JP2010114982A - High frequency power supply device and output control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To previously prevent damage of an element in a high frequency amplification circuit. <P>SOLUTION: A temperature measuring part measuring a temperature of at least one of a plurality of input-side ferrites 51 and a plurality of output-side ferrites 52 is disposed. When the temperature that the temperature measuring part measures exceeds a first threshold which is previously set, a high frequency power supply is stopped or output is reduced in a high frequency power supply device. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a high-frequency power supply device that supplies high-frequency power and an output control method thereof. For example, the present invention is applied to a vacuum processing apparatus such as a plasma CVD (Chemical Vapor Deposition) apparatus that forms a film on a substrate using plasma. The present invention relates to a high frequency power supply device and an output control method thereof.

  In recent years, a plasma enhanced chemical vapor deposition (PCVD) method has been used to form a material such as silicon on a substrate having a large area (for example, a size of 1 m or more in length and 1 m or more in width). A conventional plasma CVD apparatus is used. This plasma CVD apparatus, for example, forms a film made of amorphous silicon, microcrystalline silicon, silicon nitride, or the like used for amorphous solar cells, microcrystalline solar cells, liquid crystal display TFTs (Thin Film Transistors), etc. Some of them have a function of cleaning (self-cleaning) a film attached to a chamber or a discharge electrode by etching.

  As the discharge electrode of the plasma CVD apparatus described above, a discharge electrode in which rod-like vertical electrodes are arranged almost in parallel is often used, and such a discharge electrode has a very high frequency power source (for example, 30 MHz to 300 MHz). And is suitable when a film is formed on a substrate having a large area (see, for example, Patent Document 1).

  In the discharge electrode having the above-described configuration, the plurality of discharge electrodes are arranged side by side so as to be substantially parallel to the substrate surface on which the film formation process is performed, and the vertical ends and the high-frequency ends that are feeding points of the plurality of discharge electrodes The power supply device is electrically connected, and high frequency power is supplied to each discharge electrode from the high frequency power supply device. A matching device for adjusting the phase of the high-frequency power supplied to the discharge electrode is provided in the vicinity of the feeding point of each discharge electrode.

In such a plasma CVD apparatus, there is an impedance changing structure in the supply route until high-frequency power is supplied to the discharge electrode, and since the impedance of the plasma changes with time as the film is formed, The matching device adjusts the phase of the high frequency power supplied to the discharge electrodes so that the reflected power returning from each discharge electrode to the high frequency power supply device is minimized.
JP-A-2005-150260

  By the way, an impedance change may occur in the vicinity of the feeding point of the discharge electrode on the load side due to an influence of an impedance change due to accumulation of film adhesion due to repeated film formation or a thermal damage of a part of the feeding route. In this case, a situation occurs in which the reflected power increases rapidly and the operation is performed with the impedance deviating from the operation guarantee point of the high-frequency amplifier circuit built in the matching device, and a switching element (for example, FET or the like) used in the high-frequency amplifier circuit occurs. ) May be deteriorated or damaged.

When an impedance change occurs in the vicinity of the power feeding unit, the effect appears significantly in the reflected wave power (hereinafter referred to as “reflected power”), and the reflected power changes instantaneously. Therefore, for example, when the actually measured value of the reflected power exceeds a preset threshold, the power supply from the high frequency power supply is stopped to avoid damage to the elements in the high frequency amplifier circuit. Yes.
However, in the conventional method of detecting that the reflected power exceeds the threshold value and stopping the high-frequency power supply, when the reflected power suddenly increases, until the abnormality is detected and the supply of the high-frequency power is stopped. Therefore, it takes a long time to control the self-constant of the control circuit, and there is a possibility that the elements in the high-frequency amplifier circuit may be damaged during this time.
The phenomenon that the reflected power suddenly increases becomes prominent especially at high frequencies exceeding 40 MHz, and the amount of reflected power increases when the output exceeds 1 kW, so that the burden on the elements in the high-frequency amplifier circuit is large. Become. Furthermore, since the reflected power is continuously generated, an event in which the durability of the element with respect to the reflected power is decreased is newly discovered, and an appropriate sign for detecting the sign before the reflected power suddenly increases is detected. Avoidance measures are desired.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a high-frequency power supply apparatus that can prevent damage to elements in the high-frequency amplifier circuit.

