JPS63289925A - Plasma treatment method and device - 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 a plasma processing method and apparatus, and in particular to a microwave method suitable for increasing the efficiency of plasma processing using electron cyclotron resonance (ECR). The present invention relates to a plasma processing method and apparatus.

[Conventional technology]

The conventional magnetic field microwave plasma processing method is
As described in No. 6-155535 and No. 57-133636, plasma active species are generated in the plasma generation chamber, and the active species are placed at a position sufficiently in front of the maximum active species production rate region using a divergent magnetic field, etc. The process was performed by applying a plasma stream to the substrate to be processed.

In this method, as described in Japanese Patent Application Laid-Open No. 57-82955, a method for simultaneously processing a plurality of substrates to be processed includes arranging a plurality of substrates on the same plane and simultaneously applying a plasma stream to the substrates.

[Problem that the invention sought to solve]

The above-mentioned conventional technology uses a method of applying a plasma flow to the surface to be processed as plasma processing, and uses electron cyclotron resonance (hereinafter referred to as EC), which is the region where plasma active species are maximum generated.
R) position and plasma processing characteristics are not considered, and in order to process multiple substrates, a large-diameter plasma source is required, resulting in the large size of the processing equipment. There was a problem that required compatibility.

An object of the present invention is to improve the above-mentioned disadvantages.

[Means for solving problems]

The above object is achieved by arranging a plurality of substrates to be processed in multiple stages parallel to each other in the direction of microwave propagation, and positioning the ECR between each substrate.

[Effect]

In magnetic field microwave plasma processing, processing characteristics such as film formation and etching are almost determined by the type, concentration, and lifetime of plasma active species. The maximum generation position of plasma active species is the ECR position, the type and concentration of the active species are determined here, and whether or not they reach the object to be processed within their lifetime is determined by the distance between the ECR position and the object to be processed. Microwaves pass through materials with low free electron concentration, such as semiconductors such as Si, and insulating materials, so the semiconductor substrates to be processed are placed in multiple stages perpendicularly and parallel to each other in the direction of propagation of the microwaves. By positioning the ECR between the substrates, it is possible to perform batch processing of a plurality of substrates with the same processing characteristics as film forming or etching rate, film quality, etching selection ratio, etc., as in batch processing. Since the substrates to be processed are arranged in parallel in multiple stages in a barrel shape, it is possible to increase plasma processing efficiency without particularly requiring a large diameter plasma source or an enlarged apparatus.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic diagram of the main parts of the plasma processing apparatus of the present invention. This device consists of a vacuum container 1. Microwave introduction tube 2 (microwave 3 oscillator is omitted from illustration), ECR generation coils 4, 5
．． Exhaust port 6 (exhaust system not shown) 9 Reaction gas supply pipe 7. Plasma gas supply pipe 8. Substrate holder9. Board storage room 10.
The vacuum container 1 has a minimum diameter of 120 [n'a]φ,
It has a maximum diameter of 450 (no) φ and a length of 850 mm, and the top of the conical shape is made of quartz and serves as a microwave introduction window 11. The substrate holder can move in the direction of the center axis of the container and rotate around the center axis. FIG. 2 shows the magnetic flux density distribution on the central axis of the vacuum vessel.

The dashed line is 2.45 (for GHzl microwave,
Shows the magnetic flux density value that satisfies the ECR conditions. The magnetic flux density distribution was controlled by adjusting the current values of the six magnetic field generating coils 4 and 5.

A silicon wafer with a diameter of 100 (n oil) was used as the substrate 12 to be processed, the surface to be processed was oriented toward a microwave introduction tube, and an amorphous silicon (hereinafter referred to as a-5i) film was formed. 2.45 (GHz) from the microwave introduction pipe
Microwave was introduced, and helium (He) was introduced at 40 (mQ/min) from the plasma gas supply pipe, and monosilane (Silla) was introduced at 40 Cm n 7 m1 from the reaction gas supply pipe.
n) Introduced and 8 by the magnetic field generating coils 4 and 5
As shown in FIG. 2, a magnetic flux density of 75 (Gauss) was continuously generated in the film neck region of the substrate, and a-3i was simultaneously formed on 10 substrates. The reaction pressure is I x 10-
' (Torr). The average film formation rate is 0 within 10 tons.
．． 2 [μm] and the film quality has a photoconductivity σp of 3 x 10-
6Cs/an), dark conductivity σ is 2 X 10-1
8(s/a++3).

