JPS62257733A - Plasma device - Google Patents

Abstract

PURPOSE:To improve working efficiency largely by branching a waveguide so that microwave outlets are directed toward the reverse side and arranging both exciting coils so as to be positioned on the same axis in each microwave outlet. CONSTITUTION:The insides of plasma formation chambers 1, 1 are supplied with a gas through gas supply systems 1g, and DC voltage is applied to exciting coils 4, 4 while microwaves are introduced through a waveguide 2 and branch pipes 2a, 2a to generate plasma. A divergent magnetic field toward reaction chambers 3, 3 shaped by coils 4, 4 is projected to the peripheries of samples 5, 5 in the chambers 3, 3 regarding plasma generated, a raw material gas SiH4, O2 or N2 fed from a supply system 3g is plasma-decomposed, and the film of SiO2, Si3N4, etc. is evaporated and formed on the surfaces of the samples 5, 5. When the formation of the film is completed, base plates 6, 6 are shifted into a load locking chamber, the samples are exchanged and the base plates are returned into the chambers 3 again, and the process is repeated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is directed to CVD (Chemistry) for manufacturing semiconductor devices.
The present invention relates to a plasma device that utilizes electron cyclotron resonance and is used as a cal-capor deposition device, an etching device, a shuttering device, and the like.

[Prior art]

Plasma devices that utilize electron cyclotron resonance can generate highly active plasma at low gas pressure, allow for a wide range of ion energy selections, and can generate large ion currents and improve the directionality of the ion flow.

It has advantages such as excellent uniformity, and its research and development are progressing as it is indispensable for manufacturing high-quality semiconductor devices.

FIG. 2 is a longitudinal cross-sectional view of a conventional plasma device utilizing electron cyclotron resonance configured as a plasma CVD device, and numeral 31 indicates a plasma generation chamber. The plasma generation chamber 3I has a double structure around the surrounding wall and has a cooling water circulation chamber 31a.
A microwave inlet 31c sealed with a quartz glass plate 31b is provided in the center of the upper wall, and a plasma outlet 31d is provided in the center of the lower wall at a position opposite to the microwave inlet 31c. One end of a waveguide 32 is connected to the microwave inlet 31c, and a reaction chamber 33 is disposed facing the plasma outlet 31d, and a plasma generation chamber 31 and a waveguide connected thereto are located around the microwave inlet 31c. 32
An excitation coil 34 is disposed concentrically with these in such a manner as to surround them over one end.

The other end of the waveguide 32 is connected to a magnetron (not shown), and a plasma outlet 31d is provided in the reaction chamber 33.
A mounting table 36 for a sample 35 such as a semiconductor wafer or the like is installed opposite to the reaction chamber 33, and an exhaust system 37 is installed on the lower wall of the reaction chamber
The exhaust port 33a connected to the exhaust port 33a is opened. 31e, 3
1f is the cooling water supply system and drainage system, 31g.

33g indicates a gas supply system.

In such a plasma CVD apparatus, the sample 35 is placed on the mounting table 36, and the plasma generation chamber 3
1 through the primary gas supply system 31g, a DC voltage is applied to the IAIJ bl coil 34, and microwaves are introduced through the waveguide 32 to generate plasma in the plasma generation chamber 31. The generated plasma is formed by the excitation coil 34 through the plasma outlet 3
A diverging magnetic field whose magnetic flux density decreases toward the reaction chamber 33 side in front of 1d is projected toward the sample 35 in the reaction chamber 33, plasma decomposes the gas in the reaction chamber 33, and forms a silicon oxide film etc. on the surface of the sample 35. A semiconductor film is deposited.

[Problem that the invention seeks to solve]

By the way, when forming semiconductor films on a large number of samples using such an apparatus, it is natural to install additional plasma apparatuses according to the number of samples, but adding plasma apparatuses individually is wasteful in terms of equipment. In addition, the installation space tends to be wasted.

The inventor of the present invention sought to combine a plurality of plasma devices as described above as compactly as possible, without wasting any waste, and without sacrificing any of the individual capabilities (as a result of experiments and research).
We focused on the fact that the overall configuration could be simplified by using a waveguide that introduced microwaves from a magnetron into a plasma generation chamber, or a reaction chamber, and devised a plasma device as shown in Figure 3. .

FIG. 3 is a longitudinal cross-sectional view of a plasma device devised by the inventor in the process of conceiving the present invention, and shows a microwave waveguide 42.
A quartz glass plate is provided at the center of the upper wall of the plasma generation chamber 41, 41, with one end branched into two, each extending in opposite directions, bent at right angles in the same direction and extending in parallel. 4
The reaction chambers 43 should be connected to the microwave inlets 41c sealed at 1b, respectively, and should be disposed facing the plasma outlet ports 41d, 41d formed at the center of the lower wall of each plasma housing chamber 41.41. The reaction chamber 43 has a single structure large enough to face both plasma outlet ports 41d and 41d, and two mounting stands for samples 45°45 are provided in the reaction chamber 43 so as to face each plasma outlet port 41d and 41d. 46, 46 are arranged, and a single exhaust port 43a connected to an exhaust system 47 is opened in the center of the lower chamber of the reaction chamber 43. The other configurations are substantially the same as the device shown in FIG. 2, and their explanation will be omitted.

In such a plasma apparatus, gas is supplied to the plasma generation chamber 4L41 through the gas supply system 31g and to the reaction chamber 43 through the gas supply system 33g, and a DC voltage is applied to each excitation coil 44.44. while the waveguide 42,
Microwaves are supplied through the branch pipes 42a and 42b to generate plasma in each plasma generation chamber 41.41, and this plasma is applied to the sample 45.45 in the reaction chamber 43 by the divergent magnetic field formed by the excitation coil 44.44. It is designed to project toward the periphery and perform vapor deposition on the surface of the sample 45.45.

However, in such a configuration, both excitation coils 44.
44 are arranged in parallel, the magnetic fields formed by both excitation coils 44 interfere with each other, resulting in uneven plasma ion density and a film formed on the surface of the sample 45. It was found that there was a problem in that the thickness varied and the film quality inevitably deteriorated.

The present invention has been made in view of the above circumstances, and its purpose is to simplify and improve the efficiency of the overall configuration by effectively utilizing the magnetic fields formed on both sides in the axial direction, thereby increasing productivity. The purpose of the present invention is to provide a plasma device that is excellent and has high work efficiency.

[Means for solving problems]

A plasma device according to the present invention includes two plasma generation chambers, two sample chambers connected to each plasma generation chamber, and an excitation coil that forms a magnetic field, the excitation coils being arranged on the same axis. Arrange both plasma generation chambers so that they are located at
Microwave waveguides are branched and connected to each of the plasma generation chambers.

[Effect]

According to the present invention, the waveguide can be shortened, and each magnetic field formed on both sides in the axial direction can be used for each other plasma generation chamber.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically explained below based on drawings showing embodiments applicable to a plasma CVD apparatus.

FIG. 1 is a longitudinal sectional view of a plasma device according to the present invention (hereinafter referred to as the device of the present invention), in which 1.1 is a plasma generation chamber, 2 is a waveguide, 3, 3 is a reaction chamber which is a sample chamber, 4 indicates an excitation coil.

The plasma generation chamber 1, 1 is made of stainless steel, and the surrounding wall has a double structure to form a cooling water passage chamber 1a.

1a, - in the center of the side wall a quartz glass plate 1b, l
Equipped with microwave inlets 1c and lc sealed at b,
In addition, plasma extraction ports 1d and ld equipped with extraction electrodes (not shown) are opened in the center of the other side wall facing this, and both plasma generation chambers 1.1 have microwave introduction ports 1c and lc. They are placed opposite each other. The microwave inlets 1c and lc are provided with branch pipes 2a, which are branched waveguides 2 into a T-shape and extend in opposite directions.
, 2a are connected to each other, and a reaction chamber 3.3 is disposed facing each plasma outlet 1d, ld, and each plasma generation chamber 1, 1 and a waveguide connected thereto are connected to each other. An excitation coil 4.4 is disposed around the two branch pipes 2a and the ends of the 2a. The plasma generation chamber 1.1 and the reaction chamber 3.3 connected thereto are the plasma generation chamber 1.1.
They are arranged in rows so as to be symmetrical about the midpoint between them.

