JP2002359232A - Plasma treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma treatment apparatus that uses a counter electrode which is divided into a plurality of portions for detecting the distribution state of plasma in a treatment vessel, and at the same time, can arrange each of divided counter electrodes at optimum position according to the state of the detected plasma. SOLUTION: The plasma treatment apparatus has a placement electrode 5 where a substrate G is placed, a counter electrode 4 that is provided opposite to the placement electrode 5 and is divided into a plurality of segment electrodes 31, a driving means for separately driving each of the segment electrodes 31 to adjust the clearance to the placement electrode 5, a detection means for individually detecting the parameter used as the index of the state of plasma near each segment electrode 31, and a control means for controlling the clearance between each segment electrode 31 and the placement electrode 5 to carry out appropriate plasma treatment, by outputting a control signal to the driving means based on the detected value of the detection means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a plasma processing apparatus.

[0002]

2. Description of the Related Art In a process of manufacturing an LCD substrate, a plasma processing apparatus for performing a predetermined process such as etching and CVD film formation using a plasma on a glass substrate (hereinafter simply referred to as a substrate) to be processed is used. Have been. In such a plasma processing apparatus, for example, a substrate is mounted on a mounting electrode provided in a vacuum processing container, and between the mounting electrode and an opposing segment electrode provided opposite thereto. High-frequency power is applied to generate plasma in the chamber, and a predetermined plasma process is performed on the substrate surface by the plasma.

In the above-mentioned plasma processing, it is important to make the state of plasma in the processing chamber uniform in order to perform processing with high in-plane uniformity on the substrate. However, particularly when processing a substrate having a large area, the plasma state in the processing container is hardly uniform due to the influence of the structure of the processing container, the flow of the process gas, the pressure, and the like. It is also known that the uniformity of the state of plasma changes depending on the material, pattern, and type of process gas of the substrate.

[0004] In order to process the substrate with high in-plane uniformity by making the plasma state uniform, for example, Japanese Patent Application Laid-Open No. Sho 55-720.
Japanese Patent Publication No. 39 discloses a technique in which a counter electrode is divided into a plurality of pieces, and the voltage, power, time, and the like of the high-frequency power applied to each of the divided counter electrodes are controlled. Japanese Patent Application Laid-Open No. 57-23227 discloses a technique in which a counter electrode is divided into a plurality of pieces in the same manner as described above, and the distance between the divided counter electrode and the mounting electrode is controlled. However, none of these techniques can detect the distribution state of the plasma in the processing chamber,
It is not possible to optimize the state of the plasma by controlling the position or the like of the counter electrode divided in real time.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to optimize plasma processing in real time when performing plasma processing using a plurality of opposed electrodes. It is an object of the present invention to provide a plasma processing apparatus capable of performing the above.

[0006]

According to a first aspect of the present invention, there is provided a processing container for accommodating a substrate to be processed, and a processing container provided in the processing container and having the substrate mounted thereon. A mounting electrode, a counter electrode provided to face the mounting electrode, and divided into a plurality of segment electrodes, and a processing gas for performing plasma processing on the substrate to be processed in the processing container. A gas supply means for supplying, a high-frequency power supply for supplying high-frequency power between the mounting electrode and the counter electrode for converting the processing gas into plasma, and individually driving each of the plurality of segment electrodes Driving means for adjusting the distance from the mounting electrode, and individually detecting a parameter serving as an index of the state of plasma in the vicinity of each segment electrode in a state where plasma is formed in the processing container. A detection unit, and a control unit that outputs a control signal to the driving unit based on a detection value of the detection unit, and controls a distance between each of the segment electrodes and the placement electrode to perform appropriate plasma processing. And a plasma processing apparatus provided with:

[0007] In the first aspect of the present invention, the opposing electrode is divided into a plurality of segment electrodes, and each of the segment electrodes is individually driven. Are individually detected, and based on the detected values, the intervals between the segment electrodes and the placement electrodes are controlled in real time so that appropriate plasma processing is performed. Therefore, it is possible to always optimize the plasma state in the processing container during the plasma processing and to perform the optimum plasma processing with high uniformity on the substrate to be processed.

In the above configuration, it is preferable that the parameter serving as an index of the state of the plasma is current, and the detecting means detects a current value flowing into each of the segment electrodes. Further, the control means can control an interval between each of the segment electrodes and the placement electrode so that a detection value of the detection means becomes a predetermined value set in advance. Further, the control means can control the distance between each of the segment electrodes and the placement electrode so that the detection values of the detection means become equal.

