capable of being inserted vertically into through-holes formed in the bottom plate 13c of the lower chamber 13, intersecting perpendicularly with the bottom plate 13c. Bellows 83 are provided between one end face of the pin guide 82 and the flange surface of the pin holder 81, and sealing members (not shown) are included between the base material 61 and the pin guide 82, between the pin guide 82 and the bellows 83, and between the bellows 83 and the pin holder 81, respectively, to provide an airtight connection. The substrate mounting table 60 thermally expands due to heat input from the plasma during processing or temperature control of the substrate mounting table 60, and the lift pins 80 and pin holders 81 guided by the pin guides 82 move together with the substrate mounting table 60, causing friction on the bellows 83 and possibly causing leakage in the bellows 83.

[0045] [Second plasma processing apparatus] The second plasma processing apparatus 101 (substrate processing system) will be described with reference to Fig. 2. Fig. 2 is a vertical cross-sectional view showing an example of the second plasma processing apparatus 101.

[0046] So far, we have described a plasma processing apparatus 100 (see FIG. 1) that includes a heating resistor and a temperature control medium flow path and has a seal member between the bottom surface of the substrate mounting table 60 that forms a bias electrode and the step portion of the pedestal 62, and between the bottom surface of the pedestal 62 and the bottom plate 13c of the lower chamber 13. The configuration of the plasma processing apparatus is not limited to this. It may also be applied to a plasma processing apparatus 101 that includes a heating resistor, does not include a temperature control medium flow path, and has a substrate mounting table 160 that does not form a bias electrode, and does not have a seal member on the pedestal 162. Note that parts not specifically described have the same configuration as the plasma processing apparatus 100.

[0047] The plasma processing apparatus 101 includes a processing vessel 110 having a rectangular box shape, a substrate mounting table 160 having a rectangular outer shape in a plan view that is disposed in the processing vessel 110 and on which a substrate G is mounted, and a control unit 90. The processing vessel 110 may have a shape such as a cylindrical box or an elliptical cylindrical box, and in this configuration, the substrate mounting table 160 also has a circular or elliptical shape, and the substrate mounted on the substrate mounting table 160 also has a circular or elliptical shape.

[0048] The configuration of the upper chamber 12 of the processing vessel 110 is the same as that shown in Figure 1. A rectangular annular (endless) seal groove is formed at the upper end of the side wall 113a of the lower chamber 113 of the processing vessel 110, and a seal member 115 such as an O-ring is fitted into the seal groove. The seal member 115 is held by the abutting surface of the support frame 14, thereby forming a seal structure between the lower chamber 113 and the support frame 14.

[0049] A loading / unloading port (not shown) is provided in a sidewall 113a of the lower chamber 113 for loading / unloading the substrate G into / from the lower chamber 113, and the loading / unloading port is configured to be freely opened and closed by a gate valve (not shown). A transfer chamber (neither of which is shown) containing a transfer mechanism is adjacent to the lower chamber 113, and the gate valve is controlled to open and close, and the substrate G is loaded / unloaded by the transfer mechanism through the loading / unloading port.

[0050] Furthermore, a plurality of exhaust ports 113d are provided in a bottom plate 113c of the lower chamber 113. In the lower chamber 113, a sidewall 113a of the processing vessel 110 that accommodates the substrate mounting table 160 is formed in a rectangular cylindrical shape. In other words, the processing vessel 110 has a rectangular horizontal cross section at least at the position of the lower chamber 113 that accommodates the substrate mounting table 160. Furthermore, the substrate mounting table 160 has a rectangular shape when viewed from above in a plan view. In other words, the substrate mounting table 160 has a rectangular horizontal cross section. A plurality of exhaust ports 113d are arranged on the bottom plate 113c of the processing vessel 110 to surround the substrate mounting table 160. In other words, the exhaust ports 113d are arranged outside the substrate mounting table 160 and inside the sidewall 113a of the processing vessel 110 (lower chamber 113) in a plan view.

[0051] The substrate mounting table 160 has a base 161a and a stem portion 161b. The stem portion 161b is formed in a cylindrical shape, and one end is airtightly joined to the base 161a by welding or the like. The other end of the stem portion 161b may have a flange shape. One end of the bellows 184 has a flange shape, and a seal member (not shown) such as an O-ring is held between the flange and the bottom plate 113c of the lower chamber 113, thereby forming a seal structure between the bellows 184 and the lower chamber 113. A circular annular (endless) seal groove is formed on the other flange surface of the bellows 184, and a seal member 116 such as an O-ring is fitted into the seal groove, and the abutting surface of the other end of the stem portion 161b is held, thereby forming a seal structure between the substrate mounting table 160 and the bellows 184.

