JP2005259941A - Sputter etching apparatus, sputter etching system, and sputter etching method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect abnormal discharge related with defective products in the sputter etching utilizing high frequency plasma. <P>SOLUTION: Abnormal discharge is detected using, as the detection index of abnormal discharge, a change in the voltage such as high frequency load voltage or the like indicating the operating condition of matching in the sputter etching for conducting the matching for controlling reflection wave for the progressing wave. Generation of a large amount of defective products based on abnormal discharge can be prevented through interlocking by turning off the switch of a high frequency power supply to stop the operation of a sputter etching apparatus 100 based on detection of such abnormal discharge. Operation of the sputter etching apparatus 100 is quickly stopped when abnormal discharge is generated by connecting an abnormal discharge detecting means 20 to a matching box 17 of the sputter etching apparatus 100 and also connecting an abnormal discharge processing means 30 such as an interlocking means 30a or the like to the abnormal discharge detecting means 20. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a sputter etching technique using high-frequency plasma, and is a technique that can be effectively applied to detection of abnormal discharge leading to product defects and prevention of mass production of product defects based on abnormal discharge.

  In manufacturing a semiconductor device, for the purpose of cleaning the wafer surface, for example, a sputter etching process may be performed to remove a natural oxide film formed on a thin film. In such sputter etching processing, a technique using plasma generated by an alternating electric field in a high frequency region is known.

  In the plasma processing, a product wafer failure such as a foreign matter failure occurs due to the occurrence of abnormal discharge. However, the defect of the product wafer cannot be confirmed in real time and can be found at the time of inspection after processing a predetermined number of sheets. Therefore, in some cases, there is a possibility that a large number of product wafer defects may be created before it is confirmed that an abnormal discharge has occurred due to the defect detection at the time of inspection or the like. In addition, a defective product wafer that has been built may be transferred to a subsequent process, which causes serious damage. Therefore, there has been a demand for a technique for detecting abnormal discharge that leads to such a serious product failure.

  As an abnormal discharge monitoring technique, for example, in an argon sputter etching apparatus using argon plasma by high-frequency discharge, paying attention to the fact that emission intensity different from that in normal processing is seen when abnormal discharge occurs, the change in emission intensity changes. A technique for monitoring emission intensity at a specific wavelength of 705 nm that is easy to detect has been proposed (see Patent Document 1).

On the other hand, based on the knowledge that abnormal discharge in plasma processing is based on fluctuations in plasma processing pressure, we also propose a technology that monitors processing pressure during plasma processing and determines that it is abnormal when the processing pressure exceeds the upper limit of the set pressure (See Patent Document 2).
JP-A-5-226296 JP 2002-313775 A

  The present inventor has made various studies in order to prevent the occurrence of wafer defects due to abnormal discharge in sputter etching processing using high-frequency plasma.

  Although the proposed abnormal discharge monitoring technique is excellent, for example, the technique described in Patent Document 1 is a technique for detecting abnormal discharge as a change in emission intensity at a specific wavelength. Therefore, a measuring device such as a spectroscope is required. Further, a configuration in which such a spectroscope or the like is interlocked with a sputter etching apparatus is also required.

  In recent years, in the field of semiconductor device manufacturing, space saving has been actively promoted, and there is a strong demand for downsizing of the device configuration. However, the above configuration requires an additional configuration such as a spectroscope in addition to the original sputter etching apparatus, and further, there is a development of control for maintaining the interlocking of the device configuration, and it is difficult to meet such a request.

  On the other hand, the technique of Patent Document 2 detects abnormal discharge by monitoring pressure fluctuations during plasma processing, and is an excellent technique. However, in the experiment of the present inventors, abnormal discharge that leads to product failure is detected. Despite the occurrence, pressure fluctuations could not be found.

  Therefore, the present inventor has wondered whether a new detection index having a sensitive response can be found when detecting abnormal discharge. At the same time, it is preferable that special incidental facilities or the like are not required for monitoring the detection index.

