JPH11329787A - High frequency source system for plasma generation and plasma generator including this system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a reflection loss so as to secure a stable plasma state with a high efficiency in electric power supply. SOLUTION: A plasma generator 100 contains a high frequency source system 50 for plasma generation. The high frequency source system 50 for plasma generation generates pulse power by power of a main electric power supply supplied from a main power supplying part 1 for a specified period. At the moment of a plasma ignition, the power of an auxiliary power supply in a pulse power generating part 2 is superimposed on the power of the main power supply. Accordingly, a plasma is excited quickly at a higher level of a ignition pulse at the ignition moment, and the plasma state can continuously be retained at a low level of a main pulse.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency source system for generating plasma and a plasma generating apparatus including the system, and more particularly, to a high-frequency source system for generating plasma by pulsed power and a plasma generating apparatus including the system. It is about.

[0002]

2. Description of the Related Art At present, in the semiconductor industry, high integration and high performance of LSIs and the like are being promoted.

In order to achieve high integration of semiconductor devices, it is necessary to improve fine processing technology, and a high aspect ratio (aspect ratio) is required.
There is a strong demand for improved processing accuracy such as narrowing of minimum line width and the like.

[0004] Examples of microfabrication techniques for semiconductor devices include plasma etching (electron cyclotron resonance system, high frequency system), sputter etching, chemical dry etching and the like. There is plasma etching.

In recent years, pulsing of plasma-generating high-frequency power has attracted attention as a means of improving processing accuracy, particularly in realizing a high aspect ratio and narrowing the minimum line width.

Here, the term "pulsing" means that the high frequency power for plasma generation is turned on / off at a constant cycle and the ratio (duty ratio) is changed.

Here, a configuration of a conventional plasma generator 900 using pulsed power will be described with reference to FIG.

FIG. 7 is a diagram showing a configuration of a main part of a conventional plasma generator 900. As shown in FIG. A conventional plasma generator 900 shown in FIG. 7 includes a main power supply unit 90, a switch SW
3 and an oscillator 91.

The main power supply section 90 includes a main power supply (not shown) and supplies a constant level of power. Switch SW3
Are connected / disconnected at regular intervals. Oscillator 91
Receives power from the main power supply unit 90 via the switch SW3, and converts the power into high frequency power. The high-frequency power is supplied to a chamber (not shown). The source gas supplied into the chamber is brought into a plasma state by applying high frequency power.

FIG. 8 is a timing chart for explaining pulse power generated in the conventional plasma generator 900 shown in FIG.

In FIG. 8, a symbol T0 indicates a period of the pulse power, a symbol T1 indicates a period (power supply period) in which pulse power is applied within one cycle T0, and a symbol T2 indicates a period.
Each represents a pulse separation period (power supply suspension period) (that is, T0 = T1 + T2).

The switch SW3 shown in FIG. 7 is in a connected state for a certain period (T1) from the moment of plasma ignition, and is in a non-connected state for the following fixed period (T2). Thereby, the pulse power shown in FIG. 8 is generated.

Ultra-fine processing can be performed by controlling the density, composition, and ion amount of radicals generated by decomposing the reactive gas by pulsing (pulse-modulating) the applied power.

[0014]

By the way, while improvement of the processing technique by the pulse modulation is expected, there is a problem that the supply efficiency of the high frequency power for plasma generation is reduced and the reflection loss is increased.

This problem will be described with reference to FIG. 9 showing the effect obtained by the conventional plasma generator 900.

FIG. 9 is a diagram plotting the reflected power (reflection loss) in the conventional plasma generator 900 shown in FIG.

For example, when the off period of the power source (the power supply stop period T2 shown in FIG. 9) becomes longer, the disappearance of plasma,
Generation becomes intense. In particular, at the moment of ignition, the state of the plasma is unstable, and when viewed electrically, the plasma load has a discontinuous value only at this moment. As a result,
When the off period is long, it becomes difficult to match the impedance of the oscillator 91 with the plasma load, and a large reflection loss is caused (the level Pz in FIG. 9 increases). Therefore, it is necessary to lengthen the ON period of the power source (the power supply period T1 shown in FIG. 9) to some extent.