[0052] The base material 161a has a rectangular shape in a plan view, and has planar dimensions similar to those of the substrate G placed on the substrate placement table 160. The length of the long side of the base material 161a can be set to approximately 1800 mm to 3400 mm, and the length of the short side can be set to approximately 1500 mm to 3000 mm. For these planar dimensions, the thickness of the base material 161a can be, for example, approximately 50 mm to 100 mm. The diameter of the stem portion 161b can be set to approximately 100 mm to 400 mm, and the length can be set to approximately 500 mm to 1000 mm.

[0053] Furthermore, a plurality of resistance heating elements HTa, HTb, such as sheath heaters, are arranged on the base 161a, serpentine to cover the entire area of ​​the rectangular plane. Power feed lines 171a, 171b are connected to the resistance heating elements HTa, HTb, respectively, and pass through the cylindrical internal space of the stem portion 161b. The power feed lines 171a, 171b are connected to a power source 173, which serves as a heater power source, via a control unit 172 that performs ON / OFF control. Temperature monitor information from a plurality of thermocouples (not shown) inside the base 161a arranged near the resistance heating elements HTa, HTb is sent to the control unit 172, which controls ON / OFF switching to maintain the temperature of the base 161a at a set temperature, raise or lower the temperature of the substrate G placed on the substrate mounting table 160, and control the film formation temperature.

[0054] An example of leakage in the plasma processing apparatus 101 (see FIG. 2) will be described. The sealing member may thermally expand and deform due to heat input from the plasma during processing or radiant heat input from the substrate mounting table 160, causing the sealing member to become misaligned or the amount of sealing to be insufficient, resulting in leakage. The sealing members include a sealing member 115 between the sidewall 113a of the lower chamber 113 and the support frame 14, a sealing member (not shown) between the metal window 11 and the insulating member 25, and a sealing member 116 between the other end of the stem portion 161b of the substrate mounting table 160 and the other end face of the bellows 184.

[0055] In addition, a plurality of lift pins 180 are arranged on the substrate mounting surface of the substrate mounting table 160 to lift up the substrate G. The lift pins 180 are connected to pin holders 181 guided by pin guides 182. The pin holders 181 are connected to a drive unit (not shown) and are capable of passing through through holes formed in a bottom plate 113c of the lower chamber 113 so as to intersect perpendicularly with the bottom plate 113c, i.e., in the vertical direction. Bellows 183 are provided between the bottom plate 113c and the flange surface of the pin holder 181, and bellows 184 are provided between the bottom plate 113c and the other end of the stem portion 161b. Sealing members (not shown) are provided between the bottom plate 113c and the bellows 183 and between the bellows 183 and the pin holder 181, respectively, to provide an airtight connection.

[0056] The substrate mounting table 160 thermally expands due to heat input from the plasma during processing or temperature control of the substrate mounting table 160, and the lift pins 180 and pin holders 181 guided by the pin guides 182 move together with the substrate mounting table 160, causing friction on the bellows 183 and possibly causing leakage in the bellows 183.

[0057] Similarly, thermal expansion of the substrate mounting table 160 causes the other end of the stem portion 161b to move toward the sealing member 116 (downward in FIG. 2), which may cause flying debris, such as by-products from the process, to get caught in the expanded portion of the bellows 184, creating a tiny hole and resulting in a leak.

[0058] [Plasma emission spectrum] Next, an example of a plasma emission spectrum detected by plasma emission monitor 220 will be described with reference to FIGS.

[0059] 3 and 4 are graphs showing an example of a plasma emission spectrum. Here, a process for determining whether moisture is present in the processing vessel 10 (110) during a cleaning process or seasoning process using plasma of O2 gas or NF3 gas will be described as an example. In the cleaning process or seasoning process (moisture detection process), O2 gas and a rare gas (Ar, He, etc.) or only NF3 gas is supplied into the processing vessel 10 (110) as processing gases, and plasma is generated in the processing vessel 10 (110). This process is performed, for example, during idle time before a film formation process, with no substrate G placed on the substrate mounting table 60 (160) or with either raw glass or a dummy substrate placed on the substrate mounting table 60 (160).

