JPH11162697A - Spiral resonance device for plasma generation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spiral resonance device capable of coping with drift of the resonance point in a resonator at the time of generating a plasma and capable of generating a plasma with much lower electrical potential. SOLUTION: A spiral resonance device for plasma generation is equipped with a resonator 1 comprising a container 11 structured to permit pressure reduction and supplied with gas for the plasma, a resonance coil 12 wound around the outer circumference of the container, and an outside shield 13 disposed around the outer circumference of the resonance coil 12, and a high-frequency power supply 4 for supplying the resonator 1 with high-frequency power of prescribed frequency, and the electrical length of the resonance coil 12 is set up to be a product of one wave length at the fixed frequency multiplied by an integer. A power-supply control means 5 is annexed to the high-frequency power supply 4 for detecting reflected-wave power from the resonator 1 at the time of generating the plasma and adjusting the prescribed frequency so as to minimize the reflected-wave power.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spiral resonator for generating plasma applied to a plasma processing apparatus for performing processes such as etching, ashing, and CVD on a semiconductor substrate or the like. The present invention relates to a spiral resonance device capable of coping with a shift of a resonance point and generating plasma having a lower electric potential.

[0002]

2. Description of the Related Art A plasma processing apparatus is used for various dry processes such as dry etching, ion etching, ashing, and plasma deposition on a semiconductor substrate. Among such processes, for example, in a CVD process, it is required to promote a reaction by radicals and to reduce ion damage as much as possible. That is, excess ions can cause material mixing between layers in the substrate, oxide breakdown,
Causes invasion of contaminants and changes in traits. In addition, in an etching process for defining a selectivity with high accuracy,
It is preferred to avoid ion bombardment which results in low selectivity.

[0003] US Patent Nos. 4368092 and 491
No. 8031, No. 5,234,529, etc. propose a technique relating to a spiral resonance device for generating plasma by a resonance coil in order to efficiently excite plasma having a uniform distribution and to effectively use radicals in the plasma. I have. A spiral resonator for plasma generation is composed of a resonator formed by winding a resonance coil around a discharge tube (container) that can be decompressed, and a high-frequency power supply, supplies a material gas in a vacuum state to the discharge tube, and forms a resonator. Is a device for exciting induction plasma inside the discharge tube by supplying high-frequency power to the discharge tube.

In the above spiral resonator, in order to reduce ion damage to a semiconductor substrate and the like,
Increasing the separation distance between the plasma generation position and the substrate,
Means of disposing a shield between the discharge tube and the resonance coil or disposing a ground grid inside the discharge tube to suppress convection and diffusion of ions are disclosed.

However, when the plasma potential is high, even if there is a considerable distance between the plasma generation position and the substrate, a parasitic plasma is generated due to the plasma potential, and the ion current flowing toward the substrate can be suppressed. It will be difficult. Further, when the separation distance between the plasma generation position and the substrate is further increased, parasitic plasma due to the plasma potential can be suppressed to some extent, but the loss due to recombination of radicals increases, making it impossible to effectively use the radicals.

On the other hand, when a ground grid is provided, particles flowing from the ground grid may be generated by collision of ions flowing to the ground of the resonator or the ground of the container via the ground grid with the ground grid. Further, since the ground grid has a partial potential, a secondary plasma is generally generated between the wafer stage and the ground grid which are generally at the ground potential, and this may cause a process hindrance.

The inventors of the present invention have conducted intensive studies with a view to obtaining plasma having a low electric potential, and as a result, have found that a half-wavelength or quarter-wavelength resonance coil employed in a conventional helical resonance device has been used. If, instead, a standing wave is induced by a coil that resonates in the all-wavelength mode and an induced electric field is generated inside the discharge tube, the phase voltage and the antiphase voltage cancel each other, and the switching point of the phase voltage, that is, It has been found that a plasma having a very low potential is excited by inductive coupling at a node where the potential is substantially zero, and a patent application has already been filed as a “plasma discharge treatment method by inductive coupling” (International Publication WO 97/21).
332). In the spiral resonator disclosed in such publication, the electric potential is extremely low,
There is no need to provide ion suppression means such as a baffle, and moreover, radicals can be efficiently used by bringing the substrate close to the plasma generation position.

