JP4647253B2 - Method for stabilizing wall surface of processing chamber of plasma processing apparatus - Google Patents

Description

  The present invention relates to a plasma processing apparatus and a plasma processing method for performing processing such as etching on an object to be processed using plasma of a plasma etching apparatus or a plasma CVD apparatus.

  When dust adheres to the substrate in the manufacturing process of the semiconductor device, a pattern defect of the target device is caused, and the yield in the manufacturing process is reduced. On the other hand, in a dry etching process in which various gases are introduced into the apparatus and etching is performed using the plasma reaction of the introduced gas, a product generated along with the etching is deposited on the inner wall of the apparatus (hereinafter, It becomes a source of dust generation.

Therefore, it is necessary to periodically remove these deposition films. As such a deposition film removal method, after dry etching processing of an Al-containing film formed on a semiconductor substrate using a chlorine-based gas in a processing chamber, a gas containing O ₂ , a gas containing F, and Cl are used. The mixed gas of the gas containing is introduced into the processing chamber, and the plasma is generated to remove the residual reactive organism aluminum chlorine carbide (Al _x C _y Cl _z ) adhering to the processing chamber. It has been proposed to reduce the maintenance time (see, for example, Patent Document 1).

Furthermore, in order to keep the state of the etching chamber constant, there has also been proposed a processing method in which after the plasma cleaning is performed, the wall surface to which the deposition film is adhered is shaved with plasma (see, for example, Patent Document 2).
JP-A-8-319586 JP 7-335626 A

  However, a highly corrosive gas containing chlorine (Cl), hydrogen bromide (HBr), or the like has come to be used for the plasma etching process. As a material for the processing chamber of the etching equipment, a material with an oxide coating such as a spray coating of anodized or alumina ceramic is generally used as a material having high corrosion resistance against these gases. is there. On the other hand, when the deposition film is completely removed by plasma cleaning, even if the oxide film has a stable structure, the surface layer is corroded by a highly corrosive gas, and foreign matter is likely to be generated. Further, since the oxide film described above has a porous structure, there has been a problem that gas reaches the film base material and is corroded.

  The prior art is characterized in that the deposit film is removed or the wall surface after removal of the deposit is also removed, and no consideration has been given to the problem of the wall material surface layer or the corrosion of the base material.

An object of the present invention is to solve these problems, a deposited film of the processing chamber can be suppressed corrosion of removal and the wall material is to provide a process chamber wall stabilizing how.

  The above object is achieved by providing a processing system capable of adding a stabilization process of the processing chamber wall surface at an arbitrary timing to the operation process of the etching apparatus.

  Further, the above object is achieved by providing the etching apparatus with alarm means for detecting the corrosion of the wall surface by the monitoring means in the processing chamber and notifying the occurrence of the corrosion, and the stabilization processing step can be executed in response to the detection signal. This is achieved by having operating means.

As a method to be processed by the apparatus, oxygen or fluorine (for example, SF ₆ , CF ₄ , C ₂ F ₆₎ is preferably used immediately after the plasma cleaning process until the plasma cleaning process is shifted to the etching process. , (C _x F _y )) gas plasma will be used to replace the corrosive gas molecules associated with the process chamber material, providing a stabilization process step.

  In addition, the above purpose is to arbitrarily select, set, and input the number of wafers to be processed in the continuous processing process and the amount of time of stabilization processing to the etching apparatus. This is achieved by having the function to perform.

  An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a dry etching apparatus used for carrying out the manufacturing method of the present invention, which is an example of an apparatus using electron cyclotron resonance (ECR). In FIG. 1, a dry etching apparatus includes an etching processing chamber 101, a wall surface 102 in direct contact with plasma installed in the etching processing chamber, a substrate stage 103 on which an Si substrate 104 to be etched is placed, and a processing chamber. It has an exhaust port 105 for evacuating to a pressure. Further, the dry etching apparatus includes a UHF band electromagnetic power source 106, a matching unit 107, an antenna 108, a solenoid coil 109, a high frequency power source 111, an emission spectrometer 112, and an optical fiber that takes plasma light into the emission spectrometer. 113, an operation computer 114 for the emission spectrometer, and a control computer 115 for the entire etching apparatus.

