JP2009070844A - Plasma processing equipment and method, and storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stop the output of at least one high-frequency power supply when an excessive reflected wave arises therein and to stop the outputs of other high-frequency power supplies instantaneously in plasma processing equipment which performs plasma processing by using a plurality of high-frequency power supplies. <P>SOLUTION: Each of a plurality of high-frequency power supplies comprises an oscillator, a communication section, and an output stop section for stopping output of the oscillator by receiving a stop signal at the communication section, wherein the output stop section of at least one of the plurality of high-frequency power supplies monitors the high-frequency outputted from the oscillator of that high-frequency power supply, and stops output from that oscillator when the high-frequency is abnormal and outputs a stop signal to the communication section. The communication section of the at least one high-frequency power supply and the communication sections of other high-frequency power supplies are connected in order to transmit the stop signal from the monitoring section directly to other high-frequency power supplies. Consequently, unstable state of plasma is prevented from being sustained and damage on a workpiece can be controlled. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a plasma processing apparatus, a plasma processing method, and a storage medium for converting a processing gas into plasma with high-frequency power and performing processing such as etching on an object to be processed with the plasma.

  In the manufacturing process of flat panels such as semiconductor devices and liquid crystal display devices, plasma such as a plasma etching apparatus or a plasma CVD film forming apparatus that performs a process such as an etching process or a film forming process on a substrate to be processed such as a semiconductor wafer or a glass substrate. A processing device is used.

  For example, a parallel plate type capacitively coupled plasma processing apparatus is used as the plasma processing apparatus. FIG. 8A schematically shows the plasma processing apparatus, in which an upper electrode 11 and a lower electrode 12 on which the substrate to be processed 10 is placed are provided in the processing container. For example, in a so-called lower two-frequency type device, the lower electrode 12 is connected to a high-frequency power source 13 for plasma formation (source) and a high-frequency power source 14 for bias.

The bias high-frequency power source 14 has the role of preventing abnormal discharge in addition to securing the anisotropy of etching by drawing ions in the plasma. That is, in the plasma processing of a large substrate, the plasma P state becomes unstable depending on processing conditions with the plasma forming high frequency power supply 13 alone, and the in-plane uniformity of the ion sheath is deteriorated and arcing (abnormal discharge) occurs. There is a risk. Therefore, in addition to the high frequency for plasma formation, a high frequency from a high frequency power supply 14 for bias is applied to the lower electrode 12 in a superimposed manner to increase the in-plane uniformity of the ion sheath on the substrate 10 to be processed, and the abnormal discharge. Is avoided. In the figure, h1 is a region where the ion sheath is formed.

  By the way, for example, when etching is performed by the plasma processing apparatus 1 described above, a film having different properties may appear near the end point of etching. Specifically, for example, when the etching of the upper film, which is an insulating film, progresses and the underlying metal film is exposed and etched, the components constituting the plasma P may change, and the plasma impedance may change significantly. . When the plasma impedance changes greatly as described above, matching by the matching circuit cannot be obtained, and an excessive reflected wave is generated on the high frequency power supply 14 side.

  Here, Patent Document 1 discloses a parallel plate type plasma processing apparatus capable of stopping the plasma processing based on the reflected wave thus generated. Although details are not described, when an abnormality is detected by the monitoring means 20 in this plasma processing apparatus, an abnormality detection signal is sent to the controller, and then a stop signal is sent from the controller to each high frequency power source. Is considered to operate and stop the internal stop based on this command. On the other hand, in order to respond instantaneously, it has been considered that each high-frequency power supply has a detection function, and the oscillation operation of its own power supply is stopped instantaneously at the time of detection. In this case, if the oscillation operation of its own power supply is stopped As in Patent Document 1, it is conceivable to send an abnormality signal of one power supply to the apparatus controller and transmit a signal from this apparatus controller to another high frequency power supply to stop the oscillation of the high frequency power supply. There are the following problems when using a simple configuration.

