Vacuum processing device and vacuum processing method

Abstract

An objective of the present invention is to provide technology capable of improving the accuracy of gas flow rate measurement by a build-up method.　To this end, the vacuum processing device of the present invention comprises: a processing chamber inside which the pressure can be reduced; a first flow rate control unit for supplying a first processing gas to the processing chamber while controlling the flow rate thereof; a second flow rate control unit for supplying a second processing gas to the processing chamber while controlling the flow rate thereof; a pressure measurement unit for measuring the internal pressure of the processing chamber; and an index calculation unit for calculating an index on the basis of the output of the pressure measurement unit, wherein the index calculation unit calculates a relative index on the basis of the ratio of first pressure information that is an output of the pressure measurement unit when the first processing gas is being supplied to the processing chamber and second pressure information that is an output of the pressure measurement unit when the second processing gas is being supplied to the processing chamber, and changes the setting of the first flow rate control unit and / or the second flow rate control unit on the basis of the relative index, or suggests replacing the first flow rate control unit and / or the second flow rate control unit.

Description

Vacuum processing apparatus and vacuum processing method

[0001] The present disclosure relates to a vacuum processing apparatus and a vacuum processing method.

[0002] In the mass production of semiconductor devices, a substrate-like sample, such as a semiconductor wafer, is placed in a processing chamber inside a vacuum vessel under reduced pressure, and a predetermined process, such as an etching process, is conventionally performed using plasma generated in the processing chamber. As semiconductor device circuits have become increasingly miniaturized in recent years, the processing accuracy required for the plasma-based processes, such as etching processes, is shifting from the order of nm to the order of Å. As miniaturization progresses, processing conditions must be controlled more precisely, and for example, the flow rate of the process gas used in etching must be controlled with high precision.

[0003] As described in Patent Document 1, taking gas flow rate as an example of a control parameter, if a semiconductor manufacturing equipment is equipped with a gas measuring instrument, the gas flow rate supplied into the chamber is measured. However, many semiconductor manufacturing equipment are not equipped with a gas measuring instrument, and installing a gas measuring instrument requires a large investment. Patent Document 1 aims to "improve the accuracy of gas flow rate measurement using the build-up method," and discloses the following content as an invention of a flow rate measurement method and a flow rate control method: "The invention provides a flow rate measurement method including the steps of: supplying gas output from a flow rate controller to a chamber via a gas supply unit; closing an exhaust valve of the chamber after the flow rate supplied to the chamber has stabilized; measuring the pressure of the chamber and the pressure between the flow rate controller and the gas supply unit after closing the exhaust valve; correcting the pressure of the chamber by the pressure loss per volume of the chamber based on the difference between the measured chamber pressure and the pressure between the flow rate controller and the gas supply unit; and calculating the gas flow rate from the corrected pressure increase rate of the chamber and the volume of the chamber."

[0004] Furthermore, Patent Document 2 proposes measuring whether the gas flow rate is being controlled correctly when using the build-up method. For example, Patent Document 2 aims to "provide a method for calibrating a flow rate of a flow rate controller using the build-up (or ROR) method, which can be performed more quickly and with higher accuracy using a miniaturized calibration unit," and discloses the following as an invention of a method for calibrating a flow rate controller for a gas supply device and a method for measuring a flow rate. "A calibration unit 5 consisting of a build-up tank BT, on-off valves V1 and V2, a temperature detector Pd, and a pressure detector Td is connected in a branched manner to the gas supply path L, and on-off valve V2 is connected to a vacuum exhaust device, first on-off valves Vo1 to Von of each flow rate controller and on-off valve V0 of the gas usage location are closed and on-off valves V2 and V1 are opened, next only the on-off valve of the flow rate controller to be calibrated is opened to allow gas at the set flow rate to flow into the calibration unit 5, the gas temperature and gas pressure inside the tank are measured at time t0, thereafter on-off valve V2 is closed to allow build-up of gas inside tank BT, at time t1 on-off valve V1 is closed, and at time t2 the gas temperature and gas pressure are measured and a gas flow rate Q is calculated from each measurement value, and flow rate calibration is performed by comparing the set gas flow rate with the calculated gas flow rate Q." In gas flow measurement using the build-up method, the pressure inside a chamber into which a predetermined flow rate of gas is introduced is measured, and the slope of the pressure rise is measured to determine whether the flow rate of the gas being supplied into the chamber is being controlled correctly.

[0005] JP 2018-116583 A JP 2012-32983 A

[0006] While the required accuracy for flow rate management of process gases that affect process processing is increasing, there is a known problem that the accuracy (difference between the set flow rate and the actual flow rate) of mass flow controllers (MFCs) that measure the pressure of process gases deteriorates over time. Even when measuring the pressure inside a chamber using the build-up method, the accuracy of the mass flow controller may be affected, but this problem is not sufficiently addressed in Patent Documents 1 and 2. Therefore, an object of the present invention is to provide a technology that can improve the accuracy of gas flow rate measurement using the build-up method.

[0007] In order to solve the above-mentioned problems, one representative vacuum processing apparatus of the present invention includes a processing chamber whose interior can be depressurized, a first flow rate control unit that supplies a first processing gas into the processing chamber at a controlled flow rate, a second flow rate control unit that supplies a second processing gas into the processing chamber at a controlled flow rate, a pressure measurement unit that measures an internal pressure of the processing chamber, and an index calculation unit that calculates an index based on an output of the pressure measurement unit, wherein the index calculation unit calculates a relative index based on a ratio of first pressure information that is an output of the pressure measurement unit when the first processing gas is being supplied to the processing chamber and second pressure information that is an output of the pressure measurement unit when the second processing gas is being supplied to the processing chamber, and changes settings of the first flow rate control unit and / or the second flow rate control unit based on the relative index, or indicates whether the first flow rate control unit and / or the second flow rate control unit needs to be replaced.

[0008] According to the present disclosure, it is possible to improve the accuracy of gas flow rate measurement using the build-up method. Problems, configurations, and effects other than those described above will become apparent from the following description of the preferred embodiment of the present invention.

[0009] FIG. 1 is a diagram illustrating an example of the configuration of a plasma processing apparatus (vacuum processing apparatus) according to an embodiment of the present disclosure. FIG. 2 is a diagram illustrating the time response of the output of a pressure measurement unit according to an embodiment of the present disclosure. FIG. 3 is a diagram illustrating a change in a normalized relative index according to the number of measurements according to an embodiment of the present disclosure. FIG. 4 is a diagram illustrating a normalized relative index measurement flow according to an embodiment of the present disclosure. FIG. 5 is a diagram illustrating a normalized relative index measurement flow according to an embodiment of the present disclosure. Ｎ２ 6 is a diagram showing an example of pressure time change data P Ｎ２ Time derivative dP Ｎ２ 7 is a diagram showing an example of data of / dt. FIG. 7 is a diagram showing a normalized relative index measurement flow according to an embodiment of the present disclosure. FIG. 8 is a diagram showing the relationship between the set flow rate and the measured flow rate of a flow control unit according to an embodiment of the present disclosure. FIG. 9 is a diagram showing an abnormality determination flow of a reference flow control unit according to an embodiment of the present disclosure. FIG. 10 is a diagram showing an abnormality determination flow of a reference flow control unit according to an embodiment of the present disclosure. FIG. 11 is a diagram showing a reliability determination flow of a normalized relative index according to an embodiment of the present disclosure.