[0060] Fig. 3(a) is a graph showing an example of a plasma emission spectrum using O2 gas under normal conditions. Fig. 3(b) is a graph showing an example of a plasma emission spectrum using O2 gas under abnormal conditions. Fig. 4(a) is a graph showing an example of a plasma emission spectrum using NF3 gas under normal conditions. Fig. 4(b) is a graph showing an example of a plasma emission spectrum using NF3 gas under abnormal conditions.

[0061] Here, under normal conditions (no leaks, etc.), as shown in FIG. 3(a) or FIG. 4(a), no peak in emission intensity appears at the wavelength corresponding to OH radicals (wavelength region indicated by the dashed line frame). This indicates that no moisture is detected (sufficiently little) in the processing chamber S. In other words, this indicates that no leaks have occurred in the processing vessel 10 (110).

[0062] In contrast, when an abnormality occurs (such as when there is a leak), a peak in the emission intensity appears at the wavelength corresponding to OH radicals (the wavelength region indicated by the dashed frame) as shown in Figure 3(b) or Figure 4(b), which indicates that moisture has been detected in the processing chamber S.

[0063] FIG. 5 is a graph showing an example of a plasma emission spectrum. Here, the case of forming a silicon oxide film (SiO film) on a substrate G will be described as an example. The same applies to a case where a dummy substrate is placed on the substrate mounting table 60 (160) and a seasoning process is performed, or a case where a pre-coating process is performed without placing a substrate on the mounting table. In the silicon oxide film formation process, a source gas and a reactive gas (gas containing oxygen atoms) that reacts with the source gas are supplied into the processing vessel 10 (110) as process gases, and plasma is generated in the processing vessel 10 (110). This results in film formation by plasma CVD. The source gas used is a gas containing silicon (Si) but not hydrogen atoms (H). Specifically, silicon halide gas (SiF4, SiCl4) can be used. The reactive gas used is a gas containing oxygen atoms (O) but not hydrogen atoms (H). Specifically, O2 gas can be used as the reactive gas. This process is performed during a film formation process, for example, with the substrate G, which is the product substrate, placed on the substrate placement table 60 (160).

[0064] 5(a) is a graph showing an example of a plasma emission spectrum under normal conditions, and FIG. 5(b) is a graph showing an example of a plasma emission spectrum under abnormal conditions.

[0065] Here, under normal conditions (no leakage, etc.), as shown in Figure 5(a), no peak in emission intensity appears at the wavelength corresponding to OH radicals (wavelength region indicated by the dashed line frame), which indicates that no moisture is detected (sufficiently little) in the processing chamber S.

[0066] In contrast, when an abnormality occurs (such as when there is a leak), as shown in Figure 5(b), a peak in the emission intensity appears at the wavelength corresponding to OH radicals (the wavelength region indicated by the dashed frame), which indicates that moisture has been detected in the processing chamber S.

[0067] FIG. 6 is a graph showing an example of a plasma emission spectrum. Here, the case of forming a silicon nitride film (SiN film) on a substrate G will be described as an example. The same applies to a case where a dummy substrate is placed on the substrate mounting table 60 (160) and a seasoning process is performed, or a case where a pre-coating process is performed without placing a substrate on the mounting table. In the silicon nitride film formation process, a source gas and a reactive gas (gas containing nitrogen atoms) that reacts with the source gas are supplied into the processing vessel 10 (110) as process gases, and plasma is generated in the processing vessel 10 (110). This results in film formation by plasma CVD. The source gas used is a gas containing silicon (Si) but not hydrogen atoms (H). Specifically, silicon halide gas (SiF4, SiCl4) can be used. The reactive gas used is a gas containing nitrogen atoms (N) but not hydrogen atoms (H). Specifically, N2 gas can be used as the reactive gas. This process is performed during a film formation process, for example, with the substrate G, which is the product substrate, placed on the substrate placement table 60 (160).

[0068] 6(a) is a graph showing an example of a plasma emission spectrum under normal conditions, and FIG. 6(b) is a graph showing an example of a plasma emission spectrum under abnormal conditions.

[0069] Here, under normal conditions (no leakage, etc.), as shown in Figure 6(a), no peak in emission intensity appears at the wavelength corresponding to OH radicals (wavelength region indicated by the dashed line frame), which indicates that no moisture is detected (sufficiently little) in the processing chamber S.

[0070] In contrast, when an abnormality occurs (such as when there is a leak), as shown in Figure 6(b), a peak in the emission intensity appears at the wavelength corresponding to OH radicals (the wavelength region indicated by the dashed frame), which indicates that moisture has been detected in the processing chamber S.