[0008]

By the way, in the spiral resonance device proposed by the present inventors, the following new problems have been found when applied to a more practical plasma device. . That is, in the above-described spiral resonator using the standing wave of all wavelengths, the capacitive resonance or the inductive coupling between the resonance coil and the generated plasma causes the resonance point of the resonator to be small, though slightly. Causes a shift in the resonance state. As a result, the standing wave on the resonance coil side is disturbed,
There is a problem that the electrical potential of the plasma is slightly increased. In addition, fluctuations in capacitive coupling and inductive coupling due to plasma impair the impedance matching with the power supply side, so that in the transmission line from the power supply to the resonance coil, the effective load power is reduced by the reflected wave power.

However, in a conventional spiral resonance device, a coaxial power supply type, and a counter electrode type plasma device, a matching circuit (matching circuit) for adjusting the fluctuation of impedance in the plasma generating circuit on the container side and improving the power transfer efficiency. )
Is provided. However, since the plasma state always fluctuates, perfect matching has not been obtained with some impedance matching circuits.

The present invention has been made to further enhance the utility of the above-described spiral resonator using standing waves of all wavelengths, and an object of the present invention is to carry out processes such as etching, ashing, and CVD on a semiconductor substrate or the like. Provided is a spiral resonator for plasma generation applied to a plasma processing apparatus to be applied, which can cope with a shift of a resonance point in a resonator at the time of plasma generation and can generate plasma with a lower electric potential. It is in. Another object of the present invention is to provide a helical resonance device that can reliably compensate for a decrease in effective load power due to reflected wave power.

[0011]

In order to solve the above-mentioned problems, a spiral resonator according to the present invention is configured to be capable of reducing pressure and is provided with a container to which a plasma gas is supplied and a container wound around the container. A resonator comprising a resonance coil and an outer shield disposed on the outer periphery of the resonance coil; and a high-frequency power supply for supplying high-frequency power of a predetermined frequency to the resonator, and an electrical length of the resonance coil. Is set to an integral multiple of one wavelength at the predetermined frequency, wherein the high-frequency power source detects reflected wave power from the resonator when plasma is generated, Power supply control means for increasing or decreasing the predetermined frequency so as to minimize.

In the above spiral resonator, the specific power supply control means attached to the high-frequency power supply compensates for the shift of the resonance point in the resonator due to the variation of the capacitive coupling or the inductive coupling of the generated plasma on the high-frequency power supply side. That is, the power supply control means detects the reflected wave power due to the fluctuation of the capacitive coupling or the inductive coupling of the plasma, and detects the reflected wave power by a factor corresponding to the shift of the resonance frequency which is a factor of the reflected wave power so as to minimize the reflected wave power. Only by increasing or decreasing the predetermined frequency, a high frequency of the resonance frequency of the resonator under the plasma condition is output. Further, in order to increase the power transfer efficiency, the power supply control means may have a function of adding and outputting power equivalent to the reflected wave power.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a spiral resonator for plasma generation according to the present invention will be described with reference to the drawings. FIG.
FIG. 2 is a schematic diagram showing a basic configuration of a spiral resonator for plasma generation and a position where plasma is generated. FIG. 2 is a block diagram showing power supply control means in the spiral resonance device for plasma generation. FIG. 3 is a circuit block diagram showing an example of a frequency control circuit in the power supply control means. FIG.
FIG. 9 is a longitudinal sectional view of a plasma processing apparatus showing an application example of a spiral resonator for plasma generation. Hereinafter, in the description of the embodiment, a spiral resonator for plasma generation is referred to as a “resonator”.
Abbreviated. A semiconductor substrate or a semiconductor element as an object to be processed is abbreviated as “substrate”.

As shown in FIG. 1, the resonance device of the present invention is generally configured to be capable of reducing pressure, and has a container (11) to which a plasma gas is supplied, and a resonance coil wound around the outer periphery of the container (11). A resonator (1) comprising a coil (12) and an outer shield (13) arranged on the outer periphery of the resonance coil (12); and a high-frequency power supply (4) for supplying high-frequency power of a predetermined frequency to the resonator (1). ).

The container (11) is usually a so-called chamber made of high-purity quartz glass or ceramics in a cylindrical shape. When applied to a general plasma apparatus, the container (11) is arranged so that its axis is vertical, and is configured so that the upper and lower ends can be hermetically sealed. Although not shown, the container (11) is connected to a vacuum pump and is connected to the container (11).
An exhaust pipe for evacuating the inside and a gas supply pipe extending from the material gas supply facility and supplying a required plasma gas at a predetermined flow rate are additionally provided.

