JPS62144321A - Liquid-phase epitaxy apparatus - Google Patents

Abstract

PURPOSE:To reduce dispersion in composition of an epitaxial layer, in manufacturing a semiconductor element having a double heterostructure, by providing a slanted bottom part of a holder, which is located directly beneath an injecting port, so that used solution does not remain. CONSTITUTION:A boat is placed in the reacting of a liquid epitaxy apparatus. Temperature is increased to 700-800 deg.C in a hydrogen atmosphere. Then the temperature is kept for a specified time period. Thereafter, the boat is slowly cooled at a constant temperature decreasing speed. When the temperature is decreased to a growth starting temperature, a solution well 71 and the like are moved to the direction of an arrow (m) by one cell. At this time, a piston 42 on the solution 62 is pushed down with a tunnel 5. The solution 62 is injected to a gap formed with a substrate wafer 2 from an injecting port 9. The injected solution 62 is moved leftward in the Figure between the substrate wafer 2 and the container wall. Then the solution falls through a hole 93 at the left end and flows into a waste liquid well 8. Since a bottom part 92 of a lower holder beneath the injecting port 9 is slanted, the used solution does not remain.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for manufacturing a semiconductor element having a double heterostructure using an m-v group compound semiconductor.

[Conventional technology]

FIGS. 6 and 4 are cross-sectional views of a conventional sliding boat used to form a double heterostructure epitaxial layer on a substrate wafer when manufacturing an A7GaAs semiconductor laser. In the figure, (υ indicates the center part of the slider, (2) is the substrate wafer, (3) is a holder for holding the substrate wafer (2), (4υ, (c)... is the piston, (5 ) is a tunnel for pushing down the piston αυ, etc., (6B, (63)... are melt for growth, aυ, σ2... are melt reservoirs, and (8) is a waste fluid reservoir.

Next, the epitaxial growth method will be explained. First, the boat is kept at a high temperature in a hydrogen atmosphere for a certain period of time, and then cooled down at a certain rate of temperature drop. When the temperature drops to the growth starting temperature, the melt reservoir Qυ, (72)... is moved in the direction of the arrow in the figure. Move it by 1N to complete the arrangement shown in Figure 4.

At this time, the piston (4 rims are tunnel (5)) on the melter.
As a result, the melt bag is injected into the gap between the two substrate wafers (2).

A part of the injected melt (6) remains between the substrates (2), and the rest is discarded into the waste liquid reservoir (8).

Epitaxial growth begins when the melt tank is injected in this way, and after growth is performed for a predetermined time, the melt tank is moved by one more tank (the force is moved in the direction of the arrow (b) in the figure). A new melt is injected, and all of the original melt is washed away and replaced by the new melt. In this way, multilayer thin film crystals are continuously grown in one growth.

[Problem that the invention seeks to solve]

In the conventional boat as described above, the bottom (9υ
is at a right angle, so the new melt is at right angles to the old melt (6
When the melt 2 is washed away, the old melt pen remains at the corner of the bottom (91) of the holder (3) below the injection port (9), and the melt is not completely replaced. Therefore, the composition of the epitaxial layer has been one of the causes of variation.

This invention was made to solve the above-mentioned problems, and aims to improve the structure of the board so that no old melt remains, and to reduce variations in the composition of epitaxial 1 smoke. .

[Means for solving problems]

In order to achieve the above object, the present invention provides a liquid phase epitaxial growth apparatus in which the bottom of the holder, which is directly below one injection port, is inclined.

[Effect]

According to one embodiment of the present invention, there is no mixing of new melt and old melt, so there is little variation in the composition of the epitaxy cell layer.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure and FIG. 2, (1) to (8) are almost the same as those of the conventional device shown in FIG. 3 and the fourth factor,
An improvement is that the bottom part of the holder (3) into which the melt is injected is tilted, so that the old melt does not remain in the corner of the holder (and is completely washed away by the new melt). It is in.

Next, when epitaxial growth is performed using the boat according to the present invention, the boat is first placed in a reaction tube of a liquid phase epitaxial growth apparatus and heated to 700 to 800°C in a hydrogen atmosphere.
After raising the temperature to a certain point, hold it for a certain period of time. After that, the boat is slowly cooled down at a constant temperature drop rate, and when the temperature has dropped to the temperature at which growth starts, the melt reservoir συ etc. in Figure 1 are marked with the arrows (
e) by one tank [see Figure 2]. At this time, the piston (6) on the melt [F]a moves into the tunnel (5
), and the melt (62) is injected from the injection port (9) into the gap between the substrate wafers (2).The injected melt (621) moves between the substrate wafers (2) to the left in the figure. After that, it falls from the leftmost hole (93) and flows into the waste liquid reservoir (8).
It remains in the gap and epitaxial growth takes place. After epitaxial growth for a predetermined time, the melt reservoir σ
By moving υ, etc. by one more tank in the direction of arrow 6n1 in Fig. 1, the next new melt (63) is injected from the injection port (9), and the melt between the substrate wafers (2) is completely washed away. Since the bottom (92) of the holder below the inlet (9) is slanted, no part of the old melt remains as in the conventional case.

As described above, multilayer epitaxial layers are grown by sequentially replacing the melt.

In the above example, the boat used for liquid phase epitaxial growth of an ALGaAs semiconductor laser was explained, but if such a structure is used, the same effect as above can be obtained with other liquid phase epitaxial growth equipment. Let it go.

〔Effect of the invention〕

As described above, according to the present invention, the bottom of the holder below the injection port is tilted, so that the old melt does not mix with the new melt as in the conventional case, and the composition of the grown epitaxial layer changes. Variations can be suppressed.

[Brief explanation of drawings]

1 and 2 are cross-sectional views showing a liquid phase epitaxial growth apparatus according to an embodiment of the present invention, and FIGS.
The figure is a cross-sectional view showing a conventional epitaxial growth apparatus. In the figure, (1) is the center of the slider, (2) is the substrate wafer, (3) is the holder, αη, (6), ... are the pistons, (5) is the tunnel, (62), +6 rise, ... is melt, (71), σ2. ... is a melt reservoir, (8) is a waste fluid reservoir, and (9) is a melt injection port. Note that the same reference numerals in each Nanchu indicate the same or equivalent parts. Agent Patent Attorney Masaru Sato Figure 1 Figure 2 Figure 3 1 62 Do 9 38

Claims (1)

[Claims] In the push-out growth method, which performs epitaxial growth by injecting an epitaxial growth melt between two substrate wafers facing each other at a fixed interval, the bottom of the holder, which is directly below the injection port, is tilted diagonally. A liquid phase epitaxial growth apparatus characterized by: