JP2001085195A - High frequency discharge device and plasma treatment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely control temperature and sheath voltage in a plasma generating chamber independent of kinds of devices by forming a shield electrode for controlling capacitive coupling between an induction antenna connected to an impedance adjustable high frequency circuit and plasma in a thin film for fixing to between the antenna and an insulating part for being wound on the antenna of a vacuum container. SOLUTION: An induction antenna 4 wound around an insulating vacuum container 1 of a plasma generating chamber 22 adjacent to a plasma treatment chamber 23 having a treating material stage 16 on the inside and surrounded with a vacuum container 11 into or from which reaction gas is introduced or exhausted is connected to a high frequency power generating device 13 through an impedance matching circuit 14. A shield electrode 2 of a thin film shape formed on an insulating part having high voltage-resistance in a part or the whole of the insulating vacuum container 1 by coating or vapor deposition of an electricity conductive material is constituted at high dimensional accuracy without increasing the number of components, and prevents obstruction of heat transmission and abnormal discharge. A heating means and a cooling means are preferably installed on the outside of the insulating vacuum container 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency discharge device for generating plasma and a processing method for processing an object using the plasma.

[0002]

2. Description of the Related Art In a conventional induction discharge type plasma generator, an antenna-like induction antenna 4 is arranged outside an insulating vacuum vessel 1 made of quartz, alumina or the like as shown in FIG. The high-frequency energy generated by passing a high-frequency current through this is supplied into the insulating vacuum vessel 1. As a result, a high-frequency magnetic field is generated in the insulating vacuum vessel 1, and a high-frequency electric field is induced by the fluctuation of the magnetic field. The induced electric field combines with the electrons, accelerates them, and ionizes the gas to generate plasma 6.

However, since a voltage distribution is generated along the induction antenna 4 and a capacitive coupling is formed between the induction antenna 4 and the plasma 6, a high-frequency voltage is generated on the plasma side of the insulating vacuum vessel 1. . For this reason, the literature [HS B
utler and GS Kino, "Plasma sheath formation by
radio-frequency fields ", Phys. Fluids Vol. 6, No.
9, September 1963, pp. 1346-1355], a bias voltage more negative than the original wall voltage is generated inside the insulating vacuum vessel 1. For this reason, the ions in the plasma are accelerated by this voltage and collide with the insulating container wall 1 and cut the wall by sputtering or chemical reaction, so that impurities are generated or the life of the insulating vacuum container 1 is shortened. There was a problem.

To cope with this, a shield electrode 2 having a function of controlling the capacitive coupling between the inductive antenna 4 and the plasma as shown in FIG. 14A has been used.
The shielding electrode 2 is formed of a slit-shaped metal plate having a gap 3, and is usually grounded. The shield electrode 2 utilizes the fact that the induction magnetic field and the electric field generated by the induction antenna 4 are orthogonal to each other, and transmits only the induction magnetic field and grounds the electric field, so that the space between the induction antenna 4 and the plasma 6 is generated. Cut off capacitive coupling. A typical example of this shielding electrode 2 is
This is a shield plate called a Faraday shield, and its effect is described in detail in JP-A-07-254498.

[0005]

The shielding electrode 2 is composed of a slit-shaped metal plate part having a gap 3, and the longitudinal direction of the gap 3 is made to be perpendicular to the induction antenna. This is additionally installed between the induction antenna 4 and the insulating vacuum vessel 1. As a result, the maintenance of the apparatus is deteriorated due to an increase in the number of parts; in the case of an insulating vacuum vessel having a complicated three-dimensional structure such as a round dome shape, the dimensional accuracy of the shield electrode 2 is reduced; When the temperature of the container 1 must be controlled, a gap 5 is provided between the insulating vacuum container 1 and the shield electrode 2.
The shield electrode 2 becomes a hindrance to heat transfer; abnormal discharge easily occurs between the shield electrode 2 and the induction antenna 4; and a large amount of power is required for plasma ignition to ground the shield electrode 2. There was a problem.

The present invention has been made in view of the above problems, and has as its object to provide a high temperature control performance without impairing the maintainability and the dimensional accuracy of the shielding electrode, An object of the present invention is to provide a high-frequency discharge device capable of igniting plasma with low power without causing discharge and a plasma processing method using the same.

[0007]

SUMMARY OF THE INVENTION The present invention comprises a vacuum vessel having an at least partially insulating portion; an inductive antenna wound around the insulating portion; and an impedance connected to the inductive antenna. A high-frequency power supply including a high-frequency circuit having an adjusting function; and a shielding electrode having a function of controlling a capacitive coupling between the inductive antenna and plasma installed between the inductive antenna and the insulating portion. Wherein the shielding electrode is formed of a thin film and is physically adhered (fixed) to the insulating portion.

[0008] As long as the shield electrode is made of an electrically conductive substance, it can be made of a thin film having a thickness of, for example, 1 mm or less. Therefore, the object of the present invention is achieved by a high-frequency discharge device characterized in that a shielding electrode is formed of a thin film and is integrated with an insulating vacuum vessel. As a result, the function of the shielding electrode can be realized without increasing the number of parts,
The shield electrode can be configured with high dimensional accuracy even in an insulating vacuum vessel with a complicated three-dimensional structure. Further, since the shield electrode is integrated with the insulating vacuum vessel, it does not become a hindrance to heat transfer.

Further, the prevention of abnormal discharge is achieved by a high-frequency discharge apparatus characterized in that an insulating material having a high withstand voltage is formed integrally with the shield electrode on the surface of the shield electrode.

[0010] Further, to improve the temperature control performance, an insulating material having a high emissivity or thermal conductivity is formed on the surface of the insulating vacuum vessel and the surface of the shielding electrode by integrating the insulating vacuum vessel and the shielding electrode. This is achieved by a high-frequency discharge device characterized by being formed in the form of an electrode.

[0011] Further, to increase the heating performance during temperature control,
This is achieved by a high-frequency discharge device characterized in that the shielding electrode is made of a high-resistance substance (for example, tungsten or titanium), and heat is generated by supplying electricity to the material.

Further, instead of grounding the shielding electrode,
By connecting the means for adjusting the voltage of the shielding electrode described in Japanese Patent Application No. 9-325791, large power is not required for plasma ignition.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A high-frequency discharge device according to one embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1) As shown in FIG. 1, a high-frequency discharge device 10 includes a plasma processing chamber 23 and a plasma generation chamber 22 adjacent thereto. , A shield electrode 2, an induction antenna 4 and an external housing 18.

The material of the shield electrode 2 may be any conductive material that can be formed on the insulating vacuum vessel 1. For example, a metal such as aluminum, copper, tungsten or the like,
-It can be composed of an alloy such as Ni, carbon or a compound thereof. Further, for example, as in the case of a process such as metallizing, the material may be made of a substance that changes into a conductive substance by post-processing.

The method of forming the shielding electrode 2 may be any method as long as a thin film is formed on the insulating vacuum vessel 1. For example, application of an electrically conductive material to the insulating vacuum vessel 1, It is a deposition method, a sputtering method, a thermal spraying method, a plating method, or deposition of an electrically conductive substance from the insulating vacuum vessel 1, crystal growth of the electrically conductive substance, metallization, and adhesion of an electrically conductive film.

The plasma processing chamber 23 is constituted by a space surrounded by the electrically conductive vacuum vessel 11 grounded to the adjacent plasma generating chamber 22. A predetermined amount of reaction gas can be introduced into the plasma processing chamber 23 via the reaction gas flow control device 21, and the reaction gas in the plasma processing chamber 23 can be discharged by the vacuum pump 28 via the pressure adjusting device 17. . A stage 16 for holding a workpiece 15 such as a wafer is installed in the plasma processing chamber 23, and a bias voltage is applied to the stage 16 from a high-frequency power generator 27 via an impedance matching circuit 26. . Stage 16
Is controlled by the temperature control device 12 so as to reach a predetermined constant temperature.

The plasma generating chamber 22 is adjacent to the plasma processing chamber 23 and is constituted by a space surrounded by the insulating vacuum vessel 1 represented by quartz or alumina. Induction antenna 4
Are wound in a loop around the insulating vacuum vessel 1, and in this example, are wound three times. High frequency power from a high frequency power generator 13 is applied to the induction antenna 4 via an impedance matching circuit 14.
When the high frequency power is applied, the plasma generation chamber 2
Inside 2, plasma is generated by inductive coupling.

Next, the operation of the high-frequency discharge device will be described.
With this high-frequency discharge device 10, aluminum
The (Al) film was etched. First, chlorine gas (C) is supplied from the reaction gas flow control device 21 to the plasma processing chamber 23.
l ₂ ) at 80 sccm and boron chloride (BCl ₃ ) at 20 c
cm. The pressure in the plasma processing chamber 23 is constantly controlled to 2 Pa by the pressure adjusting device 17.

On the stage 16 cooled by the temperature controller 12, a wafer 15 to be processed is held. The bias voltage applied to stage 16 has a frequency
An 800 kHz, 100 W power is applied from a high frequency power generator 27 through an impedance matching circuit 26. High frequency power is applied to the induction antenna 4 from the high frequency power generator 13 having a frequency of 13.56 MHz and power of 2 kW through the impedance matching circuit 14. As described above, plasma is generated in the plasma generation chamber 22 by inductive coupling. When the impedances are matched, a high-frequency standing wave stands on the induction antenna 4, and a high-frequency voltage distribution is formed along the loop of the induction antenna 4. In the case of this discharge, the voltage of the high-frequency power supply terminal of the induction antenna 4 was 7 kVpp at the maximum, and the ground terminal of the induction antenna was 0 V.

Under the above-described discharge conditions, the shielding electrode 2 was removed, etching was performed for a total of 2 hours, and the amount of shaving on the plasma side of the insulating vacuum vessel 1 was measured. / h shavings were observed. Such local scraping significantly deteriorates the thermal and mechanical durability of the insulating vacuum vessel 1 made of alumina. Further, the release of impurities causes contamination of foreign matter on the wafer. FIG. 2 shows the relationship between the voltage of the induction antenna 4 and the scraping speed of alumina. From this result, it can be seen that the lower the voltage of the induction antenna, the smaller the amount of alumina shaved. Next, the shield electrode 2 was attached and grounded, and the same etching was performed.
The amount of scraping of 1 was below the measurement limit (0.2 mm / h).

(Embodiment 2) In a high-frequency discharge device 60 shown in this embodiment, a shielding electrode 2 manufactured by metallizing is coated with an insulating film 7 having an emissivity of 0.95 of infrared rays and manufactured by using alumina. Except for having a heating mechanism 19/24 for controlling the temperature of the insulated vacuum vessel 1, a cooling mechanism 20/25, and a thermometer 29 for monitoring the sound level, it has the same configuration and operation as the high-frequency discharge device 10. ing.

As shown in FIG. 3, the high-frequency discharge device 50 comprises:
The outside of the shielding electrode 2 manufactured by metallizing is covered with an insulating film 7. Since this film is a black body paint and has an emissivity of 0.95 for black infrared rays, the infrared ray absorption efficiency is close to that of a black body. Also, its heat resistance temperature is
The temperature is 1500 ° C, which is the most suitable as a temperature control paint for insulating vacuum containers. Further, since the thickness of the film is 0.2 mm or less, the heat capacity and the heat conduction characteristics of the film can be ignored, and the temperature state of the insulating film 7 is the same as that of the insulating vacuum vessel 1.

