JP2001035699A - Protection method for plasma generating high frequency power supply and power supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily calculate a loss power protecting level without performing experiment, inhibit a progressive-wave power in a sufficiently required range and protect a switching element against heat generation. SOLUTION: This high frequency power supply includes an excessive loss power protecting circuit 614 for computing a power amplifier loss power PL from a DC voltage detection signal Vi, a DC current detection signal Ii, a progressive-wave power detection signal Pf and a reflected-wave power detection signal Pr and computing a loss power subtraction signal ΔPL (<0) when the power amplifier loss power PL exceeds a power amplifier loss power protecting level PLp, and a progressive-wave power set value/detection value comparing circuit 69 for adding the loss power subtraction signal ΔPL (<0) to a signal Ps-Pf obtained by subtracting the progressive-wave power detection signal Pf from the progressive-wave power set signal Ps to inhibit a progressive-wave power error signal ΔPs to be Pf-Ps+ΔPL and inhibit progressive-wave power, whereby a heating value for a power amplifier 6 is inhibited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency power supply for generating plasma used in a plasma etching apparatus or the like.

[0002]

2. Description of the Related Art FIG. 1 is a prior art block diagram showing a prior art high frequency power supply for plasma generation (hereinafter referred to as a high frequency power supply) 1 and its peripheral devices. High frequency power supply 1
Is a power supply device for supplying high-frequency power to the plasma generation chamber 3 via the cable CB1, the matching device 2, and the cable CB2. The matching unit 2 is a high-frequency power source 1
And a load impedance ZL (impedance of the cable CB1, the matching device 2, the cable CB2, and the plasma generation chamber 3) of the high-frequency power supply 1. The plasma generation chamber 3 is a device for generating plasma using high frequency power supplied from the high frequency power supply 1.

The matching unit 2 matches the output impedance Zo of the high-frequency power supply 1 with the load impedance ZL of the high-frequency power supply 1 (hereinafter referred to as impedance matching).
In this case, the high-frequency power output from the high-frequency power supply 1 toward the plasma generation chamber 3 (hereinafter referred to as traveling wave power) is efficiently supplied to the plasma generation chamber 3.

However, when the impedances do not match, a part or all of the traveling wave power is reflected, and reflected wave power is generated from the plasma generation chamber 3 toward the high frequency power supply 1. Further, since the impedance of the plasma generation chamber 3 varies depending on the plasma generation state,
The load impedance ZL of the high frequency power supply 1 fluctuates to a high impedance or a low impedance as compared with the time of matching.

[0005] As shown in FIG.
Power supply circuit 4, high-frequency pulse oscillation circuit 5, power amplifier 6, resonance circuit 7, high-frequency power detection circuit 8, traveling-wave power set value / detection value comparison circuit 9, DC voltage detection circuit 10, resonance current detection circuit 11, excess DC It comprises a voltage protection circuit 12, an excess resonance current protection circuit 13, and an excess reflected power protection circuit 14.

[0006] The DC power supply circuit 4 is a power supply circuit for outputting DC power, and a traveling wave power error signal ΔPs inputted from the traveling wave power set value / detection value comparison circuit 9 as described later.
, The magnitude of the DC power to be output changes. The high-frequency pulse oscillation circuit 5 is an oscillation circuit that outputs a high-frequency pulse signal, and the oscillation frequency of the high-frequency power output from the high-frequency power supply 1 is set by the high-frequency pulse signal. The power amplifier 6 includes a switching element and the like, amplifies a high-frequency pulse signal output from the high-frequency pulse oscillation circuit 5 according to the magnitude of power supplied from the DC power supply circuit 4, and outputs high-frequency power. It is an amplifier circuit.
The resonance circuit 7 is a resonance circuit that passes only the fundamental wave signal component of the high-frequency power output from the power amplifier 6 (sine wave signal component having the same frequency as the frequency of the high-frequency pulse signal described above).

The high-frequency power detection circuit 8 detects the magnitude of the high-frequency power output from the resonance circuit 7, that is, the magnitude of the traveling-wave power output from the high-frequency power supply 1, and the magnitude of the reflected-wave power. The detection circuit outputs the power detection signal Pf and the reflected wave power detection signal Pr. The subtraction signal addition circuit 15 is an addition circuit that adds a subtraction signal to the external setting signal Pex and outputs a traveling wave power setting signal Ps when a protection signal described below is output from each protection circuit. The traveling wave power set value / detection value comparison circuit 9 compares the traveling wave power setting signal Ps with the traveling wave power detection signal Pf, and outputs a traveling wave power error signal ΔPs (= Ps−Pf) to the DC power supply circuit 4. This is a comparison circuit that controls the traveling wave power of the high frequency power supply 1 to be Ps by adjusting the output of the DC power supply circuit 4.

As described above, the high frequency power supply 1 adjusts the output power of the DC power supply circuit 4 by the high frequency power detection circuit 8 and the traveling wave power set value / detection value comparison circuit 9 and adjusts the output from the power amplifier 6. And outputs the traveling wave power so that the traveling wave power of the high frequency power supply 1 becomes the traveling wave power setting signal Ps.

However, when the impedances are not matched as described above, the load impedance ZL of the high-frequency power supply 1 changes to a high impedance or a low impedance. As a result, when ZL has a high impedance, the input portion and the output portion of the power amplifier 6 have a high voltage as compared with the time of matching, and when ZL has a low impedance, the input current and the output current of the power amplifier 6 have a higher voltage than at the time of matching. To increase.

Since the power amplifier 6 is designed so that the loss power is close to the minimum when the impedance is matched, the loss power of the power amplifier 6 increases when the impedance is not matched. . When the power loss of the power amplifier 6 increases, the amount of heat generated by the switching element increases.

By the way, the withstand voltage, allowable current and operating temperature of the switching elements constituting the power amplifier 6 are limited, and are usually designed on the basis of when the impedance is matched. For this reason, when the impedance is not matched, the withstand voltage, the allowable current, or the operating temperature may exceed the limit value. Therefore, the traveling wave power is simply controlled so as to become the magnitude indicated by the external setting signal Pex. Rather, it is necessary to protect the switching element from overvoltage, overcurrent, and heat so that the withstand voltage, allowable current, or operating temperature of the switching element does not exceed the limit value.

In such protection, the DC voltage detection circuit 10 detects the input signal of the power amplifier 6 in addition to the traveling wave power detection signal Pf and the reflected wave power detection signal Pr detected by the high frequency power detection circuit 8 described above. The DC voltage detection signal Vi and the output signal of the power amplifier 6 are detected using the resonance current detection signal Io detected by the resonance current detection circuit 11. Hereinafter, a conventional protection circuit will be described.

The overvoltage protection is performed by the excess DC voltage protection circuit 12 shown in FIG. Hereinafter, an example of the excess DC voltage protection circuit 12 will be described with reference to FIG. FIG.
1 is a connection diagram of a prior art excess DC voltage protection circuit showing an example of a prior art excess DC voltage protection circuit 12. FIG. In the figure, D
The C voltage protection level setting circuit 21 outputs the DC voltage protection level V
This is a circuit for setting ip. Excess DC voltage calculation circuit 22
Compares the DC voltage detection signal Vi with the DC voltage protection level Vip. Only when Vi exceeds Vip, the excess (V
DC voltage subtraction signal ΔVi (<0) proportional to i-Vip)
Is an arithmetic circuit that outputs.

