JP2000030898A - Plasma processing equipment - Google Patents

Abstract

(57) [Abstract] (with correction) [Problem] It is possible to prevent the invasion of plasma into a pipe serving as a ground side, and to prevent abnormal discharge in the pipe, thereby stabilizing the plasma discharge. A plasma processing apparatus capable of maintaining uniformity of substrate processing is obtained. An electrode pole for generating plasma is provided at an upper portion of a chamber to which a process gas for substrate processing is supplied, the electrode pole is provided with a supply port of the process gas, and the supply port is formed of an insulator. In the plasma processing apparatus configured to supply the process gas through the gas passage 35, a plurality of gas passages each having a predetermined length and a predetermined diameter are formed so that the plasma generated in the chamber does not enter. Insulation tube 5 with holes
2,62.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus, such as a plasma CVD apparatus, for performing a substrate process by using a plasma under a process gas supplied to a chamber. The present invention relates to an insulating structure for insulating a pole.

[0002]

FIG. 8 shows a conventional plasma processing apparatus.
FIG. 9 is a cross-sectional side view showing a gas introduction part structure in the plasma CVD apparatus, and FIG. 9 is a partial cross-sectional plan view of FIG. The plasma CVD apparatus includes an electrode pole 12 for generating plasma at an upper part of the chamber 1 and a gas introduction part. A substrate 14 serving as a work is provided in the chamber below the electrode pole 12 and the gas introduction part. 2 is supported.

The gas inlet extends along the side wall of the chamber 1 to the upper portion of the chamber 1, where two gas pipes (SUS pipes) 21 and 22 which are bent vertically toward the center of the chamber are connected. A gas introducing block 13 and an electrode pole 12 to which the gas introducing block 13 is attached. Gas introduction block 1
3, a gas passage 13a formed in a horizontal direction to which a gas pipe 21 for supplying a first gas is connected, and a gas passage formed in the same horizontal direction to which a gas pipe 22 for supplying a second gas is connected 13b, and a gas passage 13d formed vertically from the junction 13c where the passages 13a and 13b merge into one below the chamber.

The electrode pole 12 has a pillar shape, and has a gas passage 13d of a gas introduction block 13 in the center and in the vertical direction.
And a gas passage 12a communicating with the gas passage. The electrode pole 12 is connected to a power supply terminal of a high-frequency power supply 24 provided between the electrode pole 12 and the ground 23.

[0005] The lower end of the electrode pole 12 is in close contact with the upper surface of the temperature control plate 7, a gas dispersion plate 11 is provided below the temperature control plate 7, and a gas shower is provided below the gas dispersion plate 11. A plate 10 is provided. A through hole 7A communicating with the gas passage 12a of the electrode pole 12 is provided at the center of the temperature control plate 7, and the lower end of the through hole 7A opens above the gas dispersion plate 11. An exhaust port 4 for the supplied gas is provided at a central lower end of the chamber 1.

In these figures, 5 is a chamber lid, 6 is an insulating block for insulating the chamber lid 5 and the temperature control plate 7, 8 is a temperature control plate 7, a gas shower plate 10, a chamber lid 6, and a chamber 1. This is an insulating ring for insulating the. Reference numeral 9 denotes a gas introduction flange, and reference numeral 3 denotes a heater provided on the lower surface of the susceptor 2.

In the above configuration, in the substrate processing using plasma, a high-frequency voltage is applied to the electrode pole 12 to generate a discharge between the electrode pole 12 and the chamber 1 to generate plasma. In this case, the electrode pole 12, the gas dispersion plate 11,
In order to insulate the gas shower plate 10 from the chamber 1 side and to act as a cathode, the gas introduction block 13
Insulates the gas pipes 21, 22 and the electrode pole 12 from the electrode side and the earth side.