An annular infrared heater 19 is attached to the above-described configuration for heating the insulating vacuum vessel 1. A control device 24 that supplies heating power is connected to the infrared heater. The maximum value of the supplied power is
500W. The control device 24 has a built-in function of controlling the temperature of the insulating vacuum vessel 1 to be constant by a signal of a thermometer 29 that monitors the temperature of the insulating vacuum vessel 1.
For cooling, a cooling device (fan) 20 for blowing air to the insulating vacuum vessel 1 and a control device 25 for supplying electric power to the fan 20 are attached. This control device 25 includes:
As in the case of the control device 24, a function of controlling the temperature of the insulating vacuum vessel 1 to be constant by a signal of a thermometer 29 that monitors the temperature of the insulating vacuum vessel 1 is incorporated.

A temperature control test of the insulating vacuum vessel 1 was performed using the high-frequency discharge device 60 having the above-described configuration. As a reference experiment, the insulating film 7 after metallization
The experiment was also performed on a case where the metal was not coated and a case where the shielding electrode 2 was formed of a normal metal part as shown in FIG. 14 (indicated by FS in FIG. 4). As the contents of the experiment, the radiant heat from the infrared heater 19 was absorbed in the insulating vacuum vessel 1, and the temperature rise from room temperature was measured. As a cooling test,
Plasma discharge was performed under the same conditions as in Example 1 to raise the temperature of the insulating vacuum vessel to 120 ° C., when the temperature reached 120 ° C., the plasma discharge was stopped, and the temperature drop characteristics due to air blowing from the fan 20 were measured. did. The results are shown in Fig. 4.The heating and cooling characteristics of the result using the shielding electrode of metal parts were the worst, and the heating and cooling characteristics of the shielding electrode and black body paint manufactured by metallizing were the best. . From the above,
By forming the shielding electrode as a thin film and fixing it on the insulating vacuum vessel, and coating this with an insulating black body paint,
It has been shown that it is possible to construct a temperature control mechanism with high speed response and good performance.

(Embodiment 3) In this embodiment, an insulating vacuum vessel 1
And the pattern of the shielding electrode 2. Fig. 5 (a)
FIG. 1 shows an example of a shield electrode 2 (shaded portion) formed on an insulating vacuum vessel 1 having a truncated cone shape. In FIG. 5 (b), FIG.
The cross section of (a) is shown. As in the second embodiment, the shielding electrode 2 and the insulating vacuum vessel 1 having a truncated cone shape can be covered with an insulating film.

(Embodiment 4) In this embodiment, the insulating vacuum vessel 1 is also used.
And the pattern of the shielding electrode 2. Fig. 6 (a)
FIG. 1 shows an example of a shield electrode 2 (shaded portion) formed on an insulating vacuum vessel 1 having a truncated cone shape. In FIG. 6 (b), FIG.
The cross section of (a) is shown. As described in detail in JP-A-07-254498, the performance of the shielding electrode 2 can be realized by providing the slit portion 8 so as to be perpendicular to the induction antenna 4. However, there is no necessity to provide the slit portion 8 at a location apart from the induction antenna 4. As such a place, there is a top portion of the insulating vacuum vessel 1 having a truncated cone shape as shown in FIG. 6 (a). Here, the shield electrode can be configured in various patterns depending on the use of the shield electrode. Figure
FIG. 6A shows a special pattern example 9 in which a circular pattern is densely formed instead of the slit 8 at the top of the head. Also in this case, similarly to the second embodiment, the shield electrode 2 and the truncated cone-shaped insulating vacuum vessel 1 can be covered with an insulating film.

