WO2004006320A1

WO2004006320A1 - Plasma processing apparatus

Info

Publication number: WO2004006320A1
Application number: PCT/JP2003/008494
Authority: WO
Inventors: Tsutomu Higashiura
Original assignee: Tokyo Electron Limited
Priority date: 2002-07-03
Filing date: 2003-07-03
Publication date: 2004-01-15
Also published as: JP2004039844A; AU2003252470A1; JP4127488B2

Abstract

A simulation tube (29) has the same shape as a gas supply tube (28). The gas supply tube (28) and the simulation tube (29) are installed in an electrode housing (17) at the positions symmetrical with respect to the center point of an upper electrode (14) so that plasma generated in a vacuum chamber (11) is uniformly distributed. An upper lid (18) of the electrode housing (17) doubles as a bottom plate of a matching device (19) so that a return path of high frequency power applied to the upper electrode (14) is short.

Description

Description Plasma processing equipment Technical field

The present invention relates to a plasma processing apparatus. Background art

When performing plasma processing on a semiconductor substrate, a liquid crystal substrate, or the like, a plasma processing apparatus that performs predetermined processing using plasma is used. Examples of the plasma processing apparatus include a plasma etching apparatus for performing an etching process on a substrate, a plasma CVD apparatus for performing a CVD (Chemical Vapor Deposition) process, and the like. Among the plasma processing apparatuses, the parallel plate type plasma processing apparatus is widely used because it can perform the processing uniformly and the configuration of the apparatus is relatively simple.

The parallel plate type plasma processing apparatus is provided with a vacuum vessel (chamber) in which two electrode plates facing each other in parallel are installed vertically. One electrode plate (lower electrode) has a mounting table, and is configured to be able to mount an object to be processed. The other electrode plate (upper electrode) includes an electrode plate having a number of gas holes on a surface facing the lower electrode. The upper electrode is connected to a processing gas supply. The processing gas from the supply source is supplied to a space (plasma generation space) between the upper electrode and the lower electrode through a gas hole in the electrode plate.

The plasma of the supplied processing gas is generated by applying high frequency power to the upper electrode. The generated plasma is drawn near the lower electrode to which AC power having a frequency lower than that of the high-frequency power applied to the upper electrode is applied. The target object placed on the lower electrode is subjected to a predetermined process by the drawn plasma.

An electrode housing that supports the upper electrode is installed above the vacuum vessel. The electrode housing also functions as an outer conductor that flows when high-frequency power returns to ground. In addition, an impedance matching device is installed on the electrode housing. Electrode housing And the matching box have independent metal casings. An opening is formed in the contact surface of these metal housings, and a power supply rod is arranged in this opening. High-frequency power from the high-frequency oscillator is supplied to the upper electrode via the power supply rod. Further, inside the electrode housing, a gas supply pipe for supplying a processing gas, a refrigerant supply pipe and a refrigerant discharge pipe for flowing a refrigerant for controlling the temperature of the upper electrode through the upper electrode. And are installed.

Also, inside the electrode housing, there are a low-frequency filter for extracting the DC component from the high-frequency power and a trap circuit for virtually grounding the frequency of the power applied to the counter electrode (for example, the lower electrode). A high frequency circuit is also housed.

As described above, the plasma processing apparatus in which a plurality of structures are housed in the electrode housing has various problems as described below.

First, if there is a structure inside the electrode housing, the high-frequency electromagnetic field inside the outer conductor is disturbed. When the high-frequency electromagnetic field is disturbed, the symmetry of the generated plasma is lost. That is, the distribution of the plasma generated in the vacuum vessel becomes uneven. When the distribution of the plasma becomes non-uniform, the quality of each element formed on one object (wafer) varies.

Further, as described above, since the electrode casing and the matching box are provided with independent casings, respectively, the return path of the high-frequency power is long. If the return path of the high-frequency power is long, the impedance is high, and the loss of the high-frequency power supplied to generate plasma is large. That is, the supply amount of the high frequency power to the upper electrode is low.

In addition, when a plurality of structures are stored in the electrode housing, it is difficult to secure a place for installing a high-frequency circuit. In particular, the air-core coil constituting the high-frequency circuit has a large volume and a large size, and requires a certain space. High frequency circuits can also make it difficult to install other structures.