  An object of the present invention is to enable detection of abnormal discharge that leads to product failure in a sputter etching process using plasma.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

  In sputter etching using high-frequency plasma, the electrical physical quantity in the matching mechanism that effectively functions the etching process by suppressing the reflected wave with respect to the incident wave was used as an abnormal discharge detection index with sharp response. .

  Among the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

  An electrical physical quantity in the matching mechanism that effectively functions the etching process by suppressing the reflected wave with respect to the incident wave in sputter etching using high-frequency plasma as a detection index that has a sensitive response when detecting abnormal discharge By doing so, it is possible to easily detect abnormal discharge that leads to product failure.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

  In the present embodiment, a sputter etching method for detecting abnormal discharge in sputter etching and preventing creation of a product defect based on the abnormal discharge, and a sputter etching apparatus and a sputter etching system used therefor will be described.

  FIG. 1 is an explanatory diagram showing a schematic configuration of a high-frequency plasma sputter etching apparatus used for verification of an abnormal discharge detection index of the present invention. 2A schematically shows the voltage change of the high frequency load voltage for each wafer, FIG. 2B schematically shows the voltage change of the high frequency tune voltage for each wafer, and FIG. 2C schematically shows the voltage change of the electrode voltage for each wafer. It is explanatory drawing shown.

  The present inventor investigated through a monitor connected to the sputter etching apparatus what changes in the plasma processing by arbitrarily generating abnormal discharge in the sputter etching apparatus. The monitoring was carried out so that various electrical changes such as voltage and current when the sputter etching apparatus was operated could be monitored.

The sputter etching apparatus 10 used in the experiment has a schematic configuration as shown in FIG. That is, the sputter etching apparatus 10 has a SiO ₂ bell jar 11 formed in a substantially dome shape, the lower part thereof is surrounded by a shield 12 made of aluminum (Al), and a pedestal shield 13 is provided on the bottom side. It has been.

  Thus, the interior surrounded by the bell jar 11, the shield 12, and the pedestal shield 13 is configured in the plasma processing chamber A, and sputter etching using plasma is performed. Although not shown, a coil for applying a high frequency connected to a high frequency power source is provided around the outside of the bell jar 11.

  As shown in FIG. 1, a pedestal 14 is provided on the pedestal shield 13, and a wafer W is placed on the pedestal 14. The pedestal 14 is insulated by being provided with a quartz insulator 15 around it.

  Further, a high frequency is applied to the wafer W side from an application unit 16 connected to the pedestal 14. As shown in FIG. 1, a high-frequency power source 18 is connected to the application unit 16 via a matching box 17, and the pedestal 14 functions as an electrode.

  In the sputter etching apparatus 10 having such a configuration, for example, Ar gas or the like is introduced into the plasma processing chamber A from the air supply port provided between the shield 12 and the pedestal shield 13 until the internal pressure is reduced to a predetermined pressure. Put in. In this state, argon (Ar) plasma is generated in the plasma processing chamber A by applying a high frequency via a high frequency application coil provided outside the bell jar 11.

In the generated Ar plasma, Ar ⁺ in the Ar plasma flows as a traveling wave toward the wafer W placed on the pedestal 14 that functions as a cathode, and collides with an etching target such as a natural oxide film on the wafer W. As a result, the natural oxide film and the like are removed by sputtering.

  In the sputter etching having such a configuration, if the cations colliding with the wafer W are reflected, the efficiency of the sputter etching is deteriorated accordingly. Therefore, in the matching box 17, the capacitance is appropriately changed by using a variable capacitor to perform matching (matching) with the impedance on the wafer W side, and a traveling wave composed of positive ions at the time of sputter etching on the wafer W. A high frequency bias is stably applied so that the reflected wave is effectively suppressed.

The present inventor monitored what changed by arbitrarily generating abnormal discharge by variously changing impedance while performing sputter etching in the sputter etching apparatus 10 having such a configuration. As a result, it was noticed that a sharp change was observed in the electrical quantity such as a voltage indicating the operating state of the matching function performed in the matching box 17. In the experiment, it was noticed that a sensitive reaction was observed in the high-frequency load voltage (RF load voltage), the RF tune voltage (RF tune voltage), or the electrode voltage (V _DC ) indicating the potential between the pedestal 14 and the ground. .

