JPS6037119A - Plasma vapor phase reaction device - Google Patents

Abstract

PURPOSE:To enable mass productivity, and to increase the growth rate of a film by forming an opened hole or an opened groove to an electrode, converging the electric line of force in the region of the opened hole or the opened groove and generating high luminance discharge. CONSTITUTION:A reactive gas is fed to a quartz hood 21 from 23, and passes through a reticulate electrode 2 and reaches to a positive column region 5. Substrates 1, 1 are disposed in the positive column region in parallel with the electric lines of force 5 while the backs are fast stuck mutually. The substrate takes a shape surrounded by a quartz cage. Paired electrodes 2, 3 are supplied with high-frequency energy from the outside, and electricity is discharged in a region 20 in which a uniform electric field is formed. First glow discharge in the uniform electric field region and second glow discharge having high luminance in opened holes or opened grooves 14 having planes or recessed shapes to other electrodes are generated simultaneously by forming the opened holes or the opened grooves 14 to the electrodes. Accordingly, plasma concentrates in the electrode central sections 20.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plasma vapor phase reaction method (ie, a plasma vapor phase coating method or a plasma etching method, hereinafter simply referred to as a plasma process, or PP method).

The present invention relates to a PP method, in which a parallel plate type electrode system is used, a substrate having a surface to be formed is disposed in a positive column region, and a large amount of film is formed or etched.

Conventionally, in the parallel plate type pp method, a method is known in which the surface to be formed uses a cathode dark region or an anode dark region generated on or in the close vicinity of a cathode or anode.

In such conventionally known methods, the area of the surface to be formed cannot be made larger than the area of the electrode. Therefore, although it has the advantage of being able to produce a semiconductor, insulator, or conductor film on a large-area substrate, it is not possible to have a surface on which it is formed that is 5 to 30 times the area of the electrode.

That is, it has the disadvantage that it cannot be mass produced.

For this reason, when trying to fabricate a non-single crystal semiconductor containing amorphous silicon by the PCVD method, the substrate 1-
It has a major drawback in that it is expensive, with a manufacturing price of 1 yen or more per unit, and cannot be applied to manufacturing inexpensive products such as solar cells.

In addition, the film formation rate was not sufficient at 1 to 2 people/second, and from these points, the PCVD method, which has high productivity and a high film growth rate of 3 to 10 people/second, was desired. .

The present invention has been made to achieve this object.

That is, the method of the present invention uses a positive column of plasma glow discharge. In the present invention, substrates having formation surfaces in the positive column region are arranged in parallel and spaced apart from each other. Regarding the PCVO method using such a positive column, patent applications 57-163729 and 57-1637, which are filed in accordance with the present invention,
30 (Plasma gas phase reactor) (September 20, 1982)
(Applications filed in Japan).

The present invention allows the reaction to take place in such a positive light column, thereby achieving mass production. However, since the positive column generally spreads out over a large space, the plasma density near the surface to be formed decreases, and as a result, this method has another drawback in that a film growth rate comparable to that of a method using a dark region can be obtained.

By removing such defects, the positive column can be converged, that is, the spread of the discharge plasma can be suppressed, and the plasma density in the center can be increased, the active reactive gas can be increased, and the film growth rate can be improved. It is characterized by increasing the size by 2 to 3 times.

Figure 1 shows a parallel plate type electrode (2) in the conventional method.

(3), its lines of electric force (5), and an equipotential surface (15) that is perpendicular to the lines of electric force. These electrodes are placed in a reaction vessel (4) under reduced pressure,
A reactive gas (7) is supplied from one side of this electrode.
6) is released and a film is formed on the surface of the other substrate (1).

In FIG. 2(A), 13.56 Ml1z is applied between the electrodes (2) and (3) from the high frequency power source (10).

Unnecessary reaction products are exhausted to the outside through a valve (11), a pressure regulating valve (12), and a vacuum pump (13) in an exhaust system (8).