[0010] In the following embodiments, the description will be divided into multiple sections or examples for convenience, as necessary. However, unless otherwise specified, they are not unrelated to one another, and one is a partial or complete modification, detail, supplementary explanation, etc., of the other. Furthermore, in the following embodiments, when the number of elements (including the number, numerical value, amount, range, etc.) is mentioned, it is not limited to that specific number, and may be greater than or less than the specific number, unless otherwise specified or clearly limited to a specific number in principle. Furthermore, in the following embodiments, it goes without saying that the components (including element steps, etc.) are not necessarily essential, unless otherwise specified or clearly considered essential in principle. Similarly, in the following embodiments, when the shape, positional relationship, etc. of components, etc. are mentioned, it is intended to include those that are substantially similar or approximate to the shape, etc., unless otherwise specified or clearly considered not to be essential in principle. The same applies to the above-mentioned numerical values ​​and ranges. Furthermore, in all drawings used to explain the embodiments, the same components are generally designated by the same reference numerals, and repeated description thereof will be omitted. Hereinafter, examples of the present invention will be described using the drawings.

[0011] In this disclosure, "upper" refers to the vertically upward direction when an object is placed in its normal orientation. "Upper" refers to components or parts that are at the top. "Lower" refers to the opposite direction from "up," and "lower" refers to components or parts that are at the bottom.

[0012] <Example 1> Fig. 1 is a diagram showing an example of the configuration of a plasma processing apparatus (vacuum processing apparatus) according to an example of the present invention. Details will be described later, but in Fig. 1, the portion relating to the processing chamber 110 of the plasma processing apparatus 100 is shown in a schematic vertical cross section. The plasma processing apparatus 100 is the portion where plasma processing is performed on a sample, and includes a gas supply unit (first gas supply unit 301) １ and second gas supply unit 301 ２) and a gas exhaust unit (exhaust unit 305). In general, when n types of gases (n is an integer of 2 or more) are used in the plasma processing apparatus 100, the first gas supply unit 301 １ to the n-th gas supply unit 301 ｎ Regarding the flow rate control unit of the plasma processing apparatus 100, the first gas supply unit 301 is also used. １ First flow rate control unit 302 １ is connected to the i-th (i is an integer of 1 or more and n or less) gas supply unit 301 ｉ The i-th flow rate control unit 302 ｉ In the first embodiment, the gas supply system mainly includes a first gas supply unit 301 １ and second gas supply unit 301 ２ is used, and the first gas supply unit 301 １ First flow rate control unit 302 １ is connected to the second gas supply unit 301 ２ The second flow rate control unit 302 ２ In the following description, a case where the gas supply unit and the flow rate control unit are connected will be described. When it is not necessary to specify which gas they handle, the gas supply unit and the flow rate control unit may simply be referred to as a "gas supply unit" and a "flow rate control unit." Also, while FIG. 1 shows a case where the plasma processing apparatus 100, the gas supply unit, and the gas exhaust unit are separate, the present disclosure is not limited to this case. Both the gas supply unit and the gas exhaust unit may be included in the plasma processing apparatus 100.

[0013] In the present disclosure, the plasma processing apparatus 100 includes a processing chamber 110 capable of reducing the pressure inside, and a first flow rate control unit 302 that controls the flow rate of a first processing gas and supplies the first processing gas to the processing chamber 110. １ a second flow rate control unit 302 that controls the flow rate of a second processing gas and supplies the second processing gas to the processing chamber 110; ２The plasma processing apparatus 100 further includes an exhaust mechanism (exhaust unit lid 161, cylinder 162, exhaust pump 170) for reducing the pressure inside the processing chamber 110, and an exhaust speed control unit (exhaust adjustment unit) 307 for controlling the exhaust flow rate of the processing chamber 110. The index calculation unit 308 calculates a relative index based on a ratio between first pressure information, which is an output from the pressure measurement unit when a first processing gas is being supplied to the processing chamber 110, and second pressure information, which is an output from the pressure measurement unit when a second processing gas is being supplied to the processing chamber 110, and calculates a relative index based on the relative index. １ and / or the second flow control section 302 ２ or change the setting of the first flow rate control unit 302 １ and / or the second flow control section 302 ２ The following explains in detail.

[0014] (Configuration of Plasma Processing Apparatus and Gas Evacuation) The plasma processing apparatus 100 comprises a vacuum chamber including an upper chamber 130 and a lower chamber 150, an exhaust pump 170 connected thereto below, and a first high-frequency power supply 101 and a solenoid coil (hereinafter also simply referred to as "coil") 106 above. The upper chamber 130 and the lower chamber 150 have inner walls that are circular in horizontal cross section, and a cylindrical sample stage 140 is disposed in the center of the interior and is held by a second sample stage base 145. The second sample stage base 145 is fixed to the vacuum chamber by a plurality of hollow support beams 206.

[0015] The outer walls of the upper chamber 130 and the lower chamber 150 form a vacuum bulkhead. The hollow support beams 206 are arranged symmetrically about the central axis of the sample stage 140, which extends vertically (the gas flow path shape is approximately coaxially symmetric about the central axis of the sample stage 140). The space that is connected to the hollow support beams 206 and extends from the opening of the upper chamber 130 to the cylindrical cavity below the second sample stage base 145 has a path that is connected to the space outside the plasma processing apparatus 100 and is kept at atmospheric pressure. Gases (processing gas, particles in the plasma, and reaction products) in the space above the sample stage 140 in the upper chamber 130 pass through the space between the hollow support beams 206 and are exhausted via the lower chamber 150. This ensures uniform gas flow in the circumferential direction of the sample stage 140 on which the wafer 200, a workpiece (sample), is placed, enabling uniform processing of the wafer 200.

[0016] The upper vessel 130, the lower vessel 150, and the base plate 160 each have a flange. The upper vessel 130 and the lower vessel 150 are fastened together by screws at the flanges, and the lower vessel 150 and the base plate 160 are fastened together by screws at the flanges. Inside the vacuum vessel is a processing chamber 110, which is a cylindrical space into which a gas is introduced and an electric field and a magnetic field are supplied to form plasma. Although the members that surround the processing chamber 110 and constitute the vessel have a cylindrical interior, the horizontal cross-sectional shape of the outer wall is not limited to a circular shape and may be rectangular or have other shapes.

[0017] Above the processing chamber 110, a disk-shaped lid member 102 constituting the vacuum vessel is disposed, and below it, a disk-shaped shower plate 103 constituting the ceiling surface of the processing chamber 110. The lid member 102 and the shower plate 103 are made of a dielectric material such as quartz. For example, the lid member 102 may be a quartz plate. These members are therefore configured to be permeable to high-frequency electric fields such as microwaves, UHF, and VHF waves, and an electric field from a first high-frequency power supply 101 disposed above passes through these members and is supplied to the interior of the processing chamber 110. In addition, a cylindrical coil 106 is disposed around the outer periphery of the outer sidewall of the vacuum vessel, surrounding the outer sidewall and functioning as a magnetic field generating means, and the generated magnetic field can be supplied to the interior of the processing chamber 110.

[0018] The shower plate 103 has a plurality of process gas inlet holes, which are through-holes, arranged therein, and the process gas is supplied into the process chamber 110 through the inlet holes. The shower plate 103 has a plurality of inlet holes arranged above the sample mounting surface, which is the upper surface of the sample stage 140, in an axisymmetric region about the central axis of the sample stage 140. A process gas having a predetermined composition and made up of different gas components is introduced into the process chamber 110 through the evenly arranged inlet holes.

[0019] The process gas introduced into the process chamber 110 is excited by electromagnetic waves and a magnetic field generated by the first high-frequency power supply 101 (electric field generating means) and the coil 106 (magnetic field generating means), which are supplied into the process chamber 110. The process gas is then converted into plasma in a space (discharge unit) above the sample stage 140, which forms the upper portion of the process chamber 110. The space where the plasma is generated is surrounded by a discharge chamber 124, and a heater is attached to the outer wall of the discharge chamber 124. The heater receives power and command signals from a temperature controller including an electrically connected power supply to adjust the heater output or heat output. This configuration heats the quartz inner tube 105, which is disposed on the inner wall of the discharge chamber 124. The quartz inner tube 105 is configured to be in contact with the plasma generated inside the quartz inner tube 105. This configuration reduces the adhesion of reaction products to the surfaces of components facing the plasma in the discharge unit, including the quartz inner tube 105.