If the impedance is not matched, the supply of high-frequency power generates reflected waves. This reflected wave returns to the high-frequency oscillator and causes inconveniences such as an increase in voltage and an increase in loss of high-frequency power.

If the magnitude of the reflected wave exceeds the specified value, drop the high-frequency output or By temporarily stopping the output of the wave power, the high-frequency oscillator can be protected. However, in such a method, the generation of the plasma may become unstable or the plasma may disappear. This can have a significant effect on wafer quality.

The present invention has been made in view of the above conventional problems, and has as its object to provide a plasma processing apparatus capable of stably realizing a high-quality wafer.

Another object of the present invention is to provide a plasma processing apparatus capable of uniformly distributing generated plasma.

Another object of the present invention is to provide a plasma processing apparatus having a short current return path.

Another object of the present invention is to provide a plasma processing apparatus capable of easily securing a place for installing a structure in a housing that supports a plasma generation electrode. Another object of the present invention is to provide a plasma processing apparatus capable of stably generating plasma. Disclosure of the invention

In order to achieve the above object, a plasma processing apparatus according to a first aspect of the present invention comprises: a container (11) for confining plasma; and a container (11) disposed in the container (11) for generating the plasma. An electrode (14) to which power is applied, a power source (23) for supplying the power, and an inner conductor (21) for supplying the power from the power source (23) to the electrode (14) And an outer conductor (17) surrounding the inner conductor, wherein the container (11), the inner conductor (21), and the outer conductor (17) include the electrode (14). ), And has a shape symmetrical with respect to a central axis perpendicular to the electrode (14). The outer conductor (17) further includes a plurality of structures (28, 29, 30, 31) installed symmetrically with respect to the central axis, and at least one of the plurality of structures One may be a simulated structure (29) having the same shape as one of the other structures. The simulated structure (29) may be made of the same material as one of the other structures. A plasma processing apparatus according to a second aspect of the present invention includes: an electrode (14) disposed in a container (11) in which plasma is generated; and an electric power supply for generating the plasma. A power source (23); a power transmission line (71) for supplying power from the power source (23) to the electrode (14); and An electrode housing (17) supporting the (14); and an impedance matching between the electrode (14) and the transmission line (71), which is installed on the electrode housing (17). And a matching device (1 9), wherein the electrode housing (17) includes a ceiling plate (18), and the ceiling plate (18) includes the matching device. (17) It also serves as a floor plate. A plasma processing apparatus according to a third aspect of the present invention includes a container (11) in which plasma is generated, an electrode (14) to which power for generating the plasma is supplied, and an electrode (14). A power source (23) for supplying the power to the electrode (14), a processing circuit (50) for performing a predetermined process on the power supplied to the electrode (14), and a pipe through which gas flows. (28) In the plasma processing apparatus comprising: the tube (28) is formed in a coil shape, one end of which is electrically connected to the electrode (14); A part thereof. The pipe (28) may be a gas supply pipe for supplying a processing gas from outside to inside of the container (11). The processing circuit (50) may be a filter circuit, and the tube (28) may be used as a coil element constituting the filter circuit. The processing circuit (50) is a trap circuit, and the pipe (28) is a trap circuit. It may be used as a coil constituting a flip-flop circuit. A housing (17) installed on the container (11) and supporting the electrode (28) may be further provided, and the processing circuit (50) may be installed in the housing (17). . A plasma processing apparatus according to a fourth aspect of the present invention includes: an electrode (14) provided in a container (11) in which plasma is generated; and a power source ( 23), a transmission line (21) for supplying power from the power source (23) to the electrode (14), and impedance matching between the electrode (14) and the transmission line (21). A plasma processing apparatus comprising: a matching device (19) for performing the following; and a preventer (61) for preventing a reflected wave generated by the supply of the power from being transmitted to the power source (23). Features. The preventer (61) is constituted by a circulator having a plurality of input / output ports, one of the plurality of input / output ports is grounded, and the circulator is configured to transfer the reflected wave to ground. May be sent. The preventer (61) may control the amount of the reflected wave sent to the ground according to the intensity of the reflected wave. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a partial cross-sectional view illustrating a configuration of a plasma CVD apparatus according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the inside of the electrode housing and the like in FIG.