  In the etching process, first, the pressure is adjusted to a predetermined pressure by evacuation. Next, UHF band electromagnetic waves are introduced into the etching processing chamber 101 from the UHF band electromagnetic power source 106 through the matching unit 107 and the antenna 108. The introduced electromagnetic wave is converted into plasma from the gas in the processing chamber by resonance with the magnetic field formed by the solenoid coil 109, and etching processing is performed using the plasma 110. For the purpose of controlling the processing shape, the substrate stage 103 on which the substrate is placed is subjected to anisotropic etching by applying an RF bias by a high frequency power source 111 and drawing ions in the plasma.

Next, the flow of processing when surface processing of a Si wafer is performed with this apparatus will be described with reference to FIG. For example, in the processing of the gate electrode of a semiconductor element, polycrystalline Si is etched using a highly corrosive gas such as Cl ₂ or HBr or a plasma of a mixed gas thereof. In addition to this, since the reactivity with Si is the highest and therefore the etching rate is increased, a gas containing F, such as CF _4, tends to be used in recent years. In addition, for the purpose of preventing a reaction product of Si from depositing on the inner wall of the treatment chamber 101 after the etching to form a deposit film and forming a foreign substance containing Si, plasma of a gas having a strong reactivity with Si, such as SF ₆ , is used. The used plasma cleaning is performed. In the past, plasma cleaning was usually performed between lots. However, since the processing accuracy has become severe, the atmosphere in the processing chamber must always be kept constant. For example, there are an increasing number of cases where N = 5, for example, or every other sheet.

  As described above, in addition to plasma cleaning, F, which has a high reactivity with Si during the etching process, is frequently used. Therefore, on the wall surface of the process chamber in the series of process flows shown in FIG. There is a strong tendency for the number of deposits to be reduced.

  On the other hand, as a constituent material in the processing chamber of the etching apparatus, a material provided with an oxide film is generally used as a material having corrosion resistance against these gases. When so-called heavy metals such as Fe and Cr adhere to a small amount of Si substrate, they diffuse into the Si semiconductor and interfere with the operation of the semiconductor. Therefore, an aluminum-based oxide film such as alumite or alumina ceramic sprayed film is used. This is especially true. As the coating base material, a material having a light weight and a small specific gravity is desirable in terms of ease of work. Therefore, an aluminum alloy is generally used. An aluminum alloy is often used for the base material other than the aluminum-based coating described above.

As described above, if there are few cases where deposits are present on the wall surface of the processing chamber during a series of processing, even if the oxide film has a stable structure, the surface layer is corroded by the highly corrosive gas and foreign matter is removed. Prone to occur easily. Further, the oxide film has a porous structure, and the temperature rises due to heat input from the plasma, so that the oxide film is in an environment where cracks are likely to occur due to thermal expansion. That is, there is a problem that the gas reaches the base material of the coating through the small holes in the coating or the coating and is corroded. FIG. 3 and FIG. 4 show schematic views of cross sections of the sprayed coating and the alumite coating. Aluminum used for the coating base material is corroded by Cl and HBr, and is released into the processing chamber as AlCl ₃ and AlBr. Therefore, in terms of the life of the processing chamber wall, it affects the etching processing result. In that sense, the problem is big.

In the present embodiment, the etching apparatus is provided with a monitoring means for detecting the presence of a reactant containing the material constituting the processing chamber wall surface, and when the concentration of the reactant becomes a predetermined amount or more in a series of processing flows, A means for generating an alarm was provided. As a result, it is possible to prevent problems caused by etching processing results caused by reactants including the material constituting the processing chamber wall, such as AlCl ₃ or AlBr. It also serves as a guideline for replacing parts. In the present embodiment, an example in which a plasma emission spectroscope is used as the monitoring means has been shown. In FIG. 1, reference numeral 112 denotes an emission spectrometer, 113 denotes an optical fiber that takes plasma light into the emission spectrometer, 114 denotes an operation computer for the emission spectrometer, and 115 denotes a control computer for the entire etching apparatus. In the control computer 115 of the etching apparatus, a signal indicating a reaction product including a material constituting the processing chamber wall surface and a signal threshold value can be set in advance, and based on emission data sent from the computer 114 controlling the emission spectrometer 114. When the threshold is exceeded, an alarm is issued. The details are as follows.