[0071] FIG. 7 is a graph showing an example of a plasma emission spectrum. Here, an example of forming a silicon oxide film (SiOx film) on a substrate G will be described. FIG. 7(a) illustrates an example in which SiH4, a gas containing hydrogen atoms (H), is used as the source gas, and NO is used as the reactive gas. FIG. 7(b) illustrates an example in which SiF4, a gas not containing hydrogen atoms (H), is used as the source gas, and O2 is used as the reactive gas.

[0072] As shown in Figure 7(a), when a gas containing hydrogen atoms (H) is used, even under normal conditions (no leaks, etc.), overlapping emission intensity peaks are detected near the wavelength corresponding to OH radicals (wavelength region indicated by the dashed frame), making it difficult to detect moisture.

[0073] In contrast, as shown in Figure 7(b), by using gases (SiF4, O2) that do not contain hydrogen atoms (H) as the raw material gas and the reactive gas, it becomes easier to detect the peak of the emission intensity at the wavelength corresponding to the OH radical (the wavelength region indicated by the dashed frame).

[0074] As described above, moisture can be detected by generating O2 plasma before the film formation process and detecting the plasma light, as shown in Figure 3. Also, as shown in Figures 5 to 7, moisture can be detected during the process by using a gas that does not contain hydrogen atoms (H) as the film formation process gas (raw material gas, reactive gas), generating plasma, and detecting the plasma light.

[0075] The combination of process gases is not limited to those described above with reference to Figures 3 to 6. The process gas for generating plasma need not contain both hydrogen atoms (H) and oxygen atoms (O) at the same time.

[0076] The processing gas used during the idle period before the process is a combination (first combination) of a gas containing oxygen atoms (O) or a gas containing nitrogen atoms (N) and a rare gas, or a single gas containing fluorine atoms (F), and this combination or single gas processing gas does not contain hydrogen atoms (H).

[0077] When hydrogen atoms (H) are not contained, gases containing oxygen atoms (O) such as O2 and NO can be used. Gases containing nitrogen atoms (N) such as N2 and NO can be used. Rare gases such as Ar and He can be used. A single gas containing fluorine atoms (F) can be NF3.

[0078] In addition, the process gas used in the process of forming a silicon oxide film is a combination (second combination) of a raw material gas containing silicon atoms (Si) and a gas containing oxygen atoms (O), and this combination of process gas does not contain hydrogen atoms (H).

[0079] When hydrogen atoms (H) are not contained, the source gas containing silicon atoms (Si) can be any of silicon halide gases (SiF, SiCl), etc. The gas containing oxygen atoms (O) can be any of O, NO, etc.

[0080] In addition, the process gas used in the process of forming a silicon nitride film is a combination (second combination) of a raw material gas containing silicon atoms (Si) and a gas containing nitrogen atoms (N), and this combination of process gas does not contain at least one of hydrogen atoms (H) and oxygen atoms (O).

[0081] When hydrogen atoms (H) are not contained, the source gas containing silicon atoms (Si) can be any of silicon halide gases (SiF, SiCl), etc. The gas containing nitrogen atoms (N) can be any of N, NO, etc.

[0082] When oxygen atoms (O) are not contained, the source gas containing silicon atoms (Si) can be any of silicon halide gases (SiF4, SiCl4) or SiH4, etc. The gas containing nitrogen atoms (N) can be any of N2, NH3, etc.

[0083] [Plasma treatment method] Next, a plasma processing method of the plasma processing apparatus 100 (101) will be described with reference to FIGS.

[0084] [How to set the threshold] Fig. 8 is a flowchart showing an example of processing of the plasma processing apparatus. In the processing shown in the flowchart of Fig. 8, the first emission intensity is acquired a preset number of times (number of samplings), and a threshold value for determining the amount of moisture contained in the processing chamber S is set.

[0085] In step S101, the substrate G is loaded into the processing chamber S. Here, the control unit 90 controls a substrate transfer device (not shown) to transfer the substrate G into the processing chamber S and place the substrate G on the substrate mounting table 60 (160). Note that the substrate G may be either raw glass, a dummy substrate, or a product substrate, depending on the plasma processing in step S102 (described later). Furthermore, if the plasma processing in step S102 (described later) is a plasma processing performed without placing the substrate G on the substrate mounting table 60 (160), step S101 may be omitted.