At this time, the substrate transmission with the largest intra-lot difference is the 1st substrate closest to the microwave introduction position and the 10th substrate farthest, and the difference in deposition rate is ±5 [
%], σ, and σ4 were both ±3 [%]. The difference within the substrate is greatest at the first substrate position, and the difference is ±7% in the deposition rate, σP, σ
d was ±3 [%] and ±4 [%]. In addition, when the substrate was rotated 60 times per minute by the substrate holder 9 and reciprocated 6 times per minute at a distance of 40 (mm), the first
The difference in deposition rate between the 1st and 10th films is from ±5% to ±
2 [%], the difference between σP and σd decreased from ±3 [%] to ±2 [%], respectively. Also, there is almost no difference depending on the board position, and if we take the first board as an example,
The difference in film formation rate decreased from ±7 [%] to ±4 [%], and σ and σd decreased to ±3 [%] and Ki4 [%] to ±2 [%], respectively.

As described above, according to this example, it was found that even if the substrates to be processed were arranged in parallel in multiple stages and subjected to plasma processing in a barrel shape, it was possible to make the plasma characteristics at each substrate position the same. Therefore, in the microwave plasma processing apparatus according to the present invention, it is possible to increase the plasma processing efficiency without particularly increasing the diameter of the plasma source or increasing the size of the apparatus. Furthermore, reciprocating the processing substrate in the axial direction of the vacuum chamber and rotating it around the central axis has the effect of making the plasma processing characteristics uniform.

In this embodiment, a coil is used to generate the magnetic field, but of course a permanent magnet may also be used.

Equal magnetic flux density in the radial direction of the vacuum container or preferably parallel to the substrate surface is desirable. Furthermore, although different gas species are introduced at different positions, they may be introduced from the same location or from nearby fields. Further, the present invention is effective in forming an insulating film such as a 5iOz film, and in plasma processing such as etching.

〔Effect of the invention〕

According to this embodiment, in microwave plasma treatment,
Since multiple substrates can be processed equally without any differences in processing characteristics without the need for a larger diameter plasma source or larger equipment, plasma processing efficiency can be increased, resulting in improved throughput. There is.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a plasma processing apparatus according to an embodiment of the present invention, and FIG. 2 is a magnetic flux density distribution diagram on the central axis of a vacuum container. 1...Vacuum container, 3...Microwave, 4,5...
Magnetic field generating coil, 7... Reaction gas supply pipe, 8... Substrate holder, 11... Microwave introduction window, 12... Substrate to be processed.

Claims (1)

[Claims] 1. Microwave introduction pipe, reaction gas supply pipe, exhaust gas system,
In a plasma processing apparatus that uses electron cyclotron resonance and has a magnetic field generation section and a vacuum container, multiple substrates to be processed are arranged in a vacuum container in a row almost perpendicular to the direction of microwave propagation, and these are processed simultaneously. A plasma processing method characterized by: 2. The plasma processing method according to claim 1, wherein the electron cyclotron resonance is generated between the substrates to be processed. 3. The plasma processing method according to claims 1 and 2, characterized in that the electron cyclotron resonance is continuously generated in the direction of the central axis of the vacuum vessel within the area where the substrate to be processed is installed. 4. The plasma processing method according to claim 1, wherein the plasma processing target substrate is moved vertically, horizontally, and rotationally to make the plasma processing uniform. 5. Microwave introduction pipe, reaction gas supply pipe, exhaust gas system,
A plasma processing apparatus that uses electron cyclotron resonance and has a magnetic field generating section and a vacuum chamber, and is characterized in that substrates to be processed can be lined up almost perpendicular to the direction of propagation of microwaves and installed in the vacuum chamber. Plasma processing equipment. 6. The plasma processing apparatus according to claim 5, further comprising magnetic field strength generating means for causing the electron cyclotron resonance between the substrates to be processed. 7. Claim 5, characterized by comprising a magnetic field strength generating means that causes the electron cyclotron resonance to occur continuously in the direction of the central axis of the vacuum vessel within the area where the substrate to be processed is installed.
6. The plasma processing apparatus according to item 6. 8. Claim 5, characterized by having a jig for moving the plasma-treated substrate vertically, horizontally, and rotationally.
8. The plasma processing apparatus according to items 7 to 7.