[0008]

However, in the conventional insulating structure between the electrode pole 12 and the gas pipes 21 and 22, the cross-sectional area and length of the passage in the gas introduction block 13 are generated in the chamber. It is configured to have a size such that the plasma that has entered can easily reach the gas pipes 21 and 22 having conductivity by plasma, so that the plasma can easily enter the gas pipe side, so that abnormal discharge due to high frequency in the pipes occurs. This is problematic in that it tends to occur, hindering the stabilization of plasma discharge, and making it impossible to maintain uniformity of substrate processing such as film thickness.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and prevents an abnormal discharge generated in a gas pipe by preventing plasma from entering a gas pipe on the ground side. It is an object of the present invention to provide a plasma processing apparatus which can prevent the plasma discharge, stabilize the plasma discharge, and maintain the uniformity of the substrate processing.

[0010]

In order to solve the above-mentioned problems, the present invention comprises an electrode pole for generating plasma at an upper portion of a chamber to which a process gas for processing a substrate is supplied. A plasma processing apparatus provided with a supply port for the process gas in the vicinity thereof, wherein the process gas supplied by a gas pipe is supplied to the supply port via a gas passage made of an insulator; The passage is constituted by an insulating tube provided with a plurality of holes having a predetermined length and diameter so that plasma generated in the chamber does not enter the gas pipe side.

Further, according to the present invention, as shown in FIG. 4, each of the plurality of holes of the insulating tube is
It is constituted by one through hole penetrating the insulating tube.

Further, according to the present invention, as shown in FIGS. 5 and 6, the insulating tube has a hollow portion formed therein, and the plurality of holes penetrate between the hollow portion and both ends of the insulating tube. It is provided as follows.

In the present invention, the plurality of holes provided on both sides of the hollow portion are provided such that their cross sections do not overlap the hollow portion, as shown in FIG. It is.

Further, in the present invention, as shown in FIG. 7, a hollow portion is formed inside the insulating tube, and the plurality of holes penetrate from the electrode pole side of the insulating tube to the hollow portion. One hole penetrates from the gas pipe side of the insulating tube to the cavity. Note that the above-described through holes may be linear or curved. Also,
The diameter of the through hole may be changed.

In the present invention, the relationship between the diameter D of the hole and the length L of the hole of the insulating tube is D ≦ 0.
05L is satisfied.

According to the above configuration, the intrusion of the plasma generated in the chamber into the pipe is restricted, and the discharge in the pipe is prevented. In the embodiment, the plurality of holes described above are linear, but may be curved.

Further, in the present invention, the insulating tube is inserted into a cylindrical insulating block, and both ends of the insulating block are provided at a gas introducing flange constituting the gas pipe and at or near the electrode pole. It is designed to be attached between the supply port.

According to such a configuration, attachment of the insulating tube to the plasma processing apparatus becomes easy.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a cross-sectional side view showing a gas introduction part of the plasma processing apparatus according to the embodiment, FIG. 2 is a cross-sectional plan view taken along line EE of FIG. 1, and FIG. 3 is a cross-sectional plan view taken along line FF of FIG. In these figures, reference numeral 1 denotes a chamber, 5 denotes a chamber lid, and 21A and 22A are connected to gas pipes provided vertically upward through the chamber 1 and the chamber lid 2, and in the vicinity of the head portion of the chamber 1 in the horizontal direction. Pipes 21a and 22 for supplying bent process gas
It is a gas introduction flange for forming a.

Here, the pipe 22a is provided with a small flow of the first gas (for example, O ₂ gas in the TEOS SiO ₂ process).
The pipe 21a supplies a second gas having a larger flow rate than the first gas (for example, a TEOS gas (tetraethoxyorthosilane in the TEOS SiO ₂ process). The gas introduction flanges 21A and 22A have a front end side. Are connected to insulating pipes 50 and 60,
The second gas and the first gas described above are introduced into the gas mixer 30A via the channels 0 and 60.

