JPS5812827Y2 - Saturator for vapor phase growth - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a saturator that mixes and saturates a source gas into a carrier gas when vapor phase epitaxial growth of a semiconductor such as silicon or a III-V compound is performed.

Conventionally, the technique of growing an epitaxial crystal layer of silicon, ttt-v compound, etc. by a vapor phase growth method is well known.

Considering gallium arsenide as an example of a 1n-v compound, the most common method for growing it is to use gallium and arsenic trichloride as raw materials and hydrogen as a carrier gas.

Gallium is placed in a growth reaction tube, but arsenic trichloride, which is liquid at around room temperature, is stored in a container, and hydrogen gas is passed through this container to saturate the arsenic trichloride vapor in the hydrogen gas. Introduced into the reaction system.

FIG. 1 is a schematic diagram of the most common saturator conventionally used.

Hydrogen gas sent from pipe 1 forms bubbles in liquid arsenic trichloride 3 stored in container 2 and rises upwards, saturating the arsenic trichloride vapor during that time, and then flows out from pipe 4. It is discharged and led to the reaction system.

This structure has the disadvantage that bubbles are generated to release gas in the liquid, resulting in discontinuous gas flow, especially when the gas flow rate is low. Ta.

Furthermore, when the flow rate was high, large bubbles were generated, causing arsenic trichloride to scatter and collect in the side arms of the discharge pipe, resulting in adverse effects.

The purpose of this invention is to ensure that the saturation of the raw material gas in the carrier gas is complete, that the degree of saturation at this time is always constant, and that the gas passed through the saturator is a semiconductor gas having a structure that allows smooth flow. An object of the present invention is to provide a saturator for phase growth.

According to the present invention, a plurality of partition plates with a plurality of small holes are installed in a container large enough to be saturated with raw material gas, a carrier gas introduction pipe and a discharge pipe are provided in the container, and the A saturator for semiconductor vapor phase growth is obtained in which a raw material is placed in a container and a carrier gas is flowed through an introduction pipe to saturate the raw material vapor.

According to the saturator of the present invention, the gas flow is extremely smooth.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 is a schematic diagram of an embodiment of the present invention, in which a is a longitudinal cross-sectional view and an A-AFrffi diagram of b a is shown.

In Figure 2, reference numbers 1 to 4 are the same as in Figure 1.
1 is a carrier gas introduction pipe having an opening near the bottom of the container 2; 3 is arsenic trichloride, which is a vapor phase growth raw material contained in the container 2; and 4 is a carrier gas introduction pipe that extends laterally from the upper side of the container 2. The discharge pipe is extended and bent upward, but in the present invention, the outer diameter of the introduction pipe 1 and the container 2 are further adjusted.
A three-stage partition υ plate 5 is provided between the lower end of the introduction pipe and the inner diameter of the container, and from the lower end of the introduction pipe to approximately the middle position of the height of the container.

The partition plate 5 is made of the same high-purity quartz as the container, and has a large number of small holes 6 with a diameter of about 2Wt111.

The reason why the partition plate 5 is made of the same material as the container is, of course, to prevent contamination of the raw material by the partition plate.

In such a saturator for vapor phase growth of the present invention, the container (cylindrical high-purity quartz with an inner diameter of 55 mm and a height of 130 mm) is filled with the raw material to about 70% (arsenic trichloride 400 g).

The carrier gas entering from the pipe 1 becomes bubbles in the liquid arsenic trichloride 3 stored in the container 2 and rises upwards. The condition becomes extremely smooth, and even when the flow rate of the carrier gas is low, it will not be intermittent due to the partition plate 5, and even when the flow rate is high, the large bubbles will be blocked by the partition plate 5, and the arsenic trichloride solution will flow smoothly. Corrosion of the joint between the discharge pipe and the pipe leading into the reaction tube has been reduced due to the liquid that has spattered and accumulated on the side arm of the discharge pipe 4.

However, the degree of saturation in the carrier gas increased.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view for explaining the operating state of a conventional saturator, and FIG. 2 is a sectional view for explaining the operating state of an example of the saturator according to the present invention. The AA cross-sectional view of ba is shown. 1...Carrier gas introduction pipe, 2...
- Container, 3... Raw material for vapor phase growth, 4...
...Discharge pipe, 5...Partition plate, 6...
...A small hole drilled in the partition plate.

Claims (1)

[Scope of utility model registration request] A gas inlet pipe and an exhaust pipe are provided in a container that accommodates a raw material for vapor phase growth, and a button is pressed into a saturator for vapor phase growth that flows a carrier gas through the inlet pipe and exhausts the saturated gas of the raw material through the exhaust pipe. A saturator for vapor phase growth, characterized in that a partition plate with a large number of small holes is provided in a path through which gas entering from the introduction pipe reaches the discharge pipe.