JPS62152127A - plasma equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to plasma CVD (
Chemical Vapor Deposition
), etching equipment, and sputtering equipment.

[Prior art]

Plasma equipment using electron cyclotron resonance can generate highly active plasma at low gas pressure, allows a wide range of ion energies to be selected, and has a large ion current, with excellent directionality and uniformity of ion flow. Due to its advantages, research and development are progressing as it is indispensable for manufacturing highly integrated semiconductor devices.

FIG. 4 is a reduced cross-sectional view of a conventional plasma device using electron cyclotron resonance configured as a plasma etching device, and 31 indicates a hollow cylindrical plasma generation chamber. The plasma generation chamber 31 has a double structure around the surrounding wall and is equipped with a cooling water circulation chamber, and has a microwave inlet 31c in the center of one side wall, and a microwave inlet 31c in the center of the other side wall at a position opposite to the microwave inlet 31c. Circular plasma outlet 31d
One end of a waveguide 32 is connected to the microwave inlet 31c, and a plasma outlet 31d is connected to the microwave inlet 31c.
A hollow rectangular parallelepiped etching chamber 33 is arranged facing the
Furthermore, an annular excitation coil 34 is disposed concentrically around one end of the plasma generation chamber 31 and a waveguide 32 connected thereto so as to surround them.

The other end of the waveguide 32 is connected to a magnetron (not shown), and an f! Five stands 38 are installed, and a sample S, such as a semiconductor wafer, is placed on the surface of these mounting stands 38.

However, in such a plasma etching device,
Plasma is generated in the plasma generation chamber 31, and the generated plasma is applied to the etching chamber 3 by a divergent magnetic field, which is formed by the excitation coil 34 and whose magnetic flux density decreases toward the etching chamber 33 side in front of the plasma outlet 31d.
The surface of the sample S is etched by projecting it onto the sample S in 3 (Japanese Patent Application Laid-Open No. 60-51537).
.

[Problems to be Solved by the Invention] However, in the conventional apparatus as described above, the plasma generation chamber 31 and the plasma outlet 31d are both formed in a cylindrical or circular shape, and the excitation coil 34 is also shaped accordingly. It was formed into a cylindrical shape.

Such a configuration certainly has the advantage of uniformly projecting plasma during film formation, etching, etc. on the sample S, such as a disk-shaped semiconductor wafer, but on the other hand,
When targeting a large rectangular sample such as a thermal head, plasma is generated in the cylindrical plasma generation chamber 1, and when projected from the rectangular plasma outlet 31d, it is projected onto a circular area on the mounting table 38. As a result of plasma projection, the plasma is wasted around the rectangular sample S, resulting in low projection efficiency.
There was a problem in that the ion density varied widely with respect to various parts of the surface, making it difficult to uniformize the treatment.

[Means for solving problems]

The present invention has been made in view of the above circumstances, and its purpose is to form the inner surface of the plasma generation chamber, the plasma outlet for introducing plasma into a sample chamber such as an etching chamber, and the excitation coil into square cylinders and rectangular shapes, respectively. The object of the present invention is to provide a plasma device which can achieve uniform plasma distribution even on a rectangular sample by forming the plasma into a circumferential ring shape.

The plasma apparatus according to the present invention includes a plasma generation chamber that generates plasma using electron cyclotron resonance, a sample chamber that projects the plasma generated in the plasma generation chamber onto a sample, and a plasma generation chamber arranged around the plasma generation chamber. In the plasma apparatus, the plasma generation chamber is formed in a rectangular cylindrical shape, and a plasma outlet for guiding plasma from the plasma generation chamber to a sample chamber is formed in a rectangular shape,
Furthermore, the excitation coil is characterized in that it is formed into a rectangular ring shape.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a plasma etching apparatus will be explained in detail below with reference to the drawings.

FIG. 1 is an explanatory diagram of a plasma device according to the present invention (hereinafter referred to as the device of the present invention), and FIG. 2 is a longitudinal sectional view taken along the line ■-■ in FIG. is a waveguide,
Reference numeral 3 indicates an etching chamber constituting the sample chamber, and 4 indicates an excitation coil.

The plasma generation chamber 1 is made of stainless steel and is formed in the shape of a rectangular cylinder, more precisely a hollow rectangular parallelepiped.The surrounding wall has a double structure and is equipped with a cooling water circulation chamber 1a, and the center of the upper side wall is made of quartz. A microwave inlet 1c sealed with a glass plate 1b and having a rectangular shape in plan view is provided, and a plasma outlet 1d, which is rectangular in plan view, is opened in the center of the lower wall facing the microwave inlet 1c. . One end of a rectangular cylindrical waveguide 2 is connected to the microwave inlet 1c, and a hollow rectangular parallelepiped etching chamber 3 is provided facing the plasma outlet 1d. A rectangular ring-shaped excitation coil 4 is disposed around the end of the waveguide 2 connected to the excitation coil 4, and a magnetic flux is disposed between the excitation coil 4 and the etching chamber 3 in a manner that the excitation coil 4 is fitted around the etching chamber 3. A square cylindrical yoke 5 is provided to make the density uniform.

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 chamber 1 through the waveguide 2. Further, the excitation coil 4 is connected to a constant current power source (not shown), and when a current is passed through it, a magnetic field is formed so that plasma is generated by introducing microwaves into the plasma generation chamber l, and ions are generated. A diverging magnetic field is formed in which the magnetic flux density decreases toward the etching chamber 3 in order to project the etching toward the etching chamber.