FIG. 3 is a plan view showing the inside of the electrode housing.

FIG. 4 is a cross-sectional view showing the inside of an electrode housing and the like of the plasma CVD device according to the second embodiment.

FIG. 5 is an enlarged sectional view of FIG. FIG. 6 is a cross-sectional view showing the inside of an electrode housing and the like of a conventional plasma CVD apparatus. FIG. 7 is an enlarged sectional view of FIG.

FIG. 8 is a cross-sectional view showing the inside of the electrode housing of the plasma CVD device according to the third embodiment.

FIG. 9A is a diagram showing a specific configuration of a high-frequency circuit installed in the electrode housing shown in FIG. FIG. 9B is an equivalent circuit of the high-frequency circuit shown in FIG. 9A.

FIG. 10 is an explanatory diagram illustrating a configuration of a plasma CVD apparatus according to the fourth embodiment. .

FIG. 11 is an explanatory diagram showing a configuration of a conventional plasma CVD apparatus. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a plasma processing apparatus according to an embodiment of the present invention will be described with reference to the drawings. Hereinafter, a plasma CVD (Chemical Vapor Deposition) apparatus will be described as an example of the plasma processing apparatus.

(First Embodiment)

The plasma CVD apparatus according to the first embodiment has a configuration in which a high-frequency electromagnetic field inside an electrode housing supporting an upper electrode is not disturbed by a structure installed in the electrode housing.

FIG. 1 shows a configuration of a plasma CVD apparatus 1 according to the first embodiment.

A plasma CVD apparatus 1 according to the first embodiment is a so-called parallel plate type plasma processing apparatus having vertically and vertically opposed electrodes, and is a semiconductor wafer (hereinafter, referred to as a “wafer”) as an object to be processed. ) A Si〇F film or the like is formed on the surface of.

The plasma CVD apparatus 1 includes a vacuum vessel (chamber) 11 and a pump 12. '

As the pump 12, a turbo molecular pump or the like is used. The pump 12 exhausts the gas in the vacuum vessel 11 to generate a predetermined reduced-pressure atmosphere in the vacuum vessel 11. Specifically, the pump 12 sets the pressure in the vacuum vessel 11 to a predetermined pressure of, for example, 0.01 Pa or less.

On one side, a shutter 13 is provided. Inside the vacuum vessel 11, an upper electrode 14 and a lower electrode 15 are arranged. The lower electrode 15 is made of a conductor having a high melting point, such as molybdenum. The wafer is placed on the lower electrode 15 via an insulating material or the like (not shown). Below the lower electrode 15, a heater (not shown) composed of, for example, a nichrome wire is arranged. Further, a flow path (not shown) through which a refrigerant for controlling the temperature of the lower electrode 15 flows is provided in the lower electrode 15.

The upper electrode 14 is disposed so as to face the lower electrode 15 in parallel, and is supported by the columnar electrode housing 17 via the insulating material 16. An upper lid 18 is placed on the electrode housing 17. The electrode housing 17 also functions as an outer conductor for returning the high-frequency power applied to the upper electrode 14 to the ground.

The plasma CVD device 1 employs a two-frequency excitation method. That is, the plasma C VD device 1 includes a high-frequency oscillator 23 for supplying high-frequency power to the upper electrode 14 and a high-frequency oscillator 24 for supplying high-frequency power to the lower electrode 15. .

The high-frequency oscillator 23 is a device that outputs high-frequency power of 13 to 150 MHz. The high-frequency power output from the high-frequency oscillator 23 generates a high-frequency electric field between the upper electrode 14 and the lower electrode 15 and is used for generating plasma of the processing gas.

The high-frequency oscillator 24 is a device that outputs high-frequency power of 0.1 to 13 MHz. The high-frequency power output from the high-frequency transmitting device 24 is used to draw ions in the plasma to the vicinity of the lower electrode 15 and control the ion energy near the wafer surface.

