JPS60239391A - Device for liquid phase epitaxial crystal growth - Google Patents

Abstract

PURPOSE:To perform mutilayered epitaxial crystal growth easily in one cycle by using a growth ampule provided with melt sumps in plural stages and allowing the melt in the melt sumps to move downward to the next sumps successively by an oscillating means. CONSTITUTION:A plural numbers of melt sumps 22-27 are provided to the inside wall of a growth ampule 21 facing oppositely to each other and at different height of the stage alternately. In the first stage, plural numbers of the melt 12, 13, 14 different to each other are charged to melt sumps 22, 24, and 26 at one side in the growth ampule 21, and the ampule 21 is sealed by attaching a growth substrate 28 to the lowermost melt sump 27. Then, the ampule 21 is set in a core tube of a horizontal furnace by slanting the ampule rightward and connected to an oscillating rod of an oscillating means. Then, when the ampule 21 is slanted leftward with an oscillating rod, the melt in each melt sump is transferred to the left side melt sumps 23, 25, 27, respectively, and moved downward. By repeating the procedure, different melts are successively allowed to contact with the growth substrate 28. Thus, multilayered crystal growth is achieved.

Description

TECHNICAL FIELD The present invention relates to a closed-tube tipping type liquid phase epitaxial crystal growth apparatus, and more particularly to a method for performing multilayer crystal growth of epitaxial layers by providing a multilayer melt receiver.

Prior Art Conventionally, a closed-tube chipping type liquid phase growth apparatus was used when a component with a high vapor pressure was contained, and it was possible to grow crystals in two layers or up to three layers using special means.

Figure 1 shows an example of a conventional closed-tube tipping type liquid phase epitaxial crystal growth apparatus.
, a growth substrate 2 is placed, and the growth angle 1 is rotated to bring the growth substrate 2 into contact with the melt 3 (dotted line position) to perform epitaxial crystal growth. In this case, one layer of epitaxial crystal growth is performed. When performing two-layer epitaxial crystal growth, it is necessary to partition the melt, and there is a limit to multilayer growth.

OBJECTS OF THE INVENTION An object of the present invention is to provide a liquid phase epitaxial crystal growth apparatus that can stably and easily perform multilayer epitaxial crystal growth of crystals containing components with high vapor pressure in one cycle. shall be.

Means for Solving the Problems In order to solve the above problems, the present invention uses an ampoule having a plurality of melt reservoirs, and combines the ampoule with a swinging means.
The melts in one melt reservoir are sequentially moved to the next melt reservoir, so that a plurality of types of melts are sequentially brought into contact with the growth substrate.

FIG. 2 is an example of a growth ampoule according to the present invention.
Inside the ampoule (made of quartz) 21 are a plurality of melt reservoirs 22~
27 are provided facing the wall surface of the ampoule 21 and alternately at different levels. Further, a growth substrate 28 is attached to the melt reservoir 27 at the lowest level.

Then, as shown in FIG. 5, this growth ampoule 21 is set obliquely to the horizontal furnace (furnace tube 10, heater 9),
It is coupled to a swinging rod 11 connected to swinging means (not shown).

During growth, as shown in FIG. 4A, a plurality of different melts 12 to 14 are placed in the melt reservoirs 22, 24, and 26 on one side of the growth ampoule 21, the growth substrate 28 is attached to the lowest melt reservoir, and the ampoule is opened. Seal. When the growth ampoule 21 is tilted as shown in Figure B, the melt in each melt reservoir 9 moves to the melt reservoirs 25, 25, and 27 on the left side and descends. Thus, the melt 14 comes into contact with the growth substrate 28, and the eleventh epitaxial crystal growth can be performed.

Next, tilt the growth ampoule to the right and you will see melt reservoirs 23 and 25.
The melt moves to melt reservoirs 24 and 26 on the lower right (however, the melt in melt reservoir 27 falls).Next, when the growth ampoule 1 is tilted to the left, the melt moves to melt reservoirs 25 and 27 on the left. This time, the melt 13 comes into contact with the growth substrate 28, allowing crystal growth to occur. Thereafter, multilayer crystal growth can be performed by sequentially contacting the growth substrate 28 with different melts.

Examples of crystal growth will be shown below to more specifically illustrate the present invention.

Epitaxial crystal growth is performed on a CdTa substrate using the apparatus shown in FIGS. 3 and 4. Melt for the first layer 14
Hl Cd Tm (Hg:Cd: Ta= 15.
0 : 1.0 : 84.0 mol%), and melt reservoir 2
6, and the upper melt reservoirs 24 and 22 are filled with melts 13 and 12 for the second and third layers, respectively. Melt 13.12 is a melt doped with an impurity that has a different composition or a different conductivity type from the melt 14 for the first layer. With this configuration, when the growth ampoule 21 is tilted to the left as shown in FIG. Hty CdT
#) is carried out. For growth, for example, the initial temperature is set to 500-500
The temperature is 10°C and the cooling rate is 0.10°C/min. Thereafter, the epitaxial crystal growth of the second and third layers is performed by repeatedly tilting the growth ampoule from side to side.

Although growth examples have been shown above, the present invention can be widely applied to epitaxial crystal growth containing components with high vapor pressure.

Effects of the Invention According to the liquid phase epitaxial crystal growth apparatus of the present invention, it is possible to stably and easily perform epitaxial growth of a crystal having constituent components with high vapor pressure, and to grow multilayer epitaxial crystals in one cycle. It can be performed.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a conventional closed tube chipping epitaxial growth apparatus, Fig. 2 is a diagram (cross-sectional view) showing an example of a growth ampoule used in the liquid phase epitaxial crystal growth apparatus of the present invention, and Fig. 6 is a diagram showing a liquid phase epitaxial growth apparatus of the present invention. A schematic diagram showing one embodiment of a phase epitaxial crystal growth apparatus. FIG. 4 is a diagram showing the operation of the liquid phase epitaxial crystal growth apparatus of the present invention. (Main symbols) 9... Heater, 10... Furnace tube, 11... Rocking rod, 12°13.14... Melt, 22-27...
Melt reservoir, 28...Growth substrate. Patent applicant Fujitsu Ltd. Representative Patent Attorney Gobe Tamamushi (1 other person) Figure 1 Figure 2 Figure 3 A ″40

Claims (1)

[Claims] A plurality of opposing and alternately stepped melt reservoirs are provided on the inner wall of the growth ampoule, and rocking means is further provided to alternately tilt the growth ampoule in the two directions in which the melt reservoirs are provided, so that the melt in each melt reservoir is faced to each other. A liquid phase epitaxial crystal growth apparatus characterized in that the apparatus is configured to sequentially move the melt to a lower melt reservoir.