JPS60253213A - Vapor growth device and vapor growth method according to device thereof - Google Patents

Abstract

PURPOSE:To check deposition of a reaction product to the inside wall surface of a reaction chamber, and to contrive to enhance the rate of operation of a vapor phase growth device and yield of manufactured articles by a method wherein HCl gas is supplied into the reaction chamber apart from reactive gas for formation of epitaxial film. CONSTITUTION:When epitaxial films are to be grown on the surfaces of wafers 6, H2 gas and reactive gas are supplied from first nozzles 8, and H2 gas and HCl gas are supplied from second nozzles 21. At this time, gas supplied from the second nozzles 21 goes toward the wall surface inside of a bell jar 2, and moreover after spouted out upwards, flows upward along the wall surface inside of the bell jar 2, circulates at the upper part of reactive gas spouted from the first nozzles 8, and exhausted from an exhaust vent 12 together with reactive gas. The current of reactive gas to go toward the wall surface inside of the bell jar 2 supplied from the first nozzles 8 is controlled according to the gas current thereof, coming in contact with the wall surface inside of the bell jar 2 is restrained, and the Si etching effect of HCl gas acts to the inside wall surface of the bell jar 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a vapor phase growth apparatus for growing an epitaxial film on a semiconductor substrate and a vapor phase growth method using the apparatus.

[Technical background of the invention and its problems]

As a vapor phase growth apparatus, for example, one shown in FIG. 1 is known. In other words, 1 in the figure is a pace, and a quartz pellet 2 is placed on this pace 1, and a reaction chamber 3 is placed on top of the pace 1.
is configured.

Further, a susceptor 4 made of carbine and coated with S1C" is provided in the reaction chamber 3, and this susceptor 4
is rotatably supported.

A plurality of wafers 6 are placed on this susceptor 4. Further, a coil 7 for high frequency heating is provided at the lower part of the susceptor 4, and a nozzle 8 made of a quartz cylindrical tube passing through the pace 1 and the susceptor 4 is further provided. The -F end of the nozzle 8 is sealed by a plate 9, and a plurality of ejection holes 10 are bored in the upper and lower stages in the circumferential direction of the nozzle 8.

Therefore, when forming an epitaxial film on the surface of the wafer 6, first, N
The inside of the reaction chamber is replaced with nitrogen gas by blowing out two gases and exhausting from the exhaust port 12, and then H and gas are blowing out.
After replacing the hydrogen gas, the coil 7 in the surrounding atmosphere
Wafer 6... is heated to around 1200°C. Thereafter, a reactive gas such as 81 (J4 or 81H2C1l* or SiH, and PH3 or B, H, etc.) is supplied using the H1 gas as a diluent gas. As a result, a silicon epitaxial film is grown on the upper surface of the wafer 6. will be formed.

Incidentally, when this film is formed, a polycrystalline silicon film is formed on the exposed upper surface of the susceptor 4, the inner wall of the bell jar 2, and the top wall.

However, since the bell jar 2 itself has relatively low humidity (100 to 500° C.), the polycrystalline film attached to the inner wall of the bell jar 2 has poor density and weak adhesive strength.

Therefore, if the apparatus is operated continuously without removing these adhered films, the adhered films will easily peel off and re-adhere to the wafer 6, causing crystal defects and protrusions in the epitaxial film. Leads to.

In FIG. 1, an infrared radiation thermometer 11 is provided on the outside of the upper part of the belljar 2 to detect infrared radiation from the susceptor 4 and feed it back to the high frequency power source, but this is only a quartz belljar. It is assumed that the quartz belljar 2 is transparent, and if a polycrystalline silicon film adheres to the inner wall surface of the quartz belljar 2, the measurement temperature will naturally become unreliable. The adhesion of the film to the bell jar 2 also changes depending on the type of source gas, the shapes of the bell jar 2 and nozzle 8, the flow rate of the gas, and the like.

In 5iC14, the reduction reaction of the gas does not proceed at low temperatures, so there is little film adhesion.

However, in 5IH4 and 5iH2C12, thermal decomposition or reduction reactions of the gas occur even at relatively low temperatures, so it is important to solve the problem of reaction products adhering to the bell jar.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and its object is to provide a vapor phase growth apparatus and a more preferable method using the apparatus, which are capable of preventing the deposition of reaction products on the inner wall surface of a reaction chamber. It is intended to provide a vapor phase growth method.

5- [Summary of the Invention] In order to achieve the above object, the present invention provides a method in which HCe gas for etching is supplied to the inner wall surface of the reaction chamber, separately from the first nozzle that supplies the reaction gas for forming an epitaxial film into the reaction chamber. A second nozzle is provided to supply the liquid to the target.