  As described above, an excessive reflected wave is generated on the high-frequency power supply 14 side for bias application, the high-frequency power supply 14 stops oscillating, and then an abnormal signal from the high-frequency power supply 14 is transmitted to the device controller. If a signal is transmitted to the power supply 13 to stop the oscillation of the high-frequency power supply 13, it takes at least 100 milliseconds from the oscillation stop of the high-frequency power supply 14 to the oscillation stop of the high-frequency power supply 13. In the meantime, the state of the plasma P becomes unstable as described above, and the region where the ion sheath is formed on the surface of the substrate to be processed 10 becomes narrow as indicated by h2 in FIG. An abnormal discharge to the substrate 10 may occur, current may flow through the substrate 10 to be processed, and the substrate 10 to be processed may be damaged.

  Although Patent Document 2 describes a circuit that stops oscillation of a high-frequency power source based on the power value of a reflected wave reflected by the high-frequency power source, the problem of the present invention cannot be solved.

JP 2003-264180 A: Claim 6 and paragraph 0026 WO2003-037047

  The present invention has been made under such circumstances, and an object of the present invention is to generate an excessive reflected wave in at least one high-frequency power source when performing plasma processing on a target object using a plurality of high-frequency power sources. A plasma processing apparatus, a plasma processing method, and a plasma processing apparatus capable of stopping the output of the high-frequency power source when it occurs and instantaneously stopping the output of the other high-frequency power source, thereby suppressing damage to the object due to plasma abnormality It is to provide a storage medium for implementing this method.

The plasma processing apparatus of the present invention includes a plurality of high-frequency power sources involved in plasma, and in a plasma processing apparatus that processes a target object in a processing container with plasma,
Each of the plurality of high frequency power supplies includes an oscillator that oscillates a high frequency, a communication unit for communicating with the outside, and an output stop unit that stops the output of the oscillator when a stop signal is received by the communication unit. ,
An output stop unit of at least one high-frequency power source among the plurality of high-frequency power sources stops the output of the oscillator and detects a stop signal to the communication unit when detecting an abnormality in a high frequency output from the oscillator of the high-frequency power source Is composed of a monitoring unit that outputs
The communication unit of the at least one high frequency power supply and the communication unit of the other high frequency power supply directly transmit a stop signal from the monitoring unit to another high frequency power supply.

  For example, the abnormality of the high frequency detected by the monitoring unit of the at least one high frequency power supply is an abnormality of a reflected wave, and the communication unit of the at least one high frequency power supply and the communication unit of another high frequency power supply may May be connected to each other by a communication path for transmitting directly.

A lower electrode and an upper electrode on which a substrate is placed in the processing container are provided facing each other,
A high-frequency power source for plasma generation connected to one of the lower electrode and the upper electrode; and a high-frequency power source for bias application connected to the lower electrode and having a frequency lower than that of the high-frequency power source for plasma generation Including
The at least one high-frequency power source is a high-frequency power source for bias application, and the other high-frequency power source includes the high-frequency power source for generating plasma,
The stop signal may be directly transmitted from the communication unit of the high-frequency power source for bias application to the communication unit of the high-frequency power source for plasma generation. In this case, for example, the oscillator and plasma of the high-frequency power source for bias application by the output stop unit After the output of the generator of the high frequency power source for generation is stopped, the output is automatically restored in the order of the oscillator of the high frequency power source for applying bias and the oscillator of the high frequency power source for generating plasma. The output stop unit of the high-frequency power source for generating plasma may be configured by a monitoring unit that stops the output of the oscillator when detecting an abnormality in a high frequency output from the oscillator of the high-frequency power source. For example, the high-frequency abnormality detected by the monitoring unit of the plasma-generating high-frequency power source is a reflected wave abnormality. Furthermore, a device controller may be provided that transmits a stop signal to the communication unit of the high frequency power supply on the bias side when the output of the oscillator of the high frequency power supply for generating plasma due to the abnormal high frequency is stopped.