[0086] In step S102, plasma processing is performed. Here, the control unit 90 controls the exhaust device 50 to reduce the pressure inside the processing chamber S, and while exhausting the processing chamber S, controls the processing gas supply unit 30 to introduce the processing gas into the processing chamber S, and controls the high-frequency power supply 44 to supply high-frequency power to the high-frequency antenna 41, thereby exciting plasma of the processing gas inside the processing chamber S. The plasma processing may be processing on the substrate G (such as a film formation process) or processing on the processing vessel 10 (110) (such as a seasoning process, cleaning process, or pre-coating process).

[0087] In step S103, light in the specific wavelength region is received. Here, during the plasma processing (S102), plasma light including the specific wavelength region corresponding to OH radicals is received by light receiving unit 200 through transmission window 13b.

[0088] In step S104, the emission intensity in a specific wavelength region corresponding to OH radicals is acquired. Here, plasma emission monitor 220 acquires a first emission intensity in a specific wavelength region corresponding to OH radicals. When the plasma processing is completed, the process in control unit 90 proceeds to step S105.

[0089] In step S105, the control unit 90 records the maximum value of the first emission intensity in the specific wavelength region corresponding to the OH radicals in the plasma processing (S102) in the storage unit 91.

[0090] In step S106, it is determined whether or not the predetermined number of samplings has been repeated. Preferably, the predetermined number of samplings is at least five. If the predetermined number of samplings has not been repeated (S106: NO), the process by the control unit 90 returns to step S101. If the predetermined number of samplings has been repeated (S106: YES), the process by the control unit 90 proceeds to step S107. As a result, the maximum value of the first emission intensity in the specific wavelength range corresponding to OH radicals in the plasma processing (S102) for the predetermined number of samplings is stored in the memory unit 91.

[0091] Thereafter, a threshold value is calculated from the maximum value of the first emission intensity in the specific wavelength range corresponding to the OH radical in the plasma processing (S102) of a predetermined number of samples stored in the storage unit 91.

[0092] In step S107, the control unit 90 calculates the average value of the maximum values ​​of the first emission intensity in the specific wavelength range corresponding to the predetermined sampled number of OH radicals stored in the storage unit 91.

[0093] In step S108, the control unit 90 registers in the storage unit 91 the average value of the maximum values ​​calculated in step S107.

[0094] In step S109, the control unit 90 calculates a threshold value by multiplying the average value of the maximum values ​​calculated in step S107 by a predetermined tolerance rate, and registers the calculated threshold value in the storage unit 91. Here, the tolerance rate is a value of 1 or more.

[0095] [How to determine moisture content] Fig. 9 is a flowchart showing an example of a process performed by the plasma processing apparatus. The process shown in the flowchart of Fig. 9 is a process for determining the amount of moisture in the processing chamber S based on the threshold value set by the process shown in Fig. 8.

[0096] In step S201, the substrate G is loaded into the processing chamber S. Here, the control unit 90 controls a substrate transfer device (not shown) to transfer the substrate G into the processing chamber S and place the substrate G on the substrate mounting table 60 (160). Note that the substrate G may be either raw glass, a dummy substrate, or a product substrate, depending on the plasma processing in step S202 (described later). Furthermore, if the plasma processing in step S202 (described later) is a plasma processing performed without placing the substrate G on the substrate mounting table 60 (160), step S201 may be omitted.

[0097] In step S202, plasma processing is performed. Here, the control unit 90 controls the exhaust device 50 to reduce the pressure in the processing chamber S, and while exhausting the processing chamber S, controls the processing gas supply unit 30 to introduce the processing gas into the processing chamber S, and controls the high-frequency power supply 44 to supply high-frequency power to the high-frequency antenna 41, thereby exciting plasma of the processing gas in the processing chamber S. The plasma processing may be processing on the substrate G (such as a film formation process) or processing on the processing vessel 10 (110) (such as a seasoning process, a cleaning process, or a pre-coating process).

[0098] In step S203, light in the specific wavelength region is received. Here, during the plasma processing (S202), plasma light including the specific wavelength region corresponding to OH radicals is received by light receiving unit 200 through transmission window 13b.

[0099] In step S204, the plasma emission monitor 220 acquires the second emission intensity in the specific wavelength region corresponding to the OH radical.

[0100] In step S205, the maximum value of the second emission intensity in the specific wavelength region corresponding to the OH radicals is recorded. Here, the control unit 90 stores the maximum value of the second emission intensity in the specific wavelength region corresponding to the OH radicals in the plasma processing (S202) in the storage unit 91.