[0020] The sample stage 140 on which the wafer 200 is placed is disposed inside the processing chamber 110 so that its central axis coincides with the central axis of the shower plate 103. The sample to be processed by plasma is the wafer 200, and the wafer 200 is placed on a circular mounting surface that is the upper surface of the sample stage 140, and is attracted and held by static electricity of a dielectric film that constitutes this mounting surface (electrostatic chuck). While the wafer 200 is held on the mounting surface, processing is performed on the surface of the wafer 200.

[0021] A second high-frequency power supply 148, which is a high-frequency bias power supply, is connected to an electrode disposed inside the sample stage 140, and the supplied high-frequency power forms a high-frequency bias above the sample stage 140 and the wafer 200 placed thereon. The high-frequency bias attracts charged particles in the plasma to the surface of the wafer 200, causing them to collide with the surface, resulting in a physical reaction, and a chemical reaction between the radicals and the wafer surface, causing an etching process to proceed on the surface of the wafer 200. The temperature of the sample stage 140 can be controlled to a desired temperature by a temperature controller.

[0022] The application of a high frequency bias to the sample stage 140 and the temperature control of the sample stage 140 are performed via power supply wiring cords, temperature control wiring cords, or coolant piping wired within the cavity formed by the hollow support beam 206 and the second sample stage base 145. In addition to the above wiring cords, wiring cords for a temperature sensor and an electrostatic chuck may also be included within the cavity.

[0023] A base plate 160 having an exhaust opening and an exhaust pump 170 are disposed below the processing chamber 110. The exhaust pump 170 is connected to the bottom of the processing chamber 110 via the exhaust opening of the base plate 160. The exhaust opening provided in the base plate 160 is disposed directly below the sample stage 140. An exhaust lid 161 having a generally circular plate shape is disposed above the exhaust opening. A cylinder 162 for moving the exhaust lid 161 up and down is connected to the exhaust lid 161. By moving the exhaust lid 161 up and down using the cylinder 162, the exhaust conductance can be adjusted. The amount and speed of gas, plasma, and products inside the processing chamber 110 that are exhausted to the outside of the processing chamber 110 are adjusted by the exhaust lid 161 and the exhaust pump 170.

[0024] The exhaust lid 161 is opened when processing the wafer 200, and the pressure in the space inside the processing chamber 110 is maintained at a desired vacuum level by a balance between the supply of processing gas and the operation of an exhaust means such as the exhaust pump 170. Specifically, the pressure inside the processing chamber 110 during the etching process is monitored by a pressure measurement unit 306, and the exhaust speed control unit 307 controls the opening of the exhaust lid 161 to maintain the desired pressure inside the processing chamber 110. The pressure inside the processing chamber 110 measured by the pressure measurement unit 306 is also sent to an index calculation unit 308.

[0025] The index calculation unit 308 has a function of calculating a predetermined index, and controls the first flow rate control unit 302 based on the calculated index. １ and second flow rate control unit 302 ２ The index calculation unit 308 may be configured by, for example, a control device having a memory and a processor. The memory contains processing instructions that cause the processor to execute predetermined processing, and the processor controls the first flow rate control unit 302 by executing the processing instructions. １ and second flow rate control unit 302 ２ The index calculation unit 308 can perform processing for changing the settings of the parameters, processing for calculating the index, etc. The index calculation unit 308 may also have an input / output device for presenting information to a user of the plasma processing apparatus 100. The processing of the index calculation unit 308 will be described later.

[0026] The exhaust pump 170 is, for example, a turbomolecular pump, and is connected to an exhaust unit 305 such as a rotary pump provided in a building in which the plasma processing apparatus 100 is installed. When the exhaust unit lid 161 is closed, the exhaust pump 170 can be vacuum-sealed with an O-ring. For convenience, the exhaust unit lid 161, the cylinder 162, the exhaust pump 170, and the exhaust unit 305 are also referred to as an exhaust mechanism.

[0027] Although not shown, a gate, which is an opening that communicates between the inside and outside of the vacuum chamber, is arranged on the outer wall of the upper chamber 130, and a transfer robot passes through the gate to place the wafer 200 on the sample stage 140. During plasma processing, the opening is vacuum-sealed by a gate valve, and the vacuum seal is released only when the wafer 200 is being transferred.

[0028] (Gas Supply Configuration) The processing gas used in the plasma processing is a single type of gas or a mixture of multiple types of gases at an optimum flow rate ratio for each process condition. This gas is supplied from the first gas supply unit 301. １ , second gas supply unit 301 ２ to the plasma processing apparatus 100, and the flow rates of the gases are controlled by the first flow rate control units 302. １ , second flow rate control unit 302 ２ The first flow rate control section 302 １ and second flow rate control unit 302 ２ are, for example, control valves, and the flow rates of the gases are controlled by adjusting the openings of the valves. The gases whose flow rates have been adjusted are introduced through gas piping into a gas retention space between the shower plate 103 and the lid member 102 above the processing chamber 110 in the upper part of the vacuum vessel, mixed, and supplied to the processing chamber 110.

[0029] In the plasma processing apparatus as described above, the first flow rate control unit 302 in this embodiment １ and second flow rate control unit 302 ２ This paper describes an index measurement method (relative buildup method) for detecting flow rate abnormalities.

[0030] (Conventional Build-up Method) First, for comparison, a case where a conventional build-up method is applied to the plasma processing apparatus 100 will be described. In the conventional build-up method, the exhaust pump 170 and the like are operated to create a substantial vacuum inside the processing chamber 110, and then the exhaust unit lid 161 is closed. Next, the first flow rate control unit 302 １ or the second flow rate control unit 302 ２The process chamber 110 is filled with gas at a constant flow rate through the pressure measuring unit 306. If the time t when the gas starts to flow is set to 0, the pressure P output from the pressure measuring unit 306 exhibits a response as shown in FIG. 2. FIG. 2 is a diagram showing the time response of the output from the pressure measuring unit 306 according to an embodiment of the present disclosure. At this time, if the actual flow rate of the gas supplied to the process chamber 110 is Q and the volume of the process chamber 110 is V, then the relationship between them is expressed by Equation (1).

[0031] By differentiating both sides of equation (1) with respect to time t and rearranging, equation (2) is obtained, and the actual flow rate Q can be estimated from the response of pressure P.

[0032] However, in reality, there are many error factors, making it difficult to accurately measure the actual flow rate Q. For example, in the case of an ideal gas, the pressure P, volume V, temperature T, amount of substance n, and gas constant R ０ There is a relationship expressed by equation (3).

[0033] In reality, the pressure varies from the pressure P in the reference state to k as shown in P' in equation (4) due to the influence of temperature deviation from the reference state, volume deviation due to aging and machine error, etc. Ｔ / k Ｖ Here, the temperature deviation component is k Ｔ , the volume displacement component is k Ｖ It states that:

[0034] As a result, the measured flow rate Q' is given by equation (5) and deviates from equation (2). Although it is possible to reduce the effects of these factors by strictly controlling the temperature during measurement, it takes time for the temperature to reach equilibrium, making it impossible to measure in a short time during etching processing, which reduces the operating rate of the plasma processing equipment.