In FIG. 1, an excess DC voltage protection circuit 12
The DC voltage detection signal Vi is input from the DC voltage detection circuit 10, and the DC voltage detection signal Vi
When the voltage protection level Vip is exceeded, a DC voltage subtraction signal ΔVi (<0) is output. The subtraction signal addition circuit 15
DC voltage subtraction signal ΔVi from excess DC voltage protection circuit 12
When (<0) is output, the traveling wave power setting signal Ps is suppressed by adding the DC voltage subtraction signal ΔVi (<0) to the external setting signal Pex.

As will be described later, the resonance current subtraction signal ΔIo (<0) output from the excess resonance current protection circuit 13
Alternatively, the traveling wave power setting signal Ps is also suppressed by adding the reflected wave power subtraction signal ΔPr (<0) output from the excess reflected wave power protection circuit 14 to the external setting signal Pex.

That is, the traveling wave power setting signal Ps output from the subtraction signal adding circuit 15 is Pex + ΔVi + ΔIo
+ ΔPr, the excess DC voltage protection circuit 12
When the C voltage subtraction signal ΔVi is output, when the resonance current subtraction signal ΔIo is output from the excess resonance current protection circuit 13, or when the reflected wave power subtraction signal ΔPr is output from the excess reflected wave power protection circuit 14, The value becomes smaller by the negative signal output from the protection circuit.

The DC output from the DC power supply circuit 4
The magnitude of the power is determined by the traveling wave power set value / detection value comparison circuit 9.
Varies according to the traveling wave power error signal ΔPs output from the. When the traveling wave power setting signal Ps decreases, the DC power output from the DC power supply circuit 4 decreases by an amount corresponding to a decrease in the value of the traveling wave power error signal ΔPs = Ps−Pf. When the DC power output from the DC power supply circuit 4 decreases, the high-frequency power output from the power amplifier 6 and the high-frequency power (traveling wave power) output from the resonance circuit 7 also decrease. That is, by suppressing the traveling wave power setting signal Ps, the traveling wave power error signal ΔPs = Ps−Pf is also reduced, and the traveling wave power is reduced, so that the DC voltage at the input section of the power amplifier 6 is reduced.

Since such overvoltage protection is performed until the DC voltage detection signal Vi ≦ DC voltage protection level Vip, if the DC voltage protection level Vip is set to an appropriate value,
The switching element of the power amplifier 6 is protected from overvoltage.

The protection against the overcurrent is performed by the excess resonance current protection circuit 13 shown in FIG. Hereinafter, an example of the excess resonance current protection circuit 13 will be described with reference to FIG.

FIG. 3 is a connection diagram of an excess resonance current protection circuit showing an example of the prior art excess resonance current protection circuit 13. In the figure, a resonance current protection level setting circuit 31 is a circuit for setting a resonance current protection level Iop. The excess resonance current calculation circuit 32 calculates the resonance current detection signal Io and the resonance current protection level I
op and compares the resonance current detection signal Io with the resonance current protection level Iop and outputs a resonance current subtraction signal ΔIo (<0) proportional to the excess (Io−Iop).

In FIG. 1, the excess resonance current protection circuit 13
Receives the resonance current detection signal Io from the resonance current detection circuit 11 and outputs the resonance current subtraction signal ΔIo (<0) when the resonance current detection signal Io exceeds the resonance current protection level Iop as described above. The subtraction signal addition circuit 15
The resonance current subtraction signal ΔIo from the excess resonance current protection circuit 13
When (<0) is output, the traveling wave power setting signal Ps is suppressed by adding the resonance current subtraction signal ΔIo (<0) to the external setting signal Pex.

That is, by suppressing the traveling wave power setting signal Ps, the traveling wave power is reduced in the same process as in the above-described overvoltage protection, and the resonance current at the output of the resonance circuit 7 is reduced.

Since such overcurrent protection is performed until the resonance current detection signal Io ≦ the resonance current protection level Iop, if the resonance current protection level Iop is set to an appropriate value,
The switching element of the power amplifier 6 is protected from overcurrent.

Next, protection against heat generation of the switching element will be described. In order to protect the switching element from destruction due to heat generation, it is necessary to control the junction temperature to be equal to or lower than the maximum used junction temperature Tjp.

However, in practice, it is impossible to directly detect the junction temperature. Therefore, in the prior art, the reflected wave power is controlled to a set value (reflected wave power protection level Prp) or less. The switching element is protected from destruction due to heat generation (hereinafter referred to as excess reflected wave power protection).

Hereinafter, the protection of the excess reflected wave power will be described. When the output impedance Zo of the high-frequency power supply 1 and the load impedance ZL do not match, a reflected wave power is generated, and the switching element junction temperature increases due to an increase in power amplifier loss power.

It should be noted that if the magnitude of the reflected wave power increases, the rise in the switching element junction temperature (the magnitude of the switching element loss power) does not necessarily increase. The magnitude of the switching element loss power varies variously depending on the magnitude and phase of the load impedance ZL of the high-frequency power supply 1.

If the load impedance ZL is the same in magnitude and phase, the smaller the magnitude of the reflected wave power (the smaller the traveling wave power output from the high frequency power supply 1), the lower the power loss of the switching element. As a result, the switching element junction temperature (the magnitude of the switching element loss power) decreases.

Therefore, when the magnitude of the reflected wave power reaches the reflected wave power protection level Prp, if the traveling wave power of the high frequency power supply 1 is suppressed in order to reduce the magnitude of the reflected wave power, the switching element loss power , The switching element can be protected from destruction due to heat generation.

In this control, the reflected wave power protection level Prp is determined by experiments. As an example, consider a high-frequency power supply 1 having a maximum traveling wave power set value Ps of 2000 W. First, the maximum value 2000 W of the traveling wave power set value Ps
Setting the reflected power protection level Prp to a sufficiently small value,
For example, an experiment is performed in which the traveling wave power is output from the high-frequency power supply 1 while the load impedance ZL of the high-frequency power supply 1 is set to 50 W and the switching element is not damaged.

In this experiment, the experiment is performed by changing the load impedance ZL of the high-frequency power supply 1 to various magnitudes and phases. This is because the impedance and the phase of the plasma load vary over a wide range, and the magnitude and phase of the load impedance ZL also vary over a wide range.

Next, the reflected wave power protection level Prp is gradually increased.
Is increased, and the same experiment is performed. From the result, the reflected wave power protection level Prp at which the switching element is not damaged by heat generation can be determined.

Using the reflected power protection level Prp determined by the above experiment, protection against heat generation of the switching element is performed. Hereinafter, the protection of the switching element against heat generation will be described with reference to the drawings.

The protection of the switching element from heat generation is performed by the excess reflection power protection circuit 14 shown in FIG. Less than,
An example of the excess reflected wave power protection circuit 14 will be described with reference to FIG.

FIG. 4 is a connection diagram of the excess reflected wave power protection circuit showing an example of the prior art excess reflected wave power protection circuit 14. As shown in FIG. In the figure, the reflected wave power protection level setting circuit 41
Is a setting circuit for setting the reflected wave power protection level Prp. The excess reflected wave power calculation circuit 42 compares the reflected wave power detection signal Pr with the reflected wave power protection level Prp. Only when the reflected wave power detection signal Pr exceeds the reflected wave power protection level Prp, the excess (Pr -Prp) is an arithmetic circuit that outputs a reflected wave power subtraction signal ΔPr (<0) proportional to (−Prp).

In FIG. 1, an excessively reflected wave power protection circuit 1
4 is a reflected wave power detection signal P from the high frequency power detection circuit 8
r is input and the reflected power detection signal Pr
Output the reflected wave power subtraction signal ΔPr (<0) only when exceeds the reflected wave power protection level Prp.