[0101] In step S206, the control unit 90 determines whether the maximum value recorded in step S205 is less than the threshold value registered in S109. The determination process in step S206 is performed during plasma processing. When the determination process in step S206 is performed during plasma processing, the determination process in step S206 is repeated until the plasma processing is completed.

[0102] If the maximum value is not less than the threshold value (S206: NO), the control unit 90 determines that an abnormality has occurred (step S207). That is, it determines that the amount of moisture in the processing chamber S is equal to or greater than the allowable value. The control unit 90 also displays a warning on a display device, such as a display that visualizes and displays the operating status of the plasma processing apparatus 100 (101).

[0103] If the maximum value is less than the threshold value (YES in S206), the control unit 90 determines that the process is normal (step S208), that is, that the amount of moisture in the process chamber S is equal to or less than the allowable value.

[0104] 9, the amount of moisture in the processing chamber S can be determined based on the threshold value. Also, the amount of moisture in the processing chamber S can be determined during plasma processing.

[0105] [Processing after abnormality detection] Fig. 10 is a flowchart showing an example of processing performed by the plasma processing apparatus, which is performed when an abnormality is determined in step S207.

[0106] In step S301, the control unit 90 determines that an abnormality has occurred (also see S207 in FIG. 9).

[0107] In step S302, the plasma processing is continued. Here, similarly to step S202, the control unit 90 controls the exhaust device 50 to reduce the pressure inside the processing chamber S, and while exhausting the processing chamber S, controls the processing gas supply unit 30 to introduce the processing gas into the processing chamber S, and controls the high-frequency power supply 44 to supply high-frequency power to the high-frequency antenna 41, thereby exciting plasma of the processing gas inside the processing chamber S.

[0108] In step S303, light in the specific wavelength region is received. Here, during plasma processing (S202, S302), plasma light including the specific wavelength region corresponding to OH radicals is received by light receiving unit 200 through transmission window 13b.

[0109] In step S304, the plasma emission monitor 220 acquires the second emission intensity in the specific wavelength region corresponding to the OH radical.

[0110] In step S305, the control unit 90 records the maximum value of the second emission intensity in the specific wavelength region corresponding to the OH radicals in the plasma processing (S202, S302) in the memory unit 91.

[0111] In step S306, the control unit 90 determines whether the maximum value recorded in step S305 is less than the threshold value registered in S109.

[0112] If the maximum value is not less than the threshold value (S206: NO), the control unit 90 determines that an abnormality has occurred. The control unit 90 displays a warning on a display device, such as a display that visualizes the operating status of the plasma processing apparatus 100 (101). That is, the control unit 90 determines that the amount of moisture in the processing chamber S is equal to or greater than the allowable value (step S207).

[0113] If the maximum value is less than the threshold value (S306 YES), the control unit 90 proceeds to step S310. In step S310, the control unit 90 determines that normal operation has been restored (step S310). In this case, the plasma processing (S202, S302) continues.

[0114] On the other hand, if the maximum value is not less than the threshold value (S306: NO), the control unit 90 proceeds to step S307. In step S307, the control unit 90 determines whether the plasma processing (S302) has continued for a specified number of times or more. The specified number of times (limit on the number of times of execution) is, for example, five times. The determination interval in step S307 (in other words, the duration of the plasma processing in step S302) is within the range of 10 milliseconds to 1000 milliseconds.

[0115] If the number of times is equal to or greater than the predetermined number (YES in S307), the control unit 90 proceeds to step S311. In step S311, the control unit 90 determines that a leak has occurred in the apparatus. The control unit 90 also displays a warning on a display device, such as a display that visualizes the operating status of the plasma processing apparatus 100 (101).

[0116] On the other hand, if the number of times is less than the specified number (S307: NO), the control unit 90 proceeds to step S308. In step S308, the control unit 90 determines whether the current maximum value recorded in step 305 is less than the immediately preceding (previous) maximum value. In other words, the control unit 90 determines whether the maximum value has decreased.

[0117] If the current maximum value is less than the immediately preceding maximum value, in other words, if the maximum value has decreased (S308: YES), the process of the control unit 90 returns to step S302, and the plasma process continues.

[0118] On the other hand, if the current maximum value is not less than the immediately preceding maximum value, in other words, if the maximum value has not decreased (S308: NO), the control unit 90 proceeds to step S309. In step S309, the control unit 90 determines that a leak has occurred in the apparatus. The control unit 90 also displays a warning on a display device, such as a display that visualizes the operating status of the plasma processing apparatus 100 (101).