Further, in order to convert the material gas into plasma, it is necessary to supply power at a certain level or higher. The predetermined level is a minimum power level required to ignite the plasma, and is determined by conditions such as gas type and pressure (hereinafter, for simplicity, necessary for igniting the plasma). The minimum power level is referred to as reference level Pi). As for the applied pulse power, the lower the power level, the longer it takes for the plasma lighting to stabilize (it cannot even be turned on below the reference level Pi). The longer the unstable time, the larger the return loss (the level Pz in FIG. 9 increases). Therefore, in the conventional method, it is necessary to continuously apply power equal to or higher than the reference level Pi for a long time.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problem, and an object of the present invention is to suppress a reflection loss and to generate a stable plasma state with high power supply efficiency. A system and a plasma generator are provided.

[0020]

According to a first aspect of the present invention, there is provided a high frequency source system for generating a plasma corresponding to a plasma generating apparatus for converting a gas into a plasma state by a supplied pulse power.
At the time of ignition of the pulse power, at least a pulse power of a level higher than the reference level required to ignite the plasma is generated, and for a certain period after the ignition of the pulse power, the level of the level lower than the reference level is generated. A pulse power generation means for generating pulse power, and a conversion means for converting the pulse power output from the pulse power generation means into high frequency power and outputting the high frequency power to the plasma generator.

According to a second aspect of the present invention, there is provided the high frequency source system for generating a plasma according to the first aspect, wherein the pulse power generating means supplies a power of a level lower than a reference level. The power supply means, the second power supply means for supplying a predetermined power, and the output of the first power supply means and the output of the second power supply means are superimposed when the pulse power is ignited. As a result, a pulse power of a level higher than the reference level is generated, and after the ignition of the pulse power, a pulse power for maintaining the level lower than the reference level for a certain period of time is generated using the output of the first power supply means. Pulsing means.

According to a third aspect of the present invention, there is provided the high frequency source system for generating a plasma according to the first aspect, wherein the pulse power generating means supplies a power of a level lower than a reference level. A power supply unit, a second power supply unit for supplying a predetermined power, and a pulse for maintaining a level lower than a reference level by using an output of the first power supply unit for a certain period from the time of ignition of the pulse power A first pulsing means for generating power; and a second pulsing means for generating pulsed power using an output of the second power supply means when the pulsed power is ignited. Receiving the output of the first pulsing means,
A first converting means for converting the first high frequency power to output to the plasma generating means, and a second converting means for receiving the output of the second pulsing means, converting the output to the second high frequency power and outputting to the plasma generating means. A plasma generating device, comprising:
At the time of ignition of the pulsed power, the power of a level higher than the reference level obtained by combining the first high-frequency power and the second high-frequency power is received, and for a certain period after the ignition of the pulsed power, the level is lower than the reference level. Of the first high frequency power.

According to a fourth aspect of the present invention, there is provided the high frequency source system for generating a plasma according to the third aspect, wherein the second power supply means includes a plurality of power supplies, The means is provided corresponding to each of the plurality of power supplies, and at least one frequency of the plurality of second high-frequency powers output from each of the plurality of second pulsing means is equal to the first high-frequency power. Different from power frequency.

According to a fifth aspect of the present invention, there is provided a plasma generating apparatus for converting a gas into a plasma state by using pulsed electric power. At the time of igniting the pulsed electric power, it is necessary to at least ignite the plasma. Pulse power generating means for generating a pulse power of a level higher than the reference level to be generated, and for a certain period after the ignition of the pulse power, generating a pulse power of a level lower than the reference level,
The apparatus includes a conversion unit that converts pulse power output from the pulse power generation unit into high-frequency power, and a plasma generation unit that generates plasma by applying the high-frequency power output from the conversion unit to a gas.