When the reflected wave power subtraction signal ΔPr (<0) is output from the excess reflected wave power protection circuit 14, the subtraction signal addition circuit 15 adds the reflected wave power subtraction signal ΔPr (<0) to the external setting signal Pex. The addition sets the traveling wave power setting signal Ps.

That is, by suppressing the traveling-wave power setting signal Ps, the traveling-wave power is reduced in the same process as in the above-described overvoltage protection, and the loss power of the switching element is reduced. descend.

The protection for suppressing the reflected wave power is as follows.
Since the process is performed until Pr ≦ Prp, setting the reflected wave power protection level Prp to an appropriate value protects the switching element of the power amplifier 6 from destruction due to heat generation.

[0040]

In the prior art excess reflected wave power protection, when determining the reflected wave power protection level Prp, an experiment was performed while changing the load impedance ZL of the high frequency power supply 1 to various magnitudes and phases. Need to do a lot of work. Therefore, a high-frequency power supply 1 having a protection circuit that can easily determine a protection level is required.

Also, if the magnitude of the reflected wave power increases, the temperature rise of the switching element junction does not necessarily increase. Depending on the load impedance ZL of the high-frequency power supply 1, even when the reflected wave power exceeds the set value, the switching element may be able to tolerate further power loss. In such a case, too much protection is required to suppress the traveling wave power of the high frequency power supply 1. When the high-frequency power supply 1 is used in an etching process or the like, in order not to waste the process up to that point,
It is desirable that the output of the high-frequency power supply 1 be kept as low as possible. Therefore, the high-frequency power supply 1 is provided with a circuit for suppressing the traveling-wave power in a necessary and sufficient range without unnecessarily suppressing the traveling-wave power of the high-frequency power supply 1 and for surely protecting the switching element from destruction due to heat generation. is necessary.

An object of the present invention is to provide a plasma generating high-frequency power supply 1 provided with a novel protection circuit for solving the above-mentioned problem.

[0043]

Means for Solving the Problems Claim 1 at the time of filing
As shown in FIG. 6, the invention of the protection method for the power supply device described in (1) is based on the traveling wave power error signal ΔPs = Ps−Pf obtained by subtracting the traveling wave power detection signal Pf from the traveling wave power setting signal Ps.
In the protection method for the plasma generating high-frequency power supply having means for maintaining the traveling wave power at the level indicated by the traveling wave power setting signal Ps, a DC voltage and a DC current, and a traveling wave power and a reflected wave power are detected. Voltage detection signal Vi, DC current detection signal Ii, and traveling wave power detection signal Pf
And the reflected wave power detection signal Pr to calculate the power amplifier loss power PL. When the power amplifier loss power PL exceeds the loss power protection level PLp, the loss power subtraction signal Δ
PL (<0), and calculates the loss power subtraction signal ΔPL
(<0) is added to the external setting signal Pex to reduce the traveling wave power setting signal Ps to Pex + ΔPL.
5 is a high-frequency power supply device 61 for generating plasma, comprising:

According to the invention of the protection method of the power supply device described in claim 2 at the time of filing, the loss power subtraction signal ΔPL (<0) of claim 1 at the time of filing is determined by the D power as shown in FIG.
A DC power signal Pi which is a product of the C voltage detection signal Vi and the DC current detection signal Ii is calculated, and a traveling wave power detection signal Pf
The high-frequency output power signal Po is calculated by subtracting the reflected-wave power detection signal Pr from the DC power signal Pi.
The power amplifier loss power PL is calculated by subtracting the high frequency output power signal Po from the above, and a plasma generating high frequency power supply which is a negative signal output when the power amplifier loss power PL exceeds the loss power protection level PLp. This is a method for protecting the device 61.

The invention of a method for protecting a power supply device according to claim 3 at the time of filing is a method for protecting a high frequency power supply 61 for plasma generation according to claim 1 at the time of filing.
As shown in FIG. 6, means for detecting the resonance current, means for calculating the DC voltage subtraction signal ΔVi (<0) when the DC voltage detection signal Vi exceeds the DC voltage protection level Vip,
Means for calculating the resonance current subtraction signal ΔIo (<0) when the resonance current detection signal Io exceeds the resonance current protection level Iop, so that the DC voltage subtraction signal ΔVi and the resonance current subtraction signal ΔIo (<0) This is a method for protecting the plasma-generating high-frequency power supply device 61 that suppresses the traveling wave power by suppressing the traveling wave power setting signal Ps also by adding it to the setting signal Pex.

As shown in FIG. 6, the invention of the power supply device protection method according to claim 4 at the time of filing applies a traveling wave power error signal ΔPs obtained by subtracting the traveling wave power detection signal Pf from the traveling wave power setting signal Ps. = Ps−Pf In a high frequency power supply for plasma generation provided with means for maintaining the traveling wave power at the level indicated by the external setting signal Pex, a DC voltage detection circuit detects a DC voltage input to a power amplifier and outputs a DC voltage detection signal Vi.
A C voltage detection circuit 10, a DC current detection circuit 60 that detects a DC current input to the power amplifier and outputs a DC current detection signal Ii, a high-frequency output power of the resonance circuit 7, and a traveling-wave power detection signal Pf and a reflected-wave power A high-frequency power detection circuit 8 for outputting a detection signal Pr;
A power amplifier loss power PL is calculated from the current detection signal Ii, the traveling wave power detection signal Pf, and the reflected wave power detection signal Pr, and a loss power subtraction signal is output when the power amplifier loss power PL exceeds the loss power protection level PLp. ΔPL (<
0), and a subtraction signal addition circuit 65 that adds the loss power subtraction signal ΔPL (<0) to the external setting signal Pex to suppress the traveling wave power setting signal Ps to Pex + ΔPL. This is a high frequency power supply device 61 for plasma generation provided.

According to the invention of the method for protecting a power supply device according to claim 5 at the time of filing, the excess loss power protection circuit 614 of claim 4 at the time of filing applies a DC voltage detection signal Vi and a DC voltage as shown in FIG. D which is the product of the current detection signal Ii
A DC power calculation circuit 71 for calculating the C power signal Pi; a high frequency output power calculation circuit 72 for calculating the high frequency output power signal Po by subtracting the reflected wave power detection signal Pr from the traveling wave power detection signal Pf; and the DC power signal Pi. The high-frequency output power signal Po is subtracted from the power amplifier loss power P
A plasma composed of a loss power calculation circuit 73 for calculating L and an excess loss power calculation circuit 75 for outputting a loss power subtraction signal ΔPL (<0) when the power amplifier loss power PL exceeds the loss power protection level PLp. This is a high-frequency power supply device 61 for generation.

According to the invention of the power supply device described in claim 6 at the time of filing, in the high frequency power supply device 61 for plasma generation according to claim 4 at the time of filing, the output resonance current of the resonance circuit 7 is detected and the resonance current detection signal Io is generated. The output of the resonance current detection circuit 11 and the DC voltage subtraction signal ΔVi (<
0) and an excess resonance current protection circuit 13 that outputs a resonance current subtraction signal ΔIo (<0) when the resonance current detection signal Io exceeds the resonance current protection level Iop. , The DC voltage subtraction signal ΔVi and the resonance current subtraction signal ΔIo (<0) by the external setting signal Pex
The plasma generating high-frequency power supply device 61 suppresses the traveling wave power setting signal Ps also by adding the signal to

As shown in FIG. 8, the invention of the protection method of the power supply device according to claim 7 at the time of filing applies a traveling wave power error signal ΔPs obtained by subtracting the traveling wave power detection signal Pf from the traveling wave power setting signal Ps. = Ps-Pf, wherein the DC voltage and the DC current, the traveling wave power and the reflected wave power are provided in a method for protecting the plasma generating high-frequency power supply device having means for maintaining the traveling wave power at the level indicated by the traveling wave power setting signal Ps by Ps-Pf. And a switching element base temperature detected by the DC voltage detection signal Vi, the DC current detection signal Ii, the traveling wave power detection signal Pf, the reflected wave power detection signal Pr, and the switching element base temperature detection signal Tb. Tj is calculated, and when the switching element junction temperature signal Tj exceeds the junction temperature protection level Tjp, the junction is determined. A temperature subtraction signal ΔTj (<0) is calculated, and the junction temperature subtraction signal ΔTj (<0) is added to the external setting signal Pex to change the traveling wave power setting signal Ps to Pex +
This is a method for protecting the plasma-generating high-frequency power supply 81 that suppresses traveling wave power by suppressing it to ΔTj.