According to a second aspect of the present invention, a processing container for accommodating a substrate to be processed, a mounting electrode provided in the processing container, on which the substrate to be processed is mounted, and a mounting electrode facing the mounting electrode. Provided, a counter electrode divided into a plurality of segment electrodes, and gas supply means for supplying a processing gas for performing plasma processing on the substrate to be processed in the processing container,
A high-frequency power supply for supplying high-frequency power between the mounting electrode and the counter electrode for converting the processing gas into plasma, and a high-frequency power supply provided for each of the segment electrodes, and the segment electrode and the mounting electrode And a plurality of driving means for adjusting the interval between, and provided corresponding to each of the segment electrodes, detects the current flowing into the segment electrode, utilizing at least a part of the current flowing into the segment electrode A plasma processing apparatus is provided, comprising: a control unit that controls the driving unit and adjusts an interval between the segment electrode and the placement electrode so that appropriate plasma processing is performed.

In the second aspect of the present invention, the first aspect
In the same manner as described above, the counter electrode is divided into a plurality of segment electrodes, each of the segment electrodes is individually driven, the current flowing into each segment electrode is detected, and at least a part of the current is used. By controlling the driving means in real time, the distance between the segment electrode and the placement electrode is adjusted so that appropriate plasma processing is performed. Therefore, it is possible to always optimize the plasma state in the processing container during the plasma processing and to perform the optimum plasma processing with high uniformity on the substrate to be processed. In this case, since the driving means is controlled by using the current flowing into the segment electrodes, a complicated control system is not required, and the device configuration can be simplified.

In any of the first and second aspects, the high-frequency power supply may supply high-frequency power to the mounting electrode or supply high-frequency power to the counter electrode. Is also good. Further, the driving unit may be configured to include any of a coil for raising and lowering each of the segment electrodes, a permanent magnet, a piezoelectric element, and a motor.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, the first of the present invention
An embodiment will be described. FIG. 1 is a schematic sectional view showing a plasma etching apparatus according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA of FIG. This plasma etching apparatus performs reactive ion etching (RIE) on a glass substrate G (hereinafter simply referred to as a substrate G) as a substrate to be processed using plasma of a predetermined processing gas.

As shown in FIG. 1, this plasma etching apparatus 1 is provided, for example, in a prismatic chamber 2 made of aluminum whose surface is anodized (anodically oxidized), and provided above the chamber 2. It has a lid 3 grounded. A fixed wall 39 made of a grounded conductor is supported by the lid 3. The top wall of the chamber 2 is constituted by the lid 3 and the fixed wall 39. Inside the chamber 2, an insulating member 6 is provided on a support 7 erected from the bottom wall of the chamber 2, and a glass substrate G (hereinafter, referred to as a substrate G) is provided on the insulating member 6. A mounting electrode 5 having substantially the same shape is provided, and the substrate G can be mounted on the mounting electrode 5. This mounting electrode 5 is connected, for example, to the
A high-frequency power supply 9 having a frequency of 3.56 MHz is connected, and power is supplied from the high-frequency power supply 9 to the mounting electrode 5, so that plasma is formed between the mounting electrode 5 and a counter electrode 4 described later. It has become.

The counter electrode 4 is provided at a position facing the mounting electrode 5 so as to be supported below the lid 3. The counter electrode 4 is divided into a total of 16 segment electrodes 31 in 4 rows × 4 columns, and 16 segment electrode units 15 including the respective segment electrodes 31 are configured. FIG. 3 shows the segment electrode unit 15.
FIG. The segment electrode unit 15 is provided below the fixed wall 39. The segment electrode 31 is provided below the fixed wall 39. The segment electrode 31 includes a processing gas outlet 32 and a processing gas inlet 3.
3 and has a showerhead structure. The processing gas supply port 16 of the segment electrode 31 is connected to the processing gas supply device 16 via the gas line 18. The processing gas supply device 16 supplies the processing gas to the processing gas discharge port 32. The processing gas is supplied into the chamber 2 from the inside.

The segment electrode 31 is fixed to the fixed wall 3 via an annular insulating member 34, a lower ring member 36, a bellows 37 which elastically expands and contracts, and an upper ring member 38.
9. The bellows 37 is configured to separate the inner and outer spaces, and the processing gas is supplied to the bellows 3.
7 does not enter. In the space inside the bellows 37, a permanent magnet 41 is attached to the lower surface of the fixed wall 39 via a support member 40.
A coil 42 configured to surround the permanent magnet 41 is attached to the upper surface of the segment electrode 31 via an insulating member 35. Therefore, it is possible to move the segment electrode 31 up and down by applying an electromagnetic force to the permanent magnet 41 by energizing the coil 42,
2 by adjusting the electromagnetic force of the segment electrode 31.
Height can be controlled. Reference numeral 44 denotes the coil 4
2 shows a second control box.

Further, the side wall of the chamber 2 has an opening 12, and a gate valve 13 is provided at a position corresponding to the opening 12 outside the chamber 2, and the substrate G is opened with the gate valve 13 opened. Is transported between an adjacent load lock chamber (not shown) and the inside of the chamber 2.