The high-frequency oscillators 23 and 24 are connected to the ground of the plasma CVD device 1. However, the ground of the plasma CVD apparatus 1 can be connected to the earth ground. Matching devices 19 and 20 are arranged on the upper lid 18 and on the side of the vacuum vessel 11, respectively. The matching devices 19 and 20 prevent the generation of standing waves due to reflected waves by performing impedance matching between the electrodes 14 and 15 and the transmission lines 71 and 72. The upper cover 18 has an opening 18a, and the power supply rod 21 is arranged in the opening 18a. In addition, a power supply rod 22 is also provided between the lower electrode 15 and the matching box 20. Feeding rod 21 and 22 are inner conductors for supplying high-frequency power to the upper electrode 14 and the lower electrode 15, respectively.

The matching devices 1 and 9 include a matching circuit 25 as shown in FIG. Note that the matching device 20 also has a similar matching circuit built therein. In the matching device 19, a connecting portion 26 for electrically connecting the power supply rod 21 and the matching circuit 25 is provided. One end of the power supply rod 21 is connected to the matching circuit 25 via the connection part 26, and the other end is connected to the upper electrode 14. Thus, the high-frequency power from the high-frequency oscillator 23 is supplied to the upper electrode 14 via the matching circuit 25 and the power supply rod 21. The casing of the matching box 19 also functions as an outer conductor for returning the high-frequency power applied to the upper electrode 14 to the ground.

A flow path (not shown) through which a refrigerant for controlling the temperature of the upper electrode 14 flows is provided in the upper electrode 14. Further, a hollow portion (not shown) for diffusing the processing gas is formed inside the upper electrode 14. Further, an electrode plate 27 made of aluminum or the like is provided on a surface facing the lower electrode 15 of the upper electrode 14. The electrode plate 27 has a plurality of gas holes 27 a connected to the hollow portion of the upper electrode 14.

Inside the electrode housing 17, a gas supply pipe 28 and a simulation pipe 2.9 are provided. The gas supply pipe 28 is provided to supply a processing gas from an external processing gas supply source (not shown) to the hollow portion of the upper electrode 14.

The processing gas from the processing gas supply source is supplied to the hollow portion of the upper electrode 14 via the gas supply pipe 28, diffused in the hollow portion, and discharged from the gas hole 27a toward the wafer. Various gases can be used as the processing gas. For example, in the case of performing film formation of S i OF film, using _{S i F 4, S i H} 4, 0 2, NF 3, NH 3 gas and A r gas as a diluent gas conventionally used be able to.

The simulation tube 29 is provided for uniformly distributing the plasma, has the same shape as the gas supply tube 28, and is formed of the same material. However, the processing gas does not pass through the mock tube 29.

FIG. 3 is a diagram showing a state in which the matching device 19, the matching circuit 25, and the connection portion 26 are removed, and the inside of the electrode housing .17 is viewed from above. As shown in Fig. 3, the electrode housing 17 In addition to the gas supply pipe 28 and the simulation pipe 29, a refrigerant supply pipe 30 and a refrigerant discharge pipe 31 are installed inside.

The refrigerant supply pipe 30 is a pipe for sending the refrigerant for controlling the temperature of the upper electrode 14 into the upper electrode 14, and the refrigerant discharge pipe 31 is for discharging the refrigerant in the upper electrode 14. Tube. The refrigerant supply pipe 30 and the refrigerant discharge pipe 31 have the same shape and are formed of the same material.

As shown in FIG. 3, the gas supply pipe 28, the simulation pipe 29, the refrigerant supply pipe 30, and the refrigerant discharge pipe 31 are arranged symmetrically with respect to the center point O. The center point O passes through the center of the upper electrode 14 and is on the center axis of symmetry perpendicular to the upper electrode 14. In the present embodiment, the center axis of symmetry passes through the centers of the vacuum vessel 11, the upper electrode 14, and the lower electrode 15.

The structures inside the electrode housing 17 (gas supply pipe 28, simulation pipe 29, refrigerant supply pipe 30 and refrigerant discharge pipe 31) are subjected to the same surface treatment and are fixed by the same fixing method. is set up.

Furthermore, the high-frequency circuits and the like arranged in the electrode housing 17 are also arranged symmetrically with respect to the center point O (the center axis of symmetry). In addition, the vacuum vessel 11, the electrode housing 17, the top lid 18, the matching box 19, and the power supply rod 21 are also symmetrical with respect to the center point O (symmetric center axis), for example, a circle. It is formed in a column shape.