According to the invention of the protection method of the power supply device described in claim 8 at the time of filing, the loss power subtraction signal ΔPL (<0) of claim 7 at the time of filing is determined by the method shown in FIG.
A DC power signal Pi which is a product of the C voltage detection signal Vi and the DC current detection signal Ii is calculated, and a traveling wave power detection signal Pf
Is subtracted from the DC power signal Pi to calculate the high-frequency output power signal Po, and subtracts the high-frequency output power signal Po from the DC power signal Pi.
L is calculated, and the product of the power amplifier loss power PL and the thermal resistance Rjb between the switching element junction and the base is divided by the number n of the switching elements to calculate the junction / base temperature difference signal Tjb. The switching element junction temperature signal Tj is calculated by adding the switching element base temperature difference signal Tjb to the switching element base temperature detection signal Tb, and output when the switching element junction temperature signal Tj exceeds the junction temperature protection level Tjp. This is a method for protecting the high-frequency power supply 81 for plasma generation, which is a negative signal.

The invention of a method for protecting a power supply device according to claim 9 at the time of filing is a method for protecting a high frequency power supply device for plasma generation according to claim 7 at the time of filing.
Means for detecting the resonance current;
Means for calculating a DC voltage subtraction signal ΔVi (<0) when the C voltage protection level Vip is exceeded, and a resonance current detection signal I
a means for calculating a resonance current subtraction signal ΔIo (<0) when o exceeds the resonance current protection level Iop;
The voltage subtraction signal ΔVi and the resonance current subtraction signal ΔIo (<
0) is added to the external setting signal Pex to suppress the traveling wave power setting signal Ps, and this is a protection method for the plasma generating high-frequency power supply device 81 that suppresses the traveling wave power.

As shown in FIG. 8, the invention of the power supply device according to claim 10 at the time of filing the application is a traveling wave power error signal ΔPs = Ps− obtained by subtracting the traveling wave power detection signal Pf from the traveling wave power setting signal Ps. DC voltage detection for detecting a DC voltage input to a power amplifier and outputting a DC voltage detection signal Vi in a high frequency power supply device for plasma generation including means for maintaining the traveling wave power at a level indicated by the traveling wave power setting signal Ps by Pf A circuit 10, a DC current detection circuit 60 for detecting a DC current input to the power amplifier and outputting a DC current detection signal Ii, a traveling wave power detection signal Pf for detecting a high frequency output power of the resonance circuit 7, and a reflected wave power detection signal Pr And a switching element base temperature detection signal Tb which detects the switching element base temperature and outputs
, A DC voltage detection signal Vi, a DC current detection signal Ii, and a traveling wave power detection signal P
f, the reflected power detection signal Pr, and the switching element base temperature detection signal Tb to calculate the switching element junction temperature signal Tj. When the switching element junction temperature signal Tj exceeds the junction temperature protection level Tjp, the junction is performed. An excess junction temperature protection circuit 814 that outputs a partial temperature subtraction signal ΔTj (<0);
(<0) is added to the external setting signal Pex to suppress the traveling wave power setting signal Ps to Pex + ΔTj, thereby providing a subtraction signal addition circuit 85 for suppressing traveling wave power. is there.

According to the invention of the power supply device described in claim 11 at the time of filing, the excess junction temperature protection circuit 814 of claim 10 at the time of filing applies the DC voltage detection signal Vi and the DC current detection as shown in FIG. A DC power calculation circuit 71 for calculating a DC power signal Pi which is a product of the signal Ii and a high-frequency output power calculation circuit for calculating a high-frequency output power signal Po by subtracting the reflected wave power detection signal Pr from the traveling wave power detection signal Pf 72 and a loss power calculation circuit 73 for calculating the power amplifier loss power PL by subtracting the high-frequency output power signal Po from the DC power signal Pi, and the thermal resistance Rjb between the power amplifier loss power PL and the switching element junction / base. Is divided by the number n of switching elements to calculate a junction-base temperature difference signal Tjb. And the junction / base temperature difference signal T
A junction temperature calculation circuit 92 for calculating a switching element junction temperature signal Tj by adding a switching element base temperature detection signal Tb to jb and when the switching element junction temperature signal Tj exceeds the junction temperature protection level Tjp. This is a plasma generating high-frequency power supply device 81 including an excess junction temperature calculation circuit 94 that outputs a junction temperature subtraction signal ΔTj (<0).

The invention of the power supply device according to claim 12 at the time of filing is the invention of the high frequency power supply device 81 for plasma generation according to claim 10 at the time of filing, by detecting an output resonance current of the resonance circuit 7 and generating a resonance current detection signal Io. The output resonance current detection circuit 11 and the DC voltage subtraction signal ΔVi when the DC voltage detection signal Vi exceeds the DC voltage protection level Vip
An excess DC voltage protection circuit 12 that outputs (<0) and an excess resonance current protection circuit 13 that outputs a resonance current subtraction signal ΔIo (<0) when the resonance current detection signal Io exceeds the resonance current protection level Iop. Add the DC voltage subtraction signal ΔV
i and the resonance current subtraction signal ΔIo (<0) to the external setting signal Pex can also be used as the traveling wave power setting signal Ps.
This is a high-frequency power supply device 81 for plasma generation, which suppresses traveling wave power.

[0055]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Instead of suppressing the traveling wave power so that the reflected wave power becomes equal to or less than a predetermined value, the loss power PL of the power amplifier 6 is changed to a predetermined loss power protection level as shown in FIG. The traveling wave power is suppressed so as to be equal to or less than PLp. As will be described later, since the amount of heat generated by the power amplifier is proportional to the power loss power PL of the power amplifier, it is not necessary to carry out an experiment to determine the protection level, and it is possible to protect the switching element without suppressing the traveling wave power more than necessary. it can.

More specifically, as shown in FIG. 6, the traveling wave power is set by the traveling wave power error signal ΔPs = Ps−Pf obtained by subtracting the traveling wave power detection signal Pf from the traveling wave power setting signal Ps. In a high frequency power supply for plasma generation having means for maintaining the magnitude indicated by Ps, a DC voltage detection circuit 10 for detecting a DC voltage input to a power amplifier and outputting a DC voltage detection signal Vi;
A DC current detection circuit 60 that detects a current and outputs a DC current detection signal Ii; and a resonance current detection circuit 11 that detects an output resonance current of the resonance circuit 7 and outputs a resonance current detection signal Io
A high-frequency power detection circuit 8 for detecting a high-frequency output power of the resonance circuit 7 and outputting a traveling-wave power detection signal Pf and a reflected-wave power detection signal Pr;
Excess DC voltage protection circuit 12 that outputs DC voltage subtraction signal ΔVi (<0) when voltage protection level Vip is exceeded
And the resonance current detection signal Io is the resonance current protection level I
The excess resonance current protection circuit 13 that outputs the resonance current subtraction signal ΔIo (<0) when the current exceeds the op, the DC voltage detection signal Vi, the DC current detection signal Ii, and the traveling wave power detection signal P
f and the reflected power detection signal Pr to calculate the power amplifier loss power PL, and output the loss power subtraction signal ΔPL (<0) when the power amplifier loss power PL exceeds the loss power protection level PLp. Power protection circuit 614
And the DC voltage subtraction signal ΔVi (<0), the resonance current subtraction signal ΔIo (<0), or the loss power subtraction signal ΔPL (<0) to the external setting signal Pex to obtain the traveling wave power setting signal Ps. A plasma generating high-frequency power supply device 61 including a subtraction signal addition circuit 65 for suppressing Pex + ΔVi + ΔIo + ΔPL.