On the other hand, the esoching chamber 3 is provided with an exhaust port 3b connected to the exhaust system 3a on the lower wall facing the plasma extraction port 1d, and a mounting table 6 is installed in the center facing the plasma extraction port 1d. The sample S can be removably fixed to the surface by electrostatic adsorption.

FIG. 3 is an enlarged perspective view of the yoke, and the yoke 5 is made of a ferromagnetic material, for example iron, and is formed into a rectangular cylindrical shape that is approximately similar to the plasma generation chamber 1 and slightly larger than the plasma generation chamber 1. The upper edge of the short side extends slightly toward the opposite direction, that is, toward the center of the rectangular cylinder, forming projecting pieces 5a and 5b, which are concentric with the outer circumference of the plasma generation chamber 1. It is arranged externally in a shape.

There are no particular limitations on the size, shape, etc. of the overhanging pieces 5a, 5b, and they are used to generate a uniform magnetic field within the square cylindrical plasma generation chamber 1, and to direct the flow from the plasma generation chamber 1 to the etching chamber. Any material may be used as long as the magnetic flux density decreases toward the third side and the magnetic flux density distribution in a plane parallel to the plasma extraction port 1d can form a uniform divergent magnetic field.

Although the yoke 5 of the embodiment has a structure in which the overhanging pieces 5a and 5b are provided only on the short sides of the upper ends of the square sections, similar overhang pieces may also be provided on the short sides of the lower ends. Of course.

In the map, 1e and If are the cooling water supply system, drainage system, and Ig.
, 3g indicate the gas supply system.

In the apparatus of the present invention, the sample S is placed on the mounting table 6 in the etching chamber 3 through a load lock chamber (not shown) and etching is started. That is, gas is supplied into the plasma generation chamber l through the gas supply system 1g, current is passed through the excitation coil 4, and microwaves are introduced through the waveguide 2 to generate plasma. The plasma is projected toward the periphery of the sample S by the divergent magnetic field that is formed and directed toward the etching chamber 3 side.

The plasma decomposes c2F6, etc., which is an etching gas supplied from the gas supply system 3g, and
Etch a film such as +02.

Plasma generation chamber 1. Plasma outlet 1d, excitation coil 4
are formed in a prismatic cylindrical shape, a rectangular shape, a circumferential ring shape, etc., so that the plasma ion density remains in the prismatic cylindrical shape not only during the generation of plasma in the plasma generation chamber 1 but also during the process of introducing plasma into the etching chamber 3. Alternatively, it can be set uniformly within a rectangular area, and the plasma can be projected onto the rectangular sample S at a uniform density, making it possible to perform etching with high processing accuracy.

In particular, by making the plasma generation chamber into a hollow rectangular parallelepiped, theoretically the magnetic flux density near the short sides is relatively lower than near the long sides, but in the device of the present invention, the magnetic flux density around the plasma generation chamber l is By providing a yoke 5 at the yoke 5 and providing projecting pieces 5a and 5b on the upper edge of the short side of the yoke itself, variations in magnetic flux density can be eliminated and plasma density can be made more uniform.

It should be noted that, although the above-mentioned embodiments have been described with reference to a configuration in which the present invention is used as an etching apparatus, the present invention is not limited to this in any way, and it goes without saying that it can also be used as, for example, a plasma CVD apparatus, a sputtering apparatus, etc.

In addition, although the plasma generation chamber l is formed in the shape of a hollow rectangular parallelepiped, the plasma outlet 1d is formed in a rectangular shape, and the excitation coil 4 is formed in a square ring shape, this shape is not particularly limited to this. Instead, for example, the plasma generation chamber 1 and the excitation coil 4 may be formed in the shape of a hollow cube or a square ring, and the plasma outlet 1d may be formed in a square shape, or in other shapes such as a rectangular shape or an elliptical shape. .

〔effect〕

As described above, in the apparatus of the present invention, the plasma generation chamber is shaped like a rectangular cylinder, the plasma outlet is formed rectangular, and the excitation coil is also formed into a square annular shape that matches the plasma generation chamber and the plasma outlet. The present invention has excellent effects such as uniformity of plasma density on the sample can be easily achieved, processing such as film formation or etching on the sample can be performed with higher precision, and there is no waste in plasma projection and high efficiency is achieved. It is something.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the device of the present invention, and Fig. 2 is a diagram showing ■-■ of Fig. 1.
Figure 3 is an enlarged perspective view of the yoke;
The figure is an explanatory diagram of a conventional device. ■...Plasma generation chamber 1d...Plasma outlet 2
... Waveguide 3... Etching chamber 4... Excitation coil 5... Yoke 5a, 5b... Overhang piece 7...
・Placement stand S...Complete fee patent Applicant Sumitomo Metal Industries Co., Ltd. Agent Patent attorney Noboru Kono No.1 Figure 2 Figure 3I21 Calculation 4-en

Claims (1)

[Claims] 1. A plasma generation chamber that generates plasma using electron cyclotron resonance, a sample chamber that projects the plasma generated in the plasma generation chamber onto a sample, and an excitation coil disposed around the plasma generation chamber. In the plasma apparatus equipped with the above, the plasma generation chamber is formed into a rectangular cylinder shape, the plasma outlet for guiding the plasma from the plasma generation chamber to the sample chamber is formed into a rectangular shape, and the excitation coil is formed into a rectangular annular shape. Characteristic plasma equipment.