  The output stop unit of the other high-frequency power supply may be configured by a monitoring unit that stops the output of the oscillator when detecting an abnormality in the high frequency output from the oscillator of the high-frequency power supply. The high frequency abnormality detected by the monitoring unit is an abnormality of the reflected wave. Further, for example, the stop of the output of the oscillator is to stop the oscillator.

The plasma processing method of the present invention uses a plurality of high-frequency power sources related to plasma, and in a plasma processing method of processing a target object in a processing container with plasma,
When the high frequency power output from the oscillator of the high frequency power source is detected by the monitoring unit provided in at least one high frequency power source among the plurality of high frequency power sources, the monitoring unit stops the output of the oscillator and others Outputting a stop signal for the high-frequency power source to a communication unit included in the high-frequency power source,
Directly transmitting the stop signal from the communication unit of the one high frequency power supply to the communication unit of the other high frequency power supply;
And a step of stopping output of an oscillator of the high frequency power supply by an output stop unit provided in the high frequency power supply when the communication unit of the other high frequency power supply receives the stop signal.

The storage medium of the present invention is a storage medium that stores a computer program that is used in a plasma processing apparatus that performs plasma processing on a substrate and that operates on a computer.
The computer program includes a group of steps so as to implement the above-described plasma processing method.

  When performing plasma processing on an object to be processed using a plurality of high-frequency power sources involved in plasma, when at least one high-frequency power source detects an abnormality in a high frequency output from the oscillator of the high-frequency power source, the oscillator And the abnormal signal (stop signal) is directly transmitted from the high-frequency power source to the other high-frequency power source to stop the output of the oscillator of the other high-frequency power source. The high frequency output of the other high frequency power supply can be stopped instantaneously after the occurrence. Therefore, the occurrence of abnormal discharge due to the continued unstable plasma state can be suppressed, and damage to the object to be processed can be prevented or reduced.

  An embodiment in which the plasma processing apparatus of the present invention is applied to an apparatus for etching a glass substrate B for a liquid crystal display will be described with reference to FIG. The plasma etching apparatus 2 includes a square-tubular processing vessel 20 made of aluminum, for example, whose surface is anodized. A lower electrode 41 is provided at the center lower portion of the processing container 20, and the lower electrode 41 also serves as a mounting table on which the substrate B transferred into the processing container 20 by a transfer means (not shown) is mounted. An insulator 42 is provided below the lower electrode 41, and the lower electrode 41 is in an electrically floating state from the processing container 20 by the insulator 42. In the figure, reference numeral 43 denotes a support portion for the lower electrode 41. In addition, an opening 44 is provided in the lower part of the processing container 20, and a matching box 45 that is a grounded housing is provided outside the opening 44.

  The matching box 45 is provided with matching circuits 46 and 47 whose one ends are connected to a plasma forming (source) high-frequency power source 6A and a bias applying high-frequency power source 6B, respectively. Is connected to the lower electrode 41. In the figure, 48A and 48B are coaxial cables. The matching circuits 46 and 47 adjust the impedance between the lower electrode 41 and the high frequency power supplies 6A and 6B in accordance with the plasma impedance.

  Further, an exhaust passage 32 is connected to the side wall of the processing container 20, and a vacuum pump 33 constituting vacuum exhaust means is connected to the exhaust passage 32. Further, a gate valve 35 for opening and closing the transfer port 34 of the substrate B to be processed is provided on the side wall of the processing container 20.

  Above the lower electrode 41, an upper electrode 51 that also serves as a gas shower head that is a gas supply unit is provided so as to face the lower electrode 41. The upper electrode 51 is connected to the ceiling portion of the processing container 20 via an insulator 52 provided along the opening edge of the opening 36 provided on the upper side of the processing container 20. The upper electrode 51 is in a state of being sufficiently electrically lifted from the processing container 20.

  The upper electrode 51 is connected to the processing gas supply unit 54 via the gas supply path 53, and the processing gas supplied from the gas supply path 53 is supplied to the processing space S from a number of gas holes 55. It is configured. In the figure, 57 is a conductive path.