According to a sixth aspect of the present invention, there is provided the plasma generating apparatus according to the fifth aspect, wherein the pulse power generating means includes first power supply means for supplying power of a level lower than the reference level, The second power supply means for supplying the power of the first power supply means and the output of the first power supply means and the output of the second power supply means are superimposed at the time of the ignition of the pulsed power, so that the reference level can be obtained. A pulse generating means for generating a high-level pulse power, and after the ignition of the pulse power, using the output of the first power supply means to generate a pulse power for maintaining a level lower than the reference level for a certain period of time. Including.

According to a seventh aspect of the present invention, there is provided the plasma generating apparatus according to the fifth aspect, wherein the pulse power generating means includes first power supply means for supplying power at a level lower than the reference level, A second power supply means for supplying power of the first power supply, and a first power supply for generating a pulse power for maintaining a level lower than the reference level by using an output of the first power supply means for a certain period from the time of ignition of the pulse power. And pulsing means for generating pulsed power by using the output of the second power supply means when the pulsed power is ignited. The first converting means receives the output of the first pulse generating means and converts it into the first high frequency power and outputs it to the plasma generating means. The first converting means receives the output of the second pulsing means and converts it into the second high frequency power and converts it into the second high frequency power. Output to generation means A second conversion unit, wherein the plasma generation unit receives a power higher than a reference level obtained by combining the first high-frequency power and the second high-frequency power when the pulse power is ignited. For a certain period after the ignition, the first high-frequency power of a level lower than the reference level is received.

An eighth aspect of the present invention is the plasma generating apparatus according to the seventh aspect, wherein the second power supply means includes a plurality of power supplies, and the second pulsing means includes a plurality of power supplies. And at least one frequency of the plurality of second high-frequency powers output from each of the plurality of second pulsing means is different from the frequency of the first high-frequency power.

[0028]

[First Embodiment] A high-frequency source system for plasma generation and a plasma generator using the system according to a first embodiment of the present invention will be described.

The high-frequency source system for plasma generation and the plasma generator using the system according to the first embodiment of the present invention generate a stable plasma state with lower energy by controlling the level of pulse power. Is possible.

A high-frequency source system for plasma generation and a plasma generator using the system according to the first embodiment of the present invention will be described with reference to FIG.

FIG. 1 is a diagram showing a configuration of a main part of a plasma generator 100 including a high-frequency source system 50 for plasma generation according to the first embodiment of the present invention. The plasma generator 100 shown in FIG. 1 includes a high-frequency source system 50 for plasma generation, a directional coupler 4 for incident direction, an isolator 5, a directional coupler 6 for reflection direction, a matching unit 7, and a chamber 8.

High frequency source system 50 for plasma generation
Includes a main power supply unit 1, a pulse power generation unit 2, and an oscillator 3. As described later, main power supply unit 1 includes a main power supply, and pulse power generation unit 2 includes an auxiliary power supply. The pulse power generation unit 2 generates pulse power using a main power supply or a main power supply and an auxiliary power supply.

Here, an example of a specific configuration of the high frequency source system 50 for plasma generation shown in FIG. 1 will be described with reference to FIG.
This will be described with reference to FIG.

FIG. 2 is a diagram for explaining an example of a specific configuration of the high frequency source system 50 for plasma generation shown in FIG.

As shown in FIG. 2, the main power supply 1 includes a main power supply 10. The level Py of the power supplied by the main power supply 10 is lower than the minimum reference level Pi required to ignite the plasma (Pi> Py). Here, a 4 kV, 4 kW peak DC power supply is used as an example of the main power supply 10.

The pulse power generation section 2 includes an auxiliary power supply 11 and switches SW1 and SW2.