The resonance coil (12) has a winding diameter so as to resonate in all wavelength modes in order to form a standing wave having a predetermined wavelength.
The winding pitch and the number of turns are set. That is, the electric length of the resonance coil (12) is an integral multiple (1 time, 1 time) of one wavelength at a predetermined frequency of the power supplied from the high frequency power supply (4).
...).

Specifically, considering the applied power, the intensity of the magnetic field to be generated, and the outer shape of the device to be applied, the resonance coil (12) is, for example, 800 kHz to 50 MHz,
The container (1) has an effective sectional area of 50 to 300 mm ² and a coil diameter of 200 to 500 mm so that a magnetic field of about 0.01 to 10 Gauss can be generated by a high frequency power of 0.5 to 5 KW. About 2 to 60 turns. As a material constituting the resonance coil (12), a copper pipe, a copper thin plate, an aluminum pipe, an aluminum thin plate, a material in which copper or aluminum is deposited on a polymer belt, or the like is used.

One end or both ends of the resonance coil (12) is finely adjusted at the time of installation to make the electrical length of the resonance coil fine so that the resonance characteristics are substantially equal to those of the high-frequency power supply (4).
Usually, it is grounded via a movable tap. Further, a waveform adjusting circuit including a coil and a shield is provided at one end (or the other end or both ends) of the resonance coil (12) so that phase and anti-phase currents flow symmetrically with respect to the electrical midpoint of the resonance coil (12). May be inserted. The waveform adjusting circuit is configured to be open by setting an end of the resonance coil (12) to an electrically disconnected state or an electrically equivalent state. Further, the end of the resonance coil (12) may be ungrounded by a choke series resistor, and may be DC-connected to a fixed reference potential.

The outer shield (13) is provided with a resonance coil (1).
The electric field outside of 2) is shielded, and a capacitance component (C component) necessary for forming a resonance circuit is added to the resonance coil (12).
To be formed between them. Outer shield (1
3) is generally formed in a cylindrical shape using a conductive material such as an aluminum alloy, copper or a copper alloy. The outer shield (13) is arranged at a distance of about 5 to 150 mm from the outer periphery of the resonance coil (12). And usually,
The outer shield (13) is grounded so that the potential is equal to both ends of the resonance coil (12).
In order to accurately set the resonance number of 2), the outer shield (1
At one end or both ends of 3), the tap position can be adjusted, or a trimming capacitance may be inserted between the resonance coil (12) and the outer shield (13).

The high frequency power supply (4) is basically a normal R
f generator, as shown in FIG. 2, a power control means (control circuit) (5) including a high-frequency oscillation circuit for defining an oscillation frequency and an output, and a preamplifier;
An amplifier (output circuit) for amplifying to a predetermined output (4)
1). That is, the power control means (5)
Controls the amplifier (41) based on preset output conditions related to frequency and power through the operation panel, and the amplifier (41) is connected to the resonance coil (12) via a transmission line (45). Supply high frequency power.

Specifically, as the high frequency power supply (4),
A high-frequency generator capable of supplying power at a frequency of 80 kHz to 800 MHz can be used. Typically, a fixed-frequency type high-frequency power supply (frequency: 28.1) known as “CX-3000” manufactured by Comdel Inc.
2 MHz, output: 3 KW). Also, IFI
The use of a high-power, high-bandwidth amplification known as "TCCX3500" manufactured by Hewlett-Packard Company, together with a 0-50 MHz pulse generator known as "HP116A" manufactured by Hewlett-Packard Company, provides a frequency range of 800 kHz to 5 kHz.
A variable frequency power supply capable of outputting 2 kW in a frequency range of 0 MHz can be configured.

From the high frequency power supply (4) to the resonance coil (12)
As a transmission line (45) for supplying power to a cable, a rated coaxial cable having a coaxial insulating sheath made of polyethylene resin, specifically, a model “RG-17” manufactured by Fujikura Co., Ltd.
A known cable or the like is used as "/ U". And
The transmission line (45) may be connected via a movable tap to a point between the grounded ends of the resonance coil (12).