[0057]

(Embodiment 1) As described in the prior art, in order to protect a switching element from destruction due to heat generation, it is necessary to use the switching element at a temperature lower than a maximum used junction temperature Tjp. Therefore, it is necessary to control the traveling wave power of the high frequency power supply 1 so that the switching element junction temperature Tj is equal to or lower than the maximum use junction temperature Tjp. Further, the switching element junction temperature Tj is proportional to the switching element loss power Pd as described later. Therefore, the maximum operating junction temperature Tjp
The power loss P of the switching element that does not exceed
dp is determined, and the measured switching element loss power Pd becomes P
If the traveling wave power output from the high frequency power supply 1 is controlled so as not to exceed dp, the amount of heat generated by the switching element is reduced, and the switching element can be protected from destruction due to heat generation.

In the first embodiment of the present invention, it is assumed that the loss power PL of the power amplifier 6 is entirely due to the switching elements, and the product of the switching element loss power Pd and the number n of the switching elements is calculated as the power amplifier loss power PL.
(PL = Pd × n). Similarly, by setting the power amplifier loss protection level PLp as PLp = Pdp × n, protection is performed using this PLp. Specifically, the switching element is protected from destruction due to heat generation by suppressing the traveling wave power of the high frequency power supply 61 so that the power amplifier loss power PL becomes equal to or lower than a loss power protection level PLp described later.

Hereinafter, a method of determining the loss power protection level PLp will be described in detail. FIG. 5 is a switching element temperature / loss power explanatory diagram for explaining the relationship among the switching element junction temperature Tj, the switching element base temperature Tb, and the switching element loss power Pd. Tj = Rjb × Pd + Tb (Equation 1) (Equation 1) is an equation for explaining the relationship among the switching element junction temperature Tj, the switching element base temperature Tb, and the switching element loss power Pd. is there.

In FIG. 5, a switching element 51 is a switching element constituting the power amplifier 6, and a radiator 52 is a radiator for cooling the switching element. In FIG. 5 and Equation 1, Rjb is the thermal resistance value between the switching element junction and the base, and is described in the data sheet as the temperature rise per unit power.

The difference between the switching element junction temperature Tj and the switching element base temperature Tb is caused by the switching element loss power Pd. As shown in FIG. It is given by the product Rjb × Pd with the switching element loss power Pd, and the switching element junction temperature Tj is proportional to the switching element loss power Pd.

First, the allowable loss power Pdp of the switching element is determined so that the switching element junction temperature Tj does not exceed the maximum use junction temperature Tjp. From Equation 1, when the switching element loss power Pd is represented by the switching element junction temperature Tj, the switching element base temperature Tb, and the junction-base thermal resistance Rjb, Equation 2 is obtained. Pd = {Tj-Tb} / Rjb (2)

In Equation 2, the maximum used junction temperature Tjp and the junction-base thermal resistance Rjb described in the data sheet are substituted for the switching element junction temperature Tj and the junction-base thermal resistance Rjb, and the switching is performed. By assuming the element base temperature Tb as described later, the upper limit value Pdp of the switching element loss power Pd can be obtained. The product of the obtained switching element allowable loss power Pdp and the number n of switching elements is defined as a loss power protection level PLp.

For example, the power amplifier 6 is composed of four switching elements having the maximum use junction temperature Tjp = 150 ° C. described in the data sheet and the junction-base thermal resistance Rjb = 1.0 W / ° C. Consider the case. In this case, since the switching element junction temperature Tj is allowed up to 150 ° C., Tjp = 150 ° C. is substituted for Tj in Expression 2. In order to increase the reliability of the power amplifier 6, a value smaller than 150 ° C. may be used. Next, the upper limit value Tbp of the base temperature Tb is determined. It is assumed that the high-frequency power supply 61 is used in an environment having an ambient temperature of 45 ° C. or less (the maximum operating ambient temperature is 45 ° C.).
° C). When traveling-wave power is output from the high-frequency power supply 61, the temperature inside the housing of the high-frequency power supply 61 becomes higher than that around the high-frequency power supply 61 due to the heat generated by the elements constituting the high-frequency power supply 61. Therefore, it is assumed that the internal temperature of the high-frequency power supply 61 is higher by 15 ° C. than the ambient temperature of the high-frequency power supply 61. Further, assuming that the switching element base temperature is higher by 10 ° C. than the internal temperature of the high frequency power supply 61, the upper limit of the switching element base temperature is Tbp = 4.
5 ° C. + 15 ° C. + 10 ° C. = 70 ° C. This is expressed by T
Substitute for b.

That is, the switching element base temperature T
When the upper limit value of b is Tbp = 70 ° C., the switching element junction temperature Tj is allowed up to Tjp = 150 ° C. Therefore, the permissible power loss Pdp of the switching element is 8 from Equation 2.
0W. Therefore, the allowable loss power of the power amplifier is 80 W × 4 = 320 W, and the power amplifier loss power protection level PLp is set to a value corresponding to 320 W.

In the first embodiment, the high-frequency power supply 61 is controlled so that the power amplifier loss power PL becomes equal to or less than the aforementioned PLp.
, The switching element loss power Pd can be reduced, and the switching element can be protected from destruction due to heat generation.

Hereinafter, the protection using the power amplifier loss power PL will be described with reference to the drawings. FIG. 6 is a block diagram of the first embodiment showing the first embodiment of the present invention. FIG.
6, a DC current detection circuit 60 and an excess loss power protection circuit 614 are provided instead of the excess reflection power protection circuit 14 of the related art. Ii is DC
A current detection signal, PLp is the power amplifier loss power protection level described above, and ΔPL is a loss power subtraction signal. Other reference numerals are the same as those described with reference to FIG.

The protection against heat generation in the first embodiment is performed by the excess loss power protection circuit 614 shown in FIG.
Hereinafter, an example of the excess loss power protection circuit 614 will be described with reference to FIG. FIG. 7 is a connection diagram of the excess loss power protection circuit according to the present invention, showing an example of the excess loss power protection circuit 614 according to the present invention. In the figure, the DC power calculation circuit 71 is
An arithmetic circuit for calculating the DC power signal Pi by multiplying the DC voltage detection signal Vi by the DC current detection signal Ii. The high-frequency output power calculation circuit 72 is a calculation circuit for calculating the high-frequency output power Po by subtracting the reflected wave power detection signal Pr from the traveling wave power detection signal Pf. The loss power calculation circuit 73 is a calculation circuit for calculating the power amplifier loss power PL by subtracting the high frequency output power Po from the DC power Pi. The loss power protection level setting circuit 74 is a setting circuit for setting the loss power protection level PLp. The excess loss power calculation circuit 75 compares the power amplifier loss power signal PL with the power amplifier loss power protection level PLp, and only when the power amplifier loss power PL exceeds the loss power protection level PLp, the excess (PL-PLp ) Is an arithmetic circuit that outputs a loss power subtraction signal ΔPL (<0) that is proportional to.

