JPS60116136A - Manufacture of thin film - Google Patents

Abstract

PURPOSE:To equalize the thickness and quality of a thin film formed on a thin film by repeatedly performing an operation for growing the thin film in a vapor phase and an operation for stopping the growth. CONSTITUTION:A substrate 4 disposed in a reaction chamber 1 is heated, the chamber 1 is evacuated through an exhaust system 2 to a vacuum state. Reaction gases are fed from gas inlet systems 3a-3c in this state, and the evacuation by the system 2 is temporarily stopped. Then, the reaction gas in the chamber 2 is sealed under the prescribed pressure. Reaction is performed through reaction exciting means 6 in this state, and the desired thin film is grown on the substrate 4. On the other hand, the gas in the chamber 1 is raised at the temperature as the time goes, and vapor phase decomposition starts at the prescribed temperature or higher. When the gas is evacuated again in the chamber before decomposing the gas, and inert gas is simultaneously introduced into the chamber 1 to stop the growth of the film. Then, the chamber 1 is again evacuated, and similar operations are repeated. Thus, the thickness and quality of the thin film can be equalized.

Description

Detailed Description of the Invention This invention utilizes thermal reaction CVD (chemical vapor deposition, hereinafter also abbreviated as CVD) or plasma CVD.
The purpose of this method is to make the thickness and quality of the thin film uniform on a substrate.

Conventionally, the above-mentioned thermal reaction CVI) or plasma CVD has been frequently used in the manufacturing process of semiconductor devices, etc., but in this type of manufacturing method, a constant pressure or flow is applied in a reaction chamber in which a substrate such as a silicon wafer is placed. When the reactant gas was continuously introduced while exhausting the air so that However, there was a problem in that the film thickness distribution was uneven between substrates. In cases such as phosporous silicate glass (PSQ), Si
n, phosphorus CP) concentration distribution occurs similarly, within the substrate,
The problem was that the film quality varied between substrates.

Recently, as a means to solve these problems, a reaction gas introduction tube is inserted into the reaction chamber, and the reaction gas is introduced into the reaction chamber through a gas nozzle formed on the wall of the introduction tube, which causes a difference in the concentration of the reaction components. Measures have been proposed to prevent this from occurring, but as the size of the substrate increases (when the spacing between the substrates is narrowed by 30%), a concentration difference similar to the above occurs along the surface direction of the substrate, making it difficult to maintain a uniform density. This was not a sufficient solution to improve film thickness and film quality.

However, in the method of growing a thin film on a substrate by thermal reaction CVD or plasma CVD as described above, the present invention includes an operation in which the reaction chamber is first evacuated to a predetermined pressure, and then a reaction gas is introduced to cause vapor phase growth on the substrate. The operation of stopping the vapor phase growth was repeated alternately, and the flow 7 of the reaction gas was substantially stopped during the vapor phase growth to prevent concentration differences of the reaction components from occurring within the substrate and between the substrates. This made it possible to make the film thickness and quality uniform, and succeeded in solving the above-mentioned problems.

Embodiments of this invention will be described below. The equipment used for manufacturing may be any commonly used equipment.

For example, as shown in FIG. 1, a vacuum exhaust system is provided in the reaction chamber, and a gas introduction system 3a for reactant gas and replacement gas,
A device equipped with 3b, 3c, etc. is used.

The reaction chamber contains a substrate such as silicone urethane, etc.
It is now possible to place the boat held in the Z position.
External reaction excitation means 6 such as a heating device and a high frequency coil for plasma generation are provided.

Using the above-mentioned apparatus, the present invention grows a thin film on a substrate by the following operations.

That is, first, the substrates placed inside the reaction chamber are heated to a predetermined set temperature, and the inside of the reaction chamber is heated to an exhaust system.
By exhausting through θ. The vacuum state is 0.05 Torr or less. In this state, the gas introduction systems 3a, 3I),
If a reaction gas is introduced while exhausting through the exhaust system from 3C..., normal reduced pressure CVD will be performed, but in this invention, when introducing the reaction gas, the exhaust system is interrupted. Then, a predetermined reaction gas is introduced into the reaction chamber through the gas introduction systems 3a, 3b...
In the reaction chamber/inside the reaction gas 7 sealed at a pressure of approximately r, not only does no gas flow occur, but the concentration of the reaction gas is also uniform in each part. In this state, when the reaction gases are caused to react with each other via the reaction excitation means B, a desired thin film is grown on the substrate Z.

Note that various reactive gases are used depending on the type of film to be grown, but when using a type of reactive gas that immediately causes gas phase decomposition at a temperature higher than room temperature, the gas When introducing the material, it is necessary to cool it to about -2.0°C before introducing it, and to avoid decomposing it to the optical surface of the substrate. , particles are generated in the reaction chamber/inside, causing dust, etc.