The plasma generating circuit constituted by the resonance coil (12) is an RLC parallel resonance circuit, and when the wavelength of the high-frequency power supply (4) and the electrical length of the resonance coil (12) are the same, resonance occurs. The resonance condition of the device (1) is that a reactance component generated by a capacitance component and an inductive component of the resonator (1) is canceled out to become a pure resistance. However, in the above plasma generation circuit,
When the plasma is generated, the actual coupling is caused by the capacitive coupling between the voltage part of the resonance coil (12) and the plasma, the variation of the inductive coupling between the container (11) and the plasma, and the excited state of the plasma. The resonance frequency fluctuates slightly. In practice, the resonator resonates at a frequency slightly lower than the resonance point in the no-load state of the resonator (1).

Therefore, in the resonance device of the present invention, as shown in FIG. 2, a high-frequency power supply (4) is used for compensating the resonance deviation in the resonator (1) during plasma generation on the power supply side.
The power control means (5) has a function of detecting the power of the reflected wave from the resonator (1) when the plasma is generated and complementing the output. With such a configuration, in the resonance device of the present invention, a standing wave can be formed more accurately in the resonator (1), and plasma with extremely little capacitive coupling can be generated.

That is, the above-mentioned power supply control means (5)
The reflected wave power from the resonator (1) when plasma is generated is detected, and the predetermined frequency is increased or decreased so that the reflected wave power is minimized. Specifically, the power supply control means (5) includes a frequency control circuit (51) for correcting a preset oscillation frequency, and includes an amplifier (4).
On the output side of 1), a reflected wave power meter (as a part of a power control means (5) for detecting the reflected wave power in the transmission line (45) and feeding back the voltage signal to the frequency control circuit (51)). 54) are interposed.

As shown in FIG. 3, the frequency control circuit (51) receives an A / D converter (51a) which receives a voltage signal from the reflected wave power meter (54) and converts the voltage signal into a frequency signal. An arithmetic processing circuit (51b) for adding / subtracting the value of the frequency signal corresponding to the converted reflected wave and the value of the oscillation frequency stored in advance, and converting the frequency value obtained by the addition / subtraction processing into a voltage signal It is composed of a D / A converter (51c) for conversion, and a voltage controlled oscillator (51d) that oscillates according to an applied voltage from the D / A converter (51c). Therefore, the frequency control circuit (51) oscillates at the no-load resonance frequency of the resonator (1) before plasma lighting, and increases or decreases the predetermined frequency so that the reflected power is minimized after plasma lighting. And consequently, the transmission line (4
A frequency signal is given to the amplifier (41) so that the reflected wave in 5) becomes zero.

The power supply control means (5) may have a function of adding and outputting power equivalent to the reflected wave power. With such a configuration, in the resonance device of the present invention, it is possible to supplement the reduction of the effective load power due to the reflected wave power, and to always transmit a predetermined power to the resonator (1). Specifically, the power control means (5) is provided with an output control circuit (52) for correcting a preset output, and the output side of the amplifier (41) is connected to a transmission line (45). An output control circuit that detects the traveling wave power and outputs the voltage signal
A traveling wave power meter (53) as a part of the power supply control means (5) for feeding back the power is provided. And
The reflected wave power meter (54) is connected to the transmission line (4).
It is configured to detect the reflected wave power in 5) and feed back the voltage signal to the output control circuit (52).

That is, a traveling wave power meter (53)
Feeds back the detected traveling wave power to the output control circuit (52), and outputs the reflected wave power meter (54).
Feeds back the detected reflected wave power to the output control circuit (52). The output control circuit (52)
Based on the output conditions set and stored in advance and the magnitude of the actual traveling wave power detected by the traveling wave power meter (53) and the magnitude of the actual reflected wave power detected by the reflected wave power meter (54). The amplifier (41) is controlled so that the difference between the magnitude of the traveling wave power and the magnitude of the reflected wave power becomes the set value stored in the output control circuit (52).

In the operation of generating plasma by the resonance device of the present invention, the inside of the vessel (11) is set to, for example, 0.01 to
After reducing the pressure to 50 Torr, a plasma gas is supplied to the container (11) while maintaining the above-mentioned degree of vacuum. As the plasma gas, various material gases are used in accordance with the processing, as in the conventional case. For example, in the case of ashing processing,
Oxygen, hydrogen, argon, water and the like are used. In the case of etching, fluorine, bromine, chlorine and the like are used. When high-frequency power of, for example, 27.12 MHz and 2 KW is supplied from the high-frequency power supply (4) to the resonator (1), an induced electric field is generated inside the container (11).
The supplied gas is turned into plasma in the container (11).