An exhaust pipe 1 is provided on the bottom wall of the chamber 2.
The exhaust pipe 10 is connected to an exhaust device 11 including a vacuum pump. This exhaust device 11
By operating, the inside of the chamber 2 can be maintained at a predetermined degree of vacuum.

FIG. 4 is a block diagram schematically showing a method of controlling the height of the segment electrodes 31 according to the present embodiment in accordance with the configuration of the plasma etching apparatus 1. Since each segment electrode unit 15 performs the same control, only the first and sixteenth of the sixteen segment electrode units 15 are shown in FIG. The illustration of the third is omitted. As shown in FIG. 4, in the present embodiment, each of the segment electrode units 15 includes a control box 44,
1 are controlled independently of each other. That is, when power is supplied from the high-frequency power supply 9 to the mounting electrode 5 via the matching unit 8, plasma is formed between the mounting electrode 5 and the segment electrode 31, and each segment electrode 31 has a plasma in the vicinity thereof. (Mainly an electron current) flows according to the state (mainly the plasma density), and this current is detected by the detector 58a, and a low-pass filter (hereinafter referred to as LPF) 58b
And input to the electrode drive control unit 58c.
Then, the electrode drive control unit 58c outputs a predetermined control voltage to the coil 42 according to the input current, and thereby controls the height of the segment electrode 31 by adjusting the electromagnetic force of the coil 42.

In order to control the height of the segment electrodes 31 as described above, in the present embodiment, each segment electrode unit 15 has its input side connected to the segment electrode 31 and its output side connected to the coil 42. A control box 44 is provided. FIG. 5 is a circuit diagram for explaining an example of a circuit formed by the control box 44, the segment electrode 31, and the coil 42. The diode bridge 45 and the capacitors 46 and 47 constitute the detector 58a, the coil 48 and the capacitor 49 constitute the LPF 58b, and the other elements constitute the electrode drive control unit 58c. Further, the detector 58a (or the detector 58a and the LPF 58b) functions as a detection unit, and the electrode drive control unit 58c functions as a control unit. The variable resistor 54 is for adjusting the gain of the electrode drive control unit 58c. If it is not possible to obtain sufficient power to drive the coil 42 with a part of the current of the segment electrode 31, an external power supply 52 is required.
When the control method shown in FIG. 8 described below is used,
Output 58x of detector 58a or output 5 of LPF 58b
8y is output outside the control box 44 as a current detection signal. Thus, in the present embodiment, with a simple configuration that does not use a complicated control system such as a processor,
The height of each segment electrode 31 can be controlled.

A capacitor 4 having the other end grounded is connected to the segment electrode 31 in parallel with the control box 44.
3 are connected. The capacitor 43 is connected to the high-frequency power supply 9
Functions as a grounding circuit.

As described above, in the present embodiment, at the time of the plasma processing, in each segment electrode unit 15, the segment electrode 31 is automatically optimized in real time by utilizing at least a part of the current flowing into the segment electrode 31. Position. That is, when the plasma density is high near any one of the segment electrode units 15 and the value of the current flowing into the segment electrode 31 is high, a high control voltage is applied to the coil 42 of the segment electrode unit 15 and 31
Is raised, whereby the distance between the segment electrode 31 and the mounting electrode 5 can be increased to lower the plasma density.

FIG. 6 is a block diagram showing another method of controlling the height of the segment electrode 31. As shown in FIG.
In this control method, in each segment electrode section, the current flowing into the segment electrode 31 is detected by the detector 96, and the offset voltage from the offset power supply 94 is added to the voltage obtained by smoothing by the LPF 97. The height of the segment electrodes 31 is controlled by supplying a voltage corresponding to the input voltage to the coil 42 from an external power supply 95 by inputting the voltage to the electrode drive control unit 98.

FIG. 7 shows the control box 4 in this case.
4 shows a circuit 4 '. Diode 82 and capacitor 8
Reference numerals 1 and 83 constitute the detector 96, the coil 84 and the capacitor 85 constitute the LPF 97, and the other elements constitute the electrode drive control unit 98. In addition, the detector 9
6 (or the detector 96 and the LPF 97) functions as a detection unit, and the current drive control unit 98 functions as a control unit. When the control method shown in FIG. 8 is used, the output 58x of the detector 96 or the output 5x of the LPF 97 is used.
8y is output outside the control box 44 'as a current detection signal.

FIG. 8 is a block diagram showing another method of controlling the height of the segment electrodes 31. In FIG. Detector 5 in FIG.
8a, LPF 58b, detector 96 of FIG. 6, or LPF
The current detection signal, which is the output of 97,
3 to the arithmetic unit 204. The current detection signal is arithmetically processed by the arithmetic unit 204. The output of the arithmetic unit 204 is amplified by the output I / F circuit 205 and becomes a coil control signal for controlling and driving the coil 42.