  The source high-frequency power source 6A is for supplying high-frequency power to the processing gas to turn the processing gas into plasma (activation). As shown in FIG. 2, an oscillator 61A that outputs a high frequency of 13.56 MHz, for example, And an arc detection circuit unit 65A, which is a reflected wave monitoring unit, and a communication board 62A. The high frequency power supply unit 6B for bias is for applying a bias to the substrate B, and includes, for example, an oscillator 61B that outputs a high frequency of 3.2 MHz, an arc detection circuit unit 65B, and a communication board 62B. Yes. The first ports 63A and 63B of the communication boards 62A and 62B are respectively connected to the control board 71 by cables 66A and 66B which are communication paths for controller communication, and the control board 71 is connected to the apparatus controller 72 by a cable 73. Yes. Furthermore, the second port 64A of the high frequency power supply 6A is connected to the second port 64B of the communication board 62B of the high frequency power supply 6B by a cable 67 which is a dedicated communication path.

  Here, the communication function between each part of the high frequency power supplies 6A and 6B and the high frequency power supplies 6A and 6B and the device controller 72 will be described in detail. The arc detection circuit unit 65A of the high frequency power supply 6A detects the power value of the high frequency (traveling wave) output from the oscillator 61A and the power value (reflected power) of the reflected wave reflected to the oscillator 61A, and the detected reflected power value is It has a function of determining whether or not a preset allowable value is exceeded. The high frequency output from the high frequency power supply 6A is, for example, 10 kW, and in this case, the allowable value of the reflected wave is, for example, 200 W. If it is determined that the allowable value is exceeded, the arc detection circuit unit 65A stops the output of the oscillator 61A.

  The arc detection circuit unit 65B of the high frequency power supply 6B also detects the traveling wave power value output from the oscillator 61B and the reflected power value reflected to the oscillator 61B, and the detected reflected power value exceeds a preset allowable value. It has a function to determine whether or not. The high frequency output from the high frequency power supply 6B is, for example, 5 kW, and in this case, the allowable value of the reflected wave is, for example, 200 W. If it is determined that the allowable value is exceeded, the arc detection circuit unit 65B stops the output of the oscillator 61B and outputs an abnormal signal to the second port 64B of the communication board 62B.

  The communication board 62A of the high frequency power supply 6A transmits a signal related to the reflected power from the oscillator 61A, for example, a signal including the reflected power value, from the first port 63A to the device controller 72 via the cable 66A, the control board 71, and the cable 73. The stop command sent from the device controller 72 via the control board 71 is output to the oscillator 61A.

  On the other hand, the communication board 62B of the high frequency power supply 6B transmits a signal related to the reflected power from the oscillator 61B, for example, a signal including the reflected power value, from the first port 63B to the device controller 72 via the cable 66B, the control board 71, and the cable 73. In addition, it has a role of outputting a stop command sent from the device controller 72 via the control board 71 to the oscillator 61B. Further, the communication board 62B communicates the abnormal signal output when the arc detection circuit unit 65B determines that the reflected wave reflected by the oscillator 61B is abnormal from the second port 64B via the dedicated cable 67 to the high frequency power supply 6A. It has a function of transmitting directly to the second port 64A of the board 62A.

  The device controller 72 collects data related to the reflected power from each of the high frequency power supplies 6A and 6B, and outputs a stop command to each of the high frequency power supplies 6A and 6B when one of the reflected power values exceeds an allowable value.

  Further, the plasma etching apparatus 2 is provided with a control unit 20A composed of, for example, a computer. The control unit 20A includes a program, a memory, a data processing unit including a CPU, and the like. The control unit 20A sends a control signal to each unit of the etching apparatus 2 from the control unit 20A to advance each step to be described later. An instruction is incorporated to perform plasma processing on B. In addition, for example, the memory has an area in which processing parameter values such as processing pressure, processing time, gas flow rate, and power value are written, and these processing parameters are read when the CPU executes each instruction of the program. A control signal corresponding to the parameter value is sent to each part of the plasma etching apparatus 2. This program (including programs related to processing parameter input operations and display) is stored in a storage unit 20B such as a computer storage medium such as a flexible disk, a compact disk, or an MO (magneto-optical disk) and installed in the control unit 20A.