In the resonance apparatus according to the present invention, the power supply control means (5) attached to the high-frequency power supply (4) includes a resonator (1) based on a change in capacitive coupling or inductive coupling of generated plasma.
At the high frequency power supply (4). That is, the reflected wave power meter (54) of the power supply control means (5) detects the reflected wave power due to the fluctuation of the capacitive coupling or the inductive coupling of the plasma, and the frequency control circuit (51)
By increasing or decreasing the predetermined frequency by an amount corresponding to the shift of the resonance frequency, which is a factor of the reflected wave power, so that the reflected wave power is minimized, the resonance frequency of the resonator (1) under the plasma condition is reduced. The high frequency is output to the amplifier (41).

In other words, the resonance device of the present invention outputs a high frequency having a frequency that accurately resonates according to the shift of the resonance point of the resonator (1) when plasma is generated and when the plasma generation conditions fluctuate. The standing wave can be formed more accurately by the resonator (1). That is, as shown in FIG. 1, in the resonator (1), a complete standing wave in a state where the phase voltage and the anti-phase voltage are always canceled by the transmission of the actual resonance frequency of the resonator including the plasma. Is formed, and the highest phase current is generated at the electrical midpoint of the coil (the node where the voltage is zero). Therefore, the induction plasma excited at the electric midpoint has almost no capacitive coupling, and can form a donut-shaped plasma having an extremely low electric potential in the container (11).

Further, in the resonance device of the present invention, the power supply control means (5) compensates on the high frequency power supply (4) side for the reflected wave power caused by the shift of the resonance point of the resonator (1) (impedance mismatch). . That is, the traveling wave power meter (53) detects the traveling wave power in the transmission line (45) and outputs the magnitude to the output control circuit (52).
The reflected wave power meter (54) is connected to the transmission line (4).
The reflected wave power generated in 5) is detected, and the magnitude is output to the output control circuit (52). Then, the output control circuit (5
2) The power equivalent to the reflected wave power is added, and the added power is output to the amplifier (41) as a new set value.

The reflected wave power generated in the transmission line (45) is
For example, if the initial power output is about 2 KW as described above,
It is about W. Of course, the value of the reflected wave power depends on the amplifier (4
Although the output fluctuates depending on the output change of 1), the output from the amplifier (41) can be finally brought as close as possible to the intended set value by the continuous response of the power supply control means (5). I can do it. Therefore, the spiral resonator of the present invention can compensate for the decrease in the effective load power due to the reflected wave power, and can always supply the desired level of high-frequency power to the resonator (1) without fail. Can be generated stably. Also, like the conventional plasma device,
There is no need to provide an impedance matching circuit.

Next, a plasma processing apparatus using the resonance device of the present invention will be described. The resonance apparatus of the present invention is applied to a high frequency electrodeless discharge plasma processing apparatus (7) as shown in FIG. The plasma processing apparatus (7) is configured by arranging the above-described resonator on a pedestal having a horizontal base (70). As described above, the resonance device includes the container (1).
1) a resonance coil (12) wound around a container (11);
And a resonator (1) comprising an outer shield (13) made of aluminum or the like arranged on the outer periphery of the resonance coil (12).
And a high frequency power supply (4) (omitted in FIG. 4). And, below the resonator (1),
A processing chamber (8) for accommodating the substrate (W) is provided so as to be continuous with the container (11).

The container (11) can have various appearances, but at least its bottom surface is open.
The periphery of the slightly enlarged bottom surface is hermetically locked by a ring-shaped flange (71). The top of the container (11) is formed, for example, in a substantially dome shape, and a thin tube for introducing a plasma gas is integrally provided at the center of the top. A gas supply pipe (16) extending from a gas supply device including various gas containers and capable of supplying a plasma gas at an appropriate flow rate is connected to the thin tube.

The resonance coil (12) is in the above-mentioned mode, and is formed by a plurality of supports (21) which are formed in a flat plate shape from an insulating material and which are vertically provided on the upper end surface of the flange (71). Supported. Both ends of the resonance coil (12) are connected to an outer shield (13) electrically grounded, and a point between both ground points of the resonance coil (12) grounded at both ends is connected via a movable tap. High frequency power supply (4)
(See FIG. 1). Then, the resonance coil (1
The electrical length of 2) is adjusted to, for example, one wavelength of the power supply frequency. The above-described waveform adjustment circuit may be inserted into the transmission line at one end, the other end, or both ends of the resonance coil (12).