The sum of the power level supplied from main power supply 10 and the power level supplied from auxiliary power supply 11 is higher than reference level Pi. In the first embodiment of the present invention, a DC power supply having a peak of 1 kW is used as the auxiliary power supply 11 as an example.

The main power supply 10 is connected to one terminal of the switch SW2. The auxiliary power supply 11 is provided with a switch SW
1 is also connected to one terminal of the switch SW2. Further, the other terminal of the switch SW2 is connected to the input node of the oscillator 3.

The switch SW1 is turned on only at the moment of pulse power ignition (plasma ignition). On the other hand, the switch SW2 is in the connected state for a certain period from the moment of the ignition of the pulse power. The oscillator 3 receives supply of pulse power from the pulse power generator 2.

Referring to FIG. 1, oscillator 3 includes a waveguide (not shown). As an example of the oscillator 3, a 2.7 kW high frequency oscillator is used. The oscillator 3 outputs a μ wave (high frequency power) using the supplied pulse power.

The output μ-wave passes through the directional coupler 4 for the incident direction. The incident direction directional coupler 4 monitors the incident power (the traveling direction of the microwave). As a result, microwaves traveling in directions other than the isolator 5 described later are removed. As an example of the directional coupler 4 for the incident direction, a CM-coupled directional coupler is used.

The isolator 5 prevents the reflected power reflected from the plasma load in the chamber 8 from constantly reaching the power supply (the main power supply 10 and the auxiliary power supply 11 shown in FIG. 2). As an example of the isolator 5, a water-cooled Y-type isolator is used.

The microwave output from the isolator 5 passes through a directional coupler 6 for reflection direction for monitoring the reflected power of the plasma load. As an example of the directional coupler 6 for the reflection direction, a CM-coupled directional coupler is used.

The μ-wave output after passing through the directional coupler 6 for the reflection direction passes through a matching unit 7 in order to match the impedance between the plasma load and the oscillator 3. Further, the μ-wave that has passed through the matching unit 7 is input to the chamber 8.

A raw material gas is supplied into the chamber 8. The raw material gas is brought into a plasma state by the input microwave. For example, when the plasma generator 100 is used as a semiconductor device manufacturing apparatus, a thin film is formed on a wafer disposed in the chamber 8.

Next, the pulse power generated by the plasma generating high frequency source system 50 shown in FIG. 1 will be described.

FIG. 3 is a timing chart for explaining the pulse power generated by the high frequency source system 50 for plasma generation shown in FIG.

High frequency source system 50 for plasma generation
Controls the level of high-frequency power supplied to generate plasma in two stages, and performs power modulation of so-called pulse power.

In FIG. 3, a symbol T0 indicates a period of pulse power, a symbol T1 indicates a period (power supply period) in which pulse power is applied within one period T0, and a symbol T2 indicates a period.
Each represents a pulse separation period (power supply suspension period) (that is, T0 = T1 + T2).

As described above, the switch SW shown in FIG.
No. 2 is in a connected state for a certain period (T1) from the moment of pulse power ignition (plasma ignition). Also, switch S
W1 is connected only at the moment of ignition of the pulse power (symbol ΔT in the figure).

Therefore, the moment of ignition of the pulsed power (△
In T), the switches SW1 and SW2 are both connected. Thus, pulse power having a level (Px) equal to or higher than the reference level Pi is supplied to the oscillator 3 in accordance with the power supplied from the main power supply 10 and the power supplied from the auxiliary power supply 11. For simplicity, the pulse power at the moment of ignition is referred to as an ignition pulse.

Next, after ΔT, the switch SW1 is in a non-connected state. Thus, the power supply from the auxiliary power supply 11 stops. As a result, the level of the generated pulse power becomes the power level (Py) supplied by the main power supply 10.
For simplicity, pulse power for a certain period from the moment of ignition is referred to as a main pulse.

Further, after a predetermined pulse separation time, pulse power, which is the next cycle, is supplied.