In order to solve the above problems, the present invention employs the following means.
The present invention includes a high-frequency power source that outputs high-frequency power and a high-frequency amplification unit, and a matching unit that adjusts and outputs the high-frequency power from the high-frequency power source. The high-frequency amplification units are connected in parallel to each other. A plurality of amplifying means, each of the amplifying means comprises an input side ferrite and an output side ferrite, and the temperature of at least one of the plurality of input side ferrites and the plurality of output side ferrites is set. A high-frequency power supply device that includes a temperature measurement unit for measuring and reduces the output of the high-frequency power source or stops the high-frequency power source when the temperature measured by the temperature measurement unit exceeds a preset first threshold value I will provide a.

As a result of various tests conducted by the inventors, there are few events in which the elements of the high-frequency amplification means are suddenly damaged due to a sudden occurrence of a large reflected wave during supply of high-frequency power, and intermittent reflected waves are repeatedly generated. As a result, the internal elements of the high frequency amplification means deteriorate due to the accumulation of the overload state, and the temperature of the input side ferrite and the output side ferrite may gradually increase with the deterioration of the internal elements. found. If the overload state is accumulated due to repeated occurrence of the reflected wave and the internal element of the high frequency amplification means is deteriorated, the durability of the internal element to the reflected wave of the high frequency power is lowered, which is not preferable. In the present invention, at least one temperature of the input side ferrite and the output side ferrite is measured by the temperature measuring means, and when the temperature exceeds a predetermined value set in advance, the high frequency power supply is stopped or the output of the high frequency power supply is output. We are going to reduce. As described above, since the temperature of the ferrite, which is affected by the deterioration of the internal elements of the high frequency amplification means, is directly measured, it is possible to detect the occurrence of abnormality at an early stage. Thereby, damage to the internal element of the high frequency amplification means can be prevented beforehand.
The high frequency power refers to high frequency power of 40 MHz or more.

  In the high frequency power supply device, the high frequency amplification means includes a plurality of amplification means connected in parallel to each other, and each of the amplification means is provided between the input side ferrite, the output side ferrite, and the input side ferrite and the output side ferrite. And a plurality of impedance conversion means connected in series with each other and a switching means provided between the impedance conversion means.

  In the high-frequency power supply device, at least one temperature measuring unit is provided corresponding to the input side ferrite or the output side ferrite of each amplifier, and a temperature difference between the amplifying units is preset. When the threshold value is exceeded, the output of the high-frequency power source may be reduced or the high-frequency power source may be stopped.

Variations in the characteristics of the amplifiers connected in parallel can be cited as a factor that damages the switching means included in the high frequency amplification means. For example, when amplifiers having different characteristics are connected in parallel, a load is concentrated on one of the amplifiers, thereby causing an event in which an internal element of the amplifier is damaged.
In consideration of such cases, temperature measuring means is provided for the input side ferrite or output side ferrite corresponding to each amplification means, and the temperature of the input side ferrite or output side ferrite included in each amplification means is measured by this temperature measurement means. To do. Then, by calculating the difference between the measured temperatures, the temperature difference of the ferrite between the amplification means is obtained, and when this temperature difference exceeds the second threshold, the load balance between the amplifiers is maintained. It is determined that there is not, the output of the high frequency power supply is reduced, or the high frequency power supply is stopped. As a result, it is possible to prevent damage to internal elements due to variations in amplifier characteristics.

  The present invention includes a high-frequency power source that outputs high-frequency power, and a matching unit that adjusts and outputs the high-frequency power from the high-frequency power source. A high-frequency power supply device that supplies power to a point, based on reflected power measuring means that measures the power of the reflected wave, the power of the reflected wave measured by the reflected power measuring means, and the time at which the reflected wave was observed An evaluation value calculating means for calculating a deterioration evaluation value, and when the deterioration evaluation value calculated by the evaluation value calculating means exceeds a predetermined threshold value, the output of the high frequency power source is reduced or the high frequency Provided is a high frequency power supply device comprising a control means for stopping a power supply.

  As a result of various tests conducted by the inventors, the phenomenon that the reflected wave increases due to the deterioration of the switching element in the high-frequency amplifier circuit depends on the magnitude of the reflected wave and the integrated value of the operating time when the reflected wave is observed. Turned out to be. In other words, some state change due to film deposition and deterioration of the feeding point proceeds, and while the reflected wave increases, some state change greatly proceeds after a certain operating time, and the reflected wave It turned out to start to surge. In the present invention, by monitoring the state of such a reflected wave, the deterioration of the power feeding unit and the change in the matching means are predicted in advance. Specifically, a deterioration evaluation value is calculated based on the power value of the reflected wave and the time at which the reflected wave is observed, and the high frequency is calculated when the deterioration evaluation value exceeds a predetermined threshold value set in advance. The output of the power supply is reduced or the high-frequency power supply is stopped. As a result, the degree of deterioration of the element in the matching means or the like can be predicted, and damage to the element can be prevented in advance.