The processing chamber (8) in which the substrate (W) is loaded,
It is formed in a substantially cylindrical shape with a short axis and a bottom, and the base of the gantry (70)
Is hung on the lower surface. The processing room (8) has a base (70)
And to the container (11) via the opening formed in the top plate of the processing chamber. Processing room (8)
An exhaust pipe (14) leading to a vacuum pump is attached to the bottom of the container, and the container (11) and the processing chamber (8) are configured to be able to reduce the pressure to a predetermined degree of vacuum through the exhaust pipe (14). .

The processing chamber (8) is provided with a holder (81) for horizontally holding the substrate (W). Holder (8
1) is a holder block (81a) formed in a short-axis cylindrical shape and on which the substrate (W) is mounted, and a column (81b) inserted through the bottom plate of the processing chamber (8) and supporting the holder block (81a). It is composed of The holder block (81a) may include a commonly used electromagnetic chuck.

The column (81b) may be fixed, but is configured to be able to move up and down by a driving mechanism (not shown) composed of a combination of a servomotor and a ball screw, for example. The holder block (81a) is configured to enter the processing chamber (8) through the opening of the base (70) and substantially into the bottom of the container (1). Further, when the holder block (81a) can be moved up and down, a bellows (82) for keeping the airtight is interposed between the holder block (81a) and the bottom plate of the processing chamber (8).

A gate valve (9) is provided on the peripheral surface of the processing chamber (8), and loading and discharging of the substrate (W) can be operated through the gate valve (9). A load lock container (not shown) capable of maintaining the same degree of vacuum as the processing chamber (8) may be connected to the gate valve (9) so as to always maintain the inside of the apparatus at a constant degree of vacuum. Further, a pre-load container may be connected via a load lock container. The pressure of the load lock container or the pre-load container is usually reduced by the above-described vacuum pump that sucks the exhaust pipe (14).

In the plasma processing apparatus (7) as described above, the pre-load container or the load lock container
First, a substrate (W) as an object to be processed is loaded into a processing chamber (8) and held on a holder (81). Then, the pressure is reduced through the exhaust pipe (14) by driving the vacuum pump, and the inside of the container (11) and the processing chamber (8) is reduced to, for example,
Reduce pressure to ~ 200 mTorr. And the container (1
While maintaining the degree of vacuum in 1), the above-described plasma gas is supplied through the gas supply pipe (16), and high frequency power of, for example, 27.12 MHz is supplied from the high frequency power supply (4). As a result, an induced electric field is generated around the resonance coil (12), and a donut-shaped induction plasma is excited at, for example, an intermediate height position of the container (11) corresponding to an electrical midpoint of the resonance coil (12). You.

At this time, as described above, the resonance device of the present invention uses the power supply control means (5) attached to the high-frequency power supply (4).
Compensates for the shift of the resonance point in the resonator (1) due to fluctuations in the capacitive coupling and inductive coupling of the plasma, and more accurately forms a standing wave. It can be formed in a container (11). Therefore, in the plasma processing apparatus (7), the substrate (W) loaded at the lower end of the container (11) can be effectively treated by radicals, and ion damage to the substrate (W) can be prevented.

Further, the ions in the plasma generated in the region where the potential is substantially zero have an extremely low electric potential and are not accelerated. Therefore, in the plasma processing apparatus (7), the vessel (11) Has no sputtering effect on the peripheral wall of the container, and does not damage the peripheral wall of the container (11). As a result, the life of the apparatus can be improved, and the problem that the components of the container (11) and the like are mixed in the plasma and contaminate the substrate (W) can be prevented.

Further, as described above, the resonance device of the present invention
Power supply control means (5) attached to the high-frequency power supply (4) compensates on the high-frequency power supply (4) side for reflected wave power due to impedance mismatch generated in the resonator (1) and complements the reduction in effective load power. Therefore, the desired level of high-frequency power can always be reliably supplied to the resonator (1), and the plasma can be stabilized. Therefore, in the plasma processing apparatus (7), the substrate (W) loaded at the lower end of the container (11) can be uniformly processed at a constant rate.

In the plasma processing apparatus (7), in addition to the processing conditions such as the type and flow rate of the plasma gas and the electric field intensity, various conditions such as the flow of radicals in the vessel (11) and the temperature of the substrate (W) are used. More suitable processing is possible by controlling the conditions.