In FIG. 6, the DC voltage detection circuit 10
When the C voltage detection signal Vi, the DC current detection circuit 60 outputs the DC current detection signal Ii, and the high frequency power detection circuit 8 outputs the traveling wave power detection signal Pf and the reflected wave power detection signal Pr, the excess loss power protection circuit 614 Calculates the power amplifier loss power signal PL from the detected value as described above, compares the power amplifier loss power PL with the loss power protection level PLp, and determines that the power amplifier loss power PL is
Only when Lp is exceeded, the loss power subtraction signal ΔPL (<
0) is output. When the loss power subtraction signal ΔPL (<0) is output from the excess loss power protection circuit 62, the subtraction signal addition circuit 65 adds the loss power subtraction signal Δ to the external setting signal Pex.
By adding PL (<0), the traveling wave power setting signal Ps is suppressed. That is, the traveling wave power setting signal Ps
, The traveling-wave power is suppressed in the same process as in the case of the overvoltage protection in the above-described prior art, and the power amplifier loss power PL decreases and the switching element loss power Pd decreases, so that the switching element junction temperature Tj Drops. Such power amplifier loss power P
Since the protection for suppressing L is performed until the power amplifier loss power PL ≦ the power amplifier loss power protection level PLp, if the power amplifier loss power protection level PLp is set to an appropriate value, the switching elements of the power amplifier 6 Protected from destruction by heat.

(Embodiment 2) In the second embodiment, the switching element loss power Pd calculated from the DC voltage detection signal Vi, the DC current detection signal Ii, the traveling wave power detection signal Pf, and the reflected wave power detection signal Pr, and the switching. Using the detected value of the element base temperature Tb and the switching element junction temperature Tj calculated by Equation 1, the maximum used junction temperature Tjp
By controlling as follows, the switching element is protected from destruction due to heat generation. In the second embodiment, the maximum used junction temperature Tjp of the switching element is used as the junction temperature protection level. In order to improve the reliability of the power amplifier, a value lower than the maximum used junction temperature Tjp may be used as the junction temperature protection level.

FIG. 8 shows a second embodiment of the present invention.
It is an Example block diagram. Compared with FIG. 6, in FIG. 8, an excess junction temperature protection circuit 814 is provided instead of the excess loss power protection circuit 614. A power amplifier 86 with a temperature detection circuit and a base temperature detection circuit 80 are provided instead of the power amplifier 6. Tb is a base temperature detection signal, Tjp is the above-described maximum junction temperature (junction temperature protection level), and ΔTj is a junction temperature subtraction signal. For other symbols, refer to FIG.
6 and the description of the reference numerals in FIG.

FIG. 9 is a connection diagram of the over-junction temperature protection circuit according to the present invention, showing an example of the over-junction temperature protection circuit 814 according to the present invention. The excess junction temperature protection circuit 814
The junction temperature Tj is calculated from the base temperature detection signal Tb, the DC voltage detection signal Vi, the DC current detection signal Ii, the traveling wave power detection signal Pf, and the reflected wave power detection signal Pr,
This protection circuit compares Tj with the junction temperature protection level Tjp and outputs a junction temperature subtraction signal ΔTj (<0).

The description of the DC power calculation circuit 71, the high-frequency output power calculation circuit 72, and the loss power calculation circuit 73 is given in FIG.
Is the same as The junction / base temperature difference calculation circuit 91
By multiplying the switching element loss power Pd obtained by dividing the power amplifier loss power signal PL by the number n of the switching elements by the junction-base thermal resistance signal Rjb,
An arithmetic circuit for calculating the base temperature difference signal Tjb. The junction temperature calculation circuit 92 is a calculation circuit for calculating the junction temperature Tj by adding the base temperature detection signal Tb to the junction / base temperature difference signal Tjb.
The junction temperature protection level setting circuit 93 is a setting circuit for setting the junction temperature protection level Tjp. The excess junction temperature calculation circuit 94 compares the junction temperature signal Tj with the junction temperature protection level Tjp, and only when the junction temperature signal Tj exceeds the junction temperature protection level Tjp, the excess (Tj−Tjp). ), The junction temperature subtraction signal ΔTj
(<0).

In FIG. 8, the DC voltage detection circuit 10
The C voltage detection signal Vi, the DC current detection circuit 60 detects the DC current detection signal Ii, the high frequency power detection circuit 8 detects the traveling wave power detection signal Pf and the reflected wave power detection signal Pr, and the base temperature detection circuit 80 detects the base temperature. When the signal Tb is output, the excess junction temperature protection circuit 814 calculates the junction temperature signal Tj as described above, and when the junction temperature signal Tj exceeds the junction temperature protection level Tjp, the junction temperature subtraction signal ΔTj (<0) is output. Subtraction signal addition circuit 85
When the junction temperature subtraction signal ΔTj (<0) is output from the excess junction temperature protection circuit 82, the traveling wave power setting is performed by adding the junction temperature subtraction signal ΔTj (<0) to the external setting signal Pex. The signal Ps is suppressed. That is, by suppressing the traveling wave power setting signal Ps, the traveling wave power is suppressed in the same process as in the case of the overvoltage protection in the above-described conventional technique, the power amplifier loss power PL is reduced, and the switching element loss power Pd is reduced. Therefore, the switching element junction temperature Tj decreases. Such protection for suppressing the junction temperature of the switching element is performed until the junction temperature signal Tj ≦ the junction temperature protection level Tjp. Therefore, if the junction temperature protection level Tjp is set to an appropriate value, the power amplifier The switching element No. 6 is protected from destruction due to heat generation.

[0075]

According to the first embodiment, there is a first effect that the protection level (loss power protection level PLp) can be easily calculated without performing an experiment.

In addition to the first effect, the following second effect is also provided. In the related art, since there is no clear relationship between the magnitude of the reflected wave power Pr and the switching element junction temperature, the switching element cannot be protected within a necessary and sufficient range. On the other hand, in the first embodiment, the switching element junction temperature Tj is equal to the power amplifier loss power PL.
Is proportional to Then, the traveling wave power output from the high frequency power supply 61 is suppressed so that the power amplifier loss power PL becomes equal to or lower than the power amplifier loss power protection level PLp. Therefore, there is also a second effect that the traveling wave power of the high frequency power supply 61 can be suppressed within a necessary and sufficient range, and the switching element can be protected from destruction due to heat generation.

In the second embodiment, since the maximum used junction temperature Tjp may be used as the protection level (junction temperature protection level), it is not necessary to conduct an experiment when determining the protection level. Has an effect.

Further, in addition to the first effect, the following effect is also obtained. In the second embodiment, a protection method is used in which the traveling-wave power of the high-frequency power supply 81 is suppressed using the junction temperature Tj calculated from the detected value so that the junction temperature Tj does not exceed the maximum used junction temperature Tjp. is there. Therefore, similarly to the first embodiment, there is also a second effect that the traveling wave power of the high frequency power supply 1 can be suppressed within a necessary and sufficient range, and the switching element can be protected from destruction due to heat generation.

In the first embodiment, the base temperature Tb is set to the maximum operating ambient temperature of the high frequency
5 ° C.), the power loss protection level PLp is determined, whereas in the second embodiment, the junction temperature Tj is calculated using the detected value of the base temperature Tb. Therefore, in the second embodiment, in addition to the above-described effects, even if the high-frequency power supply 61 is used in an environment at or above the maximum operating temperature,
There is also a third effect that the switching element can be protected from destruction due to heat generation.

