JPH058154B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a liquid phase epitaxial growth method, particularly a dipping method.

[Prior Art] Among the liquid phase epitaxial methods, the dipping method, which is widely used in the epitaxial growth of GaP, is generally used as a method that is suitable for mass production. In this method, as shown in Fig. 2, the substrates 1 are arranged vertically in an epitaxial growth furnace, and a growth solution 2 is placed in the epitaxial growth furnace.
Growth is performed by bringing the substrate 1 into contact with the growth solution 2 by dropping the substrate 1 onto the substrate holder 3 on which the substrate 1 is set from above (see Figure 3) or pushing it up from the bottom (see Figure 4). It is something.

[Problems to be Solved by the Invention] However, in the prior art, as shown in FIG. 2, two substrates 1 are set in the substrate holder 3 so as to face each other, and the temperature inside the furnace is made uniform. Due to this, the growth solution 2 grows to the same thickness on both substrates 1, resulting in a problem that the film does not grow sufficiently thick.

The present invention has been made in view of the above circumstances, and its purpose is to eliminate the drawbacks of the prior art described above and to enable the growth of thick epitaxial layers on a large number of substrates. We are here to provide you with a method to do so.

[Means for Solving the Problems] The gist of the present invention is to provide a method in which growth is performed by vertically arranging substrates in an epitaxial growth furnace and bringing the substrates into contact with a growth solution, in which the temperature on the growth solution side is The liquid phase epitaxial growth method is characterized by providing a temperature gradient in which the temperature on the substrate side is lower than that on the substrate side.

[Function] By providing the growth solution with a temperature gradient where the temperature is lower on the substrate side, the solvent in the growth solution is transferred onto the substrate and is effectively used for growth.

[Example] An example of the present invention will be described below based on the drawings. FIG. 1 is an explanatory diagram showing the growth method of the present invention, and shows a solution holder 4 in which a growth solution 2 is placed before growth, a substrate holder 3 for vertically setting a substrate 1, and a growth method shown in FIG. It consists of a solution storage part 5 for receiving the growth solution 2, a shutter 7 for separating the growth solution 2 and the substrate holder 3, and a shutter 6 for separating the growth solution 2 from the substrate holder 3. There is. In the present invention, when growing a large number of substrates, each substrate 1
It is desirable to arrange the growth surfaces of the two in the same direction.

Using the above growth jig, epitaxial growth of Ga _1-X Al _X As highly mixed crystal (X=0.65) was performed. Put 500g of Ga, 42g of GaAs, and 3.3g of Al into the upper solution holder 4, and put the size of 50mm into the substrate holder 3.
One board 1 of ×45 mm was set at four locations.
In this state, it was set in a horizontal epitaxial growth furnace, and the temperature was raised to 950°C after hydrogen gas replacement. When GaAs and Al melted to a saturated state in Ga, the shutter 6 was opened and the growth solution 2 was poured onto the substrate. After dropping it into the holder 3, a heater (not shown) placed on the left side of the substrate holder 3 was cooled at a rate of 1°C/min to create a temperature gradient of 1°C/cm in the growth solution 2. . Thereafter, the temperature of the whole was lowered at a rate of 0.5° C./min over 5 hours. Next, shutter 7
was opened, and the growth solution 2 was dropped into the solution storage section 5 at the bottom. When we examined the film thickness of the epiximal wafer grown in this way, we found that it had grown to approximately 250μ.

[Effect of the invention] As explained above, when the film was grown using a soaked temperature distribution as in the prior art, the film did not grow very thick, but by providing a temperature gradient in the growth solution, the growth Solvents in solution (e.g. As and Al)
Since the GaAlAs is transferred onto the substrate and used effectively for growth, it has become possible to grow GaAlAs to a sufficient thickness.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention, and FIG.
The figure is an explanatory view showing a conventional example, and Figures 3 and 4 are cross-sectional views of the growth jig. 1: Substrate, 2: Growth solution, 3: Substrate holder, 4: Solution holder, 5: Solution storage section, 6,
7: Shutter, 8: Piston, 9: Horizontal epitaxial growth furnace.

Claims (1)

[Claims] 1. In a method of performing liquid phase epitaxial growth by arranging a substrate vertically in an epitaxial growth furnace and bringing a growth solution into contact with the growth surface of the substrate, the temperature on the substrate side is higher than on the growth solution side. A liquid phase epitaxial growth method characterized by growth by forming a low temperature gradient.