The other end of the waveguide 2 is connected to a magnetron (not shown), and microwaves generated by the magnetron are introduced into the plasma generation chambers 1, 1 through the waveguide 2 and branch pipes 2a, 2a. It has become. On the other hand, reaction chamber 3.3
The plasma extraction port 1d is provided with an exhaust port 3a+38 connected to the exhaust system 7 on the opposite wall facing ld, and a mounting table 6.6 for the samples 5 and 5 is provided inside. The mounting tables 6, 6 are equipped with a chuck function using electrostatic adsorption, and hold the sample 5.5 in front of them, and move the sample 5.5 to a position facing the plasma extraction ports ld, ld and to the reaction chamber 3.3 using a moving means (not shown). The sample is moved back and forth between a load-lock chamber (not shown) in which a long-distance cast is provided, and the sample on which film formation has been completed is exchanged with a new sample.

Excitation coils 4, 4 are connected to plasma generation chamber 1.1 waveguide 2, respectively.
The branch pipes 2a, 2a are arranged concentrically with these and on the same axis with each other, and are connected to a DC power source (not shown), whereby the plasma generation chambers 1, 1 A magnetic field is formed so that plasma is generated by introducing microwaves into the reaction chamber 3, and the plasma is projected toward the reaction chamber 3 side.
L) is configured to form a diverging magnetic field in which the magnetic flux density decreases toward the third side.

The excitation coils 4 and 4 are connected to the plasma generation chamber 1, respectively.
．． Of course, instead of being installed individually for each plasma generation chamber 1.1, a single long coil may be used so as to span both plasma generation chambers 1.1.

In addition, 1e and if in the figure are water supply systems for the water flow chamber 1a.

The drainage system, Ig, and 3g indicate the gas supply system, respectively.

In the apparatus of the present invention configured as described above, gas is supplied into the plasma generation chamber 1.1 through the gas supply system 1g, and a DC voltage is applied to the excitation coil 4.4.
Plasma is generated by introducing microwaves through the waveguide 2 and the branch pipes 2a, 2a, and the generated plasma is directed to the reaction chamber 3.3 formed by the excitation coil 4.4 with a divergent magnetic field to the reaction chamber. 5i) 14,02 which is the raw material gas projected around the samples 5 and 5 of 3 and 3 and supplied from the supply system 3g
Or by plasma decomposing N2, SiO2 is deposited on the surface of sample 5.5.
, 5i3 N, etc. are formed by vapor deposition. When the film formation is completed, the mounting tables 6, 6 are moved to a loading chamber (not shown), the sample is replaced, and the sample is returned to the reaction chamber 3, and the above-mentioned process is repeated to perform vapor deposition.

Both excitation coils 4, 4 are on the same axis and each form a divergent magnetic field toward the reaction chamber 3.3 side, so there is no disturbance of the magnetic field and the plasma ions are distributed at a uniform density to the reaction chamber 3.3 side. The quality of the film formed on the surface of the sample 5.5 is also uniform.

Although the above-mentioned embodiment has been described with reference to the case where it is configured as a plasma CVD apparatus, it is needless to say that the present invention is not limited to this and may be configured as, for example, an etching apparatus, a sputtering apparatus, or the like.

〔effect〕

As described above, in the device of the present invention, the waveguide that guides microwaves to the plasma generation chamber is branched such that the microwave outlet faces the opposite side, and both excitation coils are connected to each microwave outlet. Since the plasma generation chambers are positioned on the axis and facing the plasma generation chambers, it is possible to operate two plasma generation chambers using a single waveguide, and the excitation coils of both plasma generation chambers can be operated using a single waveguide. Since they are located on the same axis, the divergent magnetic fields formed on both sides of the same axis can be used together, and there is no waste (production with compact equipment or machining efficiency can be greatly improved, etc.). It has the following effects.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a plasma device according to the present invention, FIG. 2 is a vertical cross-sectional view of a conventional device, and FIG. 3 is a vertical cross-sectional view of a plasma device devised in the process leading to the device of the present invention.

Claims (1)

[Claims] 1. In a plasma device having a plasma generation chamber that generates plasma by electron cyclotron resonance using microwaves, and a sample chamber in which a sample to which the generated plasma is projected is arranged, two plasma generation a chamber, two sample chambers connected to each plasma generation chamber, and an excitation coil disposed around the plasma generation chamber to form a magnetic field, the excitation coils being on the same axis. 1. A plasma device characterized in that both plasma generation chambers are arranged so as to be located at the same position, and a microwave waveguide is branched and connected to each plasma generation chamber. 2. The plasma apparatus according to claim 1, wherein the two plasma generation chambers and the two sample chambers are arranged side by side. 3. The plasma device according to claim 1, wherein the excitation coil is formed in series across both plasma generation chambers.