FIG. 5 shows a plasma emission spectrum obtained at a certain time during etching of polysilicon with Cl ₂ gas plasma. The emission spectrum can be obtained as the emission intensity of each channel by dividing a certain wavelength range, here 250 nm to 850 nm, into a number of channels (2000 channels here). Here, when detecting a reactant containing a material constituting the processing chamber wall surface, the signal to be detected varies depending on the combination of the gas used for processing and the processing chamber wall surface material. A function to select a channel is provided. Specific selected wavelength signals in the control computer 115 of the etching apparatus, if it exceeds a predetermined threshold value which can be arbitrarily set, so that the alarm signal Ru notify that effect is issued.

  For example, when detecting the scraping of the Al part as in the present embodiment, the emission of 396 nm of Al atoms may be selected. Furthermore, if a plurality of signals are selected and an arithmetic function is provided in which the result of addition, subtraction, multiplication or division is used as a detection signal, the effectiveness is further increased. For example, in the example of FIG. 5, when Al is detected, the emission of Al atoms can be observed at 309 nm in addition to 396 nm. Therefore, a higher signal can be obtained by adding the signals of 309 nm and 396 nm. For example, in the example of FIG. 5, the etching of polysilicon proceeds by a reaction of Si + Cl → SiCl (281 nm). However, when the Al on the wall surface is cut, Al + Cl → AlCl (261 nm) also proceeds simultaneously. That is, since Cl radicals used for etching silicon are consumed by Al, the emission signal of SiCl, 281 nm, is lowered. Here, if the addition result of the signal intensity of Al (309 nm and 396 nm) and the signal intensity of AlCl (261 nm) or the addition result of the signal intensity of Al and AlCl is divided by the signal intensity of SiCl, the detection signal is used. A signal having a higher S / N can be obtained. Whether to select such a combination of signals varies depending on the combination of the gas used for processing and the processing chamber wall surface material, and therefore it is important to have a function that allows the detection signal to be arbitrarily selected.

  In addition to the present embodiment, the same effect can be obtained by using a gas mass analyzer, an impedance monitor, and a plasma current / voltage detector.

Next, another embodiment of the present invention will be described. In the present embodiment, a stabilization processing step is provided in which a corrosive gas molecule bonded to the processing chamber material is replaced during the transition from the cleaning process to the etching process in a series of processing flows. The processing flow in this embodiment is shown in FIG. As the stabilization treatment, plasma discharge of a gas that can be a compound having corrosion resistance against Cl ₂ , HBr, or the like is performed. For example, O ₂ or F is given for an aluminum-based material. FIG. 7 shows a schematic cross-sectional view, but as shown in the figure, it is possible to maintain the corrosion resistance by forming an oxide layer or a fluoride layer having corrosion resistance on the bottom surface of the crack. It is thought that the oxide layer or fluoride layer formed on the surface by the gas plasma is very thin, on the order of nm. However, before the oxide layer or fluoride layer is removed, the stabilization process is performed again. By doing so, it is possible to prevent the occurrence of aluminum corrosion over a long period of time.

[Experiment 1] According to experiments by the inventors of the present application, it has been found that even when ordinary corrosion-resistant aluminum is used for the wall surface of the processing chamber, there is an effect. FIG. 8 shows the experimental results. In the experiment, the processing chamber wall material was A5051 corrosion-resistant aluminum, and the SiO ₂ wafer was etched. The reason for using the SiO ₂ wafer is to eliminate the influence of the deposition film of the reaction product of Si. Condition 1 was that etching with Cl ₂ gas for 30 seconds was repeated. Etching was performed at a Cl ₂ gas flow rate of 200 sccm, a pressure of 1 Pa, a source power of 400 W, and an RF bias of 40 W. Condition 2 was that O ₂ gas plasma discharge was performed for 20 seconds before etching, and O ₂ discharge → etching was repeatedly performed. O ₂ gas discharge was performed at an O ₂ gas flow rate of 300 sccm, a pressure of 1 Pa, a source power of 800 W, and an RF bias of 0 W. A plasma emission spectrometer was attached to the processing chamber, and the above experiment was conducted while monitoring the Al emission wavelength of 396 nm. Under condition 1 where no O ₂ discharge was performed, the emission of Al was remarkable during the second processing. On the other hand, under condition 2, no light emission of Al was observed even when 10 or more sheets were processed. Clear protection of the wall material was observed by always forming an oxide layer on the surface.