The input I / F circuit 203 comprises, for example, a low-pass filter and an A / D converter. When the output of the LPF 58b or the LPF 97 is used as the current detection signal, a low-pass filter is not required. Output I / F
The circuit 205 includes, for example, a D / A converter and an amplifier. The memory 206 includes a program for calculating a coil control signal based on the current detection signal, data indicating the relationship between each current detection signal, the position (height) of each segment electrode 31 and the magnitude of each coil control signal, A predetermined reference value or the like of the current detection signal at the segment electrode is stored. Operation unit 204, output I / F circuit 205, and memory 2
06 constitutes the control means. In this method, the arithmetic unit 2
Since the coil control signal is calculated using the program stored in the memory 04 and the memory 206, flexible and versatile control can be realized.

As a specific example of such a control method, for example, an average value of a current detection signal is obtained, and in the segment electrode unit 15 having a larger current detection signal than the average value, the coil 42 is strongly driven to drive the segment electrode 31. In the segment electrode unit 15 in which the current detection signal is smaller than the average value, the coil 42 is weakly driven so that the interval between the segment electrode 31 and the mounting electrode 5 is increased.
Is controlled so as to reduce the interval between the two. Also, a comparison is made between the preset value and each of the current detection signals. If the current detection signal is large, the segment electrode 31 and the mounting electrode 5 of the segment electrode unit 15 are compared.
It is also possible to perform control to increase the distance between the segment electrode 31 and the placement electrode 5 in the segment electrode unit 15 when the current detection signal is small.

The circuit / method for detecting the current is not limited to those shown in FIGS. 4 to 7, and also controls the coil, that is, the circuit / method for controlling the position (height) of the segment electrode 31. The method is not limited to those shown in FIGS. 4 to 8, and other circuits and methods can be used as appropriate. Circuits and methods for controlling the position (height) of the segment electrode 31 shown in FIGS. 4 to 8 are not limited to the first embodiment shown in FIGS. Third, the present invention can be applied to the fourth embodiment.

Next, an operation of etching the substrate G by the plasma etching apparatus 1 configured as described above will be described. First, open the gate valve 13,
The substrate G is carried from the load lock chamber (not shown) into the chamber 2 through the opening 12 and is mounted on the mounting electrode 5. In this case, the transfer of the substrate G is performed by a lifter pin (not shown) provided so as to pass through the inside of the mounting electrode 5 and protrude and retract from the mounting electrode 5. Thereafter, the gate valve 13 is closed and the chamber 2 is exhausted by the exhaust device 11.
The inside is evacuated to a predetermined degree of vacuum.

Thereafter, the processing gas is supplied from the processing gas supply device 16 through the gas line 18, and the processing gas is discharged from the processing gas discharge port 32 provided in the segment electrode 31 of each segment electrode unit 15. By supplying high-frequency power from the high-frequency power supply 9 to the mounting electrodes 5 via the matching unit 8 and the power supply line, plasma is generated between the mounting electrodes 5 and the segment electrodes 31 of the respective segment electrode units 15. On the other hand, a self-bias voltage is generated at the mounting electrode 5, whereby ions in the plasma are drawn into the substrate G, and a predetermined film formed on the substrate G is subjected to an etching process.

When performing an etching process in such a process, the plasma etching apparatus 1
Since the height of the segment electrodes 31 is controlled in each segment electrode unit 15 as described above, the current flowing into each segment electrode 31 is detected, and the segment electrodes 31 are adjusted in real time according to the detected current. And can be arranged at an optimum position. Therefore, the plasma density in the vicinity of each of the segment electrodes 31 can be optimized, whereby the plasma in the chamber 2 can always be made uniform so that the substrate G can be etched.

Next, a second embodiment of the present invention will be described. FIG. 9 is a schematic sectional view showing a plasma etching apparatus according to the second embodiment of the present invention. This plasma etching apparatus 1 'is different from the first embodiment in the configuration of the segment electrode portion, but is otherwise the same as the first embodiment. The description is omitted with numbering.

FIG. 10 is an enlarged view of the segment electrode unit 15 'in this embodiment. The segment electrode unit 15 'has a fixed wall 39 and a segment electrode 31 similar to those of the first embodiment. Further, an upper wall 62 made of a grounded conductor is provided above the fixed wall 39. The upper wall 62 and the segment electrode 31 are integrally formed by support columns 60 and 61 penetrating the fixed wall 39. Is configured. Insulating members 65 and 66 are provided at portions of the upper wall 62 that are in contact with the support columns 60 and 61, so that the fixed wall 39 and the support columns 60 and 61 do not contact each other. A gas introduction passage 68 communicating with the treatment gas introduction port 33 of the segment electrode 31 is provided in the insulating member 65 and the support column 60. The gas introduction passage 68 is connected to the treatment gas supply device 16 via the gas line 18. Is connected. The insulating member 66 is provided with a conductive pin 67 electrically connected to the support column 61 and the segment electrode 31.
7, an input side of a control box 44 accommodating a circuit configured in the same manner as in the first embodiment and one end of a capacitor 43 are connected. The bellows 63 are provided so as to cover portions of the support columns 60 and 61 above the fixed wall 39.
And 64 are provided to prevent the processing gas in the chamber 2 from leaking to the outside.