For example, in one embodiment of the plasma processing apparatus (7), a perforated plate (8) which is located on the outer peripheral side of the holder (81) and vertically partitions the processing chamber is provided in the processing chamber (8).
3) is arranged. When such a perforated plate (83) is arranged, the flow of radicals sucked into the gas exhaust path (14) can be dispersed uniformly, and the surface of the substrate (W) can be treated more uniformly.

In another embodiment of the plasma processing apparatus (7), the holder (81) is electrically insulated from the processing chamber (8) and can be connected to a bias power supply to adjust the potential appropriately. It is configured as follows. That is, at least the substrate (W) mounting surface of the holder block (81a) may be insulated and configured as a bias electrode.
Thus, in the case of using an ion stream for processing of an extremely hardened resist or the like, the potential of the substrate (W) can be controlled to accelerate ions and enhance the sputtering effect.

Further, in another embodiment of the plasma processing apparatus (7), a heating means is provided in the holder block (81a) to appropriately raise the temperature of the substrate (W).
The heating means is configured by embedding various heaters such as a sheath heater, a ceramic heater plate, and a film heater near the upper end surface of the holder block (81a) together with a temperature measurement sensor. Thus, the reaction can be promoted by increasing the temperature of the substrate (W), and the processing efficiency can be improved.

Further, when the above-mentioned heating means is provided, a cooling means may be provided below the heating means in the holder block (81a). As the cooling means, a coil for circulating a gas such as low-temperature air or nitrogen, cooling water, or liquefied gas can be used, and such a coil is similarly embedded in the holder block (81a). When the cooling means is provided, the temperature of the substrate (W) can be quickly controlled. In addition, instead of the above-mentioned various heaters, by circulating a heating fluid through the coil, it can be used as a heating means.

The resonance apparatus and the plasma processing apparatus (7) of the present invention can generate plasma having an extremely low electric potential, and can easily control the generated plasma. It can be used for a wide range of processing techniques such as plasma chemical vapor deposition such as ion etching, remote plasma vapor deposition, and ion plasma chemical vapor deposition. In addition to devices such as semiconductor elements, flat panel displays, and microfabricated products, materials such as diamond and plastic can be used.

[0051]

As described above, according to the spiral resonator for plasma generation according to the present invention, a high frequency having a frequency that accurately resonates in accordance with the shift of the resonance point of the resonator when plasma is generated is output. Therefore, a standing wave can be more accurately formed by the resonator, and plasma having a lower electric potential can be generated. In addition, since the power of the high-frequency power supply is controlled according to the reflected wave power due to the mismatch of the resonator at the time of plasma generation, it is possible to complement the decrease in the effective load power,
The desired level of high-frequency power can always be reliably supplied to the resonator, and plasma can be stably generated.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a basic configuration of a spiral resonator and a plasma generation position.

FIG. 2 is a block diagram showing power control means in the spiral resonance device.

FIG. 3 is a circuit block diagram showing an example of a frequency control circuit in the power supply control means.

FIG. 4 is a longitudinal sectional view of a plasma processing apparatus showing an application example of a spiral resonance device.

[Explanation of symbols]

 1: resonator 11: container 12: resonance coil 13: outer shield 14: exhaust pipe 16: gas supply pipe 4: high-frequency power supply 41: amplifier 5: power supply control means 51: frequency control circuit 52: output control circuit 53: traveling wave Power meter 54: Reflected wave power meter 7: Plasma processing device 8: Processing chamber 82: Holder W: Substrate

──────────────────────────────────────────────────の Continued on front page (51) Int.Cl. ⁶ Identification code FI H01L 21/31 H01L 21/302 B

Claims (2)

[Claims] 1. A resonator comprising: a container configured to be capable of reducing pressure and supplied with a plasma gas; a resonance coil wound around the outer periphery of the container; and an outer shield disposed around the outer periphery of the resonance coil. And a high-frequency power supply for supplying high-frequency power of a predetermined frequency to the resonator, and the electrical length of the resonance coil is 1 at the predetermined frequency.
In the spiral resonator for plasma generation set to an integral multiple of the wavelength, the high-frequency power supply detects the reflected wave power from the resonator when plasma is generated, so that the reflected wave power is minimized. A spiral resonance device, further comprising a power supply control means for increasing and decreasing the predetermined frequency. 2. The spiral resonance device according to claim 1, wherein the power supply control means has a function of adding and outputting power equivalent to the reflected wave power.