  Until now, in such a matching mechanism, the variable capacitor is automatically changed in order to control the suppression of reflected waves, so naturally the measured value that is the electrical physical quantity related to the matching function should also change. There was no idea that the change value could be read from the time-varying value.

  However, in the experiment of the present inventor, although it is certainly changed by auto-matching, the change related to abnormal discharge may be much larger than the average change during auto-matching. confirmed. The change in the case of not causing a defect can be considered to be relatively averaged and small even if there is some large change, and the degree of change in the case of abnormal discharge may be extremely large confirmed. Such a phenomenon has been found for the first time by the present inventors.

  Such a state is schematically shown in FIGS. 2 (a), 2 (b), and 2 (c). FIG. 2A shows the maximum value and the minimum value of the high-frequency load voltage when the wafer is sputter-etched as one line for each wafer. The vertical axis represents the high frequency load voltage (mV), and the horizontal axis represents the number of wafers.

  The result shown in FIG. 2A is an electrical physical quantity during sputter etching by performing sputter etching one by one using the same product, the same process, and the same sputter etching apparatus with sputter etching of the same recipe. This is obtained by recording the change of the high frequency load voltage. In addition, the number of foreign matters on the processed wafer was inspected. As a result, on wafers with a clearly large number of foreign particles, the maximum load value recorded during the sputter etching process shows a noticeable change in the maximum value that cannot be seen from the change in the maximum value of the voltage change until then. It was. In FIG. 2A, the abnormal discharge is the first abnormal discharge in the processing of the ninth wafer. In the experiment, after the first abnormal discharge occurred, the abnormal discharge continued to occur after that.

  By performing such an experiment on a large number of wafers, an abnormal change to the maximum value or the minimum value of the high-frequency load voltage as shown in FIG. Was confirmed to occur. The case shown in FIG. 2A shows a case where the change due to abnormal discharge occurs on the maximum value side of the voltage change, but it may occur on the minimum value side. Or it may occur on both the maximum value side and the minimum value side.

FIGS. 2B and 2C show the respective voltage changes in the same manner as in FIG. 2A with respect to the high-frequency tune voltage and the electrode voltage (V _DC ). In FIG. 2B, the vertical axis represents the high frequency tune voltage (mV) on the horizontal axis, and in FIG. 2C, the vertical axis represents the electrode voltage (V) on the horizontal axis. FIG. 2B shows a case where a voltage change indicating abnormal discharge occurs on the minimum value side, and FIG. 2C shows a case where abnormal discharge occurs on the maximum value and minimum value side. , Respectively.

  In addition, the voltage change during abnormal discharge in one wafer is considered to occur in all of the high-frequency load voltage, high-frequency tune voltage, and electrode voltage in the matching, but in the experiment, it is considered that normal discharge is performed. In some cases, the difference was small and it was difficult to distinguish by itself. In addition, in the experiment, there is no case where the voltage change is so small that it is difficult to distinguish between the normal discharge before and after both the high-frequency load voltage and the high-frequency tune voltage, and at least one of the normal discharges can be distinguished. The change was more noticeable than in the case of. In the electrode voltage, a remarkable voltage change was always observed so that abnormal discharge could be discriminated.

  Therefore, the present inventor preferably monitors more reliably using any two of the high-frequency load voltage, high-frequency tune voltage, and electrode voltage, or all three as detection indicators for abnormal discharge. I thought.

  Of course, depending on the case, an electrical physical quantity of either a high frequency load voltage, a high frequency tune voltage, or an electrode voltage can be used as an abnormal discharge detection index. However, it may occur that it is difficult to discriminate, and it may be necessary to take a measure such as setting the sensitivity high.

  In this way, it has been found that the high-frequency load voltage, high-frequency tune voltage, and electrode voltage can be used as detection indicators having extremely sensitive response because they give significant voltage changes during abnormal discharge in sputter etching. When using such a voltage change as a detection index, for example, the following may be performed.