[0035] (Relative Build-up Method of the Present Disclosure) Therefore, consider measuring two types of gases consecutively using the build-up method and calculating the ratio of the measurement results. The time required for one build-up method (build-up method performed for one gas) is about several seconds to several tens of seconds, and it can be assumed that the temperature inside the processing chamber 110 does not change during that time. Furthermore, since measurements are performed consecutively, even if a volume difference occurs, the volume V in the two build-up methods can be assumed to be the same. For example, the first flow rate control unit 302 １ The gas controlled by nitrogen gas N ２ , second flow rate control unit 302 ２ The gas controlled by is argon gas Ar. At this time, the pressure measurement results for nitrogen gas and argon gas by the build-up method are P Ｎ２ ', P Ａｒ ', the relative index E Ａｒ／Ｎ２ is expressed by the following equation (6).

[0036] In this way, the pressure deviation component k Ｖ / k Ｔ can be considered to be approximately the same when measuring nitrogen gas and argon gas, so they can be canceled out, and the relative index E Ａｒ／Ｎ２ As a result, the actual flow rate ratio Q is not affected by temperature deviation or volume deviation. Ａｒ / Q Ｎ２ This is the basic concept of the relative build-up method. １ and second flow rate control unit 302 ２ Mass flow controllers (MFCs) commonly used as such are generally calibrated with nitrogen gas, so the following description assumes that the measurement standard is nitrogen gas and the measurement target is argon gas. However, this is not limited to this, and a stable noble gas such as argon gas may be used as the reference gas, and since this method is a relative index, it may be used in conjunction with multiple types of gases.

[0037] This method does not calculate the absolute flow rate but merely calculates the flow rate ratio, but here we will explain how to calculate the absolute flow rate. In recent years, the accuracy of MFCs has become high, and it can be considered that sufficient accuracy is guaranteed when MFCs are shipped from the factory. In other words, the relative index E when performing measurement for the first time in the plasma processing apparatus 100 is Ａｒ／Ｎ２ The initial relative index measurement result E Ａｒ／Ｎ２ (0) can be considered to be equal to the ratio of the flow rate settings of argon and nitrogen. Ａｒ (0) indicates the argon flow rate setting value, and Q Ｎ２ (0) indicates the nitrogen flow rate setting.

[0038] This first relative index measurement result E Ａｒ／Ｎ２ (0), the normalized relative index ε after τ measurements Ａｒ／Ｎ２ is defined as Equation (8).

[0039] The normalized relative index ε of Equation (8) Ａｒ／Ｎ２ (τ) is always calculated, and if there is no abnormality in the MFC of the nitrogen gas, which is the reference gas, Q Ｎ２ (0) and Q Ｎ２ If it is confirmed that (τ) has not changed, the normalized relative index ε Ａｒ／Ｎ２ (τ) is multiplied by the set flow rate of the argon MFC to obtain the actual flow rate Q of argon. Ａｒ (τ) can be found.

[0040] Furthermore, the normalized relative index ε of Equation (8) Ａｒ／Ｎ２ By using (τ), it is possible to standardize abnormality determination for flow rate control units of different gas types. Ａｒ／Ｎ２ 3 shows the change in the normalized relative index ε (τ) according to the number of measurements. Ａｒ／Ｎ２ By capturing the state in which (τ) deviates from the initial value 1, the first flow rate control unit 302 １ and / or the second flow control section 302 ２ More specifically, when the time τ becomes equal to or greater than the abnormality determination threshold value Th, the time τＴｈ The first flow rate control unit 302 １ or the second flow rate control unit 302 ２ For example, the index calculation unit 308 can perform processing to exchange the normalized relative index ε Ａｒ／Ｎ２ Based on this, the first flow rate control unit 302 １ and / or the second flow control section 302 ２ or change the setting of the first flow rate control unit 302 １ and / or the second flow control section 302 ２ The user of the plasma processing apparatus 100 can be informed of whether replacement is necessary.

[0041] (Measurement Process) Next, a measurement flow based on the relative buildup method described above will be described with reference to Fig. 4. Fig. 4 is a diagram showing a normalized relative index measurement flow according to an embodiment of the present disclosure.

[0042] In steps 401 and 402, the pressure measurement unit depressurizes the processing chamber 110 using the exhaust mechanism, and then measures pressure information while the processing chamber 110 is sealed using the exhaust speed control unit 307. Specifically, in step 401, the exhaust unit lid 161 is opened, the exhaust pump 170 and the like are operated to create a substantial vacuum inside the processing chamber 110, and then the exhaust unit lid 161 is closed, and the first gas supply unit 301 １ The nitrogen gas supplied from the first flow rate control unit 302 １ The flow rate Q set by Ｎ２ The pressure during this series of operations is measured at a constant interval by the pressure measuring unit 306, and pressure time change data P Ｎ２ (hereinafter, also referred to as "first pressure information") and store it as pressure time change data P Ｎ２ is generally a list of pressure values ​​at each time, i.e., vector data, and is shown in a graph as in Figure 5. Ｎ２ As shown in this example, in the initial stage of gas filling, the pressure response is often not linear, which deteriorates the accuracy of the actual measurement. Ｎ２ For example, the time t Ａ From time tＢ It is desirable to use data in the range

[0043] In step 402, the exhaust lid 161 is opened in the same manner, and the exhaust pump 170 and the like are operated to create a substantial vacuum inside the processing chamber 110. Then, the exhaust lid 161 is closed, and the second gas supply unit 301 is opened. ２ The argon gas supplied from the second flow rate control unit 302 ２ The flow rate Q set by Ａｒ The pressure during this series of operations is measured at a constant time interval by the pressure measuring unit 306, and pressure time change data P Ａｒ (hereinafter referred to as "second pressure information")

[0044] In step 403, the index calculation unit 308 performs a differential operation on the pressure time change data. Specifically, in step 403, the obtained pressure time change data P Ｎ２ , P Ａｒ is differentiated at time t (time differentiation), and dP Ｎ２ / dt, dP Ａｒ 6 shows the pressure time change data P Ｎ２ Time derivative dP Ｎ２ 1 is a diagram illustrating an example of data at time t Ａ From time t Ｂ The data obtained is constant within the range from time dP Ａｒ / dt, dP Ｎ２ / dt data, time t Ａ From time t Ｂ If this data is acquired at a constant interval, the difference between adjacent data may be taken instead of performing time differentiation.

[0045] In step 404, the index calculation unit 308 performs an averaging operation on the data. Specifically, in step 404, the differential results of step S403 are averaged to suppress random noise contained in the data and improve the accuracy of the differential value. The averaging operation is expressed by equations (10) and (11).

[0046] In step S405, the index calculation unit calculates the relative indexes of nitrogen gas and argon gas. Specifically, in step S405, the relative index E of nitrogen gas and argon gas is calculated by calculating the ratio between them. Ａｒ／Ｎ２ This can be expressed as a formula (12).

[0047] In step 406, the index calculation unit calculates the first flow rate control unit 302 １ and / or the second flow control section 302 ２ Specifically, in step 406, it is determined whether the relative index is calculated in the initial state of the first flow rate control unit 302 or not. １ and / or the second flow control section 302 ２ If either of the relative indices is the first time since the exchange, the relative indices are stored (step 408). If neither of the relative indices is the first time, the obtained relative indices are normalized by the stored first relative indices (the relative indices calculated in the initial state), and the normalized relative indices ε Ａｒ／Ｎ２ is obtained (step 407).

[0048] According to the above measurement flow, since the differential processing is performed in step 403, even if the output of the pressure measurement unit 306 is offset, it does not cause a problem, and it is possible to perform measurements that are not affected by the precision of the zero point adjustment. Ａ From time t Ｂ It is not a problem if the time is different.

[0049] It should be noted that the pressure sensor serving as the pressure measurement unit 306 contains quantization noise, noise due to the influence of surrounding devices, etc. Therefore, in order to improve the SNR of the data, it is desirable to continue measurement in step 401 until the pressure reaches approximately the maximum pressure measurable by the pressure measurement unit 306.