This conventional method has another drawback in that the electric lines of force (5) are applied perpendicularly to the surface to be formed, thereby damaging the surface to be formed.

In FIG. 1(B), needle-like electrodes (9) are arranged at a distance from one of the electrodes (2) in FIG. 1(A).

Here, the electrodes (2 x 50 cn + x 50 cm), the spacing between the electrodes (2>, (3)) was 4 cm, the length of the needle-shaped electrodes was 1 cm, and the spacing was 5 cm. Such needle-shaped electrodes were arranged in the apparatus shown in Fig. 1 (A). At the same time, the electric lines of force are distributed from the needle-shaped electrode and are supplied in a spreading direction, and are applied perpendicularly to the substrate (1).

The equipotential surfaces (15) are only provided perpendicular to the lines of electric force. For this reason, even when the needle electrode is installed in the device shown in Figure 1 (A), although it has certain features such as facilitating discharge initiation, it does not improve the film quality or film growth rate of the film. There wasn't.

FIG. 2 shows an electrode and its outline in the PP method of the present invention, that is, the PCVD method or the plasma etching method. The other parts of this reactor conform to the above-mentioned patent application of the present invention type.

In the drawing, this pair of mesh electrodes (2>, <3>
and a substrate (1), (1') having a surface to be formed.

The supply of reactive gas (23) leads to the quartz hood (21) and through the mesh electrode (2) to the positive column region (5). In the positive column area, electric lines of force (5) are placed on the back side in close contact with each other.
The substrates (1), (1) are placed parallel to the . Furthermore, this substrate is surrounded by a quartz cage.

The reaction product is exhausted through the lower hood (22) and then to the exhaust (2).
4) Let.

High frequency energy is supplied from the outside to the pair of electrodes (2) and (3), and a discharge is generated in a region (10) where an equal electric field is formed.

In this drawing, the electrode area is 25cmφ (electrode spacing 15cm
) 70cm x 70cn+ (electrode spacing 35c)
m), and by forming an opening or groove (14) in this electrode, the first glow discharge in the uniform electric field region of the present invention and the opening or groove (14) are formed. A high-intensity second glow discharge was generated at the same time.

As is clear from this drawing, the lower electrode (13) is, for example, simply a hole or groove (0.5-3 cm, for example about 1 cm).
φ or about ICll1). In another example, as in the case of the upper electrode, this opening or groove is provided with a curved surface (16) in the opposite direction to the positive column, and is in a concave state.

As shown in FIG. 1(B), the lines of electric force (5) are not acicular, that is, convex on the discharge surface (on the contrary, in the device of the present invention, by making the electrodes flat or concave, the lines of electric force (5) are in the region (17 )
, (18), and a high-density electric flux region is generated. By doing this, in addition to the first plasma discharge (27>, (28)) generated by the conventionally known uniform electric field, a high-intensity second plasma region is generated due to the generation of high-density electric flux. (17>, (1B)) could be generated simultaneously.

As a result, while conventionally the positive column (25) had a large horizontal spread and the plasma was dispersed, the present invention's PP
A layer was created which had a tendency to collect (35) in the electrode center (20) in the device.

Furthermore, by performing a second discharge of this high-intensity plasma, the film growth rate could be doubled or tripled.

For example, using 100% silane, 0.1 torr, 3
0W (13,56MHz), the electrode surface is 25cmφ,
When the electrode spacing was 15 cm, the film growth rate was 1 to 2 people/sec when there were no openings or grooves (14) when 6 substrates were arranged at 10 cm + + (total area 600 aa). but,
By simply providing several holes or grooves (14) on each electrode, it has become possible to increase the number of people per second by two to three times to 4 to 6 people per second.

Compared to the conventional method shown in Figure 1, this not only allows the amount of substrate to be disposed to be 5 to 20 times larger, but also increases the film formation speed by 2 to 3 times, resulting in double It can be seen that it is an excellent struggle.