As described above, all the structures built in the vacuum vessel 11, the electrode housing 17, the top lid 18, the matching box 19, and the electrode housing 17 are located at the center point O (the center axis of symmetry). ) Is configured to be symmetric about.

Next, the operation of the plasma CVD apparatus 1 according to the first embodiment will be described.

When the wafer is placed on the lower electrode 15, the wafer is electrostatically attracted by a high-temperature electrostatic chuck (not shown). Next, the shutter 13 is closed, and the gas in the vacuum vessel 11 is exhausted by the pump 12. As a result, the inside of the vacuum vessel 11 is set to a predetermined high vacuum state (for example, 0.1Pa).

In this state, the refrigerant flows through the flow path provided in the lower electrode 15, and the temperature of the lower electrode 15 is controlled to, for example, 50 ° C.

After that, the processing gas and diluent gas (carry The gas is supplied at a predetermined flow rate via the gas supply pipe 28. Process gas, for example, _{S i F 4, S i H} 4, 0 2, NF 3, NH 3 gas, diluent gas, for example, A r gas.

The supplied processing gas is supplied into the vacuum vessel 11 via the hollow portion in the upper electrode 14 and the gas hole 27 a of the electrode plate 27. At this time, the processing gas and the carrier gas are uniformly discharged from the gas holes 27a of the electrode plate 27 toward the wafer.

Thereafter, the high-frequency oscillator 23 applies high-frequency power to the upper electrode 14 via the matching box 19 and the power supply rod 21. As a result, a high-frequency electric field is generated between the upper electrode 14 and the lower electrode 15, and plasma of the supplied processing gas is generated.

On the other hand, the high-frequency oscillator 24 applies high-frequency power to the lower electrode 15 via the matching box 20 and the feed rod 22. As a result, ions in the plasma are drawn into the vicinity of the lower electrode 15, and the ion energy near the wafer surface is controlled.

The application of the high-frequency power to the upper and lower electrodes 14 and 15 generates a plasma of the processing gas, and a chemical reaction on the wafer surface generated by the plasma causes a Si OF film on the surface of the wafer. Is formed.

The current generated by the high-frequency power from the high-frequency oscillator 23 flows through the inner wall of the electrode housing 17 and the inner wall of the matching device 19 to the ground of the high-frequency oscillator 23. If the current return path is asymmetric with respect to the central axis of symmetry, the distribution of plasma generated in the vacuum vessel 11 will also be uneven. That is, the plasma is unevenly distributed.

However, as described above, the vacuum vessel 11, the electrode housing 17, the top lid 18, the matching box 19, and all the structures built into the electrode housing 17 have the center point O (symmetrical (Center axis). As a result, the generated plasma is not biased to one place and is uniformly distributed in the vacuum vessel 11 around the center axis of symmetry. As described above, according to the present embodiment, a simulation tube 29 having the same shape and the same material as the gas supply tube 28 is provided inside the electrode housing 17. Are arranged symmetrically about the center point O. Therefore, the plasma generated in the vacuum container 11 can be distributed uniformly. As a result, the quality is uniform among a plurality of chips formed on the wafer.

In this embodiment, the case where only one simulation tube 29 is provided is shown. But, The number of the simulation tubes 29 is not limited to one, and can be changed according to the number of structures in the electrode housing 17.

Further, the simulation tube 29 need not be provided. In this case, the gas supply pipe 28, the refrigerant supply pipe 30 and the refrigerant discharge pipe 31 are made of the same shape and the same material, respectively, and are symmetric with respect to the center point O. It may be arranged in three directions so that

(Second embodiment)

The plasma CVD device 1 according to the second embodiment is configured such that the feedback path of the high-frequency power applied to the upper electrodes 1.4 is short in order to suppress power loss.

FIG. 4 shows the configuration of a plasma CVD apparatus 1. according to the second embodiment.

The plasma CVD device 1 according to the second embodiment includes a matching device conventionally existing.

There is no bottom plate 19, and the top cover 18 of the electrode housing 17 also serves as the bottom plate of the matching box 19. As shown in FIG. 5, a groove 17b is formed in an end face 17a in close contact with the upper lid 18 of the electrode housing 17. A gasket 42 having elasticity and preventing high-frequency leakage is disposed in the groove 17b. When the electrode housing 17 and the upper lid 18 are fastened by screws or the like, the gasket 42 is deformed, and the gap between the electrode housing 17 and the matching box 19 is closed.