[Embodiments of the invention]

The present invention will be described below with reference to an embodiment shown in FIG. Note that the same parts as those shown in FIG. 1 are given the same numbers, and the explanation thereof will be omitted. Inside the reaction chamber 3,
A second nozzle 21 along with a first nozzle 8 supplying dilution gas H2 and a reaction gas (for example J91 C14 gas).
is provided. The ejection hole 22 of this second nozzle 21
is opposed to the inner wall surface of the bell jar 2 and HCI +a.

It is designed to eject a mixture of gases.

In addition, this second nozzle 21 is provided so as to be movable up and down,
The height can be adjusted by an adjustment mechanism (not shown), and the gas flow rate can also be adjusted, so that the optimum conditions can be set.

Thus, when forming an epitaxial film on the surface of the wafer 6, H2 and HCl gases are supplied from the first nozzle 8, and H2 and HCl gases are supplied from the second nozzle 2. At this time, the gas supplied from the second nozzle 2 is ejected upward toward the inner wall surface of the bell jar 2, flows upward along the inner wall surface of the bell jar 2, and is ejected from the first nozzle 8. It circulates above the reaction gas and is exhausted through the exhaust port 12 together with the reaction gas. Due to this gas flow, the flow of the reaction gas supplied from the first nozzle 8 and directed toward the inner wall surface of the bell jar 2 is regulated, and contact with the inner wall surface of the bell jar 2 is suppressed, and the HC
The Si etching effect of l gas acts on the inner wall surface of the bell jar 2.

In this way, the flow of the reaction gas is regulated and the Sl etching effect is exerted, so that the adhesion of reaction products to the inner wall surface of the bell jar 2 is suppressed.

Note that the present invention is not limited to the above embodiment,
As shown in FIG. 3, the second nozzle 31 is inserted into the first nozzle 8, and its spout 22 is opposed to the ceiling wall surface of the bell jar 2, so that H2 and HCl gas are spouted. This embodiment also has the same effects as the above embodiment.

In the embodiment described above, H from the second nozzles 21 and 31
Although an example has been shown in which the Cl gas is ejected at the same time as the reaction gas is ejected from the first nozzle 8, the invention is not limited to this.
The second nozzle 2 may be used to intermittently eject HCl gas from the second nozzle 1 or before or after supplying the reaction gas.
HCl gas may be ejected from 1.31 to remove any deposited film that has already formed, so that the layer is held down to a point where it is not substantially harmful.

Furthermore, it goes without saying that the present invention can be applied to various types of vapor phase growth apparatuses, and can be modified in various ways within the scope of the gist.

〔Effect of the invention〕

As explained above, in the present invention, H (J gas) is supplied into the reaction chamber separately from the reaction gas for forming an epitaxial film. Since this prevents the accumulation of water, it is possible to improve the equipment operating rate and product yield.

In addition, if HCl gas is supplied from the second nozzle together with the reaction gas, the flow of the reaction gas toward the inner wall of the reaction chamber can be restricted by the Si etching effect of the HCl gas and the flow of HC/gas, which further improves This has the effect of reliably suppressing the adhesion of reaction products.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view showing the Tathagata example, Fig. 2 is a side sectional view showing a vapor phase growth apparatus which is an embodiment of the present invention, and Fig. 3 is a side sectional view showing another embodiment of the invention. It is. 6... Wafer (semiconductor substrate), 3... Reaction chamber, 8...
...first nozzle, 21.31...second nozzle.

Claims (1)

[Scope of Claims] (1) A reaction chamber; a first nozzle for supplying a reaction gas for forming an epitaxial film into the reaction chamber; A vapor phase growth apparatus characterized in that the second nozzle supplies the HCl gas to the inner wall surface of the reaction chamber. The vapor phase growth apparatus according to claim 1. (3) The vapor phase growth apparatus according to claim 1, wherein the second nozzle supplies HCl gas toward the ceiling of the reaction chamber. (4 The vapor phase growth apparatus according to any one of claims 1 to 3, wherein the position of the second nozzle and the amount of HCl gas supplied are adjustable. [5] A semiconductor substrate is placed in a reaction chamber, and a reaction gas for epitaxial film formation is supplied from a first nozzle provided in the reaction chamber, and H is supplied from a second nozzle provided in the reaction chamber toward the inner wall surface thereof. (A vapor phase growth method characterized in that vapor phase growth is carried out by supplying J gas. (Recited in claim 5, characterized in that the supply of 63HCl gas is carried out in synchronization with the supply of reaction gas. (7J H) The vapor phase growth method according to claim 5, characterized in that the supply of J gas is performed intermittently.