  That is, for each of the high frequency load voltage, the high frequency tune voltage, and the electrode voltage, a voltage threshold is set to a predetermined voltage level, and when the voltage threshold is exceeded, it is detected that an abnormal discharge has occurred. You can do it.

  As described above, the voltage threshold is set by actually performing sputter etching on a large number of wafers, recording the voltage change at that time, and setting the maximum value and the minimum value of the voltage change on the large number of wafers. Based on the average value, a predetermined voltage may be added to the average value.

FIG. 3A shows a state in which a voltage threshold value is set for the electrode voltage, which is displayed on a monitor screen for monitoring the voltage change of the electrode voltage for each wafer. In FIG. 3A, the voltage threshold L1 ⁺ is set on the maximum value side of the voltage change, and the voltage threshold L1 ⁻ is set on the minimum value side of the voltage change.

When the voltage change exceeds the voltage thresholds L1 ⁺ and L1 ⁻ , it is determined that abnormal discharge has occurred, and processing for occurrence of abnormal discharge may be performed. In the present specification, exceeding the voltage threshold may be interpreted to mean either case of including the voltage threshold or not including the voltage threshold. FIG. 3A shows a state in which the sputter etching process is stopped when the first occurrence of abnormal discharge is detected.

  When the occurrence of abnormal discharge is detected in this way, the abnormal discharge occurrence is notified to the operator of the sputter etching apparatus, or the sputter etching apparatus is stopped, etc. What is necessary is just to be able to perform the process at the time of discharge generation automatically.

  As the notification means, a notification means such as a buzzer warning, a voice warning, or a flashing lamp may be used in the sputter etching apparatus or the sputter etching process. Alternatively, an abnormality occurrence warning may be displayed on a monitoring monitor such as a sputter etching apparatus or a sputter etching process management monitor.

  Further, as the interlock means, for example, a means for stopping the sputter etching apparatus can be considered. For example, means for stopping the high-frequency power supply of the sputter etching apparatus or turning off the operating power of the sputter etching apparatus when the current sputter etching process is finished can be considered. When such an interlock is applied, it is only necessary to prevent the next wafer processing from being performed unless reset is performed again.

  By applying the interlock in this way, when the first abnormal discharge is detected, the apparatus is stopped as shown in FIG. 3A, and a large number of defects may be created before the occurrence of defects is found during inspection. There is no. By detecting the occurrence of abnormal discharge, the high-frequency application for plasma generation is stopped, and the stopped sputter etching apparatus can be inspected and maintained.

FIG. 3B shows a case where a plurality of voltage thresholds are set for the electrode voltage. The voltage thresholds L1 ⁺ and L2 ⁺ are set on the maximum value side of the voltage change, and the voltage thresholds L1 ⁻ and L2 ⁻ are set on the minimum value side of the voltage change. In such a configuration, the voltage change exceeds the voltage thresholds L1 ⁺ and L1 ⁻ ,
If the voltage thresholds L2 ⁺ and L2 ⁻ are not exceeded, a warning notice is given that there is a risk of abnormal discharge. In the case of such danger notice, it is possible to take measures such as advancing the maintenance period and take measures to prevent abnormal discharge.

When the voltage change exceeds the voltage thresholds L2 ⁺ and L2 ⁻ , it is determined that the abnormal discharge has occurred as described above, and the application of the high frequency for plasma generation is stopped as described above by applying the interlock. Then, the sputter etching apparatus may be stopped. FIG. 3B shows a state in which the apparatus is stopped when the first occurrence of abnormal discharge is detected.

  In addition, the present inventor can monitor the high-frequency load voltage, high-frequency tune voltage, or electrode voltage so that the sputter etching of the same product based on the same recipe can be performed between a plurality of sputter etching apparatuses of the same model. It was found that there was a machine difference. That is, it has been found that the generation levels of the maximum value and the minimum value are different for each device. Therefore, it is necessary to set the voltage threshold for each sputter etching apparatus.