  In the high-frequency power supply device, the evaluation value calculating unit accumulates a power integrated value obtained by multiplying the power of the reflected wave measured by the reflected power measuring unit and the time when the reflected wave is observed. The deterioration evaluation value may be calculated.

Further, the evaluation value calculating means may calculate the deterioration evaluation value using a weighting value corresponding to the reflected power level.
The control means predicts the degree of deterioration of the internal elements by considering not only the deterioration evaluation value but also the temperature of the input side ferrite and / or the temperature of the output side ferrite, and based on this result, the operation of the high frequency power supply is stopped. Alternatively, output reduction may be controlled.

  In the high-frequency power supply device, the evaluation value calculation unit calculates the deterioration evaluation value for each reflected power level, and the control unit calculates the deterioration evaluation value of each reflected power level calculated by the evaluation value calculation unit and the A threshold value associated with the reflected power level may be compared, and the output of the high-frequency power supply may be reduced or the high-frequency power supply may be stopped according to the comparison result.

  As described above, the evaluation accuracy can be improved by calculating the deterioration evaluation value for each reflected power level and evaluating the allowable operation time for a large reflected wave. By comparing the degradation evaluation value and the threshold value for each reflected power level, it is determined whether or not to control the output of the high-frequency power supply, so that it is possible to make a detailed judgment according to the power level of the reflected wave. . Thereby, it becomes possible to prevent damage to the internal elements more reliably.

  The present invention provides a vacuum processing apparatus including any one of the above-described high-frequency power supply apparatuses.

  The present invention includes a high-frequency power source that outputs high-frequency power and a matching unit that has high-frequency amplification means and adjusts and outputs the high-frequency power from the high-frequency power supply, and the high-frequency amplification means are connected in parallel to each other. A plurality of amplifying means, each of the amplifying means comprising an input side ferrite and an output side ferrite, and an output control method for a high frequency power supply apparatus, wherein each of the amplifiers includes the input side ferrite or the output side ferrite. When the measured temperature exceeds a preset first threshold value, or when the temperature difference between the amplifiers exceeds a preset second threshold value, Provided is an output control method for a high frequency power supply apparatus that reduces the output of the high frequency power supply or stops the high frequency power supply.

  The present invention includes a high-frequency power source that outputs high-frequency power, and a matching unit that adjusts and outputs the high-frequency power from the high-frequency power source. An output control method for a high-frequency power supply device that supplies power to a point, which measures the power of the reflected wave and accumulates the integrated power value obtained by multiplying the measured reflected wave power and the time at which the reflected wave was observed. Output control of the high-frequency power supply apparatus that reduces the output of the high-frequency power supply or stops the high-frequency power supply when the deterioration evaluation value is calculated and the calculated deterioration evaluation value exceeds a predetermined threshold value set in advance Provide a method.

  In the output control method of the high frequency power supply device, the deterioration evaluation value is calculated for each reflected power level, the deterioration evaluation value of each reflected power level is compared with a threshold value associated with the reflected power level, and the comparison result Accordingly, the output of the high frequency power supply may be reduced or the high frequency power supply may be stopped.

  According to the present invention, it is possible to prevent damage to elements in the high frequency amplifier circuit.

  Hereinafter, each embodiment when the high frequency power supply device according to the present invention is applied to a plasma CVD apparatus will be described with reference to the drawings. Here, the high-frequency power supply device according to the present invention is widely applied to devices that require high-frequency (for example, 40 MHz or higher) power as a power source. As an example of the application, the high-frequency power supply device is manufactured on a substrate using plasma. A vacuum processing apparatus that performs film processing and the like can be given. As an example of the vacuum processing apparatus, in addition to the plasma CVD apparatus, for example, a dry etching apparatus, a sputtering apparatus, a plasma surface modification apparatus, and the like can be given.

[First Embodiment]
FIG. 1 is a partial perspective view showing a part of the configuration of a plasma CVD apparatus to which the high frequency power supply device of the present invention is applied, and FIG. 2 is a diagram showing a schematic circuit configuration of the high frequency power supply device according to the present embodiment. . The plasma CVD apparatus according to the present embodiment includes, for example, eight discharge electrodes 3 (3a to 3h). As shown in FIG. 2, feed points ch1 to ch8 provided at one end portions (upper end portions) of the discharge electrodes 3a to 3h are connected to matching devices 13a to 13h via coaxial feed portions 12a to 12h. The feeding points ch9 to ch16 provided at the other end portions (lower end portions) of the discharge electrodes 3a to 3h are connected to the matching devices 17a to 17h via the coaxial feeding portions 16a to 16h.