Next, the meaning of providing various kinds of patterns such as the special pattern 9 on the shielding electrode 2 will be described.
Since the shielding electrode 2 faces the plasma via the insulating vacuum container 1, the special electrode 2 and the plasma are capacitively coupled. As described in Japanese Patent Application No. 9-325791, when a high-frequency voltage is generated on the special electrode 2, the reference [H. S. But
ler and G. S. Kino, "Plasma sheath formation by
radio-frequency fields ", Phys. Fluids Vol. 6, N
o. 9, September 1963, pp. 1346-1355], a bias voltage more negative than the original wall voltage is generated inside the insulating vacuum vessel 1. This negative bias voltage is determined by the high-frequency voltage of the shield electrode 2, the capacitance between the shield electrode 2 and the plasma, and the impedance of the plasma. However, if the capacitance per unit area between the shielding electrode 2 and the plasma varies depending on the location, the negative bias voltage generated inside the insulating vacuum vessel 1 varies depending on the location, and the negative bias voltage varies. A distribution occurs in the voltage.

At this time, as described with reference to the relationship between the induction antenna voltage and the shaving amount of the vacuum vessel in FIG.
The shaving of the inner wall will differ depending on the location,
The thermal and mechanical durability of the insulating vacuum vessel 1 is deteriorated. This can be prevented by adjusting the pattern of the shielding electrode and keeping the capacitance per unit area constant. The pattern shown in FIG. 6A shows that the coverage of the side surface of the insulating vacuum vessel 1 having the slit portion 8 (the ratio of the area of the shielding electrode to the area of the insulating vacuum vessel) is 40%. , By applying a special pattern 9
This is a pattern when adjusted to 0%. Thereby, the shaving amount of the inner surface of the insulating vacuum vessel can be controlled to be constant. Conversely, if it is desired to sharpen only a specific part, the coverage of that part can be made higher than that of other parts, and the capacitance per unit area of that part can be increased.

In the present invention, the shielding electrode is formed of a thin film. As a method of forming the shielding electrode, there are methods such as coating and vapor deposition. In these methods, the degree of freedom of the shape of a mask for forming a pattern is high. Therefore, even if the pattern of the shielding electrode 2 is complicated, it can be easily formed.

(Embodiment 5) In this embodiment, the insulating vacuum vessel 1
And the pattern of the shielding electrode 2. Fig. 7 (a)
Is an example of a shield electrode 2 (shaded portion) formed on a round dome-shaped insulating vacuum vessel 1. In FIG. 7 (b),
7 shows a cross section of FIG. 7 (a). In the case of the insulating vacuum vessel 1 having a complicated three-dimensional structure as shown in FIG. 7 (a), when the shielding electrode 2 is made of a metal component, there is a drawback that the processing accuracy is significantly reduced. For this reason, the size of the gap 5 shown in FIG. 14 becomes irregular, and the capacitance per unit area between the shielding electrode and the plasma differs depending on the place, and there is a problem that the temperature control performance is significantly reduced. . On the other hand, in the present invention, since the shielding electrode is formed of a thin film and fixed to the insulating vacuum container, the shielding electrode can be configured with high accuracy for an insulating vacuum container of any shape. Also in this case, similarly to the second embodiment, the shield electrode 2 and the insulating vacuum vessel 1 can be covered with an insulating film.

In the pattern of the shielding electrode 2 shown in FIG. 7A, the slit portion 8 is formed in a triangular shape, and the slit portion is arranged axially symmetric with the induction antenna 4. This pattern has the advantage that the above-mentioned coverage is constant over the entire shielding electrode.

(Embodiment 6) This embodiment is shown in FIGS. 8 (a) and 8 (b).
The difference from the fifth embodiment is that the shape of the insulating vacuum vessel 1 is a flat plate, and the effect is the same as that of the fifth embodiment.

(Embodiment 7) The present embodiment is characterized in that a heater 30 for controlling the temperature of the insulating vacuum vessel 1 is incorporated while keeping the function of the shield electrode 2 from being lost. Fig. 9 (a)
The pattern of the shield electrode 2 and the heater 30 and the induction antenna 4 are shown below. As shown in FIG. 9 (a), the shield electrode 2 is divided into two parts, an inner part and an outer part, and the heater 30 passes between them. Further, the two shield electrodes 2 are configured to be conductive by the bridge 32. With this structure, the heater 30 can be used without impairing the function of the shield electrode 2.
Can be incorporated.