By applying a voltage between the fixed wall 39 and the upper wall 62 as described above, a maximum of 200
a piezoelectric element 72 that generates a displacement of μm;
And a pressure transducer 70 for expanding the displacement of the pressure transducer to a maximum of 10 mm. Pressure transducer 70
A large-diameter piston 74 mounted on a piezoelectric element 72 via a support member 73; a small-diameter piston 75 provided opposite the large-diameter piston 74;
A contact member 77 placed on the upper surface of the upper wall 62 via a support member 76 and abutting against the lower surface of the upper wall 62; a fluid 78 sealed between the large-diameter piston 74 and the small-diameter piston 75; And a case 71 for accommodating 72. According to such a configuration of the pressure transducer 70, the displacement of the large-diameter piston 74 is reduced by the small-diameter piston 75.
, The displacement of the piezoelectric element 72 can be enlarged to raise or lower the upper wall 62, and thus the segment electrodes 31 integrally formed with the upper wall 62 by the support columns 60 and 61 can be raised and lowered. be able to.

Therefore, by applying a control voltage obtained by the control box 44 from the current flowing into the segment electrode 31 to the piezoelectric element 72, the height of the segment electrode 31 is controlled in the same manner as in the first embodiment. be able to.

According to such a configuration, a predetermined film formed on the substrate G is subjected to etching by the same operation as in the first embodiment. At that time, in each segment electrode unit 15 ', the height of the segment electrode 31 is controlled in the same manner as in the first embodiment, so that the current flowing into each segment electrode 31 is detected and the magnitude of the detected current is increased. According to the segment electrode 3
1 can be moved up and down in real time and arranged at an optimum position. Therefore, each segment electrode 31
Plasma density in the vicinity of can be optimized,
This makes it possible to perform etching on the substrate G while keeping the plasma in the chamber 2 uniform at all times.

Next, a third embodiment of the present invention will be described. FIG. 11 is a schematic sectional view showing a plasma etching apparatus according to the third embodiment of the present invention. The plasma etching apparatus 1 ″ differs from the first embodiment in a part of the configuration of the segment electrode, but otherwise has the same structure as the first embodiment.
Since they are the same as those of the first embodiment, they are assigned the same reference numerals as those of the first embodiment, and description thereof is omitted.

FIG. 12 is an enlarged view of the segment electrode unit 15 "in the present embodiment. The segment electrode unit 15" has the same fixed wall 3 as the segment electrode unit 15 in the first embodiment.
9, a segment electrode 31 and a bellows 37.

A support frame 101 is provided above the fixed wall 39, and a stepping motor 102 is mounted on the support frame 101. A male screw is formed on the surface of the rotating shaft 103 of the stepping motor 102. On the other hand, a conductive prism 104 is provided upright on the segment electrode 31, and an insulating member 105 is attached to the top of the column 104. The insulating member 105 is provided with an opening formed with a female screw so as to mesh with the male screw of the rotating shaft 103, and the rotating shaft 103 is screwed into this opening. Further, the prism 104 penetrates through the fixed wall 39, and an insulating support member 106 is provided at a portion of the fixed wall 39 that contacts the prism 104. In such a configuration, by rotating the rotating shaft 103 of the stepping motor 102, the prism 104 and the segment electrode 31 are integrally moved up and down, whereby the height of the segment electrode 31 can be controlled. .

In the segment electrode unit 15 ″, the stepping motor 102 is driven by using the current flowing into the segment electrode 31, and the height of the segment electrode 31 is adjusted by substantially the same control as in the first embodiment. For this purpose, the above-mentioned control box 44 is provided in which the input side is connected to the segment electrode 31 and the output side is connected to the pulse generator 108. With such a configuration, the stepping motor 102 is output from the control box 44. Pulse generator 108 according to the applied voltage
Are driven by the generated pulse. Similarly to the first embodiment, a capacitor 43 having the other end grounded is connected to the segment electrode 31 in parallel with the control box 44.

On the other hand, inside the prism portion 104 of the segment electrode unit 15 ″, one end communicates with the processing gas inlet 33 of the segment electrode 31, and the other end has a side surface above the fixed wall 39 on the side of the processing gas supply device 16. Gas line 1 from
A processing gas flow path 107 communicating with the processing gas supply port 8 is provided. The processing gas is supplied from the processing gas discharge port 32 by supplying the processing gas from the processing gas supply device 16 through the gas line 18 and the processing gas flow path 107. It is designed to be ejected.