  It has also been found that even when wafers of the same product are processed by the same sputter etching apparatus, the generation levels of the maximum value and the minimum value are different if the sputter etching recipe is different. Furthermore, even if the apparatus and the recipe are the same, if the product type is different, the generation levels of the maximum value and the minimum value are different.

  Therefore, when using the high-frequency load voltage, high-frequency tune voltage, or electrode voltage as a detection index for detecting the occurrence of abnormal discharge, it is set for each element for each product, for each sputter etching apparatus, and for each recipe. It is considered necessary.

  In addition, the present inventor has found that even when abnormal discharge occurs surely exceeding the voltage threshold in tracking the voltage change, it does not necessarily lead to product failure. Therefore, for such a case, the time during which abnormal discharge continues may be added as one of the detection indices.

For example, as shown in FIG. 4A, when the duration t of the voltage change exceeding the voltage threshold L2 ⁺ continues for a second or more, it may be considered that abnormal discharge has occurred. As shown in FIG. 4B, it can be considered that the abnormal discharge does not occur even if the voltage threshold L2 ⁺ is exceeded in less than a seconds.

  In order to perform the sputter etching using the high frequency load voltage, the high frequency tune voltage, or the electrode voltage related to the matching described above as a detection index, a sputter etching apparatus as shown in FIG. 5 may be used.

  That is, in FIG. 5, the sputter etching apparatus 100 includes a processing chamber A and the like in the same manner as shown in FIG. For example, a computer 20a is connected to the matching box 17 as the abnormal discharge detecting means 20 for monitoring the voltage change of the high-frequency load voltage and the electrode voltage during matching. The computer 20a tracks whether or not the change in the electrode voltage exceeds a preset voltage threshold value, and when it exceeds, it is determined that an abnormal discharge has occurred.

  Furthermore, the computer 20a is provided with setting means 21 for updating the setting of the voltage threshold value. The setting means 21 stores the voltage change in the sputter etching process of the wafer using the arithmetic processing function and the storage function of the computer 20a, and calculates the average value of the maximum value and the minimum value of the voltage change stored in the past. It is supposed to be. The voltage threshold can be updated and set by adding a preset voltage to the calculated average maximum and minimum values.

  In order to obtain the average value of the past voltage changes, the update setting may be automatically performed periodically every predetermined number of wafers set in advance. By configuring so that such update setting is possible, even when the average voltage is changing, the voltage threshold value can be set periodically along the change transition of the average voltage. The setting condition of such a voltage threshold is shown in FIG.

  Furthermore, the computer 20a is inputted with the result of matching the duration of the voltage change exceeding the voltage threshold of the past sputter etching voltage change with the defective result of the product in the inspection at the time of quality control or the like. The set value of the duration used for determining the occurrence of abnormal discharge may be automatically updated and changed as necessary.

  Furthermore, in the sputter etching apparatus 100, the setting of the voltage threshold is automatically changed for each process for each product to be input and for each recipe. The voltage threshold setting can be changed by appropriately calling the voltage threshold for each past product type, recipe type, and process type stored in the computer 20a.

  As shown in FIG. 5, the computer 20a is connected to an interlock unit 30a as a processing unit 30 at the time of abnormal discharge, and can receive a command to generate an abnormal discharge from the computer 20a and issue a command to stop the sputter etching apparatus. It can be done. In the case shown in FIG. 5, the interlock means 30 a is connected to the high frequency power supply 18, and switches off the high frequency power supply 18 based on a command for occurrence of abnormal discharge to stop plasma generation in the processing chamber A. It is like that.

  By thus interlocking and stopping the generation of plasma, it is possible to prevent a large amount of defective products from being created by the sputter etching continuation process. Further, by stopping the generation of plasma, it is possible to avoid the expansion of burnout of the bell jar 11, the shield 12, etc. constituting the processing chamber A due to the continued abnormal discharge of the sputter etching apparatus. Can be expedited.

  Further, as shown in FIG. 5, as the abnormal discharge processing means 30, a notification means 30b such as a buzzer, sound, flashing light, etc. may be connected to the computer 20a to notify the operator of the occurrence of abnormal discharge. Absent.