FIG. 9B is a cross-sectional view of the insulating vacuum vessel 1 and shows a state where the insulating film 7 for protecting the heater 30 and the shield electrode 2 is covered. FIG. 9 (c) shows a detailed cross section of the insulating vacuum vessel 1 around the bridge 32 and the heater 30. The bridge 32 has a function of electrically connecting the inner and outer shield electrodes 2 shown in FIG.
It must be electrically insulated from 0. Therefore, FIG. 9 (c)
As shown in FIG. 7, the bridge 32 and the heater 30 need to be electrically insulated by the insulating film 7. The terminal 31 for supplying power to the heater is directly connected to the heater 30 by means such as brazing.

Next, the results of a heating test on the insulating vacuum vessel 1 using Example 7 will be described. At this time, the insulating vacuum vessel 1 was made of alumina, and the shielding electrode 2 was formed by metallizing. The material of the heater 30 is tungsten (W), titanium (T
i), the heater 30 can be made of a high resistance metal such as nickel chromium (NiCr). Here, W is used and the heater 30 is formed by thermal spraying. The width a between the shield electrodes shown in FIG. 9A was 10 mm, the thickness of W constituting the heater 30 was 50 mm, the line width b was 2 mm, and the effective length of the heater was 2 m. This gives 40
The resistance of the heater 30 at 0K is about 3W.

The heater 30, the induction antenna 4, and the shield electrode 2
The peripheral equivalent circuit is shown in FIG. Heating control device 24 is 50
It has a capacity of 0W, 100VAC and its output is coil 33-3
The power is supplied to the heater 30 through a filter composed of 6 (1 mH) and capacitors 42-43 (0.1 mF). In this equivalent circuit, the heater 30 is shown by a dotted line surrounding two resistors 37-38. The shield electrode 2 is indicated by a black dot and a dotted line surrounding the black dot, but has a capacitance between the shield electrode 2 and the heater 30, and is represented by a capacitor 39 (500 pF). Shield electrode 2
Has a capacitance between the plasma 6 (represented by the symbol for resistance), which is represented by a capacitor 41 (400 pF). The induction antenna 4 is represented by a black dot and a dotted line surrounding it, to which a high-frequency power generator 13 is connected through an impedance matching circuit 14.
There is also a capacitance between the induction antenna 4 and the shield electrode 2, which is represented by a capacitor 40 (100pF). As can be seen from this equivalent circuit diagram, the high frequency radiated from the high frequency power generator 13 is induced in the heater 30. The above-mentioned filter functions to cut off the generated high-frequency wave so as not to reach the heating control device 24.

A temperature control test was performed on the insulating vacuum vessel 1 using the insulating vacuum vessel 1 having the above-described configuration and shown in FIG. FIG. 10 shows the results. Figure as reference data
Data in the case of FS (metal part) shown in FIG. 4 is shown in FIG. As a result, the heating characteristics of the tungsten heater were the best. As described above, it has been shown that a heating mechanism having high-speed response and good performance can be formed by forming a heater from a thin film and fixing it on an insulating vacuum vessel in the same manner as the shielding electrode.

(Embodiment 8) In this embodiment, as shown in FIG. 11, a shielding electrode 44 having a refrigerant passage is formed on a shielding electrode 2 formed of a thin film. Such a shielding electrode
The method of forming 44 can be achieved by brazing the shielding electrode 44 on the shielding electrode 2 or bonding the shielding electrode 2 and the shielding electrode 44 with an electrically conductive adhesive. The shield electrode 44 is provided with a refrigerant inlet 49 and a refrigerant outlet 50, and a refrigerant circulation passage 45, a refrigerant circulation pump 46, a refrigerant tank 47,
The refrigerant can be circulated in a closed circuit by the temperature control device 48. The temperature controller 48 has a function of controlling the refrigerant to a predetermined temperature in accordance with the output of the thermometer 29.