The gas mixer 30A is formed on the electrode pole 30, and sends a mixed gas obtained by mixing the first gas and the second gas into the chamber. This gas mixer 3
0A is provided in a space 33 composed of compartments 33a and 33b formed for mixing a gas for substrate processing, and a wall of the space forming the compartment 33a, and is provided with a first substrate processing substrate. A first gas inlet 32a into which a gas flows, and a second gas inlet provided in a wall of a space forming the compartment 33b and through which a second gas for substrate processing having a larger flow rate than the first gas flows. 31a and a space between the first gas inlet 32a and the second gas inlet 31a.
a, a porous plate 34 provided with a large number of through holes for communicating the partitioned spaces (compartment chambers 33a, 33b), and a second gas inlet 31a of the compartment 33b. And a gas outlet 33c for supplying the gas mixed in the compartment 33b to the substrate processing chamber, which is provided on a wall (lower end face of the space) downstream of the divided wall.

The space formed in the electrode pole 30 has a circular cross section, and the diameter of the compartment 33a is larger than the diameter of the compartment 33b.
3b, and the upper part of the periphery is defined as a compartment 3
The lower end of the adapter 36 inserted in 3a is pressed. The wall thickness of the cylindrical portion of the adapter 36 is determined so that the cross-sectional area of the flow passage in the space of the compartment 33a is the same as the cross-sectional area of the flow passage in the compartment 33b. The upper end surface of the adapter 36 is pressed by the flange 40 so that the perforated plate 34 does not move between the compartment 33b and the adapter 36.
In addition, the replacement and the exchange depending on the type of gas used are easily supported.

The perforated plate 34 is made of quartz, ceramics, metal, or heat-resistant aluminum. The diameter and the number of the through holes 34a are determined by, for example, the diameter of the through-holes 34a so as not to cause a sharp pressure gradient and flow rate change. Pressure gradient is 2-5
The number is set to be about twice. The hole diameter of the perforated plate 34 is set to be within 1.5 mm in order to reduce the plasma generated in the chamber 1 from entering the piping.

A gas passage 35 continuing from the gas outlet 33c of the gas mixer 30A passes through the through hole 7A of the temperature control plate 7 to reach a dispersion chamber 11a in which the gas dispersion plate 11 is provided. From 10, it is led out onto the substrate in the chamber 1.

2 and 3, the insulating pipes 50 and 60 are connected to the gas mixer 30A of the electrode pole 30 at an angle of 90 degrees to each other. Electrode pole 3
0 has a substantially square shape, and insulating pipes 50 and 60 are connected to adjacent surfaces. Insulated piping 50, 6
Numeral 0 denotes insulating tubes 52, 6 made of quartz or alumina ceramic in cylindrical insulating blocks 51, 61 made of polyimide or polyacetal, respectively.
2 are inserted, and both ends of the insulating block 51 are connection portions 37 which are supply ports formed in the electrode poles 30 respectively.
B and the connecting portion 21B formed on the gas introduction flange 21A
And both ends of the insulating block 61 are connected to a connecting portion 37A, which is a supply port formed in the electrode pole 30, and a connecting portion 22B formed in the gas introduction flange 22A.

At each connection between the gas introducing flanges 21A, 22A and the insulating pipes 50, 60, the flanges 21C, 22C of the gas introducing flanges 21A, 22A abut against the flanges 51A, 61A of the insulating blocks 51, 61. Then, although not shown in the drawing, it is screwed. In this case, the distal end portions 52a and 62a of the insulating tube are connected to the connecting portion 21.
B and 22B are in contact with the contact plane portions in the concave portions.

The electrode pole 30 and the insulating pipes 50, 6
In each connection portion with the electrode pole 30, the front ends 51B and 61B of the flange portions of the insulation blocks 51 and 61 are screwed so as to contact the outer wall surfaces of the connection portions 37B and 37A of the electrode pole 30. , 62 tip 52
b and 62b are in contact with the contact plane portions in the recesses of the connection portions 37B and 37A.

FIGS. 4 to 7 show detailed structural examples of the insulating tubes 52 and 62. FIG. 4 to 7 are diagrams showing first to fourth configuration examples of the insulating tube. In each of the drawings, (a) is a front view, and (b) is a side view seen from the left side of (a). FIG. 2C is a side view as viewed from the right in FIG.