That is, the oscillator 3 according to the first embodiment of the present invention operates at the time (moment) when the pulse power rises.
It receives power supply at a level Px higher than the reference level Pi, and continuously receives power supply at a level Py equal to or lower than the reference level Pi for a predetermined period, and converts them into high-frequency power.

With this configuration, in the initial stage of the pulse power (ΔT), the high-frequency power of the reference level Pi required for igniting the plasma is supplied to the plasma. Plasma excitation is performed.

On the other hand, once the plasma is ignited, it has a property of generating a so-called power history such that the state is maintained even if the power is lower than the reference level Pi. Therefore, after the ignition of the pulse power, there is no need to supply a large power, and the excited plasma is maintained even with the high-frequency power of the level Py lower than the reference level Pi.

Note that the period ΔT of the ignition pulse may be sufficiently shorter than the period (T1−ΔT) of the main pulse.

Next, the reflection loss when the high frequency source system 50 for plasma generation shown in FIG. 1 is used is shown in FIG.
This will be described with reference to FIG.

FIG. 4 is a diagram showing the reflection loss in the plasma generator 100, and plots the reflection loss measured under the following conditions.

The main power supply 10 is a DC power supply of 4 kW and 4 kW peak, and the auxiliary power supply 11 is a DC power supply of 1 kW peak.
A C power source and a 2.7 kW oscillator 3 were used. 2 kW from main power supply 10 for 50 μs (frequency 1
0 KHz), 400 W was applied from the auxiliary power supply 11 for 3 μs to generate a high-frequency power of 2.45 GHz.

As the directional coupler 4 for the incident direction and the directional coupler 6 for the reflection direction, a CM-coupled directional coupler, an isolator 5, a water-cooled Y-type isolator, a matching unit 7, and an EH An automatic mold matching device was used. Further, as the plasma load, ECR plasma (EC
R: Electron Cycrotron Resonance Plasma)
An FC318 / oxygen mixed gas was provided at a pressure of 1 mTorr.

Under the above conditions, as shown in FIG. 4, a reflection loss occurs in the initial stage ΔT (ignition pulse) of the pulse power. However, since the applied power level is lower than the reference level Pi, the reflection loss occurs. Almost no loss occurs.

That is, by using the plasma generator 100 according to the first embodiment of the present invention, it is possible to reduce the reflection loss as compared with the conventional plasma generator 900 (see FIG. 9).

Note that a plurality of auxiliary power supplies may be used instead of the auxiliary power supply 11 shown in FIG. In this case, the power level of the ignition pulse can be finely adjusted using the power output from each auxiliary power supply.

[Second Embodiment] A high-frequency source system for plasma generation according to a second embodiment of the present invention and a plasma generator provided with the system will be described.

In the first embodiment of the present invention, the auxiliary power supply 11 is arranged in series with respect to the main power supply 10, and both are converted into high-frequency power having the same frequency. On the other hand, one of the two-stage power is 2.45 GHz and the other is 13.56 MHZ.
The same effect can be obtained even if the frequency is converted to a plurality of frequencies and applied to the plasma, such as z or 500 MHz for one and a DC electric field (ignition plug) for the other.

Therefore, in the second embodiment of the present invention, a switch for controlling the power level supplied to the plasma is provided, and a plurality of oscillators having different oscillation frequencies are provided.

FIG. 5 is a diagram showing a configuration of a main part of a plasma generator 200 including a high-frequency source system 60 for plasma generation according to the second embodiment of the present invention. In addition,
In the following description, the same components as those of the plasma generator 100 shown in FIG. 1 are denoted by the same reference numerals and symbols, and description thereof will be omitted.

The plasma generating apparatus 200 shown in FIG. 5 differs from the plasma generating apparatus 100 shown in FIG. 1 in that a plasma generating high-frequency source system 60 is provided instead of the plasma generating high-frequency source system 50.

High frequency source system 60 for plasma generation
Includes pulse power generation units 21 and 22, oscillators 3 and 23, and timing controller 20.