  In the stage where the voltage thresholds used for detecting abnormal discharge are set at a plurality of levels and the risk of occurrence of abnormal discharge is informed as described above, only the notification means 30b is operated, and the operator is informed of the next maintenance time. It may be possible to take measures such as prompting the user to speed up.

  In the configuration shown in FIG. 5, the abnormal discharge detection means 20 and the abnormal discharge processing means 30 are incorporated in the sputter etching apparatus 100, and the processing when an abnormal discharge occurs is performed on the individual sputter etching apparatus 100 side. Although it was necessary to carry out, by adopting the sputter etching system 200 shown in FIG. Monitoring can be performed.

  For example, in the sputter etching system 200 shown in FIG. 7, a plurality of sputter etching apparatuses 10 are installed in the sputter etching process region B. The sputter etching apparatus 10 is configured, for example, as shown in FIG. The sputter etching apparatus 10 is connected to a computer 20a of the abnormal discharge detection means 20 provided in the management area C as shown in FIG. 7 via a backbone network N provided in the semiconductor manufacturing apparatus factory. . In the computer 20a, there is provided setting means 21 for performing update setting of the voltage threshold described above.

  The computer 20a is further connected to monitoring means 40 configured in a monitor 40a and the like. On the monitor 40a as the monitoring means 40, the voltage change tracked in real time by the computer 20a of the abnormal discharge detection means 20 connected to each sputter etching apparatus 10 via the backbone network N is displayed on the screen, and the operator can visually check the change. Can be monitored.

  On the other hand, the computer 20a of the abnormal discharge detection means 20 is connected to the abnormal discharge processing means 30 as shown in FIG. The abnormal discharge occurrence processing unit 30 is constituted by, for example, an interlock unit 30a or a notifying unit 30b (not shown). The abnormal discharge occurrence processing means 30 is connected to the individual sputter etching apparatus 10 via the backbone network N so as to be able to transmit commands to, for example, the high frequency power source 18.

  Therefore, when the abnormal discharge generation processing unit 30 receives an abnormal discharge generation command from the abnormal discharge detection unit 20, for example, the power supply of the high frequency power supply 18 of the sputter etching apparatus 10 in which the abnormal discharge has occurred from the abnormal discharge processing unit 30. The sputter etching apparatus 10 is stopped by interlocking by turning off the switch.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

  For example, in the above description, the voltage change indicating the matching operation state is used as the detection index, but an electrical physical quantity such as a current value and a resistance value that can be converted into the voltage change may be used as the direct detection index.

  INDUSTRIAL APPLICABILITY The present invention can be effectively used for detecting abnormal discharge that leads to product failure in sputter etching having a matching function.

It is explanatory drawing which shows schematic structure of the high frequency plasma sputter etching apparatus used for verification of the detection parameter | index of abnormal discharge of this invention. (A) schematically shows the voltage change of the high-frequency load voltage for each wafer, (b) schematically shows the voltage change of the high-frequency tune voltage for each wafer, and (c) shows the voltage change of the electrode voltage for each wafer. It is explanatory drawing. (A) is explanatory drawing which shows the case where the setting of one voltage threshold value is set to the maximum value side and the minimum value side, and (b) is the case where a plurality of voltage threshold value settings are set to the maximum value side and the minimum value side. It is explanatory drawing which shows. (A), (b) is explanatory drawing which shows the case where the duration of the voltage change exceeding a voltage threshold value is considered at the time of detection of abnormal discharge generation | occurrence | production. It is explanatory drawing which shows typically an example of a structure of the sputter etching apparatus concerning this invention. It is explanatory drawing which shows the case where a voltage threshold value is set according to transition of an average voltage. It is explanatory drawing which shows typically the structure of the sputter etching system which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Sputter etching apparatus 11 Berja 12 Shield 13 Pedestal shield 14 Pedestal 15 Insulator 16 Application part 17 Matching box 18 High frequency power supply 20 Abnormal discharge detection means 20a Computer 21 Setting means 30 Abnormal discharge processing means 30a Interlock means 30b Notification means 40 Monitoring means 40a computer 100 sputter etching apparatus 200 sputter etching system A processing chamber B sputter etching process area C management area N backbone network L1 ⁺ voltage threshold L1 ^- voltage threshold L2 ⁺ voltage threshold L2 ^- voltage threshold W wafer