In addition, as a result of the convergence of the positive light column, this positive light column splashes the inner wall of the reactor, activating water adsorbed on the inner wall and impurities attached to it, and incorporating it into the coating.
Considering the fact that the possibility of deteriorating the film quality can be further reduced, it has been found to be triple superior.

In addition, in the above description, only the preparation of the semiconductor film was described. However, it is also effective to use the method of the present invention for plasma etching used for positive columns.

That is, for the substrate to be etched, CFjBr,
The method of the present invention is particularly effective when an etching gas W such as CHFJ is introduced to perform anisotropic etching on a surface to be processed on a substrate in a direction parallel to the surface of the substrate. That is, plasma etching is only supposed to cause deep (anisotropic etching) in the vertical direction of the substrate. is parallel to the substrate, and C
A high-intensity plasma discharge is generated in addition to a so-called one-stage glow discharge, which provides enough energy for the -F bond, which has a high bonding energy, to decompose and form radicals, thereby generating a large amount of F radicals. It was possible to perform selective etching only on the convex portions of the substrate, and the etching could be carried out particularly effectively.

The present invention is supplemented by further adding Examples below.

Example 1 A case is shown in which silicon is formed by the PCVD method using FIG. 2. Numbers correspond to FIG.

In the drawing, three high-intensity plasma discharge areas are provided on the lower mesh electrode (3) and four areas on the upper side. The substrate (1) is placed in a quartz holder, and this jig is
It rotates at ~5 times/minute.

Non-single crystal silicon was prepared using silane as a reactive gas. That is, the substrate temperature was 210°C and the pressure was 01 orr.

Silane 30cc/min, discharge output 30W (13,56P
IIIz), it takes 20 minutes to reach a thickness of 5000 A, and the film growth rate is 4.1 people/sec.

No discharge was observed in the space outside the quartz holder where the substrate was placed, indicating that there was little possibility of spattering the stainless steel wall of the reaction vessel and introducing impurities such as water.

Six 10cm x 10c+aA' substrates are arranged, and the yield of reactive gas (components forming the film/supplied gas, etc.) is nearly 8 times that of the shape shown in Figure 1 (A). Ta. Further, in Fig. 2, apertures or grooves (
14) was able to be doubled compared to the case where it was not provided.

Example 2 This figure 3 shows methane (CI!4) and silane (SiH4)
and 1:1(7) ratio, 5ixC+-t(
A film with 0<x<1) was prepared.

In the drawing, a high-intensity plasma discharge was observed in the open groove. Compared to the case without such local gB discharge, there were a large amount of 5i-C bonds that became silicon carbide, and even if chemical etching occurred, the film remained hard and dense. Others are Example 1
It is similar to

Embodiment 3 This embodiment is a case where FIG. 2 is used as plasma etching.

FIG. 3 shows the case where the silicon nitride film at the apex of the convex portion is removed. As shown in Figure 3 (A), the surface of the silicon single crystal substrate (1) has convex portions (3) rllll~2μ and concave portions (
1 to 2μ). The depth was 1.5μ. Furthermore, silicon nitride (31) was formed to a thickness of 1000 nm on the upper surface, and then a resist (32) was coated.

Next, using the apparatus shown in FIG. 2, 5% oxygen was added to the CF5 Br using plasma in a direction perpendicular to the drawing (parallel to the surface of the substrate). The frequency of this plasma was set as low as 30 KHz.

Then, as shown in FIG. 3(B), only the resist (32) on the protrusion (33) could be removed. Furthermore, the silicon nitride was removed and the resist was removed by a known method to obtain FIG. 3(C).

Thereafter, by performing a process such as selectively mixing impurities into the convex portions, various semiconductor devices could be manufactured.

Example 4 In this example, a silicon single crystal has irregularities, the upper surface is made flat, and the recesses are filled with silicon oxide. That is, as shown in FIG. 3(A), silicon nitride (
33) and silicon oxide (32) were laminated.