In this embodiment, one matching device is provided for each feeding point of each discharge electrode, but the number of discharge electrodes and the number of feeding points corresponding to one matching device are not particularly limited. For example, one matching device may be provided for two feeding points. The number of discharge electrodes is not limited to eight, and the number of discharge electrodes can be selected as appropriate.
Further, for example, as shown in FIGS. 1 and 2, among the feeding points ch1 to ch8 provided at one end portions (upper end portions) of the discharge electrodes 3a to 3h, matching devices 13a to 13 corresponding to the feeding points ch1 to ch4 are provided. 13d may be stored and managed in one box 10a. In the present embodiment, four alignment devices are accommodated in one box, but the number of alignment devices accommodated in the box can be arbitrarily selected. In this embodiment, the alignment devices 13e to 13h are accommodated in the box 10b, the alignment devices 17a to 17d are accommodated in the box 10c, and the alignment devices 17e to 17h are accommodated in the box 10d.

  As shown in FIG. 1, four sets are shown in the frame for the feeding points ch1 to ch16 of the discharge electrodes 3a to 3h, but each is controlled independently. In addition to the matching device 13a, a coaxial power feeding portion 12a, a heat medium supply pipe 14a, and a raw material gas pipe 15 are provided on the power supply point ch1 side of the discharge electrode 3a, and a matching device 17a, A coaxial power supply unit 16a, a heat medium supply pipe 18a, and a source gas pipe 19 are provided.

Similarly, for each of the discharge electrodes 3b to 3h, a coaxial power feeding unit and a heat medium supply pipe are provided at the upper end and the lower end, respectively. The raw material gas pipes 15 and 19 are distributed so that the amount of supplied gas is equal and supplied to the discharge electrodes 3a to 3h, and are further evenly distributed inside each discharge electrode and blown out from each discharge electrode. Yes.
A deposition preventing plate 4 is provided around the discharge electrodes 3a to 3h to limit the film forming atmosphere. Further, the surrounding constituent elements including the discharge electrodes 3a to 3h are supported by the film forming chamber door 6 so as not to cause structural deformation due to a difference in thermal expansion between each other.

As shown in FIG. 2, the matching devices 13a to 13d and the matching devices 13e to 13h are connected to the high frequency power source 20a, and the matching devices 17a to 17d and the matching devices 17e to 17h are connected to the high frequency power source 20b. The high frequency power supplies 20 a and 20 b are connected to a setting device 21 and a phase modulator 22.
The high frequency power supplies 20a and 20b supply high frequency power, for example, power in a frequency band of VHF (Very High Frequency: 30 MHz to 300 MHz), more preferably power having a frequency of about 40 MHz to 100 MHz. Further, the high frequency power supplies 20a and 20b can change the frequency of the supplied high frequency power. For example, in the case of a 60 MHz high frequency power supply, the frequency ranges from 58.5 MHz to 59.9 MHz, or from 60.1 MHz to 61.5 MHz. It is configured to be variable.
The matching device 13a includes a high-frequency amplifier circuit 30a, a directional coupling unit 31a, a matching device 32a, and a monitoring device 33a. Each of the matching devices 13b to 13h and 17a to 17h has the same configuration.

In the high frequency power supply device having such a configuration, various command values such as phase and voltage level are given from the setting device 21 and the phase modulator 22 to the high frequency power sources 20a and 20b, and the matching devices 13a to 13h and 17a to 17a. A detection value such as actual power is input from 17h.
The high frequency power supplies 20a and 20b generate high frequency power of a predetermined output level based on the input information and supply the high frequency power to the matching devices 13a to 13h and 17a to 17h. Each of matching devices 13a to 13h and 17a to 17h adjusts the output level, phase, and the like of the high-frequency power according to the reflected power and supplies the adjusted high-frequency power to the corresponding supply point. As a result, high frequency power is supplied from the matching devices 13a to 13d to the supply points ch1 to ch4, high frequency power is supplied from the matching devices 13e to 13h to the supply points ch5 to ch8, and high frequency power is supplied from the matching devices 17a to 17d to the supply point ch9. -Ch12, high-frequency power is supplied to the supply points ch13-ch16 from the matching devices 17e-17h. The power supplied at this time is, for example, 1.0 kW or more per channel.