According to such a configuration, a predetermined film formed on the substrate G is subjected to etching by the same operation as in the first embodiment. At this time, since the height of the segment electrodes 31 is controlled in the same manner as in the first embodiment, the current flowing into each of the segment electrodes 31 is detected, and the segment electrodes 31 are moved in accordance with the magnitude of the detected current. It can be moved up and down in real time and placed at the optimal position. Therefore, each segment electrode 3
1, the plasma density in the vicinity of 1 can be optimized, whereby the plasma in the chamber 2 can always be made uniform and the substrate G can be etched.

Next, a fourth embodiment of the present invention will be described. FIG. 13 is a schematic sectional view showing a plasma etching apparatus according to a fourth embodiment of the present invention, and FIG. 14 is a sectional view taken along the line BB of FIG. This plasma etching apparatus 150 differs from the above-described embodiment in the configuration of the upper part of the chamber and the like, but has the same configuration as the above-described embodiment. .

As shown in FIG. 13, the plasma etching apparatus 150 according to the present embodiment comprises a box-shaped chamber 151 and a conductor.
1 has a fixed wall 152 that partitions the inside of the housing 1 up and down. A sealing member (not shown) is provided on the periphery of the fixed wall 152. With this seal member, the space below the fixed wall 152 is kept airtight. On the bottom wall of the chamber 151, a mounting electrode 189 supported by the support member 190 and grounded is provided. An annular outer electrode 153 having an opening 159 below the fixed wall 152 so as to face the mounting electrode 189, an intermediate electrode 160 provided in the opening 159 of the outer electrode 153 and having an opening 166, The central electrode 167 provided in the opening 166 of the intermediate electrode 160 is arranged. Outer circumference and opening 159 of outer electrode 153 and outer circumference and opening 16 of intermediate electrode 160
6 and the outer periphery of the center electrode 167 are both formed in a rectangular shape according to the shape of the substrate G. These outer electrodes 1
The 53, the intermediate electrode 160, and the center electrode 167 correspond to the segment electrodes 31 in the above-described first to third embodiments.
Function as a counter electrode 4 of

A plurality of (two shown in FIG. 12) support rods 156 are attached to the upper portion of the outer peripheral electrode 153 via an insulating member 154. Each of the support rods 156 penetrates the fixed wall 152 and is fixed to the fixed wall 15.
2 is connected to a support member 157 provided above the second member. The outer periphery of the support member 157 is guided by a guide 158, so that the support member 157 can move up and down while keeping a horizontal state together with the support rod 156 and the outer electrode 153. The support member 157 is provided with a shaft receiver 173 having a hole formed with a female screw. A rotary shaft 174 having a male screw is inserted into the shaft receiver 173, and the female screw of the shaft receiver 173 is connected to the shaft receiver 173. The external thread of the rotating shaft 174 is engaged. In such a configuration, the rotation of the rotation shaft 174 by the stepping motor 175 causes the support member 15 to rotate.
7, the support rod 156, and the outer peripheral electrode 153 can be integrally moved up and down. A bellows 155 is provided between the fixed wall 152 and the outer peripheral electrode 153 so as to surround the support rod 156.
55 defines a vacuum portion and a normal pressure portion. Further, the matching device 18 is provided on the outer peripheral electrode 153.
6, high-frequency power from a high-frequency power supply 187 can be supplied.

A plurality of (two shown in FIG. 12) support rods 163 are mounted on the intermediate electrode 160 via an insulating member 161. Each of the support rods 163 penetrates through the fixed wall 152 to form the fixed wall 1.
It is connected to a support member 164 provided above the 52. The outer periphery of the support member 164 is guided by a guide 165, so that the support member 164 can move up and down while keeping the horizontal state together with the support rod 163 and the intermediate electrode 160. The support member 164 is provided with a shaft receiver 176 having a hole formed with a female screw. A rotary shaft 177 having a male screw formed around the outer periphery of the shaft receiver 176 is inserted into the shaft receiver 176.
6 and a male screw of the rotary shaft 177 are engaged with each other. In such a configuration, the stepping motor 1
By rotating the rotation shaft 177 by 78, the support member 164, the support rod 163, and the intermediate electrode 160
Can be integrally moved up and down. In addition, fixed wall 1
52 and the intermediate electrode 160, the support rod 16
A bellows 162 is provided so as to surround 3, and a vacuum portion and a normal pressure portion are defined by the bellows 162. Further, the intermediate electrode 160 includes
The high frequency power from the high frequency power supply 187 can be supplied via the matching unit 186.