[0050] By using the index based on the relative buildup method described in the above embodiment, the first flow rate control unit 302 can be controlled without being affected by temperature deviation, volume deviation, or offset of the pressure measurement unit 306. １ and second flow rate control unit 302 ２This makes it possible to detect changes in flow rate due to time-dependent changes or abnormalities with high accuracy. Measurement can be performed after eliminating changes that occur in the flow rate control unit, thereby improving the accuracy of gas flow rate measurement using the build-up method.

[0051] Example 2 In this example, the first flow rate control unit 302 using the relative buildup method described in Example 1 was used. １ and second flow rate control unit 302 ２ In the second embodiment, the index calculation unit 308 calculates the second flow rate control unit 302. ２ The second flow control unit 302 calculates a relative index for each flow rate (set flow rate) set in ２ and the actual flow rate of the second process gas supplied to the process chamber 110. ２ In the following description, the same or equivalent components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be simplified or omitted.

[0052] 7 is a diagram showing a normalized relative index measurement flow according to an embodiment of the present disclosure. The difference from the flow shown in FIG. 4 of the first embodiment is that the first flow rate control unit 302 １ and second flow rate control unit 302 ２ The key point is to perform measurements multiple times while changing the flow rate. This is because the relationship between the set flow rate of the flow control unit and the actual flow rate may differ for each flow rate, so it is desirable to measure and calibrate this relationship over the entire usable flow rate range, which is the range of usable flow rates. An example will be described in which this usable flow rate range is divided into 10 parts and measurements are taken at openings of 10%, 20%, ..., 100%, but the number of divisions is not limited to 10. The number of divisions can be set as appropriate; for example, increasing the number of divisions can improve calibration accuracy, while decreasing the number of divisions can shorten measurement time.

[0053] In step 701, the flow rate Q Ｎ２ to the first flow rate control unit 302 １ However, the first flow rate control unit 302 １When nitrogen gas is used as the reference gas, the measurement target is the second flow rate control unit 302. ２ Therefore, the first flow rate control unit 302 １ The opening of the valve does not necessarily need to be changed, and may be kept at the same opening of 100%. This allows measurement at a large flow rate, making it possible to complete measurement of nitrogen gas in a short time.

[0054] In step 401, the same processing as in step 401 in the first embodiment is performed.

[0055] In step 702, the flow rate Q Ａｒ to the second flow rate control unit 302 ２ Set to.

[0056] Steps 402 to 408 are the same as steps S402 to S408 in the first embodiment.

[0057] In step 703, if the opening is equal to or less than the set division number, the process returns to step 701 again, and steps 701 and 702 are repeated until the opening reaches 20%, then 30%, and so on, repeating steps 701 to 708 until the set division number is reached.

[0058] The above measurement results, for example, as shown in Fig. 8. Fig. 8 shows the relationship between the set flow rate Q and the measured flow rate Q of the flow rate control unit according to the embodiment of the present disclosure. ｍ The horizontal axis is the set flow rate Q, and the vertical axis is the measured flow rate Q. ｍ The following explanation applies to any gas type, so the gas type is omitted. ｍ can be obtained by multiplying the normalized relative index ε by the set flow rate Q as shown in Equation (9). ｍ is vector data having measurement data for the set number of divisions, and is indicated by white circles in FIG.

[0059] Ideally, the set flow rate Q and the measured flow rate Q ｍ , the relationship should be as shown by the dotted line in Figure 11. However, in reality, the measured flow rate Q ｍ is the data shown by the solid line in FIG. ｍBased on this, a polynomial such as Equation (13) is approximated. The coefficient α of this polynomial １ , α ２ , α ３ , α ４ is the measured flow rate Q ｍ This can be calculated using the least squares method from the measurement data.

[0060] When setting the set flow rate Q, the set flow rate Q is substituted into the formula (14) to obtain the estimated actual flow rate Q. ｍ Calculate the set flow rate Q and the estimated actual flow rate Q ｍ Corrected set flow rate is calculated by dividing by the corrected set flow rate Q ｃ It is possible to calculate

[0061] The corrected set flow rate Q ｃ is the first flow rate control unit 302 １ and second flow rate control unit 302 ２ and registers it as firmware of the first flow rate control unit 302 １ and second flow rate control unit 302 ２ The first flow rate control unit 302 may be appropriately corrected within the １ and second flow rate control unit 302 ２ The set value to be input to the corrected set flow rate Q ｃ You can correct it and input it.

[0062] Although the formula (13) shows a third-order polynomial as an example, it is not limited to this, and the measured flow rate Q ｍ Any method that can express this with a small error will suffice. For example, if there is only an offset, a zero-order polynomial will suffice, and if there is a deviation from the set flow rate by a constant multiple, a first-order polynomial will suffice; lower-order polynomials can reduce calculation costs. Also, instead of polynomials, exponential functions or logarithmic functions may be used.

[0063] By using the calibration method based on the relative buildup method described in the above examples, it is possible to detect with high accuracy changes in the flow control unit over time and changes in flow rate due to abnormalities without being affected by temperature deviations, volume deviations, or offsets in the pressure measurement unit, and to correct the actual flow rate of the flow control unit.

[0064] Example 3 This example describes a method for detecting an abnormality with respect to a reference gas in the relative buildup method described in Example 1. In the following description, components that are the same as or equivalent to those in Examples 1 and 2 above are given the same reference numerals, and descriptions thereof will be simplified or omitted.

[0065] In Example 1, the time differential ratio is used as the relative index E Ａｒ／Ｎ２ Therefore, the first flow rate control section 302 of the nitrogen gas, which is the reference gas, １ If the flow rate is out of sync due to aging or an abnormality, the second flow rate control unit 302 of the argon gas ２ Even if the reference gas flow control unit is normal, the relative index will deviate. If only these two gas types are used, it is difficult to determine which is abnormal. However, since the plasma processing apparatus 100 uses many gases for different processes, it usually has several tens of gas types, i.e., flow control units. Therefore, if the reference gas flow control unit is abnormal, all of the measured relative indexes will deviate in the same way, making it possible to determine this.

[0066] Therefore, a method for calculating correlations between relative index data for n types of flow rate control units mounted on the plasma processing apparatus 100 and determining that the flow rate control unit for the reference gas is abnormal if there are many relationships with strong correlations will be described using the flow chart in Fig. 9. Fig. 9 is a diagram showing an abnormality determination flow for the reference flow rate control unit according to an embodiment of the present disclosure.

[0067] In step 801, the normalized relative index ε is calculated by the processing of steps 401 to 408 in the first embodiment shown in FIG. 4 or steps 701 to 703 in the second embodiment shown in FIG. ｉ In addition, this normalized relative index ε ｉ is vector data including the measurement results of the past τ times, and the i-th (i is an integer from 1 to n) flow rate measurement unit 302 ｉ The data regarding can be expressed as in equation (15).

[0068] In step 802, it is determined whether measurements have been completed for all of the n types of flow rate control units, and step 801 is carried out while changing i until all measurements have been completed. Note that in this disclosure, the reference gas in step 801 is always the first flow rate control unit 302. １ The reference gas is not limited to nitrogen gas, and other gases may be set as the reference gas. The flow rate control unit is also appropriately selected depending on the set reference gas.

[0069] In step 803, the normalized relative index ε measured in step 801 is ｉ Each element of the vector data is logarithmized as shown in Equation (16). Because the relative index is the ratio of two measurement data, it is better to express it as a linear combination in order to find the correlation, and logarithmization makes it possible to express it as a linear combination.

[0070] In step 804, the logarithmic vector data is smoothed to reduce variations between measurements.