  FIG. 3 is a diagram illustrating a schematic configuration of the high-frequency amplifier circuits 30a to 30h included in the matching devices 13a to 13h and 17a to 17h. Here, the configuration of the high-frequency amplifier circuit 30a included in the matching device 13a will be described as a representative, and the details will be described, but each of the matching devices 13b to 13d and 17a to 17h includes a high-frequency amplifier circuit having the same configuration and function. Yes.

As shown in FIG. 3, the high-frequency amplifier circuit 30a includes two amplifiers 41a and 41b connected in parallel to each other.
The amplifying units 41a and 41b are provided between the input-side ferrite 51, the output-side ferrite 52, and the input-side ferrite 51 and the output-side ferrite 52, respectively, and two impedance conversion circuits 53 and 54 connected in series with each other. And a switching circuit 55 provided between the impedance converters 53 and 54. The switching circuit 55 is configured by, for example, a circuit including two FETs connected in series.
Further, any one of the output side ferrites 52 is provided with a temperature sensor (not shown), and the detection value of the temperature sensor is supplied to the monitoring device 33a (see FIG. 2). The temperature sensor is preferably a thermocouple having a small heat capacity. For example, a sheath type thermocouple having a diameter of about 1 mm is attached while being insulated with a polyimide tape or the like.

In such a high-frequency amplifier circuit 30a, the high-frequency power supplied from the high-frequency power source 20a is input from the input terminal RF In and supplied to the amplifiers 41a and 41b. In each of the amplifying units 41 a and 41 b, the high frequency power is supplied to the impedance conversion circuit 53 via the input side ferrite 51 and then supplied to the impedance conversion circuit 54 via the switching circuit 55. The high frequency power processed by the impedance conversion circuit 54 is output from the output terminal RF Out of the high frequency amplifier circuit 30a to the directional coupling unit 31a (see FIG. 2) provided at the subsequent stage via the output side ferrite 52.
Further, the temperature of the output side ferrite 52 is sequentially detected by the temperature sensor, and this detected value is output to the monitoring device.

  The monitoring device 33a (see FIG. 2) compares the preset first threshold value with the detected value of the temperature sensor, and if the detected value of the temperature sensor exceeds the first threshold value, the monitoring device 33a In response to this, an operation stop signal or an output level reduction signal is output, and a notification that an abnormality has occurred is reported. As the notification means, various known methods such as displaying an error message on a display screen or the like, issuing a buzzer, or the like can be employed.

  As described above, according to the high frequency power supply device according to the present embodiment, the temperature sensor for measuring the temperature of the output-side ferrite 52 is provided, and when the detected value of the temperature sensor exceeds the first threshold value, Since an operation stop signal or an output level reduction signal is output to the high-frequency power source and a notification that an abnormality sign has been detected is provided, the internal elements of the high-frequency amplifier circuit incorporated in the matching devices 13a to 13h and 17a to 17h ( For example, it is possible to prevent damage to FETs constituting the switching circuit.

In the above embodiment, the temperature of the output-side ferrite 52 is measured, but instead, the temperature of the input-side ferrite 51 may be measured. Moreover, it is good also as measuring the temperature of both the input side ferrite 51 and the output side ferrite 52, and the monitoring apparatus 33a catching the sign of abnormality generation based on these temperatures.
The first threshold value may be determined in advance by performing a test operation in advance and based on the temperature of the ferrite at that time and the degree of deterioration of the internal elements. For example, when the temperature gradually increases from 40 ° C. to 150 ° C. due to the occurrence of an abnormality, the offset is arbitrarily determined to be 40 ° C., which is the normal operating temperature. What is necessary is just to use the value which added quantity (for example, 20 degreeC) as a threshold value.

  Further, for example, a step may be given depending on the temperature. For example, an error message may be presented at about 40 ° C., the output level of the high frequency power supply may be reduced at about 50 ° C., and the high frequency power supply may be stopped at about 60 ° C.

  In this embodiment, the case where the monitoring device 33a is provided for each matching device has been described. However, one monitoring device 33a may be provided for a plurality of matching devices. Moreover, it is good also as providing one monitoring apparatus corresponding to all the alignment apparatus 13a-13h, 17a-17h, and managing the condition of all the alignment apparatuses 13a-13h, 17a-17h by one alignment apparatus. .