[Experiment 2] FIG. 9 shows an example of a wall surface material subjected to alumite treatment. A wall material that has been used for more than a year, and in particular, an anodized metal that had been exposed to the base metal after cutting. In the experiment, Si was etched using Cl ₂ gas. Condition 1 was that etching was repeated for 60 seconds after cleaning, and condition 2 was O ₂ gas plasma 20 seconds before etching. Again, a plasma emission spectrometer was installed in the processing chamber and the above experiment was conducted while monitoring the Al emission wavelength of 396 nm. Under condition 1, Al emission was already observed on the second piece. In condition 2, no light emission of Al was observed even after 25 sheets were processed.

  In this way, by providing a stabilization step between the cleaning process and the etching process, and constantly performing a stabilization process in which an oxide layer or a fluoride layer is formed on the surface by gas plasma, the occurrence of aluminum corrosion, That is, it becomes possible to prevent the wall material from being scraped. That is, the discharge condition of the stabilization step is set and the etching apparatus has a function that can be executed between the cleaning process and the etching process. For example, the control computer of the apparatus can prevent corrosion of the apparatus wall surface. This is an effective means for stable operation over a long period of time.

  The above embodiment has been described by taking an example in which the stabilization step is performed for each plasma cleaning step. However, it is not always necessary to perform the stabilization step for each plasma cleaning step, and the stabilization step is performed at an arbitrary timing. May be implemented. In other words, the effectiveness increases by providing the etching apparatus with a function capable of arbitrarily setting the timing and timing of performing the stabilization process. For example, not only products having the same device structure are always processed in the same processing chamber, but various product processings with different film thickness, film quality, mask area, etc. are usually performed. That is, since the etching conditions, that is, the gas pressure, the gas flow rate, the input power, and the like are different for each product, the degree of influence on the apparatus wall surface is different for each condition. The safest device operation is to perform a stabilization step after every cleaning step on all products. However, even under conditions where the influence of corrosion is small on the wall of the apparatus, the stabilization processing step is performed after the cleaning step, and the time used for actual product processing and the actual operation time are pressed. . Therefore, the stabilization interval is determined for each product. For example, the product A uses a very corrosive condition, so the stabilization processing step is performed every plasma cleaning, and the product B has a smaller influence than the A. Therefore, the effect of product C is smaller once every 4 lots, so the effect of the product C is smaller, so it is possible to minimize the reduction in the actual operation time of the equipment by performing it once every 8 lots. Can be prevented over a long period of time.

  In the above example, the interval for the stabilization process was described. However, even if the stabilization process time is changed for each product, that is, the effect of corrosion on the device wall is small, the stabilization process is performed in a short time. If a long-term stabilization treatment step is performed under conditions where corrosion is severe, an effect of achieving both corrosion resistance and throughput can be obtained. Furthermore, both the time and interval of the stabilization process may be changed. As described above, it is important to have a function for setting the control computer of the processing apparatus so that the timing and time for performing the stabilization process can be flexibly executed depending on the type of product.

Next, another embodiment of the present invention will be described with reference to FIG. The present embodiment is characterized in that a monitor means for detecting the release of the wall material into the plasma is provided, and the wall surface stabilization process is executed by detecting the scraping of the processing chamber member by the monitor means.

  As the monitoring means, first, as described in the first embodiment, there is a spectroscope that detects light emission from plasma. The emission spectrometer may be a detector that extracts light of a single wavelength, such as a monochromator, but it is optimal to be a detector that outputs a large number of signals, such as a spectrometer that outputs a wavelength-resolved emission spectrum. is there. Moreover, the mass analyzer which can monitor the gas in a process chamber for every value of mass number may be used. Furthermore, it can be detected by a current detector or voltage detector installed in the path for applying power to the plasma generation means, or a current voltage phase difference detector, a traveling wave detector of power, a reflected wave detector, an impedance monitor, etc. It is. Wall monitors are very sensitive to the impedance of the plasma, and these monitors, installed in the power path for plasma generation, are very sensitive and can detect even slight wall scraping. The above-described monitoring means outputs a signal at regular intervals or every set number of sampling times. Here, as in the first embodiment, an example using a plasma emission spectrometer will be described.