By adopting such a configuration, the refrigerant can exchange heat with the insulating vacuum vessel 1 by direct heat conduction without passing through air, and the temperature of high efficiency and high speed response can be obtained. It becomes possible to have a control function.

(Embodiment 9) This embodiment is an example in which the present shield electrode structure is applied to the shield electrode voltage adjusting means described in Japanese Patent Application No. 9-325791. With the device configuration shown in FIG. 12 (a), an actual discharge is performed in the discharge system shown by the equivalent circuit in FIG. did. Here, the high-frequency power generator 13
The one having a frequency of 13.56 MHz and an output of 2 kW was used. The impedance matching circuit 14 has 53 (Load: VC1: 1000) as a variable capacitor of the impedance matching circuit.
pF), 54 (Phase: VC2: 250 pF) and a variable capacitor 55 for adjusting the potential distribution of the induction antenna 4 (VC3: 1000 pF). The capacitance 52 between the shield electrode 2 and the induction antenna 4 is approximately
It was 500 pF. As a result, as shown in FIG.
By changing the capacitance, the shield electrode voltage indicated as EDCS voltage could be changed from about 0V to 1000V.

The result of measuring the voltage (sheath voltage) generated on the plasma side of the insulating vacuum vessel at this time is shown in FIG.
Is shown as data for a gap of 0 mm. For comparison,
FIG. 13 (b) also shows the result of measurement with the shielding electrode 2 having the gap 5 (1 mm) shown in FIG. 14 as data of the gap 1 mm. It can be seen from the results of FIG. 13 (b) that even a gap of only 1 mm has a large effect on the sheath voltage, and there is no gap for effectively setting the shield electrode voltage to the sheath voltage. It is more advantageous.

Further, in the case of FIG. 14, if the gap 5 is slightly deviated, the distribution of the sheath voltage may occur, or a machine error may occur. From this, the gap is definitely 0 mm
Advantageously, the method according to the invention can be controlled to a minimum.

[0044]

As described above, according to the present invention, the maintainability of the plasma generation chamber is not impaired.
A shield electrode capable of reliably controlling the temperature of the plasma generation chamber and the sheath voltage with high accuracy and high speed response without causing any machine difference can be formed, and good process performance in semiconductor manufacturing can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a plasma processing apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a relationship between a shaving amount of an insulating vacuum container made of alumina and a voltage of an induction antenna of the plasma processing apparatus according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram of a plasma processing apparatus according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a time change of the average temperature of the vacuum container when the alumina insulating vacuum container of the plasma processing apparatus according to the second embodiment of the present invention is air-cooled or heated.

FIG. 5 is an explanatory view of a plasma reactor according to a third embodiment of the present invention.

FIG. 6 is an explanatory view of a plasma reactor according to a fourth embodiment of the present invention.

FIG. 7 is an explanatory view of a plasma reactor according to a fifth embodiment of the present invention.

FIG. 8 is an explanatory view of a plasma reactor according to a sixth embodiment of the present invention.

FIG. 9 is an explanatory view of a plasma reactor according to a seventh embodiment of the present invention.

FIG. 10 is an explanatory diagram showing a time change of an average temperature of a vacuum container when an insulating vacuum container made of alumina is heated in a plasma processing apparatus according to a seventh embodiment of the present invention.

FIG. 11 is an explanatory diagram of a plasma processing apparatus according to an eighth embodiment of the present invention.

FIG. 12 is an explanatory view of a plasma processing apparatus according to a ninth embodiment of the present invention.

FIG. 13 is an explanatory diagram showing a relationship between a shield electrode voltage and a sheath voltage on an inner surface of an insulating vacuum vessel of a plasma processing apparatus according to a ninth embodiment of the present invention.