  Next, the operation of the plasma etching apparatus 2 will be described with reference to FIGS. 3 and 4 show the signal flow in each part of the etching apparatus 2, and FIG. 5 shows the waveform data of the outputs of the high-frequency power supplies 6A and 6B near the end point of the etching. In FIG. 5, the chain line indicates the output of the high-frequency power source 6B for bias application, and the solid line indicates the output of the high-frequency power source 6A for plasma formation.

  First, the operator inputs the processing conditions such as the gas type, the pressure in the processing container 20 and the power of the high frequency power supplies 6A and 6B from an input screen (not shown). Then, the gate valve 25 is opened, and for example, the substrate B having an insulating film formed on the surface and a metal film formed on the lower layer is loaded into the processing container 20, and the cooperative action of an unillustrated transfer arm and lift pins are provided. Thus, it is placed on the lower electrode 41. Subsequently, the gate valve is closed, and the inside of the processing container 20 is evacuated while the processing gas is being supplied into the processing container 20 from the gas supply unit that also serves as the upper electrode 51, so that the set pressure is reached.

  Thereafter, an input command is transmitted from the device controller 72 to the first port 63A of the communication board 62A and the first port 63B of the communication board 62B via the control board 71. In response to this input command, the oscillators 61A and 61B operate to output a high frequency.

  The high frequencies output from the oscillators 61A and 61B flow through the coaxial cables 48A and 48B → the matching circuits 46 and 47 → the lower electrode 41 → the upper electrode 51 → the conductive path 57 → the wall of the processing vessel 20 → the matching box 45. . For this reason, the processing gas is turned into plasma by the high frequency from the oscillator 61A, plasma P is formed in the processing space S, and a bias is applied to the substrate B by the high frequency of the oscillator 61B. The insulating film on the surface of the substrate B is etched with anisotropy by being drawn into the B side (FIG. 3A). Further, as described in the background art, this bias also has an effect of making the sheath layer on the surface of the substrate B uniform in the plane.

  A signal corresponding to the power value of the reflected wave reflected from the oscillators 61A and 61B to the oscillators 61A and 61B and the high-frequency power value output from the oscillators 61A and 61B is sent to the first ports 63A of the communication boards 62A and 62B. 63B and the control board 71 to the device controller 72, and the device controller 72 monitors the reflected power value and the high frequency power value. Arc detection circuit units 65A and 65B each determine whether or not the reflected power exceeds an allowable value, for example, 200W.

  When the etching of the insulating film of the substrate B proceeds and the metal film under the insulating film is exposed on the surface of the substrate B, and the metal film starts to be etched, the impedance of the plasma P changes. When this impedance change occurs, an instantaneous mismatch occurs, and a large reflected wave is instantaneously generated in the oscillators 61A and 61B. When the arc detection circuit unit 65B of the high frequency power supply 6B on the bias side determines that the power value of the reflected wave reflected to the oscillator 61B exceeds 200 W, the arc detection circuit unit 65B outputs the output of the oscillator 61B. While stopping (time t1 in FIG. 5), an abnormal signal is output to the second port 64B of the communication board 62B. This abnormal signal, that is, a stop signal for stopping the high frequency power supply 6A is transmitted directly from the communication board 62B to the communication board 62A of the high frequency power supply 6A for source and input to the arc detection circuit unit 65A (FIG. 3B). . Receiving this stop signal, the arc detection circuit unit 65A stops the output of the oscillator 61A (time t2 in FIG. 5). The period between t1 and t2 is, for example, several microseconds. When the oscillator 61B of the high-frequency power source 6B is stopped, the ion sheath formation region is narrowed as shown in FIG. 3B, but immediately after that (so to speak, the generation of the plasma P is stopped).