Claims (10)

A sputter etching apparatus having the following means;
(A) a matching means for performing matching to suppress a reflected wave with respect to a traveling wave used for sputter etching;
(B) Abnormal discharge detecting means for detecting occurrence of abnormal discharge in the sputter etching from a voltage change of at least one of a high-frequency load voltage, a high-frequency tune voltage, and an electrode voltage indicating the matching operation state. The sputter etching apparatus according to claim 1, wherein
A sputter etching apparatus having an abnormal discharge processing means for performing at least one of notification of occurrence of abnormal discharge and stop of the sputter etching apparatus based on detection of abnormal discharge. A sputter etching apparatus having the following means;
(A) a matching means for performing matching to suppress a reflected wave with respect to a traveling wave used for sputter etching;
(B) Abnormality in the sputter etching when the maximum value or the minimum value of the voltage change of at least one of the high frequency load voltage, the high frequency tune voltage, and the electrode voltage indicating the matching operation state exceeds a set voltage threshold value. Abnormal discharge detection means for detecting that discharge has occurred;
(C) Based on detection of abnormal discharge, abnormal discharge processing means for performing at least one of notification of occurrence of abnormal discharge or stop of the sputter etching apparatus;
(D) Setting means for updating and setting the voltage threshold based on the average voltage of the maximum value or the minimum value of the voltage change in a predetermined number of sputter etchings until immediately before. A sputter etching system having the following means;
(A) a sputter etching apparatus for performing matching to suppress a reflected wave with respect to a traveling wave used for sputter etching;
(B) monitoring means for monitoring a voltage change of at least one of a high-frequency load voltage, a high-frequency tune voltage, and an electrode voltage indicating the matching operation state in a region different from the process region in which the sputter etching is performed;
(C) When the voltage change exceeds a preset voltage threshold value, it is determined that abnormal discharge has occurred in the sputter etching, and at least one of notification of abnormal discharge occurrence and stop of the sputter etching apparatus is performed. Abnormal discharge treatment means for performing, The sputter etching system according to claim 4, comprising the following means:
(A) Setting means for updating and setting the voltage threshold based on an average voltage of the voltage change in a predetermined number of sputter etchings up to immediately before.   A sputter etching method for detecting an abnormal discharge generated during the sputter etching from a change in an electrical physical quantity indicating a matching operation state for suppressing a reflected wave with respect to a traveling wave used for sputter etching. The sputter etching method according to claim 6.
The change in the electrical physical quantity is a sputter etching method in which the electrical physical quantity is a change in at least one of a high frequency load voltage, a high frequency tune voltage, and an electrode voltage. A sputter etching method comprising the following steps;
(A) performing a matching for suppressing a reflected wave with respect to a traveling wave used for sputter etching;
(B) detecting the occurrence of abnormal discharge in the sputter etching from a voltage change of at least one of a high-frequency load voltage, a high-frequency tune voltage, and an electrode voltage indicating an operation state of the matching;
(C) A step of performing at least one of notification of occurrence of abnormal discharge and stop of the sputter etching apparatus based on detection of abnormal discharge. The sputter etching method according to claim 8.
The detection of abnormal discharge is determined as abnormal discharge when the maximum value or minimum value of voltage change of at least one of the high-frequency load voltage, the high-frequency tune voltage, and the electrode voltage exceeds a set voltage threshold. Is to detect
The sputter etching method, wherein the voltage threshold is set based on an average value of the voltage change of the past sputter etching. The sputter etching method according to claim 8.
The detection of abnormal discharge is determined as abnormal discharge when the maximum value or minimum value of voltage change of at least one of the high-frequency load voltage, the high-frequency tune voltage, and the electrode voltage exceeds a set voltage threshold. Is to detect
The voltage threshold value is set for each product, for each recipe, for each process, and for at least one element of each sputter etching apparatus to be used.

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