The central electrode 167 has one prismatic support rod 170 mounted on an upper part thereof via an insulating member 168. The support rod 170 has a hole formed with a female screw at the top. This support rod 1
The rotary shaft 1 having a male screw formed on the outer periphery of the hole 70
79 is inserted, and the female screw of the support rod 170 and the male screw of the rotating shaft 179 are engaged. In such a configuration, the rotation shaft 1 is driven by the stepping motor 180.
By rotating 79, the support rod 170,
The central electrode 167 and the central electrode 167 can be moved up and down integrally.
Further, between the fixed wall 152 and the center electrode 167,
A bellows 169 is provided so as to surround the support rod 170, and the bellows 169 partitions a vacuum portion and a normal pressure portion. Further, a high frequency power supply 187 is connected to the center electrode 167 via a matching unit 186.
Is configured to be able to supply high frequency power from

In such a configuration, by driving the stepping motors 175, 178, 180, the outer peripheral electrode 153, the intermediate electrode 160, and the central electrode 167 can be individually raised and lowered to control the height. Therefore, a control box 181 is provided on a power supply line connecting the matching box 186 and the outer peripheral electrode 153, and the matching box 1
A control box 183 is provided on a power supply line connecting the 86 and the intermediate electrode 160, and a control box 185 is provided on a power supply line connecting the matching device 186 and the center electrode 167. These control boxes 181, 183, and 185 supply the power supplied from the high-frequency power supply to the outer peripheral electrode 153, the intermediate electrode 160, and the central electrode 167, detect the current flowing into each of the electrodes, and according to the current value. The pulse generators 182, 184, and 186 generate predetermined pulses, and thereby drive the stepping motors 175, 178, and 180. Therefore,
Each of these control boxes 181, 183, 185 functions as a detection means and a control means.

A processing gas supply nozzle 188 is provided on the side wall of the chamber 151. The processing gas is supplied from the processing gas supply device 16 to the processing gas supply nozzle 188, so that the processing gas is supplied into the chamber 151. Supplied.

Next, the operation of etching the substrate G by the plasma etching apparatus 150 having the above configuration will be described. First, similarly to the above-described embodiment, the gate valve 13 is opened, the substrate G is carried into the chamber 151 through the opening 12, and is placed on the placement electrode 189. Then, the gate valve 13 is closed and the exhaust is performed. The inside of the chamber 151 is evacuated to a predetermined degree of vacuum by the apparatus 11.

Thereafter, while the processing gas is supplied from the processing gas supply device 16 through the processing gas supply nozzle 188, the matching device 186 and the control box 1 are supplied from the high frequency power supply 187.
High-frequency power is supplied to the outer peripheral electrode 1 through 81, 183, 185.
By supplying power to the intermediate electrode 160, the center electrode 167, and the center electrode 167, plasma is generated between the mounting electrode 189 and each of the electrodes, and a predetermined film formed on the substrate G is subjected to etching by the plasma. Is done.

When performing the etching process in such a process, the plasma etching apparatus 150 detects the current flowing into each of the outer peripheral electrode 153, the intermediate electrode 160, and the central electrode 167 as described above, and determines the magnitude of this current. Accordingly, each electrode can be raised and lowered in real time to be arranged at an optimum position.
Therefore, the plasma density in the vicinity of each of the outer peripheral electrode 153, the intermediate electrode 160, and the central electrode 167 can be optimized, whereby the plasma in the chamber 151 can be constantly subjected to the etching process on the substrate G in a uniform state. It becomes possible.

The present invention can be variously modified without being limited to the above embodiment. For example, in the above embodiment, the current flowing into the segment electrode 31 is detected. However, the present invention is not limited to this, and any value may be detected as long as it is a value that is an index of the plasma state. Is also good. For example, the temperature of the segment electrode 31 may be detected, and the height of the shower head may be controlled based on the detected temperature, or the self-bias voltage VDC may be detected. In the above embodiment, the plasma is made uniform by controlling the interval between the electrodes. However, it is also possible to control the power and frequency of the applied high-frequency power. Further, in the above embodiment, the case where the present invention is applied to a plasma etching apparatus has been described, but the present invention can also be applied to a plasma CVD film forming apparatus, a plasma ashing apparatus, and the like. Furthermore, the substrate to be processed is not limited to a glass substrate, and may be another substrate.

[0053]

As described above, according to the first aspect of the present invention, the counter electrode is divided into a plurality of segment electrodes, and each of the segment electrodes is individually driven. Is detected individually in the vicinity of, and the intervals between the segment electrodes and the placement electrodes are controlled in real time based on the detected values so that appropriate plasma processing is performed. Therefore, it is possible to always optimize the plasma state in the processing container during the plasma processing and to perform the optimum plasma processing with high uniformity on the substrate to be processed.

According to the second aspect of the present invention, the first
In the same manner as described above, the counter electrode is divided into a plurality of segment electrodes, each of the segment electrodes is individually driven, the current flowing into each segment electrode is detected, and at least a part of the current is used. By controlling the driving means in real time, the distance between the segment electrode and the placement electrode is adjusted so that appropriate plasma processing is performed. Therefore, at the time of plasma processing, it is possible to always optimize the plasma state in the processing container and to perform the optimum plasma processing with high uniformity on the substrate to be processed, and to utilize the current flowing into the segment electrode. Since the driving means is controlled, a complicated control system is not required, and the device configuration can be simplified.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a plasma etching apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the plasma etching apparatus shown in FIG.
Sectional view.