[Brief description of the drawings]

FIG. 1 is a prior art block diagram showing a prior art high frequency power supply device for plasma generation 1 and its peripheral devices.

FIG. 2 shows a prior art excess DC voltage protection circuit 12;
FIG. 4 is a connection diagram of an excess DC voltage protection circuit according to the related art, showing the example of FIG.

FIG. 3 shows a prior art excess resonance current protection circuit 13;
FIG. 4 is a connection diagram of an excess resonance current protection circuit showing an example of the above.

FIG. 4 is a prior art excess reflected wave power protection circuit 1;
FIG. 4 is a connection diagram of an excess reflected wave power protection circuit showing an example 4 of FIG.

FIG. 5 is an explanatory diagram of a switching element temperature and a loss power for explaining a relationship among a switching element junction temperature Tj, a switching element base temperature Tb, and a switching element loss power Pd.

FIG. 6 is a block diagram showing a first embodiment of the present invention.

FIG. 7 shows an excess loss power protection circuit 6 according to the present invention.
FIG. 14 is a connection diagram of an excess loss power protection circuit according to the present invention, showing Example 14;

FIG. 8 is a block diagram of a second embodiment showing the second embodiment of the present invention.

FIG. 9 is a connection diagram of the over-junction temperature protection circuit according to the present invention, showing an example of the over-junction temperature protection circuit 814 according to the present invention.

[Explanation of symbols]

 High frequency power supplies 1, 61, 81 Matching device 2 Plasma generation chamber 3 DC power supply circuit 4 High frequency pulse oscillation circuit 5 Power amplifier 6 Resonance circuit 7 High frequency power detection circuit 8 Traveling wave power set value / detection value comparison circuit 9, 69, 89 DC voltage detection circuit 10 Resonant current detection circuit 11 Excessive DC voltage protection circuit 12 Excess resonance current protection circuit 13 Excessive reflected wave power protection circuit 14 Subtraction signal addition signal 15, 65, 85 DC voltage protection level setting circuit 21 Excessive DC voltage calculation circuit 22 Resonant current protection level setting circuit 31 Excess resonance current calculation circuit 32 Reflected wave power protection level setting circuit 41 Excess reflected wave power calculation circuit 42 Switching element 51 Heat sink 52 DC current detection circuit 60 Excess loss power protection circuit 614 DC power calculation circuit 71 High frequency output power calculation circuit 72 Loss power calculation circuit 73 Loss power protection Level setting circuit 74 Excess loss power calculation circuit 75 Base temperature detection circuit 80 Power amplifier 86 with temperature detection circuit Excess junction temperature protection circuit 814 Junction / base temperature difference calculation circuit 91 Junction temperature calculation circuit 92 Junction temperature protection level setting Circuit 93 Excess junction temperature calculating circuit 94 Cable CB1 Cable CB2 Output impedance Zo of high frequency power supply 1 Load impedance ZL Traveling wave power error signal ΔPs External setting signal Pex Traveling wave power setting signal Ps Traveling wave power detection signal Pf Reflected wave power detection signal Pr DC voltage detection signal Vi Resonant current detection signal Io DC current detection signal Ii Power amplifier loss power PL DC voltage protection level Vip Resonant current protection level Iop Reflected wave power protection level Prp Power amplifier loss power protection level PLp Maximum junction temperature ( Junction temperature protection level Tjp DC voltage subtraction signal ΔVi Resonant current subtraction signal ΔIo Reflected wave power subtraction signal ΔPr Loss power subtraction signal ΔPL Junction temperature subtraction signal ΔTj Switching element junction temperature (signal) Tj Switching element base temperature (detection signal) Tb Switching element loss power (Signal) Pd Switching element junction-base thermal resistance Rjb DC power signal Pi High-frequency power signal Po Junction-base temperature difference signal Tjb

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tatsumi Ono 2-1-1-11 Tagawa, Yodogawa-ku, Osaka-shi F-term in Daihen Corporation (reference) 5F004 AA16 BA04 BB11 CA03 CB05

Claims (12)