Also, a groove 18c is formed on an end face 18b of the upper cover 18 which is in close contact with the matching device 19. A gasket 43 having elasticity and preventing high-frequency leakage is arranged in the groove 18c. Then, when the upper cover 18 and the matching box 19 are fastened with screws or the like, the gasket 43 is deformed, and the gap between the top cover 18 and the matching box 19 is closed.

As described above, the insides of the electrode housing 17 and the matching box 19 are sealed. The high-frequency power applied to the upper electrode 14 passes through the electrode housing 17, the top cover 18, and the inner wall of the matching box 19, as indicated by an arrow 75 in FIG. Return to device 23.

In the conventional plasma CVD apparatus, as shown in FIG. 6, the bottom plate 41 of the matching box 19 is provided separately from the top cover 18 of the electrode housing 17. For this reason, in the conventional plasma CVD apparatus, as shown by an arrow 76 in FIG. After passing through the electrode housing 17 and the upper lid 18, the power returns to the high-frequency oscillator 23 via the bottom plate 41 of the matching box 19. As described above, in the conventional plasma CVD apparatus, the return path of the high frequency power is long.

However, in plasma CVD apparatus 1 according to the present embodiment, there is no bottom plate of matching box 19, and upper lid 18 also serves as the bottom plate of matching box 19. For this reason, the return path of the high-frequency power is shorter than the conventional one. If the high-frequency power return path is short, the impedance is small, and as a result, the loss of high-frequency power can be kept low. Therefore, the operation of the plasma CVD device 1 is stabilized.

(Third embodiment)

In the plasma CVD apparatus 1 according to the third embodiment, a gas supply pipe 28, which is one of the structures, is provided in order to easily secure an installation place of the structure to be installed inside the electrode housing 17. This is used as a coil element.

As shown in FIG. 8, a high-frequency circuit 50 is provided inside the electrode housing 17. As described below, the gas supply pipe 28 as a coil element forms a high-frequency circuit 50.

In the third embodiment, the high-frequency voltage supplied by the high-frequency oscillator 23 is added to the direct-current voltage and supplied to the upper electrode 14.

As shown in FIG. 9A, one end of the gas supply pipe 28 is connected to the upper electrode 14, and the other end is connected to the electrode housing 17 via the dielectric 51. The gas supply pipe 28 is made of metal (conductor) and is wound in a coil shape. Dielectric 51 disconnects gas supply tube 28 from ground potential. The gas supply pipe 28 and the dielectric 51 constitute a low-pass filter that is a high-frequency circuit 50.

The dielectric 51 is formed, for example, in a ring shape so that gas can flow. Further, instead of the gas supply pipe 28, the above-described refrigerant supply pipe 30 or the refrigerant discharge pipe 31 may be wound in a coil shape and used as a coil element.

The other end of the gas supply pipe 28 is connected to a covered wire 52 made of an insulating material. The covered wire 52 extends to the outside of the electrode housing 17 and is connected to an external DC detection circuit. In addition, polytetrafluoroethylene or the like is used for the covering material of the covered wire 52. An insulating material 53 is inserted between the covered wire 52 and the electrode housing 17. I have. The insulating material 53 supports the covered wire 52 and seals the inside of the electrode housing 17. Figure 9B shows the equivalent circuit.

The gas supply pipe 28 and the dielectric 51 act as an inductance and a capacitor, respectively, and constitute a low-pass filter. This low-pass filter is formed on the upper electrode 14. When high-frequency power is supplied from the high-frequency oscillator 23 to the upper electrode 14, the DC component of the high-frequency power passes through the low-pass filter and is output to the DC detection circuit via the covered wire 52.

As described above, since the gas supply pipe 28 also serves as a coil element having a large volume and a large dimension, the space inside the electrode housing 17 can be saved. Thereby, the installation place of the high-frequency circuit 50 and the above-mentioned plurality of structures can be easily secured in the electrode housing 17.