[0119] As described above, when an abnormality is determined (S301, also see S207 in FIG. 9), if the maximum value is decreasing (S308 YES), plasma processing is continued (S302). Then, when the maximum value becomes less than the threshold value (S306 YES), it is determined that the plasma processing has recovered (S310).

[0120] For example, when moisture adsorbed on the substrate G is transported to the processing chamber S together with the substrate G, the maximum value temporarily exceeds the threshold value as the moisture is released from the substrate G, and it is determined that an abnormality has occurred. Then, when the moisture is exhausted from the processing chamber S by the exhaust device 50, it is determined that the processing chamber S has recovered. Also, when the processing chamber S is opened to the atmosphere for maintenance or the like, and moisture has been adsorbed on the wall surface or the like of the processing chamber S, the maximum value temporarily exceeds the threshold value as the moisture is released from the wall surface or the like, and it is determined that an abnormality has occurred. Then, when the moisture is exhausted from the processing chamber S by the exhaust device 50, it is determined that the processing chamber S has recovered.

[0121] On the other hand, if an abnormality is determined (S301, also see S207 in FIG. 9), and the maximum value does not decrease (S308: NO), it is determined that a leak has occurred in the device (S309). Also, even if the maximum value has decreased, if the device does not recover after a specified number of times (S307: YES), it is determined that a leak has occurred in the device (S309).

[0122] In this way, according to the process shown in FIG. 10, it is possible to determine whether the moisture in the process chamber S is due to a leak or due to moisture released from the wall surface or the substrate G.

[0123] In the above description, if an abnormality is determined during substrate processing (S207), the same plasma processing as that in step S202 is continued (S302), but the present invention is not limited to this.

[0124] For example, if an abnormality is determined during or after substrate processing (S207), additional processing may be performed after the plasma processing of step S202 is completed. In this case, the additional processing is performed in step S302 shown in FIG. 10. The additional processing is performed after the product substrate that has been subjected to the plasma processing of step S202 is unloaded, with a dummy substrate or the like placed on the substrate mounting table 60 (160) or with no substrate placed on the substrate mounting table 60 (160). In the additional processing, O gas and a rare gas (Ar, He, etc.) are supplied as processing gases into the processing vessel 10 (110), and plasma is excited in the processing vessel 10 (110).

[0125] In the additional process, the temperature of the processing chamber S is increased. This causes moisture adsorbed to the sprayed film formed on the wall surface of the processing chamber S to be released and exhausted by the exhaust device 50.

[0126] The temperature rise in the additional process will be explained using FIG. 11. FIG. 11 is a diagram showing an example of the moisture content of a substrate. Here, a substrate G on which a thermally sprayed film (Al2O3 film) was formed was made to adsorb moisture, simulating the sidewall of a processing chamber S, and then the moisture was released under conditions 1 to 6. Initial indicates the weight of the substrate before moisture was adsorbed. Immediately after immersion indicates the weight of the substrate immediately after moisture was adsorbed. Conditions 1 to 6 indicate the weight of the substrate G after the substrate with moisture adsorbed was heated at the bake temperature (processing chamber temperature). As shown in FIG. 11, moisture is released from the thermally sprayed film by heating to 60°C or higher. The heating temperature is preferably 450°C or lower.

[0127] In this way, in the additional processing, by heating the inside of the processing chamber S to 60°C or higher (and 450°C or lower), the moisture adsorbed on the wall surface inside the processing chamber S can be released and exhausted. This makes it possible to efficiently remove moisture inside the processing chamber S. Therefore, in substrate processing of product substrates such as a film formation process, changes in film quality due to moisture can be suppressed.

[0128] The above describes embodiments of the plasma processing method, but the present disclosure is not limited to the above embodiments, and various modifications and improvements are possible within the scope of the gist of the present disclosure as described in the claims. [Explanation of symbols]

[0129] 10,110 Treatment vessel 30 Processing gas supply unit 41 High frequency antenna (inductively coupled antenna) 44 High frequency power supply 50 Exhaust system 60,160 Board mounting stand 90 Control Unit 91 Memory section 100, 101 Plasma processing apparatus 200 Light receiving section 210 Optical Fiber 220 Plasma Emission Monitor Antenna Room A S Processing Room G board

