JPS592536B2 - gas injection device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a gas injection device used in a vapor phase growth apparatus.

In a vapor phase growth reaction, the state of the flow of gas introduced into the reaction apparatus is an important factor in determining the uniformity of the film thickness and film quality of the reaction product.

The present invention enables uniformly and efficiently depositing a clean reaction product onto an object by controlling the flow of introduced gas,
The present invention provides a reliable gas injection device.

Conventionally, when depositing a reaction product on a target object using a gas phase chemical reaction, the reaction components are mixed in a base carrier gas, and the mixed gas is heated to an appropriate reaction temperature after preparing the target object. This was carried out by introducing the gas through a gas injection device into a reactor whose temperature was raised to .

FIG. 5 shows a gas injection device used in a conventional vapor phase growth apparatus.

The one shown is a blow-up type gas injection device, which has a gas introduction port 2 below the gas introduction pipe 1, and a gas injection device with a pipe diameter narrower than that of the gas introduction port 2 on the opposite side of the gas introduction port 2. Part 3
', and has a gas ejection port 4 at the tip of the gas ejection part 3'.

FIG. 4 shows a schematic cross-section of a vapor phase growth apparatus using this gas injection device, and the flow of gas injected from the gas injection device will be explained.

The blow-up type gas injection device is arranged at the center of the vapor phase growth apparatus, and a mixed gas containing reactive components is introduced from the gas introduction port 2 of the gas introduction pipe 1 into the reaction chamber 6 from the gas injection port 4. is ejected.

After the ejected gas reaches the upper part of the Pelger 9, it is guided to the lower part of the reaction chamber 6, and a part of the gas is heated to an appropriate temperature for placing the target object T and performing a gas phase chemical reaction. reaches above the susceptor 8.

The mixed gas containing the reaction components undergoes a chemical reaction on the object 7 and the susceptor 8, and a reaction product is deposited on the object 7.

Thereafter, the mixed gas flows toward the center of the susceptor 8 and is again drawn into the upper part of the Pelger 9 while being engulfed by the mixed gas ejected from the gas injection device 1 located at the center.

In other words, the flow of gas in a vapor phase growth apparatus using a blow-up type gas injection device is in a convection state from the center of the reaction chamber to the outside, and a portion of the mixed gas introduced into the reaction chamber is However, the following drawbacks were caused by the fact that only the target object was reached.

(1) The components of the convective gas that reach the target γ are:
The introduced mixed gas components, by-product gases already generated by the gas phase reaction on the susceptor 8, and trace amounts of impurity gases generated in the reaction chamber 6, such as from the susceptor 8 heated to a high temperature and the target object 7. Components generated by the ρ reaction between the diffused adsorbed gas and mixed gas components and the friendly substance 7, such as aluminum compounds generated by the reduction action of alumina hydrogen carriers during 5OS (silicon, on, sapphire) crystal growth, are components of the convective gas. Therefore, the reaction products deposited on the object T cannot necessarily be said to be clean.

(2) A part of the mixed gas introduced into the reaction chamber passes through the gap between the Pel jar 9 and the susceptor 8 and is discharged to the outside of the apparatus from the gas exhaust port 10 disposed below the vapor phase growth apparatus.

Since this gas flow does not contribute to the deposition of the reaction product on the target object γ, the utilization efficiency of the introduced mixed gas decreases.

Next, the conventional gas injection device shown in FIG. 6 has a gas introduction port 2 at the tip of a gas introduction pipe 1, and the other end is sealed by a gas shielding plate 5.

Further, a plurality of gas ejection ports 4 are provided on the gas introduction pipe 1 near the gas shielding plate 5.

This gas injection device is disposed at the center of the vapor phase growth apparatus, similar to the gas injection device shown in FIG.

The ejecting direction of the ejected gas is a lateral direction outward from the center of the susceptor, but since the gas traveling direction in the gas ejecting pipe 1 is from the bottom to the upward direction, the ejected gas is ejected from the plurality of gas ejection ports 4. Each ejected gas is ejected upward rather than horizontally due to inertia.

As described above, a gas injection device in which the gas traveling direction in the gas injection pipe is different from the gas ejection direction has the following drawbacks.

(1) The uniformity of the reaction products deposited on the object placed on the susceptor depends largely on the positional relationship between the gas injection device and the susceptor and the gas ejection speed, so the reaction products can be accurately reproduced. Difficult to deposit on target.