[Experiment 3] FIG. 10 shows a result of applying the wall material subjected to the alumite treatment to the apparatus. The present invention was applied to an apparatus that had been using the wall material 102 for over a year and was in a state of being replaced. In the experiment, the Si bare wafer was etched using Cl ₂ gas under the same conditions as in Experiment 1. In order to remove the deposited film of Si, plasma cleaning using SF ₆ plasma is performed for 10 seconds without a dummy wafer for each sheet. A plasma emission spectrometer was attached to the processing chamber, and while monitoring the Al emission wavelength of 396 nm, etching was performed to output the average value of the emission wavelength of 396 nm during etching. The sampling interval was once per second.

  First, continuous processing was performed under condition 1 without using a stabilization step, and processing was performed under condition 2 where the stabilization step was performed when a preset upper limit value was exceeded. Since it was confirmed that the emission intensity at a wavelength of 396 nm stably shifted between 10 and 20 until the 10th sheet after the start of continuous processing, the upper limit of the emission intensity was set to 30 (201 in the figure). Since the upper limit was reached at the 56th sheet (202 in the figure), it gradually increased from around the 45th processed (202 in the figure), and when the stabilization step was switched to Condition 2 to be performed after plasma cleaning, the emission intensity at a wavelength of 396 nm was continuous. It was confirmed that the level dropped to the level at the start of processing. As described above, by automatically executing the stabilization step using the Al release detection signal from the monitor, it is possible to effectively prevent the wall corrosion while suppressing the decrease in the operation rate. In addition, even if the stabilization step is performed, if there is a possibility that Al release may be observed during long-term production, a certain extension time is set and an Al release detection signal is output from the monitor. In response, the stabilization step may be automatically extended. For example, in FIG. 10, the stabilization step S is 20 seconds, but when the threshold value is exceeded for the second time, it increases to 30 seconds, and when the threshold value is removed for the third time, it increases to 40 seconds. With this, wall stabilization can be achieved effectively. Here, the time is increased every 10 seconds, but the degree of corrosion of the wall surface varies depending on the plasma power and processing time in the plasma processing, so the increasing time can be arbitrarily set on the apparatus side according to the processing conditions. Is preferred. In the present embodiment, the average value of the emission intensity is used as monitor data, but it may be determined by the maximum value measured during etching.

  In this way, the etching apparatus is provided with alarm means for detecting corrosion of the wall surface by the monitoring means in the processing chamber and notifying the occurrence of corrosion, and operating means capable of executing the stabilization processing step upon receiving the detection signal, for example, stable By providing means for setting parameters such as timing for executing the conversion step, time, and extension of time, stable production can be continued.

  As in this embodiment, detection of Al release by the monitoring means is also effective for device management. If the monitor value exceeds a preset threshold value, if it is output immediately, it also serves as means for notifying the operator of the device status. The output form may be an alarm such as a buzzer, a display on the operation panel, or a display on the personal computer of the device operator.

No matter how the stabilization step is performed, if the surface coating such as anodized or sprayed coating becomes thin or becomes partially uncut, the base material is easily corroded and an alarm is frequently issued. It is also effective to divide the warning level according to how many times the threshold has been exceeded or the number of warnings accumulated. For example, if it deviates from the threshold once and then returns, the construction will continue as a minor warning, but if it deviates from the threshold three times in a row, maintenance will be prohibited and the threshold will be exceeded Applications such as performing maintenance when the number of integrations exceeds a set value are possible. In addition, when wall stabilization is performed by extending the time when the threshold value is exceeded, a maximum extension time is determined, and if that time is exceeded, stabilization is already impossible. It is possible to apply it by judging that there is a part, giving an alarm for replacement of parts, and performing maintenance. Thus, if maintenance such as cleaning of the inside of the apparatus is performed, it is possible to prevent the cause of defects such as contamination of the wafer being processed and adhesion of foreign matter.

In the above embodiment, an example in which an aluminum base material having an alumite layer or a ceramic film formed on the surface of the processing chamber is used as the material and O ₂ gas is used as the wall protection gas has been described. However, the object of the present invention can be achieved as long as the inner wall surface material of the treatment is an oxide ceramic film. In the case of a fluoride ceramic coating, the object of the present invention can be achieved by using an F-based gas as the wall surface protective gas.