[0071] In step 805, a correlation matrix R between vector data for each flow control unit is calculated. First, the correlation coefficient ρ between vector data for two logarithmic i-th flow control unit and j-th (j is an integer from 1 to n) flow control unit is calculated. ij As shown in Equation (17), the covariance of the logarithmized normalized relative index is expressed as a standard deviation σ ｉ and σ ｊ This is calculated between the data of all n types of gases to obtain the n×n correlation matrix R shown in Equation (18).

[0072] In step 806, the number of elements in this correlation matrix R that exceed a preset correlation coefficient threshold is calculated, and it is determined whether or not this number exceeds a preset threshold for the number of elements. If the threshold for the number of elements is not exceeded, it can be said that there is little correlation between the deviations of the flow rate control units. １On the other hand, if the number of elements exceeds the threshold value, there is a large correlation between the deviations of the flow rate control units, that is, the deviation of the reference gas is smaller than the normalized relative index ε ｉ (i is 1 to n), in which case the process of step 807 is carried out.

[0073] In step 807, the vector data for the flow control unit that is determined to have a high correlation in step 806 is averaged for each element, and this is used as the first flow control unit 302 of the reference gas. １ As a deviation of all normalized relative indices ε ｉ (i is 1 to n) vector data is divided element by element and corrected.

[0074] In step 808, it is determined whether or not the corrected normalized relative index exceeds a predetermined determination threshold, and if it does, it is determined to be abnormal, and if it does not, it is determined to be normal.

[0075] In this example, the calculated normalized relative index ε ｉ (i is 1 to n) is corrected in step 806. １ If it is determined that there is an abnormality, the first flow rate control unit 302 １ In addition, it is possible to replace the first flow rate control section 302 of the reference gas. １ It is also possible to improve reliability by using an MFC that can self-detect abnormalities.

[0076] The first flow rate control section 302 of the reference gas in the relative buildup method described in the above embodiment １ By using the abnormality detection method and correction method, it is possible to detect with high accuracy the change in flow rate due to the time-dependent change of the flow rate control unit and the abnormality without being affected by the temperature deviation, the volume deviation, or the offset of the pressure measurement unit 306. For example, when the plasma processing apparatus 100 is １ and second flow rate control unit 302 ２ In addition, a third flow rate control unit 302 supplies a third processing gas to the processing chamber 110 at a set flow rate. ３The index calculation unit 308 of the plasma processing apparatus 100 calculates a first relative index based on the ratio between the first pressure information and the second pressure information, calculates a second relative index based on the ratio between the first pressure information and the third pressure information, which is an output from the pressure measurement unit when the third processing gas is being supplied to the processing chamber 110, and calculates a second relative index based on the correlation coefficient between the first relative index and the second relative index. １ or change the setting of the first flow rate control unit 302 １ , second flow rate control unit 302 ２ , and the third flow rate control unit 302 ３ It is possible to indicate whether or not at least one of the above needs to be replaced.

[0077] Example 4 This example describes a method for improving measurement accuracy and reliability in the relative build-up method described in Example 2. In steps 901 and 902 of Fig. 10 described below, the pressure measurement unit 306 measures pressure information after repeatedly supplying and exhausting the first process gas and / or the second process gas into the process chamber 110 a predetermined number of times. In the following description, components that are the same as or equivalent to those in Examples 1 to 3 above are designated by the same reference numerals, and their description will be simplified or omitted.

[0078] In the normalized relative index measurement flow shown in FIG. 7 of the second embodiment, the first flow rate control unit 302 １ and second flow rate control unit 302 ２ When determining the index of the predetermined flow rate, buildup measurement is performed only once for each gas, but this may not be sufficient depending on the gas type. For example, ４ In the case of gases that easily liquefy, such as those mentioned above, gas molecules may be adsorbed to the wall surfaces inside the processing chamber 110, resulting in a lower than expected pressure in the build-up measurement. Furthermore, when measuring, gas molecules that were adsorbed to the wall surfaces in the previous measurement may be released, resulting in a higher than expected pressure. The influence of these pressure changes due to outgassing also results in measurement errors in the relative build-up method, thereby reducing measurement accuracy. The influence of this outgassing can be suppressed by sufficiently filling the processing chamber 110 with the gas to be measured before measurement. Therefore, a method of measuring after filling the processing chamber 110 multiple times in advance will be described.

[0079] 10 is a diagram showing a reference flow for determining an abnormality in a flow control unit according to an embodiment of the present disclosure, which differs from the flow shown in FIG. 7 of the second embodiment in that measurements are performed multiple times using the same gas.

[0080] Steps 701 and 401 perform the same processing as steps 701 and 401 in FIG. 7 of the second embodiment.

[0081] In step 901, the first flow rate control unit 302 １ The pressure measurement unit 306 and the index calculation unit 308 determine whether build-up measurement has been performed a predetermined number of times, and repeat the build-up measurement until the predetermined number of times is reached. Note that this predetermined number of times may be set in advance, or may be determined by checking the linearity of the measured pressure change, or may be determined based on whether the same pressure change is obtained.

[0082] Steps 702 and 402 are the same as steps 702 and 402 in FIG. 7 of the second embodiment.

[0083] In step 902, the second flow rate control unit 302 ２ It is determined whether build-up measurement for the target has been performed a predetermined number of times, and the build-up measurement is repeated until the predetermined number of times is reached.

[0084] Steps 403 to 408 are the same as steps 403 to 408 in FIG. 7 of the second embodiment.

[0085] By using an index based on the relative buildup method described in the above examples, it is possible to detect with high accuracy changes in the flow control unit over time and changes in flow rate due to abnormalities without being affected by temperature deviations, volume deviations, or offsets in the pressure measurement unit 306, and further reducing the impact of outgassing.

[0086] Example 5 This example describes a method for improving reliability in the relative build-up method described in Example 1. The index calculation unit 308 calculates a first relative index based on the ratio between the first pressure information and the second pressure information, calculates a second relative index based on the ratio between the second pressure information and third pressure information, which is the output of the pressure measurement unit when the first process gas is being supplied to the process chamber 110, and determines whether the difference between the first relative index and the second relative index is within a predetermined range. In the following description, components that are the same as or equivalent to those in Example 1 above are denoted by the same reference numerals, and their description will be simplified or omitted.

[0087] In the first embodiment, it was explained that the relative index is valid because "it can be assumed that the temperature inside the processing chamber 110 does not change during that time." However, when measurements are performed using the relative buildup method during actual plasma processing, the temperature is considered to be changing strictly. The reliability of the index can be ensured by checking whether this is within an allowable range before use.

[0088] 11 is a diagram showing a flow of determining the reliability of a normalized relative index according to an embodiment of the present disclosure. The flow differs from the flow shown in FIG. 4 of the first embodiment in that buildup measurement using a reference gas is increased.

[0089] Step 1001 corresponds to steps 401, 403, and 404 in FIG. 4 of the first embodiment, and is executed by the first flow rate control unit 302. １ Build-up measurements are performed.

[0090] Step 1002 corresponds to steps 402, 403, and 404 in FIG. 4 of the first embodiment, and is executed by the second flow rate control unit 302. ２ Build-up measurements are performed.

[0091] In step 1003, a first normalized relative index (first relative index) is calculated based on the data obtained in steps 1001 and 1002.

[0092] In step 1004, similarly to step 1001, the first flow rate control unit 302 １The pressure measured by the pressure measuring unit 306 in step 1001 is the first pressure information, and the pressure measured by the pressure measuring unit 306 in step 1002 is the second pressure information. For convenience, the pressure measured by the pressure measuring unit 306 in step 1004 can be referred to as the third pressure information.

[0093] In step 1005, a second normalized relative index (second relative index) is calculated based on the data obtained in steps 1004 and 1002.