FIG. 14 is an explanatory diagram of a plasma processing apparatus according to a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Insulating vacuum container, 2 ... Shielding electrode, 3 ... Gap, 4 ... Induction antenna 5 ... Gap between shielding electrode and vacuum container, 6 ... Plasma, 7 ... Insulating film, 8 ... Slit of shielding electrode, 9 ... Special pattern part of shielding electrode, 10 ... High frequency discharge device 11 ... Vacuum container (electric conductor), 12 ... Temperature control device, 13 ... High frequency power generation device, 14 ... Impedance matching circuit, 15 ...
Workpiece, 16… Workpiece stage, 17… Pressure adjustment device,
18 ... external housing, 19 ... heating device, 20 ... cooling device, 21 ... reaction gas flow control device, 22 ... plasma generation chamber, 23 ... plasma processing chamber, 24 ... heating control device, 25 ... cooling control device, 26
... impedance matching circuit, 27 ... high frequency power generator, 28 ... vacuum pump, 29 ... thermometer, 30 ... heater, 31 ...
Terminal, 32 ... Bridge, 33-36 ... Reactance, 37-
38: resistance, 39-43: condenser, 44: shielding electrode having a refrigerant passage, 45: refrigerant circulation passage, 46: refrigerant circulation pump, 47
... refrigerant tank, 48 ... temperature control device, 49 ... refrigerant inlet, 50
... coolant outlet, 51 ... insulating gap filler, 52 ... induction antenna
Capacitance between 4 and shielding electrode 2, 53 ... Variable capacitor of impedance matching circuit, 54 ... Variable capacitor of impedance matching circuit, 55 ... Variable capacitor for adjusting potential distribution of induction antenna 4, 60 ... High frequency discharge device,
61… High frequency discharge device, 62… High frequency discharge device

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takeshi Yoshioka 794, Higashi-Toyoi, Katsumatsu-shi, Yamaguchi Prefecture Inside Kasado Plant, Hitachi, Ltd. (72) Inventor Shinichi Suzuki 6-16-2 Shinmachi, Ome-shi, Tokyo Inside Hitachi, Ltd. Device Development Center (72) Inventor Keiji Kuroki 2-16-16 Shinmachi, Ome-shi, Tokyo 2 Inside Hitachi, Ltd. Device Development Center (72) Inventor Saburo Kanai 794, Higashi-Toyoi, Katsumatsu-shi, Yamaguchi Prefecture F-term in the Kasado Plant of Hitachi, Ltd.

Claims (6)

[Claims] A vacuum vessel having an at least partially insulating portion; an induction antenna wound around the insulating portion; and a high-frequency circuit having an impedance adjusting function connected to the induction antenna. A plasma reaction vessel comprising: a high-frequency power source; and a shielding electrode provided between the inductive antenna and the insulating portion and having a function of controlling capacitance coupling between the inductive antenna and plasma. A high-frequency discharge device wherein the shielding electrode is formed of a thin film and is physically closely attached (fixed) to the insulating portion. 2. The high-frequency discharge device according to claim 1, wherein a part or the whole of the shield electrode and the insulating portion is covered with an insulating material. 3. The high-frequency discharge device according to claim 1, further comprising means for heating and cooling the vacuum vessel outside the vacuum vessel. 4. A vacuum vessel having an at least partially insulating portion; an induction antenna wound around the insulating portion; and a high-frequency circuit having an impedance adjusting function connected to the induction antenna. A plasma reaction vessel comprising: a high-frequency power source; and a shielding electrode provided between the inductive antenna and the insulating portion and having a function of controlling capacitance coupling between the inductive antenna and plasma. A plasma processing method, wherein the shielding electrode is formed of a thin film and is physically adhered (fixed) to the insulating portion. 5. The plasma processing method according to claim 4, wherein a part or the whole of the shielding electrode and the insulating portion is covered with an insulating material. 6. The plasma processing method according to claim 4, further comprising means for heating / cooling the vacuum vessel outside the vacuum vessel.