Thereafter, the protrusions are removed using a plasma etching device that applies an electric field parallel to the substrate surface as shown in FIG. 2, and the protrusions (33
) and the recess (34), with the silicon oxide (23) remaining on the upper surfaces of the recesses (34) to make these upper surfaces flat.

Embodiment 5 This embodiment is a case where the concave portion of the electrode portion in a VLSI is removed. That is, a case is shown in which the concave portion of the electrode portion is filled with a conductor to substantially form an electrode lead pattern.

In FIG. 4, the semiconductor surface (1) includes a buried field insulator (36), source and drain regions (37),
(38 and gate (39), interlayer insulator (41), 1-2
It has an opening (42><depth 0.5 to 2μ) of μφ.

Even if a lead (43) is not formed in this electrode portion, it is not possible to cut a thin pattern of 2μ or less even by using electron beam exposure technology because of the recess in the opening groove (42). For this reason, in this embodiment, silicon-doped aluminum (43) was formed on the entire surface to a thickness of 0.5 to 2 .mu.m. Then, this aluminum has a recess (
40). Further, this substrate was subjected to anisotropic plasma etching using the apparatus shown in FIG. 2 using reactive gas of CCI to remove the protrusions (33). In this way, the upper surface of the concave portion (34-convex convex portion) was made approximately flat as shown in FIG. 4(B).

This made it possible for the aluminum to selectively remain in the openings (42) and to make the upper surfaces of the holes (33) and (34) substantially flat. For this reason, a second aluminum (44) was further added to the top surface and copper was added to 0.2
It was formed to a thickness of ~0.5μ.

Thereafter, a lead pattern with a width of 1 to 2 .mu.m could be obtained using a known plasma etching device that performs anisotropic etching in the vertical direction.

FIGS. 4 and 3 are extremely necessary for the fabrication of three-dimensional devices in which semiconductor elements are vertically superimposed on a substrate.

As described above, the present invention is as shown in FIG.
In this device, an aperture or groove is provided in the electrode, and lines of electric force are converged in this region to generate a high-intensity discharge. Such a method is shown in Fig. 1 (If a substrate is disposed on parallel plate electrodes, a part of this substrate may have a high electric flux reaction area. However, it is necessary to take into account the spatter effect due to high intensity discharge. It is effective to improve the film quality by arranging the surface to be formed on this discharge and reducing its spackle (damage).As a result, the method of the present invention allows the substrate to be parallel to the lines of electric force in the positive column. It has been found that this method is particularly effective for the PP method.

Further, the embodiments of the present invention include non-single crystal St, and 5ixC+1
It is. However, using silane and germane, 5ixGe+
(0x<1>, Sμs using silane and tin chloride
It is valid even if n(<(0x≦1).
ICI.

5 by SiH4 and NI et al.
When forming iO1I with 5fltl and NLO, an insulating film is produced by PCVD method, or selectively SiO*ISt+5t)N4 by plasma etching method.
The present invention is also effective in removing photoresists and other compound semiconductors.

[Brief explanation of drawings]

FIG. 1 shows a conventional plasma vapor phase reactor. FIG. 2 is an outline of the vicinity of the electrode substrate of the plasma vapor phase reactor according to the method of the present invention. FIGS. 3 and 4 show other embodiments in which a semiconductor device was manufactured using the apparatus of the present invention. Patent applicant CA) CD) (CJ (A) (11)

Claims (1)

[Claims] 1. In a gas phase reaction device using a parallel plate type plasma glow discharge, an electrode region where lines of electric force are concentrated from at least one of a pair of electrodes toward the other electrode is A plasma vapor phase reaction device characterized in that it is constructed by providing a hole or a groove in a part of a flat electrode. 2. A plasma vapor phase reactor according to claim 1, characterized in that the end of the opening or groove has a flat or concave shape relative to the other electrode.