(2) Since the gas ejection direction in the vertical direction is upward rather than horizontal, and the gas flow distribution in the horizontal direction of the gas injection device is maximum in the opening direction of the gas ejection port 4, the amount of gas introduced The ratio of the amount of mixed gas containing reaction components that passes over the target object becomes small, the efficiency of using the introduced gas is poor, and the mixed gas that does not contribute to the reaction on the susceptor is deposited on the inner wall of the Pelger or inside the reaction chamber. An incomplete reaction occurs in the atmosphere, forming a substance different from the reaction product deposited on the target object.

Furthermore, since this foreign substance falls and deposits on the target object, only the target reaction product cannot be deposited on it.

That is, the purity of the reaction product decreases.

The present invention aims to solve these drawbacks, and one embodiment thereof will be described below with reference to the drawings.

FIG. 2 shows the configuration of a gas injection device in an embodiment of the present invention.

A gas introduction port 12 is provided below the gas introduction pipe 11, and the other end of the gas introduction pipe 11 is sealed with a gas shielding plate 13 disposed perpendicular to the gas introduction direction. A plurality of gas ejection ports 1 are provided on a nearby gas introduction pipe 11.
4, and a gas flow control plate 15 disposed in parallel with the gas shielding plate 13 on the opposite side of the gas shielding plate 130 with the gas jet port 14 interposed therebetween.

The gas flow ejected from this gas injection device due to the interaction between the gas flow control plate 15 and the gas shielding plate 13 is as follows:
The vertical flow is regulated and a horizontal force flow is ejected.

Further, since the flow in the vertical direction is regulated, the gas corresponding to the regulated amount is ejected in a horizontally expanded state.

A schematic cross-sectional view of a vapor phase growth apparatus using a gas injection apparatus according to the present invention is shown in FIG. 1, and the flow of gas within the vapor growth apparatus will be described.

The gas injection device is arranged in the center of the vapor phase growth apparatus, and a mixed gas containing a base carrier gas and a reaction component is introduced from the gas introduction port 12 of the gas introduction pipe 11 into the reaction chamber from the gas injection port 14. It is ejected within 16 minutes.

As described above, the flow of the ejected gas is a horizontally parallel flow regulated by the gap between the gas shielding plate 13 and the gas flow control plate 15, and is expanded laterally, that is,
The width of the gas flow in the lateral direction is expanded in the same way as if the opening number of the gas outlet 14 was made larger than the actual opening number, and the target object 11 was placed and a gas phase chemical reaction was performed. It passes over a susceptor 18 which has been heated to an appropriate temperature for cooling.

Thereafter, the gas passes through the gap between the susceptor 18 and the perger 19 and is discharged out of the apparatus from the gas exhaust port 20 provided below the vapor growth apparatus.

The effects produced when using the gas injection device according to the present invention are as follows.

(1) Since the gas flow on the susceptor 18 and the target object 17 is parallel and the lateral gas flow distribution is well-balanced, a reaction product with uniform film thickness and film quality can be deposited and deposited with good reproducibility. becomes possible.

(2) During the vapor phase growth reaction, the entire surface of the target object 1γ is constantly covered by a gas flow containing clean reaction components, making it possible to efficiently deposit and coat clean reaction products. .

(3) Since most of the gas that has passed above the susceptor 18 flows below the vapor phase growth apparatus, the susceptor 18 and the target object 1
Since the adverse effects due to outdiffusion from impurity gases generated on the surface of the substrate 7 can be prevented, clean reaction products can be deposited and deposited.

As described above, when the gas injection device of the present invention is used in a gas phase generation device, a clean reaction product can be uniformly and efficiently deposited on a target object.

[Brief explanation of the drawing]

Fig. 1 is a schematic vertical cross-sectional view of a vapor phase growth apparatus used in an embodiment of the present invention, Fig. 2 is a side view of the gas injection apparatus, Fig. 3 is a plan view of the same, and Fig. 4 is a conventional gas injection apparatus. FIG. 5 is a side view of the gas injection device, and FIG. 6 is a side view of another example of the conventional gas injection device. 11...Gas introduction pipe, 13...Gas shielding plate, 14...Gas outlet, 15...
Gas flow control board.

Claims (1)

[Claims] 1. A gas introduction pipe having a plurality of gas ejection ports on the side surface;
a gas shielding plate disposed at one end of the gas introduction pipe so as to be perpendicular to the gas introduction direction; and a gas shielding plate disposed on the gas introduction pipe on the opposite side of the gas shielding plate via the gas outlet. 1. A gas injection device comprising: a gas flow control plate disposed in parallel with the gas shielding plate and the gas flow control plate, and ejecting gas in parallel with the gas shielding plate and the gas flow control plate.