JPS61272386A - Gas feeder - Google Patents

Abstract

PURPOSE:To control a plasma stream and to form a thin film uniform in the thickness by providing the second gas introducing means opposite to a plasma conduction port of an electric discharge chamber and providing plural pieces of both the passage of the plasma stream and an injection hole of the second gas to the introducing means. CONSTITUTION:The first gas such as N2 introduced into the inside of an electric discharge chamber 1 via an introduction means 12 is made to a plasma with the microwave which is generated in a magnetron 3 and introduced via the waveguides 4, 5. This plasma stream 15 is introduced into a reaction chamber 7 through the plural passages provided to a tip part 10A of the second gas introduction means 10 via a connection port 8. The introduced plasma stream 15 is induced on a substrate 14 with the second gas such as SiH4 which is injected through plural injection holes via a feed path 17 of the second gas introduction means. The reaction and the combination are performed on the surface of the substrate 14 and a thin film such as silicon nitride is formed on the surface of the substrate 14.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to microwave plasma CVD (CVD) for forming a thin film on a substrate for manufacturing semiconductor devices.
This is related to the gas supply device used in the device.

[Background of the invention]

A conventional microwave plasma CVD apparatus has a first gas introduction means 25 and an introduction window 2, as shown in the drawing (FIG. 5) K described in, for example, Japanese Patent Application Laid-Open No. 56-155545.
3, the discharge chamber 2 communicates with the microwave introduction tube 24' through
1, communicates with the discharge chamber 21 via a plasma extraction window 28, has a second gas guide means 26, and has a base 3.
The reaction chamber 22 accommodates a substrate 31 placed on top of the reaction chamber 22.

An electron cyclotron 29 is provided on the outer periphery of the discharge chamber 21, and below the plasma extraction window 28,
An annular pipe 26A, which is a main part of the second gas introduction means 26, is installed having an arbitrary number of ejection holes (not shown).

In the above structure, since the relative position of each jet hole of the annular tube 26A is different with respect to each substrate 51, each substrate 31
Since the gas flow conditions in each substrate 31 are not similar,
It is difficult to make the thickness of the film formed on the zero surface uniform.

[Purpose of the invention]

In view of the above points, it is an object of the present invention to provide a gas supply device suitable for forming a thin film having a uniform thickness on the surface of a substrate.

[Summary of the invention]

In order to achieve the above object, the present invention communicates a discharge chamber and a reaction chamber that constitute a microwave plasma CVD apparatus, provides a second gas introduction means in the reaction chamber near the communication part, and provides a means for introducing a second gas into the reaction chamber. The means is provided with a plurality of passages through which the plasma flow from the discharge chamber flows, and each ejection hole for the second gas is provided in the vicinity of and parallel to each of the passages, or each of the ejection holes is provided so as to be orthogonal to each of the passages. It is characterized by providing.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a sectional view showing the basic configuration of the same embodiment. In the figure, a discharge chamber 1 is provided within a circular waveguide 5 that communicates with a rectangular waveguide 4 provided with a magnetron 5.
A first gas introduction means 2 is attached to the. Coils 6A and 6B are provided on the outer periphery of the circular waveguide 5.

A connection port 8 is installed below the discharge chamber 1 and connected to the discharge chamber 1.
A second gas introduction means 1o is installed in the vicinity of the communication port 8 in the reaction chamber Z, which communicates with the reaction chamber Z through the communication port 8, and a base 15 on which a substrate 14 is placed below the second gas introduction means 10. is installed. Further, an exhaust port 9 is provided at the bottom of the reaction chamber 7.
As shown in FIG. 6 (A-A sectional view in FIG. 2), a plurality of passages 11 through which the plasma flow 15 flows and buttons near the passages 11 are arranged in parallel. A distal end portion 10A provided with a plurality of second gas ejection holes 12, and a second gas supply path 17 (see FIG. 1) that is formed integrally with the distal end portion 10A and communicates with the second gas ejection holes 12. It consists of a base portion 10B having a base portion 10B. Said passage M11 and jet hole 1
The size and position of 2 shall be appropriately selected depending on the size, position, and number of substrates 14.

Next, the operation of this embodiment configured as described above will be explained.

A first gas, for example, N2, introduced into the discharge chamber 1 via the first gas introducing means 2 is generated in the magnetron 3 and is introduced into the waveguide 4.
, 5 into the discharge chamber 1 and is converted into plasma by microwaves. This plasma gas flow 15 (
A passage 11 provided at the tip 10A of the second gas introduction means passes through the communication port 8 of the discharge chamber 1 to the plasma flow (hereinafter referred to as plasma flow).
is introduced into the reaction chamber 7 through the flow.

The plasma flow 15 introduced into the reaction chamber 7 passes through a supply path 17 provided at the base 10B of the second gas introduction means, and is ejected from the ejection hole 12 provided at the tip 10A of the second gas introduction means. A gas such as 5LHa is introduced onto the substrate 14. As the N2 and 5LH4 react and combine on the surface of the substrate 140, a thin film of silicon nitride is formed on the surface of the substrate 140. On the other hand, the exhaust gas in the reaction chamber 7 is exhausted through the exhaust port 9.

In this case, the coils 6A and 6B generate a magnetic field within the discharge chamber 1, thereby increasing the plasma density.

In the above-mentioned embodiment, the ejection holes 1 of the second to gas introduction means 10
2 was installed parallel to the passage 11 through which the plasma flow 15 flows, but instead, the second gas ejection hole 12A may be provided perpendicular to the passage 11 as shown in FIG. With this configuration, the rate of excitation of the second gas can be increased due to the collision between the first gas and the second gas flowing through the passage 11 and the ejection hole 12A, respectively.

〔Effect of the invention〕

As explained above, according to the present invention, the second
Since the gas introduction means is installed to face the plasma outlet of the discharge chamber, and the second gas introduction means is provided with a plurality of plasma flow passages and a plurality of second gas ejection holes, it is possible to control the plasma flow. Therefore, it is possible to form a thin film with a uniform thickness on the surface of the substrate.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the basic configuration of a microwave plasma CVD apparatus to which an embodiment of the gas supply device according to the present invention is applied, FIG. 2 is a plan view of the gas supply device shown in FIG. 1, and FIG. FIG. 4 is a cross-sectional view showing a modification of the second gas introducing means, and FIG. 5 is a cross-sectional view showing the basic configuration of a conventional microwave plasma CVD apparatus. DESCRIPTION OF SYMBOLS 1...Discharge chamber, 2...First gas introduction means, 7...
Reaction chamber, 8... Plasma outlet, 10... Second gas introduction means, 11... Passage, 12.12A... Ejection hole, 14... Substrate. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] a discharge chamber that has a first gas introduction means and is excited by microwaves to generate plasma; and a reaction chamber that communicates with the discharge chamber and has a second gas introduction means and that grows a thin film on the substrate surface. In the plasma CVD apparatus, the second gas introduction means is disposed opposite to the plasma outlet of the discharge chamber, and the second gas introduction means has a plurality of passages for guiding the plasma flow from the discharge chamber to the substrate side. 1. A gas supply device, characterized in that each ejection hole for the second gas is provided in the vicinity of and parallel to each of the passages, or is provided perpendicularly to each of the passages.