The pulse power generators 21 and 22 generate pulse power. The timing controller 20 adjusts the generation timing of the pulse power in the pulse power generation units 21 and 22, as described later.

The oscillator 3 is supplied with pulse power output from the pulse power generator 21. The oscillator 23 has
The pulse power output from the pulse power generation unit 22 is supplied. The oscillation frequency of the oscillator 3 and the oscillation frequency of the oscillator 23 have different values.

Here, an example of a specific configuration of the high frequency source system 60 for plasma generation shown in FIG.
This will be described with reference to FIG.

FIG. 6 is a diagram for explaining an example of a specific configuration of the plasma generating high frequency source system 60 shown in FIG.

As shown in FIG. 6, the pulse power generator 21
Includes a main power supply 10 and a switch SW2.

The pulse power generation section 22 includes an auxiliary power supply and a switch. The number of auxiliary power supplies and the number of switches are one or more, respectively. In the second embodiment of the present invention, as shown in FIG.
And the case of the switch SW1) will be described.

The main power supply 10 is connected to one terminal of the switch SW2. The other terminal of switch SW2 is connected to the input node of oscillator 3. The auxiliary power supply 11 is connected to one terminal of the switch SW1. Switch SW1
Is connected to the input node of the oscillator 23.

The timing controller 20 adjusts the timing of connection / disconnection between the switch SW2 and the switch SW1. The switch SW1 is turned on only at the moment of pulse power ignition (plasma ignition). The switch SW2 is in a connected state for a certain period from the moment of the ignition of the pulse power.

At the moment of the ignition of the pulse power, the electric power corresponding to the ignition pulse (the pulse having a level equal to or higher than the reference level at the moment of the ignition of the pulse power) is based on the main power supply 10 and the auxiliary power supply 11 as shown in FIG. Is supplied to the chamber 8 shown in FIG.

For a certain period from the moment of the ignition of the pulse power, the power corresponding to the main pulse (a pulse that maintains a level below the reference level for a certain period after the moment of the ignition of the pulse power) is supplied from the main power supply 11. Is supplied to the chamber 8 shown in FIG.

Specifically, the moment of ignition of the pulsed power is
For example, the high-frequency power (2.45 GHz, 2 kW, 10 kW) output via the pulse power supply unit 21 and the oscillator 3
(KHz, 50 μs), the high-frequency power (13.56 MHz, 400 W, 3 μs) output via the pulse power supply unit 22 and the oscillator 23 can be applied to the raw material gas in the chamber 8 in synchronization with the moment of application. It becomes possible. In addition, for a certain period after the moment of the ignition of the pulse power, high-frequency power (2.45 GHz, 2 KW, 10 KHz, 50 μs)
Is applied.

With this configuration, in the initial stage of ignition, the plasma is ignited by applying power equal to or higher than the reference level Pi, and immediately thereafter, a stable plasma with the power equal to or lower than the reference level Pi is generated. It is possible to excite and maintain a plasma state.

Further, by using high-frequency powers of different frequencies, it becomes possible to excite plasma with lower high-frequency energy.

When a plurality of auxiliary power supplies are used, it is possible to finely adjust the power level of the ignition pulse using the power output from each of the auxiliary power supplies.

When a plurality of auxiliary power supplies are used, an oscillator may be provided for each of them.
In this case, respective frequencies including the oscillator 3 are adjusted (different frequencies). This makes it possible to excite plasma more efficiently.

[0086]

As described above, according to the high frequency source system for plasma generation according to the first aspect of the present invention, the instant of the ignition of the pulse power is a level higher than the reference level required to ignite the plasma. , It is possible to generate high-frequency power using power at a level lower than the reference level for a certain period from the moment of ignition of pulsed power. Thus, in the plasma generating apparatus that receives high-frequency power, plasma can be quickly excited, and the plasma state can be maintained using power at a level lower than the reference level. Therefore, the reflection loss is suppressed,
Power can be supplied efficiently.