  Oscillators 61A and 61B whose output has been stopped by a stop signal from each arc detection circuit unit automatically return to the original output at a predetermined rise time after a predetermined pause period has elapsed. For the purpose of sufficiently suppressing the influence of the reflected wave, the pause time is 300 ms to 500 ms, for example, 400 ms for the high frequency power source 6B for bias, and is 400 ms, for example, 400 ms for the high frequency power source 6A for the source. 600 ms, for example 500 ms.

  The oscillator 61B of the high frequency power supply 6B has the same output as before the time t1 when it was turned off at the time t5, and the output is maintained constant after the time t5. Further, the oscillator 61A of the high frequency power supply 6A has the same output as the time t2 that was turned off at the time t6 after the time t5, the plasma P is formed again (FIG. 4C), and the plasma processing is performed on the substrate B. Is called. After time t6, the output of the high frequency power supply 61A is kept constant. Assuming that the period in which the outputs of the high-frequency power supplies 6A and 6B are recovered in this way is the restart period, the time t3t5 which is the restart period for the high-frequency power supply 6B is 0.1 second to 2.0 seconds, for example 0.7 seconds. The time t4t6, which is the restart period for the high frequency power supply 6A, is 0.1 second to 2.0 seconds, for example 0.7 seconds.

  According to the plasma etching apparatus 2 described above, when performing the plasma etching process on the substrate B using the source high-frequency power source 6A and the bias high-frequency power source 6B, which are high-frequency power sources involved in plasma, the oscillator of the high-frequency power source 6B is used. When abnormality of the reflected wave reflected to 61B occurs, the built-in arc detection circuit unit 65B stops the oscillator 61B of the high-frequency power supply 6B, and also directly stops the high-frequency power supply 6A for source from the high-frequency power supply 6B. Since the arc detection circuit unit 65A of the high frequency power supply 6A stops the oscillator 61A, after the oscillator 61B of the high frequency power supply 6B stops due to an abnormality in the reflected wave, the high frequency power supply 6A is instantaneously, for example, on the order of μs. The high frequency output from can be stopped. For this reason, it is possible to suppress the occurrence of abnormal discharge due to the continued unstable state of the plasma, so that damage to the substrate B can be prevented or reduced. For example, as described above, when the underlying film is exposed in the vicinity of the end point of the film to be etched, the plasma state changes, and the substrate B is processed in a state in which matching cannot be taken and the high frequency for bias disappears. This technique is extremely effective because it is prevented.

  When the time between times t1 and t2 in FIG. 5 was actually measured using the above-described plasma etching apparatus 2, it was about 1.7 μs (microseconds). As shown in the background art, the effect of the present invention was shown because the conventional apparatus configuration takes 100 ms (milliseconds) or more. Note that the time from when the reflected power exceeding the allowable value was detected in the high frequency power supply 6B for bias application to when the oscillator 61B of the high frequency power supply 6B was turned off was 80 ns.

  When the source-side arc detection circuit unit 65A detects a reflected wave exceeding the allowable value, the arc detection circuit unit 65A stops the output of the oscillator 61A and a reflected wave exceeding the allowable value is generated in the oscillator 61A. The arc detection circuit unit 65A transmits a signal corresponding to the stop of the oscillator 61A to the device controller 72. Upon receiving the signal, the device controller 72 transmits a stop signal to the arc detection circuit unit 65B via the communication board 62B, and the arc detection circuit unit 65B stops the bias-side oscillator 61B. The time required for the stop signal from the device controller 72 to reach the arc detection circuit unit 65B in this way after the output of the oscillator 61A stops is, for example, about 100 ms.