  As is apparent from the above description, the present invention is a plasma processing apparatus that introduces a processing gas into a processing chamber to generate plasma, and vacuum-processes an object to be processed. Monitoring means for detecting the presence of the reaction product containing, and alarm means for notifying that the presence of the reaction product containing the material constituting the processing chamber wall has reached a predetermined amount or more. In addition, the monitor means is a plasma emission spectrometer, a mass analyzer, an impedance monitor detection means, a current detector, a voltage detector, or a current voltage phase installed in a path for applying power to the plasma generation means disposed in the plasma processing chamber. The detector was either a traveling wave detector of power or a reflected wave detector or a combination thereof.

  The present invention has a function of selecting an arbitrary signal out of signals that can be detected by the monitor as a detection signal indicating the presence of a reactant containing the material constituting the processing chamber wall from a plurality of signals obtained from the monitoring means. And a means for arbitrarily setting a threshold value of a signal value for generating an alarm, further selecting at least two signals from a plurality of signals obtained from the monitoring means, and adding, subtracting, multiplying, and dividing these signals An arithmetic function that uses any one or a combination thereof as a detection signal is provided.

  The present invention relates to a plasma processing apparatus for introducing a processing gas into a processing chamber in which an object to be processed is installed to generate plasma, and vacuum-processing the object to be processed, and includes an etching processing step, a plasma cleaning step, A function of setting the wall stabilization step for protecting the processing chamber wall and arbitrarily setting the order and frequency of each step is provided.

Further, the present invention generates a plasma by introducing a processing gas into a processing chamber where the object to be processed is placed, a stabilizing processing method in the processing chamber wall of the plasma processing apparatus for vacuum processing an object to be processed, After the plasma cleaning process following the etching process, a process chamber wall surface stabilization process is performed in which an inner wall protective gas for protecting the surface of the process chamber wall is introduced to perform a plasma process. Furthermore, the present invention provides the method of stabilizing a processing chamber wall surface of the plasma processing apparatus, wherein the inner wall protective gas includes oxygen (O ₂ ) gas or fluorine (F) gas, and oxygen (O ₂ ) The flow rate ratio of gas or fluorine-based (F) gas is at least 50% or more.

In the plasma processing apparatus , the plasma processing apparatus has a function of receiving a signal indicating an increase in reactants including a material constituting the processing chamber wall generated by the processing chamber monitoring means and executing a preset wall stabilization processing step. Equipped. Further, the predetermined wall stabilization processing step time is extended by a predetermined time according to the number of integration of signals indicating the increase in reactants including the material constituting the processing chamber wall generated by the processing chamber monitoring means. It has the function to do.

The whole block diagram which shows the plasma processing apparatus for describing embodiment of invention. Conventional wafer processing flow. The schematic sectional drawing of the apparatus wall surface material for demonstrating embodiment of this invention. The schematic sectional drawing of the apparatus wall surface material for demonstrating embodiment of this invention. An example of the monitor signal for demonstrating this embodiment. The wafer processing flow for demonstrating embodiment of this invention. The schematic sectional drawing of the apparatus wall surface material for demonstrating embodiment of this invention. The process result example for demonstrating the effect of this invention. The process result example for demonstrating the effect of this invention. The process result example for demonstrating the effect of this invention.

Explanation of symbols

101: Etching chamber, 102: Wall material in contact with plasma, 103: Substrate stage, 104: Substrate, 105: Vacuum exhaust port, 106: Power supply, 107: Matching unit, 108: Antenna, 109: Coil, 110: Plasma, 111 :
High-frequency power source, 112: emission spectrometer, 113: optical fiber, 114: control PC of the emission spectrometer, 115: control PC of the etching treatment, 201: signal threshold, 202: stabilization step start point.

Claims (1)

In the processing chamber wall surface stabilization method of a plasma processing apparatus for introducing a processing gas into a processing chamber in which a processing target is installed to generate plasma and vacuum processing the processing target ,
After the plasma cleaning process subsequent to etching grayed processing, the processing chamber wall surface of the flop plasma processing apparatus corrosion by introducing an inner wall protective gas to prevent subjecting the processing chamber wall stability Kasho sense to plasma treatment in the process chamber wall surface stabilizer processing a method, before Symbol wall protective gas is oxygen (O ₂₎ seen containing gas, or a fluorine-based and (F) gas, oxygen (O ₂₎ with respect to the total gas flow rate gas, or fluorine-based (F ) processing chamber wall stabilization method for a plasma processing apparatus the flow rate ratio of the gas is characterized that you at least 50% or more.

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