A high frequency source system for plasma generation according to a second aspect is the high frequency source system for plasma generation according to the first aspect, wherein a main power supply and an auxiliary power supply are used.
The level of the pulse power can be controlled at the moment of ignition of the pulse power and thereafter.

A high-frequency source system for plasma generation according to a third aspect is the high-frequency source system for plasma generation according to the first aspect, wherein a main power source and a plurality of auxiliary power sources are used to determine the moment of ignition of pulsed power. After that, the level of the pulse power can be controlled.

A high-frequency source system for plasma generation according to a fourth aspect is the high-frequency source system for plasma generation according to the third aspect, wherein the main power supply and the auxiliary power supply are converted into high-frequency powers having different frequencies. It becomes possible to excite plasma with lower high-frequency energy.

Furthermore, according to the plasma generating apparatus of the present invention, at the moment of ignition of the pulse power, the plasma is quickly excited by using a power of a level higher than a reference level required to ignite the plasma. Then, for a certain period from the moment of the ignition of the pulsed power, the plasma state can be maintained by using power of a level lower than the reference level. As a result, power can be efficiently supplied while suppressing reflection loss, and a stable plasma state can be obtained.

According to a sixth aspect of the present invention, there is provided the plasma generating apparatus according to the fifth aspect, wherein the main power source and the auxiliary power source are used to generate the pulse power at the moment of ignition of the pulse power and thereafter. You can control the level.

A plasma generator according to a seventh aspect is the plasma generator according to the fifth aspect, wherein a pulse is generated by using a main power supply and a plurality of auxiliary power supplies at the moment of ignition of pulsed power and thereafter. The power level can be controlled.

The plasma generator according to claim 8 is the plasma generator according to claim 7, wherein the main power supply and the auxiliary power supply are converted into high-frequency powers having different frequencies, so that the plasma is generated with lower high-frequency energy. Can be excited.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a main part of a plasma generator 100 according to Embodiment 1 of the present invention.

FIG. 2 is a diagram for explaining an example of a specific configuration of the high frequency source system for plasma generation 50 shown in FIG.

FIG. 3 is a timing chart for explaining pulse power generated by the high frequency source system for plasma generation 50 shown in FIG.

FIG. 4 is a diagram in which the reflection loss in the plasma generator 100 shown in FIG. 1 is plotted.

FIG. 5 is a diagram showing a configuration of a main part of a plasma generator 200 according to Embodiment 2 of the present invention.

6 is a diagram for explaining an example of a specific configuration of the high frequency source system for plasma generation 60 shown in FIG.

FIG. 7 is a diagram showing a configuration of a main part of a conventional plasma generator 900.

8 is a timing chart for explaining pulse power generated by the conventional plasma generator 900 shown in FIG.

FIG. 9 is a diagram in which reflection loss in the conventional plasma generator 900 shown in FIG. 7 is plotted.

[Explanation of symbols]

1 main power supply section, 2, 21, 22 pulse power generation section, 3, 23 oscillator, 4 directional coupler for incident direction,
5 isolator, 6 directional coupler for reflection direction, 7
Matching device, 8 chambers, 10 main power supply, 11 auxiliary power supply, 20 timing controller, 50, 60 High frequency source system for plasma generation, 100, 200 Plasma generator.