  FIG. 6 shows an example of an output waveform when the high-frequency power source 6A is first raised at the start of etching to obtain a predetermined output and restarted as described above, and an example of a waveform of a reflected wave generated at that time. The allowable value of the arc detection circuit unit 65A is set to 200W. When the output of the oscillator 61A of the high-frequency power supply 6A is set to a predetermined output at the start of etching (period from S1 to S2 in the figure), the power is consumed earlier than the restart period (period between S4 and S5 in the figure). Increase to a predetermined value. In this way, a reflected wave is more likely to be generated than in the restart period. For example, in the period from S1 to S2, the arc detection circuit unit 65A outputs the output of the oscillator 61A even if the reflected power exceeds the allowable value. It is preferable to set so as not to stop. Similarly, the arc detection circuit unit 63B of the high frequency power supply 61B is set so that the output of the oscillator 61B is not stopped even when the reflected power exceeds an allowable value when the high frequency power supply 61B is first started up at the start of etching. preferable.

  FIG. 7 is a diagram showing the configuration of another plasma etching apparatus, and this plasma etching apparatus 9 includes a high frequency power source 6C configured similarly to the high frequency power source 6A. The coaxial cable 48C of the high frequency power source 6C is connected to the coaxial cable 48A of the power source 6A via the combiner box 91, and the high frequency power sources 6A and 6C are configured as a high frequency power source for the source. When the arc detection circuit unit 63B connected to the biasing high-frequency power source 6B detects the reflected power exceeding the allowable value, the arc detection circuit unit 63B stops the output of the oscillator 61B and the high-frequency power sources 6A and 6C. A signal is transmitted to the arc detection circuit units 65A and 65C via the communication boards 62A and 62C, and the arc detection circuit units 65A and 65C stop the output of the oscillators 61A and 61C. In this way, the signal is directly transmitted from the arc detection circuit unit of one high frequency power supply to the arc detection circuit units of a plurality of other high frequency power supplies, and the high frequency power supply connected to each arc detection circuit unit is stopped. It may be.

  In each of the above-described embodiments, an example in which a stop signal is sent from the communication board 62B of the bias high-frequency power supply 6B to the communication board 62A of the source high-frequency power supply 6A has been described. Is not limited to being transmitted. For example, when the arc detection circuit 65A of the high frequency power supply 5A detects an excessive reflected wave in the oscillator 61A, a stop signal is directly sent from the communication board 62A of the source high frequency power supply 6A to the communication board 62B of the bias high frequency power supply 6B. The arc detection circuit unit 65B may stop the oscillator 61B. Further, the transmission of the stop signal is not limited to one direction as described above, and the stop signal may be transmitted bidirectionally between the communication boards 62A and 62B.

  In the above embodiment, the arc detection circuit of the high frequency power source on the bias side outputs a stop signal based on the abnormality of the reflected wave. However, when detecting the abnormality of the traveling wave, the stop signal is output in the same manner. Also good. Instead of connecting the communication board 62B and the communication board 62A with the dedicated cable 67 and transmitting and receiving the stop signal, the stop signal may be transmitted and received between these communication boards wirelessly.

It is a vertical side view of the plasma etching apparatus which is embodiment of this invention. It is a block diagram of the high frequency power supply of the said plasma etching apparatus. It is explanatory drawing which showed the flow of the signal in the said plasma etching apparatus. It is explanatory drawing which showed the flow of the signal in the said plasma etching apparatus. It is the wave form diagram which showed the output of each high frequency power supply when an etching stopped. It is explanatory drawing which showed the output of the high frequency power supply at the time of an etching start and restart, and the waveform of a reflected wave. It is the block diagram which showed the other structure of the high frequency power supply of the plasma etching apparatus. It is explanatory drawing which showed a mode that abnormal plasma generate | occur | produces.