[0094] In step 1006, the first normalized relative index obtained in step 1003 is compared with the second normalized relative index obtained in step 1005, and if the difference therebetween exceeds a predetermined range, it is determined that the cause is, for example, a sudden change in temperature, and remeasurement is performed. On the other hand, if the difference is within the predetermined range, it is determined that there was no sudden change in temperature.

[0095] In this description, step 1004, which is the buildup measurement of the reference gas, is performed to check for this deviation, but since it is necessary to perform the buildup measurement of the reference gas for the measurement of the next flow rate control unit or the next opening, this may also be performed. That is, the deviation check of this embodiment may be performed by sequentially measuring the first gas (reference gas) → second gas (measurement object 1) → first gas (reference gas) → third gas (measurement object 2) → first gas (reference gas) → ...

[0096] By using an index based on the relative buildup method described in the above examples, it is possible to detect with high accuracy changes in the flow control unit over time and changes in flow rate due to abnormalities without being affected by temperature deviations, volume deviations, or offsets in the pressure measurement unit, and after confirming that there are no temperature changes.

[0097] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present invention.

[0098] 1. A vacuum processing apparatus comprising: a processing chamber capable of reducing the pressure inside the processing chamber; a first flow rate control unit configured to supply a first processing gas into the processing chamber at a controlled flow rate; a second flow rate control unit configured to supply a second processing gas into the processing chamber at a controlled flow rate; a pressure measurement unit configured to measure an internal pressure of the processing chamber; and an index calculation unit configured to calculate an index based on an output of the pressure measurement unit, the index calculation unit calculating a relative index based on a ratio of first pressure information output from the pressure measurement unit while the first processing gas is being supplied to the processing chamber to second pressure information output from the pressure measurement unit while the second processing gas is being supplied to the processing chamber, and changing settings of the first flow rate control unit and / or the second flow rate control unit based on the relative index, or indicating whether the first flow rate control unit and / or the second flow rate control unit needs to be replaced. (Aspect 2) The vacuum processing apparatus according to Aspect 1, further comprising: an exhaust mechanism that depressurizes the interior of the processing chamber; and an exhaust adjustment unit that controls an exhaust flow rate of the processing chamber, wherein the pressure measurement unit measures pressure information after the exhaust mechanism has depressurized the processing chamber and then the exhaust adjustment unit has sealed the processing chamber. (Aspect 3) The vacuum processing apparatus according to Aspect 1 or Aspect 2, wherein the index calculation unit normalizes the relative index based on a relative index calculated in an initial state of the first flow rate control unit and / or the second flow rate control unit. (Aspect 4) The vacuum processing apparatus according to any one of Aspects 1 to Aspect 3, wherein the index calculation unit time-differentiates the first pressure information and the second pressure information. (Aspect 5) A vacuum processing apparatus according to any one of Aspects 1 to 4, wherein the index calculation unit calculates a relative index for each flow rate set in the second flow rate control unit, derives a relationship between the flow rate set in the second flow rate control unit and the actual flow rate of the second processing gas supplied to the processing chamber from the calculated relative indexes, and changes the setting of the second flow rate control unit based on the derived relationship.(Aspect 6) The vacuum processing apparatus according to any one of Aspects 1 to 5, further comprising a third flow rate control unit configured to supply a third process gas to the processing chamber at a set flow rate, wherein the index calculation unit: calculates a first relative index based on a ratio between the first pressure information and the second pressure information, calculates a second relative index based on a ratio between the first pressure information and third pressure information, which is an output of the pressure measurement unit while the third process gas is being supplied to the processing chamber, and changes a setting of the first flow rate control unit based on a correlation coefficient between the first relative index and the second relative index, or indicates whether at least one of the first flow rate control unit, the second flow rate control unit, and the third flow rate control unit needs to be replaced. (Aspect 7) The vacuum processing apparatus according to any one of Aspects 1 to 6, further comprising: an exhaust mechanism configured to reduce the pressure inside the processing chamber; and an exhaust adjustment unit configured to control an exhaust flow rate of the processing chamber, wherein the pressure measurement unit measures the pressure information after repeating the supply and exhaust of the first process gas and / or the second process gas to the processing chamber a predetermined number of times. (Aspect 8) A vacuum processing apparatus according to any one of Aspects 1 to 7, wherein the index calculation unit calculates a first relative index based on a ratio between the first pressure information and the second pressure information, calculates a second relative index based on a ratio between the second pressure information and third pressure information, which is an output of the pressure measurement unit when the first processing gas is being supplied to the processing chamber again, and determines whether a difference between the first relative index and the second relative index is within a predetermined range.(Aspect 9) A vacuum processing method for an apparatus including a processing chamber capable of reducing the pressure inside, a first flow rate control unit that supplies a first processing gas to the processing chamber at a controlled flow rate, and a second flow rate control unit that supplies a second processing gas to the processing chamber at a controlled flow rate, the vacuum processing method comprising: a pressure measurement step of measuring an internal pressure of the processing chamber; an index calculation step of calculating a relative index based on a ratio of first pressure information that is an output of the pressure measurement step when the first processing gas is being supplied to the processing chamber and second pressure information that is an output of the pressure measurement step when the second processing gas is being supplied to the processing chamber; and a change suggestion step of changing settings of the first flow rate control unit and / or the second flow rate control unit based on the relative index, or suggesting whether the first flow rate control unit and / or the second flow rate control unit needs to be replaced. (Aspect 10) The vacuum processing method according to Aspect 9, comprising: an exhaust step of decompressing the interior of the processing chamber; and an exhaust adjustment step of controlling an exhaust flow rate of the processing chamber, wherein the pressure measurement step measures pressure information after the processing chamber is decompressed by the exhaust step and in a state where the processing chamber is sealed by the exhaust adjustment step. (Aspect 11) The vacuum processing method according to Aspect 9 or Aspect 10, wherein the index calculation step normalizes the relative index based on a relative index calculated in an initial state of the first flow rate control unit and / or the second flow rate control unit. (Aspect 12) The vacuum processing method according to any one of Aspects 9 to 11, wherein the index calculation step time-differentiates the first pressure information and the second pressure information. (Aspect 13) A vacuum processing method according to any one of Aspects 9 to 12, characterized in that the index calculation step calculates a relative index for each flow rate set in the second flow rate control unit, and derives from the calculated relative indexes a relationship between the flow rate set in the second flow rate control unit and an actual flow rate, which is the flow rate observed in the processing chamber, and the change presentation step changes the setting of the second flow rate control unit based on the derived relationship.(Aspect 14) A vacuum processing method according to any one of Aspects 9 to 13, wherein the apparatus further includes a third flow rate control unit that supplies a third processing gas to the processing chamber; the index calculation step calculates a first relative index based on a ratio between the first pressure information and the second pressure information; and calculates a second relative index based on a ratio between the first pressure information and third pressure information, which is an output of the pressure measurement step when the third processing gas is being supplied to the processing chamber; and the change suggestion step changes a setting of the first flow rate control unit based on a correlation coefficient between the first relative index and the second relative index, or suggests whether at least one of the first flow rate control unit, the second flow rate control unit, and the third flow rate control unit needs to be replaced. (Aspect 15) The vacuum processing method according to any one of Aspects 9 to 14, comprising: an exhaust step of reducing the pressure inside the processing chamber; and an exhaust adjustment step of controlling an exhaust flow rate of the processing chamber, wherein the pressure measurement step measures pressure information after repeating the supply of the first processing gas and / or the second processing gas to the processing chamber and exhausting the processing chamber a predetermined number of times. (Aspect 16) The vacuum processing method according to any one of Aspects 9 to 15, wherein the index calculation step calculates a first relative index based on a ratio between the first pressure information and the second pressure information, and calculates a second relative index based on a ratio between the second pressure information and third pressure information that is an output of the pressure measurement step when the first processing gas is again being supplied to the processing chamber, and the change presenting step determines whether a difference between the first relative index and the second relative index is within a predetermined range.