The gas supply pipe 28 described above can be used not only for a low-pass filter, but also for various high-frequency circuits (for example, a trap circuit) for performing a predetermined process on the high-frequency power supplied to the upper electrode 14.

(Fourth embodiment)

The plasma CVD device 1 according to the fourth embodiment includes a high-frequency oscillator 23 and a matching device so that the operation of the high-frequency oscillator 23 does not become unstable due to reflected waves generated by the supply of high-frequency power. A circulator (Circulator) is interposed between 1 and 19.

FIG. 10 shows a configuration of a plasma CVD apparatus 1 according to the fourth embodiment.

In the plasma CVD device 1 according to the fourth embodiment, a circulator 61 is interposed between the high-frequency oscillator 23 and the matching device 19.

The circulator 61 has three input / output ports, one of which is grounded via the dummy load 62. One of the remaining two is connected to the high-frequency oscillator 23, and the other is connected to the matching box 19 via the effective value monitor 63.

The circulator 61 has a characteristic that an input from a certain input / output port is output to a certain specific port. The circulator 61 incorporates a ferrite element and the like. The circulator 61 applies a magnetic field to this ferrite element. As a result, it has such characteristics.

Due to this characteristic, the circulator 61 supplies the incident wave supplied from the high-frequency oscillator 23 to the matching unit 19 via the effective value monitor 63, and the reflected wave supplied from the effective value monitor 63 to Dispatch to ground via pseudo load 62. The circulator 61 changes the amount of the reflected wave sent to the ground according to the intensity of the reflected wave. Further, the effective value monitor 63 detects the difference between the incident wave and the reflected wave, and supplies a monitor signal indicating the detection result to the high-frequency oscillator 23. The high-frequency oscillator 23 controls the supplied high-frequency power based on the detection result indicated by the monitor signal supplied from the effective value monitor 63 so that the difference between the incident wave and the reflected wave is constant.

Note that a similar circulator may be inserted between the high-frequency oscillator 24 and the matching device 20.

Next, the operation of the plasma CVD apparatus 1 according to the fourth embodiment will be described.

The incident wave from the high-frequency oscillator 23 is input to the circulator 61. The circulator 61 outputs the incident wave to the matching unit 19 via the effective value monitor 63. When impedance matching is not established between the load 64 of the upper electrode 14 and the transmission line, a reflected wave is transmitted from the matching device 19 to the high-frequency oscillator 23.

As shown in Fig. 11, when circuit circulator 61 is not installed, matching box 1

The reflected wave from 9 is transmitted to the high-frequency oscillator 23 and has a great effect on the high-frequency oscillator 23.

However, when the circulator 61 is provided between the high-frequency oscillator 23 and the matching box 19 as shown in FIG. 10, the reflected wave from the matching box 19 is input to the circuit And separated from the incident wave. The circulator 61 sends the reflected wave from the matching box 19 to the installation via the pseudo load 62.

At this time, the effective value monitor 63 detects the difference between the incident wave and the reflected wave, and outputs a monitor signal indicating the detection result to the high-frequency oscillator 23. The high-frequency oscillator 23 controls the supplied high-frequency power based on the detection result (difference) represented by the monitor signal from the effective value monitor 63 so that the difference between the incident wave and the reflected wave is constant.

As described above, by installing the circulator 61 between the high-frequency oscillator 23 and the matching box 19, the high-frequency oscillator 23 can be easily protected from reflected waves. You. Therefore, the stable operation of the high-frequency oscillator 23 can be maintained without dripping the high-frequency power supplied by the high-frequency oscillator 23 or temporarily stopping the supply of the high-frequency power. Can be. As a result, plasma can be generated stably, and the quality of the wafer can be maintained.

By keeping the magnitude of the incident wave transmitted to the load 64 constant, the effective value monitor 63 can be omitted.

Various embodiments are conceivable for carrying out the present invention, and the present invention is not limited to the above embodiments.

For example, the object to be processed is not limited to a semiconductor wafer, but may be a liquid crystal display device or the like. Further, the film formed on the target object _{is, S i 0 2, S i} N, S i C, S i COH, may be of any type CF film.

Further, the present invention can be applied not only to the film forming process but also to the case of performing an etching process or the like. Furthermore, not only a parallel plate type plasma processing apparatus but also any type of plasma processing apparatus having an electrode in a lance, such as a magnet type, can be applied.