[Claims] 1. A high frequency power supply for plasma generation comprising means for maintaining a traveling wave power at a magnitude indicated by a traveling wave power setting signal by a traveling wave power error signal obtained by subtracting a traveling wave power detection signal from a traveling wave power setting signal. In the protection method for the device, a DC voltage, a DC current, a traveling wave power, and a reflected wave power are detected, and a power amplifier loss power is obtained from the DC voltage detection signal, the DC current detection signal, the traveling wave power detection signal, and the reflected wave power detection signal. Is calculated, and a loss power subtraction signal that is a negative signal when the power amplifier loss power exceeds the loss power protection level is calculated, and the loss power subtraction signal is added to an external setting signal to set the traveling wave power setting. A method for protecting a high-frequency power supply for plasma generation for suppressing a signal. 2. The loss power subtracted signal according to claim 1, wherein
A DC power signal which is a product of the C voltage detection signal and the DC current detection signal is calculated, and a reflected wave power detection signal is subtracted from the traveling wave power detection signal to calculate a high frequency output power signal.
The high-frequency output power signal is subtracted from the C power signal to calculate a power amplifier loss power, and a negative signal output when the power amplifier loss power exceeds a loss power protection level. Protection method. 3. A high frequency power supply for plasma generation, comprising: means for maintaining a traveling wave power at a magnitude indicated by a traveling wave power setting signal by a traveling wave power error signal obtained by subtracting a traveling wave power detection signal from a traveling wave power setting signal. In a protection method for a device, a DC voltage, a DC current, a traveling wave power, a reflected wave power, and a resonance current are detected, and a DC voltage subtraction signal that is a negative signal when a DC voltage detection signal exceeds a DC voltage protection level is calculated. Then, when the resonance current detection signal exceeds the resonance current protection level, a resonance current subtraction signal that is a negative signal is calculated, and the DC voltage detection signal, the DC current detection signal, the traveling wave power detection signal, the reflected wave power detection signal, Calculate the power amplifier loss power from, calculate a loss power subtraction signal that is a negative signal when the power amplifier loss power exceeds the loss power protection level, Serial power loss subtraction signal or the DC voltage subtraction signal or protection method of the resonant current subtraction signal externally set signal to the adder to suppress plasma generating high-frequency power source the forward power setting signal. 4. A high-frequency power supply for plasma generation comprising means for maintaining a traveling wave power at a magnitude indicated by a traveling wave power setting signal by a traveling wave power error signal obtained by subtracting a traveling wave power detection signal from the traveling wave power setting signal. In the device, a DC voltage detection circuit that outputs a DC voltage, and a DC voltage that outputs a DC current
A current detection circuit, a high-frequency power detection circuit for detecting traveling wave power and reflected wave power, and power amplifier loss power from a DC voltage detection signal, a DC current detection signal, a traveling wave power detection signal, and a reflected wave power detection signal. An excess loss power protection circuit that computes a loss power subtraction signal that is a negative signal when the power amplifier loss power exceeds a loss power protection level, and adds the loss power subtraction signal to an external setting signal. A high frequency power supply for plasma generation, comprising: a subtraction signal addition circuit for suppressing the traveling wave power setting signal. 5. A DC power calculation circuit for calculating a DC power signal which is a product of a DC voltage detection signal and a DC current detection signal, and an excess loss power protection circuit according to claim 4. -Frequency output power calculation circuit for calculating high-frequency output power signal by subtracting wave power detection signal and DC
Loss power calculation circuit for calculating a power amplifier loss power by subtracting a high-frequency output power signal from a power signal, and excess calculating a loss power subtraction signal that is a negative signal when the power amplifier loss power exceeds a loss power protection level. A high frequency power supply for plasma generation comprising a power loss calculation circuit. 6. A high-frequency power supply for plasma generation comprising means for maintaining a traveling wave power at a level indicated by a traveling wave power setting signal by a traveling wave power error signal obtained by subtracting a traveling wave power detection signal from the traveling wave power setting signal. In the device, a DC voltage detection circuit that outputs a DC voltage, and a DC voltage that outputs a DC current
A current detection circuit, a high-frequency power detection circuit for detecting traveling wave power and reflected wave power, a resonance current detection circuit for detecting resonance current, and a negative signal when the DC voltage detection signal exceeds the DC voltage protection level. An excess DC voltage protection circuit that outputs a certain DC voltage subtraction signal, an excess resonance current protection circuit that outputs a negative current resonance signal subtraction signal when the resonance current detection signal exceeds a resonance current protection level, and a DC voltage detection A power amplifier loss power is calculated from the signal, the DC current detection signal, the traveling wave power detection signal, and the reflected wave power detection signal, and the loss power is a negative signal when the power amplifier loss power exceeds a loss power protection level. An excess loss power protection circuit for calculating a subtraction signal; and adding the loss power subtraction signal, the DC voltage subtraction signal, or the resonance current subtraction signal to an external setting signal to proceed. Plasma generating high frequency power supply device and a suppressing subtraction signal adding circuit wave power setting signal. 7. A high-frequency power supply for plasma generation, comprising: means for maintaining a traveling wave power at a magnitude indicated by a traveling wave power setting signal by a traveling wave power error signal obtained by subtracting a traveling wave power detection signal from a traveling wave power setting signal. In the protection method for the device, a DC voltage, a DC current, a traveling wave power, a reflected wave power, and a switching element base temperature are detected, and a DC voltage detection signal, a DC current detection signal, a traveling wave power detection signal, a reflected wave power detection signal, Calculate the switching element junction temperature signal from the switching element base temperature detection signal,
When the switching element junction temperature signal exceeds the junction temperature protection level, a junction temperature subtraction signal which is a negative signal is calculated, and the junction temperature subtraction signal is added to an external setting signal to add the traveling wave power. A method for protecting a high-frequency power supply for plasma generation that suppresses a setting signal. 8. The junction temperature subtraction signal according to claim 7, wherein
DC which is the product of the DC voltage detection signal and the DC current detection signal
A high-frequency output power signal is calculated by subtracting the reflected-wave power detection signal from the traveling-wave power detection signal.
The power amplifier loss power is calculated by subtracting the high-frequency output power signal from the power signal, and the product of the power amplifier loss power and the thermal resistance between the switching element junction and the base is divided by the number of switching elements to obtain the junction. Calculating a base temperature difference signal and calculating a switching element junction temperature signal by adding the junction / base temperature difference signal to a switching element base temperature detection signal, wherein the switching element junction temperature signal is a junction temperature protection level. A method for protecting a high-frequency power supply for plasma generation, which is a negative signal output when the power supply exceeds the threshold value. 9. A high frequency power supply for plasma generation, comprising: means for maintaining a traveling wave power at a level indicated by a traveling wave power setting signal by a traveling wave power error signal obtained by subtracting a traveling wave power detection signal from a traveling wave power setting signal. In a protection method for a device, a DC voltage, a DC current, a traveling wave power, a reflected wave power, a resonance current, and a switching element base temperature are detected, and a DC signal that is a negative signal when a DC voltage detection signal exceeds a DC voltage protection level. Calculates a voltage subtraction signal, calculates a resonance current subtraction signal that is a negative signal when the resonance current detection signal exceeds a resonance current protection level, and calculates a DC voltage detection signal, a DC current detection signal, a traveling wave power detection signal, and a reflection. The power amplifier loss power is calculated from the wave power detection signal and the switching element base temperature detection signal, and the power amplifier loss power is stored as the loss power. Calculating a loss power subtraction signal, which is a negative signal when the level is exceeded, and adding the loss power subtraction signal or the DC voltage subtraction signal or the resonance current subtraction signal to an external setting signal to generate the traveling wave power setting signal; Of protecting a high-frequency power supply for plasma generation, which suppresses noise. 10. A high frequency power supply for plasma generation, comprising: means for maintaining a traveling wave power at a level indicated by a traveling wave power setting signal by a traveling wave power error signal obtained by subtracting a traveling wave power detection signal from a traveling wave power setting signal. In the apparatus, a DC voltage detection circuit for detecting a DC voltage and a D voltage for detecting a DC current are provided.
C current detection circuit, high frequency power detection circuit for detecting traveling wave power and reflected wave power, base temperature detection circuit for detecting switching element base temperature, DC voltage detection signal, DC current detection signal, and traveling wave power detection A switching element junction temperature signal is calculated from the signal, the reflected wave power detection signal, and the switching element base temperature detection signal, and the junction is a negative signal when the switching element junction temperature signal exceeds the junction temperature protection level. A high frequency power supply for plasma generation, comprising: an excess junction temperature protection circuit that calculates a partial temperature subtraction signal; and a subtraction signal addition circuit that adds the junction temperature subtraction signal to an external setting signal and suppresses a traveling wave power setting signal. apparatus. 11. The over-junction temperature protection circuit according to claim 10, wherein the over-junction temperature protection circuit calculates a DC power signal that is a product of the DC voltage detection signal and the DC current detection signal and a traveling wave power detection signal. A high-frequency output power calculation circuit for calculating a high-frequency output power signal by subtracting a reflected wave power detection signal, a loss power calculation circuit for calculating a power amplifier loss power by subtracting a high-frequency output power signal from a DC power signal, and the power amplifier loss A junction / base temperature difference calculation circuit for calculating a junction / base temperature difference signal by dividing a product of power and a thermal resistance value between the switching element junction / base by the number of switching elements; and the junction / base temperature Calculating a switching element junction temperature signal by adding a difference signal to the switching element base temperature detection signal; Degree signal plasma generating high frequency power supply device comprising excess junction temperature calculation circuit for calculating a junction temperature subtraction signal is a negative signal when it exceeds the junction temperature protection level. 12. A high frequency power supply for plasma generation comprising means for maintaining a traveling wave power at a magnitude indicated by a traveling wave power setting signal by a traveling wave power error signal obtained by subtracting a traveling wave power detection signal from a traveling wave power setting signal. In the apparatus, a DC voltage detection circuit for detecting a DC voltage and a D voltage for detecting a DC current are provided.
A C current detection circuit; a high-frequency power detection circuit for detecting traveling wave power and reflected wave power; a resonance current detection circuit for detecting a resonance current detection signal; a base temperature detection circuit for detecting a switching element base temperature; Voltage detection signal is DC
An excess DC voltage protection circuit that outputs a negative DC voltage subtraction signal when the voltage protection level is exceeded, and outputs a negative resonance current subtraction signal that is a negative signal when the resonance current detection signal exceeds the resonance current protection level. A switching element junction temperature signal from a DC voltage detection signal, a DC current detection signal, a traveling wave power detection signal, a reflected wave power detection signal, and a switching element base temperature detection signal. An excess junction temperature protection circuit that calculates a junction temperature subtraction signal that is a negative signal when the element junction temperature signal exceeds the junction temperature protection level, and the loss power subtraction signal or the DC voltage subtraction signal or the A high frequency circuit for plasma generation, comprising: a subtraction signal addition circuit for adding a resonance current subtraction signal to an external setting signal to suppress a traveling wave power setting signal. Power supply.