FIG. 3 is an enlarged sectional view of a segment electrode unit in FIG.

FIG. 4 is a block diagram showing one control method of height control of segment electrodes.

FIG. 5 is a circuit diagram of a control box and the like in the case of FIG. 4;

FIG. 6 is a block diagram showing another control method for controlling the height of the segment electrodes.

FIG. 7 is a circuit diagram of a control box and the like in the case of FIG. 6;

FIG. 8 is a block diagram showing another control method for controlling the height of the segment electrodes.

FIG. 9 is a schematic sectional view showing a plasma etching apparatus according to a second embodiment of the present invention.

FIG. 10 is an enlarged view of a segment electrode unit in FIG. 9;

FIG. 11 is a schematic sectional view showing a plasma etching apparatus according to a third embodiment of the present invention.

FIG. 12 is an enlarged sectional view of the segment electrode unit in FIG. 11;

FIG. 13 is a schematic sectional view showing a plasma etching apparatus according to a fourth embodiment of the present invention.

FIG. 14 is a sectional view taken along the line BB of FIG. 13;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1; Plasma etching apparatus 2; Chamber 3; Lid 4; Counter electrode 5; Mounting electrode 9; High frequency power supply 15; Segment electrode unit 31; Segment electrode 39;

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (Reference) H05H 1/46 H01L 21/302 CF term (Reference) 4G075 AA24 AA30 AA61 BC04 BC06 CA47 DA02 DA03 DA04 EB42 EC21 ED01 ED13 FC11 FC15 4K030 CA06 FA03 JA03 KA15 KA39 KA41 LA18 5F004 AA01 BA06 BA07 BB13 BD01 BD04 CA05 CA08 5F045 AA08 BB02 CA15 DP03 EB02 EF05 EH04 EH05 EH14 EH20 EM10 GB15

Claims (10)

[Claims] 1. A processing container for accommodating a substrate to be processed, a mounting electrode provided in the processing container, on which the substrate to be processed is mounted, and a plurality of segments provided opposite to the mounting electrode. A counter electrode divided into electrodes, a gas supply unit for supplying a processing gas for performing a plasma processing on the substrate to be processed in the processing container, and a mounting electrode for converting the processing gas into plasma A high-frequency power supply that supplies high-frequency power between the first electrode and the counter electrode; a driving unit that individually drives each of the plurality of segment electrodes to adjust a distance between the plurality of segment electrodes and the placement electrode; In a state where plasma is formed, in the vicinity of each of the segment electrodes, detecting means for individually detecting a parameter serving as an index of the state of plasma, and the driving means based on a detection value of the detecting means. The plasma processing apparatus characterized by comprising a control means for controlling so that the output a control signal interval of proper plasma processing with the segment electrodes and the placement electrode is performed. 2. The plasma processing apparatus according to claim 1, wherein a parameter serving as an index of the state of the plasma is a current, and the detecting means detects a current value flowing into each of the segment electrodes. 3. The apparatus according to claim 2, wherein the control unit controls an interval between each of the segment electrodes and the placement electrode so that a detection value of the detection unit becomes a predetermined value set in advance. The plasma processing apparatus according to claim 1 or 2. 4. The apparatus according to claim 1, wherein said control means controls an interval between each of said segment electrodes and said placement electrode such that a detection value of said detection means becomes equal. The plasma processing apparatus according to claim 1. 5. A processing container for accommodating a substrate to be processed, a mounting electrode provided in the processing container, on which the substrate to be processed is mounted, and a plurality of segments provided opposite to the mounting electrode. A counter electrode divided into electrodes, a gas supply unit for supplying a processing gas for performing a plasma processing on the substrate to be processed in the processing container, and a mounting electrode for converting the processing gas into plasma And a high-frequency power supply that supplies high-frequency power between the counter electrode and a plurality of driving units that are provided corresponding to the segment electrodes, respectively, and that adjust an interval between the segment electrode and the placement electrode. Each of the segment electrodes is provided in correspondence with each of the segment electrodes, a current flowing into the segment electrode is detected, and the driving means is controlled by using at least a part of the current flowing into the segment electrode. A plasma processing apparatus comprising: control means for controlling an interval between the segment electrode and the placement electrode so that proper plasma processing is performed. 6. The plasma processing apparatus according to claim 1, wherein the high-frequency power supply supplies high-frequency power to the mounting electrode. 7. The plasma processing apparatus according to claim 1, wherein the high-frequency power supply supplies high-frequency power to the counter electrode. 8. The plasma processing apparatus according to claim 1, wherein the driving unit has a coil for raising and lowering each of the segment electrodes and a permanent magnet. 9. The plasma processing apparatus according to claim 1, wherein the driving unit includes a piezoelectric element that raises and lowers each of the segment electrodes. 10. The plasma processing apparatus according to claim 1, wherein the driving unit includes a motor that moves the segment electrodes up and down.