The first configuration example shown in FIG.
Each of the plurality of holes 52A-a of the 2A is constituted by one through hole penetrating the insulating tube 52A.

The second configuration example shown in FIG.
A hollow portion 52B-b is formed inside 2B, and a plurality of holes 5B are formed.
2Ba is connected to the insulating tube 52 through the cavity 52B-b.
B is configured to penetrate both ends. The length and diameter of the cavity are determined experimentally.

In this case, the insulating tube 52B is a bilaterally symmetrical shape of the insulating tube pieces 52B-1, 52B-2.
From the left and right, the joints 52B-c are joined to each other so that the insulating tube can be easily manufactured.

The third configuration example shown in FIG.
Each of the plurality of holes 52C-a and 52C-b of 2C
The configuration is such that the position of the center line is provided to be different at both end surfaces of the insulating tube 52C so that the cross sections of the holes do not overlap each other with respect to the cavity 52C-c.

Also in this case, the insulating tubes 52C have the same length and have a plurality of holes 52C-a and 52C-a, respectively.
b and the insulating tube pieces 52C-1 and 52C-2 in which the half of the hollow portion 52C-c is formed can be joined by joining the joining portions 52C-d from the left and right from each other. In addition, the manufacture of the insulating tube becomes easy.

The fourth configuration example shown in FIG.
A cavity 52D-c is formed inside the 2D, and a plurality of holes 5D-c are formed.
2D-a is provided so as to penetrate from the electrode pole side (the left side in FIG. 7) of the insulating tube 52D to the hollow portion 52D-c, and from the piping side (the right side in FIG. 7) of the insulating tube 52D to the hollow portion 52D-c.
Up to one hole 52D-b having substantially the same diameter as the pipe.
Is provided so as to penetrate through. Such an insulating tube can be manufactured, for example, by casting.

In the first to fourth structural examples of the insulating tube described above, the relationship between the diameter D of the hole and the length L of the hole in each insulating tube satisfies the relationship of D ≧ 0.05L. ing. Such a relationship is more effective in preventing plasma generated in the chamber from entering the hole of the insulating tube and entering the SUS-based piping side, where discharge is generated.

The number and diameter of these holes are also determined by the flow rate and pressure of the gas used, and the holes are provided so that the total area thereof becomes the basic pipe cross-sectional area. In the embodiment, the diameter of each through hole of the insulating tube is set to 1.5 mm or less.

In the above configuration, the gas dispersion plate 11, the gas shower plate 10, and the temperature adjustment plate 7 are provided with the insulating pipes 50, 6
0, the insulating plate 6A, and the insulating cover 8A, together with the electrode pole 30, are connected to the power supply side to function as a cathode, and are connected to the chamber 1 and pipes (gas introduction flanges 21A, 2A).
2A) and dropped to ground.

At the time of plasma processing, a discharge is generated between the cathode and the anode arranged opposite to the cathode (not shown) to generate plasma. This plasma tries to penetrate into the pipe side via the electrode pole 30, but because the diameter of the through holes of the insulating tubes 52 and 62 is smaller than the length, the penetration is hindered. ,
It is possible to prevent the occurrence of high-frequency discharge, which has conventionally occurred in the pipe, to obtain a stable plasma discharge state, and to obtain uniformity in film thickness, refractive index, and etch rate.

When the gas is supplied, the first gas passes through the chamber 1 and the chamber lid 5 and passes through the gas introducing flange 2.
After entering 2A, passing through the insulating pipe 60 and entering the space (compartment room 33a) of the electrode pole 30, it enters the compartment 33b through the through hole 34a of the perforated plate 34. On the other hand, the second gas passes through the chamber 1 and the chamber lid 5, enters the gas introduction flange 21A, passes through the insulating pipe 50, and passes through the electrode pole 3
0 (the compartment 33b), where the perforated plate 34
It mixes with the first gas that has passed through. The mixed gas mixed in the compartment 33b then passes through the passage 35 and enters the chamber via the gas dispersion plate 11 and the gas shower plate 10.