On the other hand, the temperature of the reaction gas sealed in the reaction chamber increases over time because the reaction chamber is not exhausted. As the temperature increases, the growth rate of the thin film also increases, but above a certain temperature, gas phase decomposition of the reactant gas begins. Therefore, before starting this gas phase decomposition, - once again, the exhaust system 2 is connected to the reaction chamber/
At the same time as exhausting the reaction gas inside, the gas introduction systems 3a, 3
By introducing N, gas or other inert gas into the reaction chamber via one of the b..., the reaction gas in the reaction chamber is diluted and cooled to stop the growth of the thin film.

Next, as described above (after stopping the growth of the thin film, the inert gas introduction 7 is stopped, and the reaction chamber is evacuated again by the exhaust system 2, and the reaction chamber is returned to the original vacuum of about O20, ITor r). After returning to the initial state in this way, the operations of growing the thin film and stopping the growth are performed again as described above.However, by repeating the above cycle several times at A desired thin film can be formed to a desired thickness.During the process of growing a thin film, the reaction gas concentration in each part of the reaction chamber can be made uniform, so the film thickness can be controlled within the substrate and between the substrates. , the film quality can be made uniform.

FIG. 2 shows a timing chart in the thermal reaction CVD of the above embodiment, and FIG. 3 shows the plasma CCVD of the above embodiment.
A timing chart for VD is shown. As is clear from FIG. 3, the operation to stop the odor or the growth of the thin film is performed by shutting off exhaust and RF power, and without introducing inert gas.

In the above example, the exhaust system is interrupted during the thin film growth operation, but the exhaust system is not interrupted (
It goes without saying that the present invention can also be carried out even if the displacement is reduced to a very small amount and the flow of gas in the reaction chamber is substantially eliminated.

As explained above, according to the present invention, the operation of growing the thin film in the vapor phase and the operation of stopping the vapor phase growth are repeated, and during the operation of growing the thin film in the vapor phase, no flow of the reactant gas occurs. In addition, since no pressure gradient is generated, there is an effect that the film thickness and film quality can be made uniform regardless of whether the film is a single-component film or a multi-component film. Furthermore, it is possible to increase the density of the substrates arranged in the reaction chamber, and the reaction chamber and exhaust system 7 can be made smaller, which has the effect of increasing mass productivity and making the apparatus more compact.

Furthermore, since the reaction of the reaction gas occurs mainly on the narrow surface of the substrate, coverage can be improved.On the other hand, wafer hand linkage is easy to achieve. It has various effects such as being able to be made very small and obtaining a film quality close to the desired one.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an apparatus for carrying out this invention, and FIGS. 2 and 3 are timing charts of an embodiment of this invention.
Figure 1 is a chart of thermal reaction CVD, Figure 3 is a chart of plasma C
VD (7) Chart. /...Reaction chamber C...Exhaust chamber 3a, 3b, 3G...Gas introduction system D...Substrate S...
... Boat 6 ... Reaction excitation means Patent applicant Dynamic International Co., Ltd. Agent Tadashi Suzuki 1 Figure '2 Timing of thermal-chaosic CVD (example') FILM, 5102 (SiH<+NO)
Procedure NJ, iF (Method) lIr I March 1959 5 To 1 1, Indication of Matter A 11 1982 Special Patent Application No. 2271809R2, Title of Invention Process for Manufacturing Thin Film 3, Overturns Amendment What is the relationship between the applicant and the applicant? Dynamic International Co., Ltd. 4, Agent: ゛16o Telephone (353) 3407 Showa 5
February 28, 2009 [1 (2) Detailed description of the invention in the specification (3) In the drawings,
Figure 2 and Figure 3 7, Contents of amendment (1) Kanji is as attached. (2) Page 40 of the specification, lines 16 to 19 [shown in Figure 2]. '' has been corrected as below. In Fig. 2, Si l-1, + N'O, Si
A timing chart of an example in which an O film was grown by thermal reaction CVD is shown in FIG. →-8it-1. The timing chart i~ of the example in which the film was grown by plasma CVD is shown. C1) The drawing is as attached. 8. List of documents (1) Application for correction 1 copy (2) Correction drawings (Fig. 2, 3) 1 copy Fig. 2 Fig. 3

Claims (1)

[Claims] / A method for growing a desired thin film in a vapor phase on a substrate placed in a reaction chamber by utilizing a chemical reaction of a reaction gas,
After the reaction chamber is evacuated to a predetermined pressure, the reaction gas for vapor phase growth is introduced into the reaction chamber to grow a thin film on the substrate in vapor phase at ℃, and the operation to stop the vapor phase growth on the substrate is alternated. A method for manufacturing a thin film, characterized in that the operation of stopping vapor phase growth is performed by evacuation of the reaction chamber and introduction of an inert gas into the reaction chamber. Method 3: The method for producing a thin film according to item 1 of the ifα section of the patent claim, in which the reaction gas for vapor phase growth is cooled to a low temperature and introduced.The vapor phase growth is carried out via thermal reaction or plasma. Method for producing a thin film according to scope 1