Explanation of symbols

2 Plasma etching apparatus 20 Processing vessel 41 Upper electrode 51 Lower electrode 6A High-frequency power supply 6B for source High-frequency power supply 61A, 61B Oscillators 62A, 62B Communication boards 65A, 65B Arc detection circuit unit 72 Device controller

Claims (13)

In a plasma processing apparatus that includes a plurality of high-frequency power sources related to plasma and processes a target object in a processing container with plasma,
Each of the plurality of high frequency power supplies includes an oscillator that oscillates a high frequency, a communication unit for communicating with the outside, and an output stop unit that stops the output of the oscillator when a stop signal is received by the communication unit. ,
An output stop unit of at least one high-frequency power source among the plurality of high-frequency power sources stops the output of the oscillator and detects a stop signal to the communication unit when detecting an abnormality in a high frequency output from the oscillator of the high-frequency power source Is composed of a monitoring unit that outputs
The plasma processing apparatus, wherein the communication unit of the at least one high frequency power supply and the communication unit of the other high frequency power supply directly transmit a stop signal from the monitoring unit to another high frequency power supply.   The plasma processing apparatus according to claim 1, wherein the high frequency abnormality detected by the monitoring unit of the at least one high frequency power supply is an abnormality of a reflected wave.   3. The plasma processing according to claim 1, wherein the communication unit of the at least one high-frequency power source and the communication unit of the other high-frequency power source are connected to each other through a communication path for directly transmitting the stop signal. apparatus. A lower electrode and an upper electrode on which a substrate is placed in the processing container are provided facing each other,
A high-frequency power source for plasma generation connected to one of the lower electrode and the upper electrode; and a high-frequency power source for bias application connected to the lower electrode and having a lower frequency than the high-frequency power source for plasma generation Including
The at least one high-frequency power source is a high-frequency power source for bias application, and the other high-frequency power source includes the high-frequency power source for generating plasma,
4. The plasma processing apparatus according to claim 1, wherein a stop signal is directly transmitted from the communication unit of the high-frequency power source for bias application to the communication unit of the high-frequency power source for plasma generation.   After the output of the high frequency power source oscillator for bias application and the high frequency power source oscillator for plasma generation is stopped by the output stop unit, the high frequency power source oscillator for bias application and the high frequency power source oscillator for plasma generation are automatically 5. The plasma processing apparatus according to claim 4, wherein the output is restored.   The output stop unit of the high-frequency power source for generating plasma is configured by a monitoring unit that stops the output of the oscillator when an abnormality in a high frequency output from the oscillator of the high-frequency power source is detected. Item 6. The plasma processing apparatus according to Item 4 or 5.   7. The plasma processing apparatus according to claim 6, wherein the high-frequency abnormality detected by the monitoring unit of the high-frequency power source for generating plasma is an abnormality of a reflected wave.   The apparatus controller is provided for transmitting a stop signal to a communication unit of the high frequency power supply on the bias side when the output of the oscillator of the high frequency power supply for generating plasma is stopped due to the abnormality of the high frequency. 8. The plasma processing apparatus according to 6 or 7.   2. The output stop unit of the other high-frequency power source is configured by a monitoring unit that stops the output of the oscillator when an abnormality in a high frequency output from the oscillator of the high-frequency power source is detected. The plasma processing apparatus as described in any one of thru | or 3.   The plasma processing apparatus according to claim 9, wherein the high-frequency abnormality detected by the monitoring unit of the other high-frequency power source is a reflected wave abnormality.   11. The plasma processing apparatus according to claim 1, wherein the stop of the output of the oscillator is to stop the oscillator. In a plasma processing method in which a plurality of high-frequency power sources related to plasma are used and a target object in a processing container is processed with plasma,
When the high frequency power output from the oscillator of the high frequency power source is detected by the monitoring unit provided in at least one high frequency power source among the plurality of high frequency power sources, the monitoring unit stops the output of the oscillator and others Outputting a stop signal for the high-frequency power source to a communication unit included in the high-frequency power source,
Directly transmitting the stop signal from the communication unit of the one high frequency power supply to the communication unit of the other high frequency power supply;
And a step of stopping the output of the oscillator of the high-frequency power source by an output stop unit provided in the high-frequency power source when the communication unit of the other high-frequency power source receives the stop signal. Processing method. A storage medium that stores a computer program that is used in a plasma processing apparatus that performs plasma processing on a substrate and operates on a computer,
A storage medium characterized in that the computer program includes a set of steps so as to implement the plasma processing method according to claim 12.

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