Further, the plasma processing apparatus can be configured by appropriately combining the first to fourth embodiments.

The present invention is based on Japanese Patent Application No. 2002-1944431 filed on July 3, 2002, and its description, claims, and drawings are as follows.含む Includes summary. The disclosure in the above application is incorporated herein by reference in its entirety. Industrial potential

INDUSTRIAL APPLICATION This invention can be utilized for the industrial field which uses a plasma processing apparatus.

Claims

The scope of the claims

1. A container (11) for confining plasma, an electrode (14) arranged in the container (11) and to which power for generating the plasma is applied, and power for supplying the power A source (23), an inner conductor (21) for supplying the power from the power source (23) to the electrode (14), and an outer conductor (17) surrounding the inner conductor. Equipped with a plasma processing device,

The container (11), the inner conductor (21), and the outer conductor (17) pass through the center of the electrode (14) and are symmetric with respect to a central axis perpendicular to the electrode (14). Having a shape,

A plasma processing apparatus characterized by the above-mentioned.

2. A plurality of structures (28, 29, 30, 31) installed symmetrically with respect to the central axis in the outer conductor (17),

At least one of the plurality of structures is a simulated structure (29) having the same shape as one of the other structures.

2. The plasma processing apparatus according to claim 1, wherein:

3. The plasma processing apparatus according to claim 2, wherein the simulated structure (29) is made of the same material as one of the other structures.

4. An electrode (14) arranged in a container (11) in which plasma is generated, a power source (23) for supplying power for generating the plasma, and the power source (23) A power transmission line (71) for supplying electric power from the electrode (14) to the electrode (14); and an electrode housing (17) installed on the container (11) for supporting the electrode (14). A matching device (19) that is installed on the electrode housing (17) and that performs impedance matching between the electrode (14) and the transmission line (71). And

The electrode housing (17) includes a ceiling plate (18),

The ceiling plate (18) also serves as a floor plate of the matching device (17), A plasma processing apparatus characterized by the above-mentioned.

5. A container (11) in which plasma is generated, an electrode (14) to which power for generating the plasma is supplied, and a power source (23) for supplying the power to the electrode (14). ), A processing circuit (50) for performing predetermined processing on the electric power supplied to the electrode (14), and a pipe (28) through which gas flows.

The tube (28) is formed in a coil shape, one end of which is electrically connected to the electrode (14), and constitutes a part of the processing circuit (50).

A plasma processing apparatus characterized by the above-mentioned.

6. The plasma processing apparatus according to claim 5, wherein the pipe (28) is a gas supply pipe for supplying a processing gas from outside to inside of the container (11).

7. The processing circuit (50) is a filter circuit,

The plasma processing apparatus according to claim 6, wherein the tube (28) is used as a coil element constituting the filter circuit.

8. further comprising a housing (17) installed on the container (11) and supporting the electrode (14);

The processing circuit is installed in the housing;

8. The plasma processing apparatus according to claim 7, wherein:

9. The processing circuit (50) is a trap circuit,

The plasma processing apparatus according to claim 6, wherein the tube (28) is used as a coil constituting the trap circuit.

10. A housing (17) installed on the container (11) and supporting the electrode (28), The processing circuit (50) is installed in the housing (17);

10. The plasma processing apparatus according to claim 9, wherein:

1 1. An electrode (14) installed in a vessel (1 1) in which plasma is generated, a power source (23) for supplying power for generating the plasma, and the power source (2

3) A transmission line (21) for supplying the electric power from the electrode (14) to the electrode (14), and a matching device (19) for performing impedance matching between the electrode (14) and the transmission line (21). And a plasma processing apparatus comprising:

A power source (23) for preventing a reflected wave generated by the power supply from being transmitted to the power source (23);

A plasma processing apparatus characterized by the above-mentioned.

12. The preventer (61) comprises a circulator having a plurality of input / output ports,

One of the plurality of input / output ports is grounded;

The circulator transmits the reflected wave to the ground,

The plasma processing apparatus according to claim 11, wherein:

13. The plasma processing apparatus according to claim 12, wherein the preventer (61) controls an amount of the reflected wave sent to the ground according to an intensity of the reflected wave.