[0099] 100: Plasma processing apparatus, 101: First high frequency power supply, 102: Cover member (quartz plate), 103: Shower plate, 105: Quartz inner cylinder, 106: Solenoid coil, 110: Processing chamber, 120: Discharge block, 124: Discharge chamber, 125: Earth ring, 130: Upper vessel, 140: Sample stage, 148: Second high frequency power supply, 150: Lower vessel, 160: Base plate, 161: Exhaust section cover, 162: Cylinder, 170: Exhaust pump, 200: Wafer, 206: Hollow support beam, 301 １ : first gas supply unit, 302 １ : First flow rate control unit, 301 ２ : second gas supply unit, 302 ２ 305: Second flow rate control unit, 306: Pressure measurement unit, 307: Exhaust speed control unit, 308: Index calculation unit

Claims

a processing chamber whose interior can be decompressed; a first flow rate control unit that controls the flow rate of a first processing gas and supplies the first processing gas to the processing chamber; a second flow rate control unit that controls the flow rate of a second processing gas and supplies the second processing gas to the processing chamber; a pressure measuring unit that measures the internal pressure of the processing chamber; an index calculation unit that calculates an index based on a pressure measurement unit output that is an output of the pressure measurement unit, The index calculation unit calculating a relative index based on a ratio between first pressure information, which is an output of the pressure measuring unit when the first process gas is being supplied to the process chamber, and second pressure information, which is an output of the pressure measuring unit when the second process gas is being supplied to the process chamber; changing the setting of the first flow control unit and / or the second flow control unit based on the relative index, or indicating whether or not the first flow control unit and / or the second flow control unit needs to be replaced; A vacuum processing apparatus characterized by:

2. The vacuum processing apparatus according to claim 1, an exhaust mechanism for reducing the pressure inside the processing chamber; an exhaust adjustment unit that controls an exhaust flow rate of the processing chamber, the pressure measuring unit measures pressure information in a state in which the processing chamber is sealed by the exhaust adjusting unit after the processing chamber is decompressed by the exhaust mechanism; A vacuum processing apparatus characterized by:

2. The vacuum processing apparatus according to claim 1, the index calculation unit normalizes the relative index based on the relative index calculated in an initial state of the first flow rate control unit and / or the second flow rate control unit. A vacuum processing apparatus characterized by:

2. The vacuum processing apparatus according to claim 1, The index calculation unit differentiates the first pressure information and the second pressure information with respect to time. A vacuum processing apparatus characterized by:

2. The vacuum processing apparatus according to claim 1, the index calculation unit calculates a relative index for each flow rate set in the second flow rate control unit, derives a relationship between the flow rate set in the second flow rate control unit and the actual flow rate of the second process gas supplied to the process chamber from the calculated relative indexes, and changes the setting of the second flow rate control unit based on the derived relationship. A vacuum processing apparatus characterized by:

2. The vacuum processing apparatus according to claim 1, a third flow rate control unit that sets a flow rate of a third process gas and supplies the third process gas to the process chamber; The index calculation unit Calculating a first relative index based on a ratio between the first pressure information and the second pressure information; calculating a second relative index based on a ratio of third pressure information, which is an output of the pressure measuring unit while the third process gas is being supplied to the process chamber, to the first pressure information; changing a setting of the first flow control unit based on a correlation coefficient between the first relative index and the second relative index, or indicating whether or not at least one of the first flow control unit, the second flow control unit, and the third flow control unit needs to be replaced; A vacuum processing apparatus characterized by:

2. The vacuum processing apparatus according to claim 1, an exhaust mechanism for reducing the pressure inside the processing chamber; an exhaust adjustment unit that controls an exhaust flow rate of the processing chamber, the pressure measuring unit measures pressure information after repeating supplying and exhausting the first processing gas and / or the second processing gas into the processing chamber a predetermined number of times; A vacuum processing apparatus characterized by:

2. The vacuum processing apparatus according to claim 1, The index calculation unit Calculating a first relative index based on a ratio between the first pressure information and the second pressure information; calculating a second relative index based on a ratio of third pressure information, which is an output of the pressure measuring unit when the first process gas is being supplied to the process chamber again, to the second pressure information; determining whether a difference between the first relative index and the second relative index is within a predetermined range; A vacuum processing apparatus characterized by: 　 A vacuum processing method in an apparatus including a processing chamber capable of reducing the pressure inside, a first flow rate control unit that controls the flow rate of a first processing gas to the processing chamber, and a second flow rate control unit that controls the flow rate of a second processing gas to the processing chamber, a pressure measuring step of measuring an internal pressure of the processing chamber; an index calculation step of calculating a relative index based on a ratio of first pressure information, which is an output of the pressure measurement step when the first process gas is being supplied to the process chamber, to second pressure information, which is an output of the pressure measurement step when the second process gas is being supplied to the process chamber; and a change indicating step of changing the setting of the first flow control unit and / or the second flow control unit based on the relative index, or indicating whether or not the first flow control unit and / or the second flow control unit needs to be replaced. A vacuum processing method characterized by:

10. The vacuum processing method according to claim 9, an exhaust step of reducing the pressure inside the processing chamber; an exhaust adjustment step of controlling an exhaust flow rate of the processing chamber. the pressure measuring step measures pressure information in a state where the processing chamber is hermetically sealed in the exhaust adjusting step after the processing chamber is depressurized in the exhaust step. A vacuum processing method characterized by:

10. The vacuum processing method according to claim 9, the index calculation step normalizes the relative index based on the relative index calculated in an initial state of the first flow rate control unit and / or the second flow rate control unit. A vacuum processing method characterized by:

10. The vacuum processing method according to claim 9, the index calculation step differentiates the first pressure information and the second pressure information with respect to time; A vacuum processing method characterized by:

10. The vacuum processing method according to claim 9, the index calculation step calculates a relative index for each flow rate set in the second flow rate control unit, and derives a relationship between the flow rate set in the second flow rate control unit and an actual flow rate, which is a flow rate observed in the processing chamber, from the calculated relative indexes; The change suggestion step changes the setting of the second flow rate control unit based on the derived relationship. A vacuum processing method characterized by:

10. The vacuum processing method according to claim 9, the apparatus further includes a third flow rate control unit that supplies a third process gas to the process chamber; The index calculation step includes: Calculating a first relative index based on a ratio between the first pressure information and the second pressure information; calculating a second relative index based on a ratio of third pressure information, which is an output of the pressure measuring step when the third process gas is being supplied to the process chamber, to the first pressure information; The change suggestion step changes a setting of the first flow control unit based on a correlation coefficient between the first relative index and the second relative index, or suggests whether or not at least one of the first flow control unit, the second flow control unit, and the third flow control unit needs to be replaced. A vacuum processing method characterized by:

10. The vacuum processing method according to claim 9, an exhaust step of reducing the pressure inside the processing chamber; an exhaust adjustment step of controlling an exhaust flow rate of the processing chamber, the pressure measuring step measures pressure information after repeating supplying and exhausting the first process gas and / or the second process gas into the process chamber a predetermined number of times; A vacuum processing method characterized by:

10. The vacuum processing method according to claim 9, The index calculation step includes: Calculating a first relative index based on a ratio between the first pressure information and the second pressure information; calculating a second relative index based on a ratio of third pressure information, which is an output of the pressure measurement step when the first process gas is being supplied to the process chamber again, to the second pressure information; The change presentation step determines whether a difference between the first relative index and the second relative index is within a predetermined range. A vacuum processing method characterized by:

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