[Second Embodiment]
Next, a second embodiment of the present invention will be described.
In the high frequency power supply device according to the present embodiment, a temperature sensor is provided for each output side ferrite 52 provided in each amplifier 41a, 41b, and the temperature of each output side ferrite 52 of each amplifier 41a, 41b is measured by this temperature sensor. This is different from the high-frequency power supply device according to the first embodiment described above.
Here, the operation of the high-frequency amplifier circuit 30a and the monitoring circuit 33a in the matching device 13a will be described. The high-frequency amplifier circuit and the monitoring circuit included in the other matching devices 13b to 13h and 17a to 17h have the same configuration and function.

  In the high frequency amplifier circuit 30a, the temperature of the output side ferrite 52 of each amplifier 41a, 41b measured by each temperature sensor is output to the monitoring device. The monitoring device determines whether there is a temperature that exceeds a preset first threshold among the input temperatures, and if the temperature that exceeds the first threshold matches, the high frequency An operation stop signal or an output level reduction signal is output to the power source 20a, and a notification that an abnormality has been detected is notified. This function is the same as in the first embodiment described above.

  Furthermore, the monitoring device 33a obtains a temperature difference notified from each temperature sensor. Thereby, the difference between the temperature of the output side ferrite 52 of the amplifier 41a and the temperature of the output side ferrite 52 of the amplifier 41b is calculated. Subsequently, the monitoring device determines whether or not the temperature difference exceeds a preset second threshold value, and if the temperature difference exceeds the second threshold value, the monitoring apparatus determines whether the temperature difference exceeds the second threshold value. An operation stop signal or an output level reduction signal is output, and a notification is made that a sign of occurrence of an abnormality has been captured.

  As described above, according to the high frequency power supply device according to the present embodiment, the temperature sensor is provided corresponding to each of the amplifiers 41a and 41b, and the output side ferrite 52 of each of the amplifiers 41a and 41b is provided by this temperature sensor. Measure the temperature. Then, by calculating the difference in measured temperature, the temperature difference of the output side ferrite 52 between the amplifiers is obtained, and when this temperature difference exceeds the second threshold value, the load balance between the amplifiers is maintained. Judge that it is not leaning, stop the operation of the high-frequency power supply or reduce the output. In this way, abnormal signs are detected based on two indicators, so that damage to internal elements of the high-frequency amplifier circuit can be more reliably prevented without being affected by changes in the ambient temperature of the ambient atmosphere of each temperature sensor. It becomes possible to do.

  In the above embodiment, the temperature of the output-side ferrite 52 is measured, but instead, the temperature of the input-side ferrite 51 may be measured. Moreover, the temperature of both the input side ferrite 51 and the output side ferrite 52 is measured, and the monitoring device calculates each temperature difference based on these temperatures, and catches the sign of abnormality occurrence based on these temperature differences. It is good.

[Third Embodiment]
Next, a third embodiment of the present invention will be described.
The high frequency power supply according to the present embodiment does not detect an abnormality based on the temperature as in the first or second embodiment described above, but detects an abnormality occurrence sign based on the power of the reflected wave. Specifically, each of the feeding points ch1 to ch16 shown in FIG. 1 is provided with a reflected power measuring unit that measures the power of the reflected wave, and the monitoring devices of the matching devices 13a to 13h and 17a to 17h correspond respectively. A sign of abnormality is detected based on the power level of the reflected wave detected by the reflected power measuring unit.
Hereinafter, the monitoring circuit 33a in the matching device 13a will be described. The monitoring circuits included in the other matching devices 13b to 13h and 17a to 17h also have the same configuration and function.

  As shown in FIG. 4, the monitoring device 33a of the matching device 13a calculates an evaluation value for calculating a degradation evaluation value based on the power of the reflected wave measured by the reflected power measuring unit and the time when the reflected wave is observed. Unit (evaluation value calculation means) 61 and a control unit (stops the high frequency power supply 20a or reduces the output when the integrated power value calculated by the evaluation value calculation unit 61 exceeds a preset threshold value ( Control means) 62.

  In such a configuration, for example, the reflected power value at the feeding point ch1 measured by the reflected wattmeter side part is input to the evaluation value calculation unit 61 of the monitoring device 33a of the matching device 13a. The evaluation value calculation unit 61 calculates a degradation evaluation value for each feeding point based on the power of the reflected wave measured by the reflected power measurement unit and the time when the reflected wave of the power is observed. The deterioration evaluation value is calculated by, for example, integrating the values obtained by multiplying the power of the reflected wave and the time when the reflected wave of the power is observed, as shown in the following equation (1).