At this time, the first gas and the second gas are supplied to the perforated plate 34.
Is sufficiently mixed by the action of the gas mixer 30A provided with the above, a more stable plasma discharge state is obtained in combination with the above-described discharge prevention action in the pipe, and the uniformity of the film thickness, the refractive index, and the etch rate is obtained. Is further improved.

The mixing effect of the perforated plate 34 is particularly remarkable in a gas having a high molecular weight, such as a TEOS gas or a BST gas, in which liquefaction is likely to occur.

[0042]

As is apparent from the above description, according to the present invention, an electrode pole for generating plasma is provided above a chamber to which a process gas for substrate processing is supplied, and the electrode pole is provided with the electrode pole. In a plasma processing apparatus having a process gas supply port and supplying the process gas through a gas passage made of an insulator to the supply port, a plasma generated in the chamber is formed by a gas passage made of an insulator. In order to prevent intrusion, the insulated tube is provided with a plurality of holes having a predetermined length and diameter, so that it is possible to prevent intrusion of plasma into the piping, and no abnormal discharge occurs in the piping. This has the effect of stabilizing discharge and obtaining a plasma processing apparatus capable of maintaining uniformity of substrate processing. Further, according to the present invention, the insulating tube is inserted into the insulating block, and the insulating block is mounted on the gas introduction flange or the electrode pole, so that the insulating tube can be easily mounted.

[Brief description of the drawings]

FIG. 1 is a cross-sectional side view showing a gas introduction unit of a plasma processing apparatus according to an embodiment.

FIG. 2 is a cross-sectional plan view taken along line EE of FIG.

FIG. 3 is a sectional plan view taken along line FF of FIG. 1;

FIG. 4 is a diagram showing a first configuration example of an insulating tube.

FIG. 5 is a diagram showing a second configuration example of the insulating tube.

FIG. 6 is a diagram showing a third configuration example of the insulating tube.

FIG. 7 is a diagram showing a fourth configuration example of the insulating tube.

FIG. 8 is a sectional side view showing a gas introduction part in a plasma CVD apparatus as a conventional technique.

9 is a partial cross-sectional plan view of FIG.

[Explanation of symbols]

 Reference Signs List 1 chamber 10 gas shower plate 11 gas dispersion plate 30 electrode pole 50, 60 insulating pipe 52, 62, 52A to 52D insulating tube

Claims (7)

[Claims] An electrode for generating plasma is provided at an upper portion of a chamber to which a process gas for processing a substrate is supplied, and a supply port for the process gas is provided at or near the electrode and supplied by a gas pipe. In the plasma processing apparatus, the process gas to be supplied is supplied to the supply port through a gas passage made of an insulator. A plasma processing apparatus comprising an insulating tube provided with a plurality of holes having a predetermined length and diameter so as not to enter. 2. The plasma processing apparatus according to claim 1, wherein each of the plurality of holes of the insulating tube is one through-hole penetrating the insulating tube. 3. The plasma processing apparatus according to claim 1, wherein the insulating tube has a cavity formed therein, and the plurality of holes penetrate between the cavity and both ends of the insulating tube. . 4. The plasma processing apparatus according to claim 3, wherein the plurality of holes provided on both sides of the cavity are provided such that their cross sections do not overlap with the cavity. apparatus. 5. The plasma processing apparatus according to claim 1, wherein the insulating tube has a cavity formed therein, and the plurality of holes penetrate from the electrode pole side of the insulating tube to the cavity. A plasma processing apparatus, wherein one hole penetrates from the gas pipe side of the tube to the cavity. 6. The plasma processing apparatus according to claim 1, wherein a relationship between a diameter D of the hole and a length L of the hole included in the insulating tube is D ≦ 0.05L. Plasma processing equipment that satisfies the relationship. 7. The plasma processing apparatus according to claim 1, wherein the insulating tube is inserted into a tubular insulating block.
A plasma processing apparatus wherein both ends of the insulating block are mounted between a gas introduction flange constituting the gas pipe and a supply port provided at or near the electrode pole.