Claims (8)

[Claims] 1. A high-frequency source system for plasma generation corresponding to a plasma generation apparatus for converting a gas into a plasma state by a supplied pulse power, wherein at least the plasma is ignited when the pulse power is ignited. A pulse power generating means for generating a pulse power of a level higher than the reference level required for the pulse power generation, and for a certain period after the ignition of the pulse power, generating a pulse power of a level lower than the reference level; A conversion means for converting the pulse power output from the power generation means into high-frequency power and outputting the high-frequency power to the plasma generation device. 2. The pulse power generation means includes: first power supply means for supplying power at a level lower than the reference level; second power supply means for supplying predetermined power; and ignition of the pulse power. In some cases, the output of the first power supply means and the output of the second power supply means are superimposed to generate pulse power of a level higher than the reference level, and the ignition of the pulse power is performed. And a pulsing means for generating a pulse power that maintains a level lower than the reference level for the predetermined period by using an output of the first power supply means after the time. High frequency source system. 3. The pulse power generation means includes: first power supply means for supplying power at a level lower than the reference level; second power supply means for supplying predetermined power; and ignition of the pulse power. A first pulsing unit that generates a pulse power that holds a level lower than the reference level by using the output of the first power supply unit, and A second pulsing unit that generates pulse power using an output of the second power supply unit, wherein the conversion unit receives an output of the first pulsing unit, A first conversion unit that converts the power into high-frequency power and outputs the high-frequency power to the plasma generation unit; and receives an output from the second pulse generation unit, converts the power into a second high-frequency power, and outputs the high-frequency power to the plasma generation unit Second Wherein the plasma generation device receives power of a level higher than the reference level obtained by combining the first high-frequency power and the second high-frequency power when the pulse power is ignited, From the time after the ignition of the pulsed power, the certain period of time,
The high-frequency source system for plasma generation according to claim 1, wherein the first high-frequency power is lower than the reference level. 4. The second power supply means includes a plurality of power supplies, and the second pulsing means is provided corresponding to each of the plurality of power supplies; 4. The high frequency source system for plasma generation according to claim 3, wherein at least one frequency of the plurality of second high frequency powers output from each of the means is different from the frequency of the first high frequency power. 5. A plasma generator for converting a gas into a plasma state using pulsed power, wherein at the time of igniting the pulsed power, at least higher than a reference level required to ignite the plasma. A pulse power generating means for generating a pulse power of a level and generating a pulse power of a level lower than the reference level for a certain period after the ignition of the pulse power, and the pulse power output by the pulse power generating means A plasma generating apparatus, comprising: a conversion unit that converts the RF power into high-frequency power; and a plasma generation unit that generates the plasma by applying the high-frequency power output from the conversion unit to the gas. 6. The pulse power generation means, a first power supply means for supplying a power lower than the reference level, a second power supply means for supplying a predetermined power, and an ignition of the pulse power In some cases, the output of the first power supply means and the output of the second power supply means are superimposed to generate pulse power of a level higher than the reference level, and the ignition of the pulse power is performed. 6. The plasma generating apparatus according to claim 5, further comprising: a pulsing unit that generates a pulse power that maintains a level lower than the reference level for the predetermined period by using an output of the first power supply unit after time. . 7. The pulse power generation means, a first power supply means for supplying a power lower than the reference level, a second power supply means for supplying a predetermined power, and an ignition of the pulse power A first pulsing unit that generates a pulse power that holds a level lower than the reference level by using the output of the first power supply unit, and A second pulsing unit that generates pulse power using an output of the second power supply unit, wherein the conversion unit receives an output of the first pulsing unit, A first conversion unit that converts the power into high-frequency power and outputs the high-frequency power to the plasma generation unit; and receives an output from the second pulse generation unit, converts the power into a second high-frequency power, and outputs the second high-frequency power to the plasma generation unit. Second Wherein the plasma generating means receives power of a level higher than the reference level obtained by combining the first high-frequency power and the second high-frequency power when the pulse power is ignited, From the time after the ignition of the pulsed power, the certain period of time,
The plasma generator according to claim 5, wherein the first high-frequency power at a level lower than the reference level is received. 8. The second power supply means includes a plurality of power supplies, and the second pulsing means is provided corresponding to each of the plurality of power supplies, wherein the plurality of second pulsing means are provided. The plasma generator according to claim 7, wherein at least one frequency of the plurality of second high-frequency powers output from each of the means is different from the frequency of the first high-frequency power.