Claims

1. A plasma processing method for performing a predetermined plasma processing in a processing chamber, comprising: The plasma treatment is a step of performing a plasma process a predetermined number of times to obtain a first emission intensity, and setting a threshold value for determining the amount of moisture contained in the processing chamber based on the obtained first emission intensity; determining the moisture content based on the second emission intensity in the plasma treatment after the preset number of times and the threshold value; The step of setting the threshold value includes: (a) exciting a plasma of a processing gas in the processing chamber; (b) receiving light in a specific wavelength region of the emission spectrum of the plasma, the wavelength region being correlated with the amount of moisture in the processing chamber, and acquiring the first emission intensity; (c) recording the first luminescence intensity value; (d) calculating the threshold value from the first emission intensity for the preset number of times; (e) recording the threshold value. Plasma treatment method.

2. The step (a) is performed in a state where no substrate is placed on a substrate placement table in the processing chamber. The plasma processing method according to claim 1 .

3. The step (a) is performed in a state where either raw glass or a dummy substrate is placed on a substrate placement table in the processing chamber. The plasma processing method according to claim 1 .

4. The step (a) is performed in a state where a product substrate is placed on a substrate placement table in the processing chamber. The plasma processing method according to claim 1 .

5. the processing gas is a combination of a gas containing oxygen atoms or a gas containing nitrogen atoms and a rare gas, or a single gas containing fluorine atoms; The processing gas is a gas that does not contain hydrogen atoms. The plasma processing method according to claim 1 .

6. The gas containing oxygen atoms or the gas containing nitrogen atoms is O ２ , N ２ O, N ２ Either the rare gas is either He or Ar, The single gas containing fluorine atoms is NF ３ That is, The plasma processing method according to claim 5 .

7. the process gas is a combination of a source gas containing silicon atoms and a reaction gas that reacts with the source gas, The processing gas does not contain at least one of hydrogen atoms and oxygen atoms. The plasma processing method according to claim 1 .

8. The source gas containing silicon atoms is SiF ４ , SiCl ４ , SiH ４ Either The reaction gas is O ２ , N ２ O, N ２ , N.H. ３ Either The plasma processing method according to claim 7 .

9. The preset number of times is at least five or more times. The plasma processing method according to claim 1 .

10. The step of determining the moisture content includes: (f) determining whether the water content has increased or decreased based on the increase or decrease in the second luminescence intensity, The determination of the increase or decrease in the moisture content is When the second luminescence intensity increases, the moisture content is determined to be increased; When the second luminescence intensity decreases, the moisture content is determined to be decreased. The plasma processing method according to claim 1 .

11. the specific wavelength region correlated with the amount of moisture in the processing chamber is a wavelength region from 305 nm to 310 nm; The plasma processing method according to claim 1 .

12. The step (c) recording the maximum value of the first emission intensity in the specific wavelength region; The plasma processing method according to claim 11 .

13. the threshold value is a value obtained by multiplying the average value of the maximum values ​​of the first emission intensity by a predetermined coefficient. The plasma processing method according to claim 12.

14. In the step of determining the moisture content, performing an additional process to reduce the moisture content; The plasma processing method according to claim 1 .

15. The additional process may be limited in the number of times it can be executed. The plasma processing method according to claim 14.

16. The execution limit is five times. The plasma processing method according to claim 15.

17. The additional treatment is at least O ２ introducing gas to excite the plasma; The plasma processing method according to claim 14.

18. The additional process involves increasing the temperature of the process chamber. The plasma processing method according to claim 17.

19. The temperature rise of the processing chamber is 60° C. or higher. The plasma processing method according to claim 18.

20. a processing vessel having a processing chamber; a substrate mounting table provided in the processing chamber; a processing gas supply unit that introduces a processing gas into the processing chamber; a plasma generating unit that excites plasma of the processing gas in the processing chamber; A plasma processing apparatus comprising: The control unit a step of performing a plasma process a predetermined number of times to obtain a first emission intensity, and setting a threshold value for determining the amount of moisture contained in the processing chamber based on the obtained first emission intensity; determining the moisture content based on the second emission intensity in the plasma treatment after the preset number of times and the threshold value; The step of setting the threshold value includes: (a) exciting a plasma of the processing gas in the processing chamber; (b) receiving light in a specific wavelength region of the emission spectrum of the plasma, the wavelength region being correlated with the amount of moisture in the processing chamber, and acquiring the first emission intensity; (c) recording the first luminescence intensity value; (d) calculating the threshold value from the first emission intensity for the preset number of times; (e) recording the threshold value. Plasma processing equipment.

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