JPH054892A - Carbon boat for liquid phase epitaxial growth - Google Patents

Abstract

(57) [Abstract] [Purpose] When a carbon boat for liquid phase epitaxial growth using a slider is used to grow epitaxially on a substrate, the solution for the epitaxial layer should remain on the substrate surface after growth when there is a difference in the thickness of the substrate. Therefore, the carbon boat is constructed so that such a residue does not occur. [Structure] A slider is fitted into a slider substrate and a through hole formed in the slider substrate, and
It is formed by combining solution reservoirs that can move vertically.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carbon boat for liquid phase epitaxial growth used as a liquid phase epitaxial growth apparatus for compound semiconductors and the like.

[0002]

2. Description of the Related Art Liquid phase epitaxial growth by the slide method is carried out using a carbon boat as shown in cross section in FIG. As shown in the figure, a substrate holder 5 is formed with a substrate housing portion 5 in which the substrate 4 is housed. On the other hand, the slider 1 is provided with an opening for accommodating the first epitaxial layer solution 7 and the second epitaxial layer solution 8, for example. The bottom of this opening is open,
Is held on the substrate holder 6 with the substrate holder 6 as the bottom, and the hook 13 holds the slider 1 on the substrate holder 6.
A predetermined epitaxial thin film can be formed on the surface of the substrate by sliding it in the longitudinal direction and contacting the solutions 7 and 8 with the substrate 4 successively.

[0003]

When liquid phase epitaxial growth is performed by the slide method using a carbon boat as described above, the distance between the substrate (wafer) and the solution reservoir is important. If it is too large, the solution cannot be removed well after the epitaxial growth, and the solution remains on the grown substrate. Further, if the substrate is too thick, the solution reservoir collides with the substrate and smooth sliding cannot be performed, so that the solution may remain or scratches may occur on the substrate surface. In order to solve this problem, a mechanism for adjusting the depth of the substrate housing portion by screws has been devised (for example, Japanese Patent Application No. 56-173827). However, in such a method, it is necessary to adjust each time the thickness of the substrate changes.

[0004]

In order to solve the above-mentioned problems, the present invention has improved a slider which constitutes a carbon boat for liquid phase epitaxial growth, and the slider is constituted by a slider substrate and a solution reservoir independent of the slider substrate. By fitting the solution reservoir into a through hole formed on the substrate surface so that the solution reservoir can be moved in the vertical direction with respect to the substrate, and at the lower end of the solution reservoir, an upward inclination is given in the traveling direction of the slider during growth, When the slider advances, the slight unevenness in the substrate holding portion of the substrate holder can be smoothly advanced. The present invention will be described below with reference to the embodiments shown in FIGS. The same parts as those in FIG. 6 are designated by the same reference numerals. 1 is a top view and FIG. 2 is a cross-sectional view. The slider 1 is a slider substrate 9
And the first and second epitaxial layer solution reservoirs 2 and 3. The number of solution reservoirs is not limited to two in the figure.
These independent solution reservoirs 2 and 3 are open vertically.
The solution reservoirs 2 and 3 are fitted in holes corresponding to the outer cross section of the solution reservoir provided in the longitudinal direction of the slider substrate 9 and penetrating the slider substrate surface so that the solution reservoirs 2 and 3 can move vertically with respect to the slider substrate 9. Be combined. The slider substrate 9
The lower surface of the is provided with legs 10 on both lower sides in the longitudinal direction. The substrate holder 6 has a substrate housing portion 5 formed on its surface, and guide portions 11 contacting the leg portions 10 on both sides of the slider substrate 9 are provided on both sides in the longitudinal direction thereof. Further, the lower surfaces of the respective solution reservoirs 2 and 3 which are front portions in the sliding direction during the liquid phase epitaxial growth of the slider 1 are inclined upward to form an inclined surface 12. The widths of the lower openings of the solution reservoirs 2 and 3 are formed to be smaller than the width of the substrate 4, and the depth of the substrate housing portion 5 is set to the depth of the substrate 4.
The thickness is the same as or slightly shallower.

[0005]

FIG. 3 shows the state before the growth, and FIG. 4 shows the state during the growth of the first epitaxial layer. In the state of FIG. 4, the solution reservoir 2 is on the substrate 4, but between the state of FIG. 3 and the state of FIG. Even if thicker than the above, the inclined surface 12
Due to the presence of, the solution reservoir 2 rises slightly, and a smooth slide becomes possible. FIG. 5 shows a state during the growth of the second epitaxial layer. In this case, the solution slides smoothly from the position shown in FIG. 4 to the position shown in FIG. 5, and the solution reservoir 2 slightly descends by its own weight to come into contact with the surface of the substrate holder 6, and the solution reservoir 3 slightly ascends to rest on the substrate 4. Become. Since a smooth slide state is possible in this way, it is possible to reduce the amount of solution remaining on the substrate surface after epitaxial growth.

[0006]

[Test Example] Using this carbon boat, two AlGaAs epitaxial layers were grown on a GaAs substrate.
The amount of the epitaxial growth solution is shown in Table 1. Two thicknesses of the substrate 4 were tried, 400 μm and 420 μm. The depth of the substrate housing portion 5 is 400 μm. In the state of FIG. 3, the temperature was maintained in the reaction tube in which hydrogen gas was flown and the temperature was raised to 850 ° C. Then, the slider was operated from the outside of the reaction tube to the state of FIG. Then, in the state shown in FIG.
The mixture was cooled to 20 ° C. in 20 minutes, further slid the slider, cooled to room temperature, and taken out of the reaction tube. The thickness of the obtained epitaxial layer is 10 μm for the first layer and 8 μm for the second layer.
It was m. Both two types of substrates, 400 μm and 420 μm,
Almost no growth solution remained on the substrate.

[0007]

[Table 1]

[0008]

As described above, according to the present invention, it is possible to obtain an epitaxial substrate in which the growth solution does not remain without special adjustment even if the thickness of the substrate changes in the liquid phase epitaxial growth by the slide method. I can.

[Brief description of drawings]

FIG. 1 shows a plan view of an embodiment of the present invention.

2 is a sectional view taken along line AA of the embodiment shown in FIG.

FIG. 3 is a sectional view taken along line BB of the embodiment shown in FIG.

FIG. 4 is an operation explanatory diagram of the embodiment in FIG.

5A and 5B are operation explanatory diagrams of the embodiment in FIG.

FIG. 6 shows a conventional carbon boat in a longitudinal sectional view.

[Explanation of symbols]

 1 Slider 2 First Epitaxial Layer Solution Reservoir 3 Second Epitaxial Layer Solution Reservoir 4 Substrate 5 Substrate Storage Section 6 Substrate Holder 7 First Epitaxial Layer Solution 8 Second Epitaxial Layer Solution 9 Slider Substrate 10 Leg 11 Guide

Claims (1)

Claim: What is claimed is: 1. A carbon boat for liquid-phase epitaxial growth by a slide method, comprising a substrate holder having a substrate housing and a slider movable in the longitudinal direction of the substrate holder, the slider being a substrate. A carbon boat for liquid phase epitaxial growth characterized in that the slider substrate is provided with a solution reservoir that can move vertically with respect to the holder, the width of the lower opening is smaller than that of the substrate, and the lower surface in the sliding direction has an upward slope.