  Degradation evaluation value = Σ {(power of reflected wave) × (observation time of the reflected wave)} (1)

  Each deterioration evaluation value calculated by the evaluation value calculation unit 61 is output to the control unit 62. The control unit 62 determines whether or not each deterioration evaluation value exceeds a preset threshold value, and when there is a deterioration evaluation value exceeding the threshold value, a signal for stopping the high-frequency power supply or reducing the output Is output to a high-frequency power source.

As described above, according to the high frequency power supply device according to the present embodiment, the deterioration evaluation value is calculated based on the power value of the reflected wave and the observation time of the reflected wave, and the abnormal evaluation value is calculated based on the deterioration evaluation value. Occurrence is determined. Thereby, it becomes possible to prevent damage to the element.
For the threshold value, a test operation may be performed in advance, and an appropriate value may be determined based on the deterioration evaluation value at that time and the deterioration degree of the elements in the matching device.

  Moreover, the evaluation value calculation part 61 may hold the weighting value according to the reflected power level, and it is good also as calculating a degradation evaluation value using such a weighting value. For example, as shown in the following formula (2), when the power value is large, there is a high possibility that the element is deteriorated. Therefore, by further multiplying the weighting coefficient α according to the magnitude of the power value, The deterioration evaluation value may be calculated.

Degradation evaluation value = Σ {(power of reflected wave) × (observation time of the reflected wave) × α} (2)
Α is a weighting coefficient that is changed according to the power level of the reflected wave.

The monitoring device takes into account not only the degradation evaluation value but also the temperature of the input-side ferrite 51 and / or the output-side ferrite 52 according to the first or second embodiment described above, so that the internal elements of the high-frequency amplifier circuit The degree of deterioration may be predicted.
In this way, by detecting the sign of occurrence of abnormality using both the temperature and the degradation evaluation value, it becomes possible to detect the sign of abnormality occurrence more reliably and to prevent damage to the elements of the high-frequency amplifier circuit. Can be prevented.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described.
In the high-frequency power supply device according to this embodiment, the power level of the reflected wave is divided into a plurality of ranks, and the above-described deterioration evaluation value is calculated for each divided reflected power level to evaluate the deterioration degree of the element. This is different from the high-frequency power supply device according to the third embodiment.

  Specifically, the evaluation value calculation unit 61 calculates a deterioration evaluation value for each reflected power level divided according to the power intensity of the reflected wave, and associates the calculated deterioration evaluation value with the reflected power level to the control unit. To 62. The control unit 62 has a threshold value for each reflected power level, and determines whether or not the deterioration evaluation value notified from the evaluation value calculation unit 61 exceeds the threshold value corresponding to the reflected power level. As a result, if it exceeds, an operation stop or output level reduction command is output to the high frequency power supply.

  FIG. 5 shows an example of the relationship between the threshold set for each reflected power level and the actual deterioration evaluation value. The threshold value for each reflected power level is a white square bar, and the actual reflected wave integrated value is shown in a hatched state in each bar. As shown in FIG. 5, the threshold is set lower as the reflected power level is higher. This is because the higher the reflected power level, the greater the effect on the internal elements.

  As described above, according to the high frequency power supply device according to the present embodiment, the power of the reflected wave and the observation time of the reflected wave are obtained for each reflected power level, and the degradation evaluation value is determined based on these values. It is calculated for each level, and for each reflected power level, it is determined whether or not the deterioration evaluation value exceeds a predetermined value, and it is determined whether or not to perform output control of the high-frequency power source. As a result, it is possible to make a detailed determination according to the power level of the reflected wave, and to improve the reliability.

In the present embodiment, the relationship between the deterioration evaluation value and the threshold value at each current reflected power level may be displayed on a display or the like, and the current operating status of the high-frequency power supply device may be notified to the administrator or the like. For example, the deterioration evaluation value at the present time with respect to the threshold value may be notified to the administrator or the like by representing the deterioration evaluation value at each reflected power level with a graph as shown in FIG.
In this way, by notifying the administrator of the current situation, it is possible to let the administrator know in advance how long it is likely that an abnormality will occur, and maintenance maintenance can be performed in advance. This improves the operating rate of the apparatus.

It is a fragmentary perspective view which shows a part of structure of the plasma CVD apparatus to which the high frequency power supply device of this invention is applied. It is the figure which showed schematic circuit structure of the high frequency power supply device which concerns on the 1st Embodiment of this invention. It is the figure which showed schematic structure of the high frequency amplifier circuit with which each matching apparatus is provided. It is the functional block diagram which expanded and showed the function of the monitoring apparatus in the high frequency power supply device which concerns on the 3rd Embodiment of this invention. An example of the relationship between the threshold set for each reflected power level and the actual deterioration evaluation value is shown.

Explanation of symbols

3a to 3h Discharge electrodes 12a to 12h, 16a to 16h Coaxial power supply units 13a to 13h, 17a to 17h Matching devices 20a and 20b High frequency power supply 30a High frequency amplifier circuit 31a Directional coupling unit 32a Matching device 33a Monitoring devices 41a and 41b Amplifying unit 51 Input-side ferrite 52 Output-side ferrite 53, 54 Impedance conversion circuit 55 Switching circuit 61 Evaluation value calculation unit 62 Control units ch1 to ch16 Feed point

Claims (9)

A high frequency power supply that outputs high frequency power;
A high-frequency amplification means, and a matching means for adjusting and outputting high-frequency power from the high-frequency power source,
The high-frequency amplification means includes a plurality of amplification means connected in parallel to each other,
Each of the amplification means includes
Input side ferrite,
The output side ferrite,
With
Provided with a temperature measuring means for measuring at least one of the plurality of input side ferrites and the plurality of output side ferrites,
A high-frequency power supply apparatus that reduces an output of the high-frequency power supply or stops the high-frequency power supply when a temperature measured by the temperature measurement unit exceeds a preset first threshold value. At least one temperature measuring means is provided corresponding to the input side ferrite or output side ferrite of each amplifier,
The high frequency power supply device according to claim 1, wherein when the temperature difference between the amplifying means exceeds a preset second threshold, the output of the high frequency power supply is reduced or the high frequency power supply is stopped. A high-frequency power source that outputs high-frequency power; and a matching unit that adjusts and outputs the high-frequency power from the high-frequency power source, and supplies the high-frequency power output from the matching unit to each feeding point provided in the discharge electrode A high frequency power supply device,
Reflected power measuring means for measuring the power of the reflected wave;
Evaluation value calculating means for calculating a degradation evaluation value based on the power of the reflected wave measured by the reflected power measuring means and the time when the reflected wave was observed;
A high-frequency power supply apparatus comprising: control means for reducing the output of the high-frequency power supply or stopping the high-frequency power supply when the deterioration evaluation value calculated by the evaluation value calculation means exceeds a predetermined threshold value set in advance .   The evaluation value calculating means calculates the deterioration evaluation value by accumulating a power integrated value obtained by multiplying the power of the reflected wave measured by the reflected power measuring means and the time when the reflected wave is observed. The high frequency power supply device according to claim 3. The evaluation value calculation means calculates the deterioration evaluation value for each reflected power level,
The control means compares the deterioration evaluation value of each reflected power level calculated by the evaluation value calculating means with a threshold value associated with the reflected power level, and outputs the output of the high-frequency power source according to the comparison result. The high frequency power supply device according to claim 3 or 4, wherein the high frequency power supply is reduced or stopped.   A vacuum processing apparatus comprising the high-frequency power supply device according to any one of claims 1 to 5. A high frequency power source that outputs high frequency power, and a matching unit that has high frequency amplification means, adjusts and outputs high frequency power from the high frequency power supply, and the high frequency amplification means includes a plurality of amplifications connected in parallel to each other Each of the amplifying means is an output control method of a high frequency power supply device comprising an input side ferrite and an output side ferrite,
In each amplifier, measure the temperature of the input side ferrite or the output side ferrite, respectively,
When the measured temperature exceeds a preset first threshold, or when the temperature difference between the amplifiers exceeds a preset second threshold, the output of the high-frequency power source is reduced or An output control method for a high-frequency power supply device for stopping the high-frequency power supply. A high-frequency power source that outputs high-frequency power; and a matching unit that adjusts and outputs the high-frequency power from the high-frequency power source, and supplies the high-frequency power output from the matching unit to each feeding point provided in the discharge electrode An output control method for a high frequency power supply device,
Measure the power of the reflected wave,
Calculate the degradation evaluation value by accumulating the integrated power value obtained by multiplying the measured power of the reflected wave and the time when the reflected wave was observed,
An output control method for a high-frequency power supply apparatus that reduces the output of the high-frequency power supply or stops the high-frequency power supply when the calculated deterioration evaluation value exceeds a predetermined threshold value set in advance. Calculate the degradation evaluation value for each reflected power level,
The deterioration evaluation value of each reflected power level is compared with a threshold value associated with the reflected power level, and the output of the high-frequency power source is reduced or the high-frequency power source is stopped according to the comparison result. Output control method for a high-frequency power supply device.

Images