JPH0260065B2 - - Google Patents

Description

[Detailed Description of the Invention] [Summary] Closed-tube tipping in which a substrate and melt material are placed in a quartz ampoule, and epitaxial growth is performed on the substrate by bringing the substrate and melt into contact or separating them by rotating the quartz ampoule. We propose a crystal growth apparatus having a structure that eliminates the influence of quartz fragments caused by quartz pieces scraping together when a substrate fixing jig is inserted into a holding jig that holds the substrate.

[Industrial application field]

The present invention relates to a closed-tube type chipping crystal growth apparatus having a structure that eliminates the influence of quartz fragments generated when a substrate is loaded into a quartz jig.

When liquid-phase epitaxial growth of mercury cadmium tellurium (HgCdTe) crystals is performed on a cadmium tellurium (CdTe) substrate, the HgCdTe melt is grown in a closed tube system using a quartz ampoule because the vapor pressure of mercury (Hg) is high. There is.

In this case, when loading the CdTe substrate into a quartz jig, quartz pieces adhere to the surface of the CdTe substrate, causing crystal defects.

Since quartz pieces are generated at the slit joint of the quartz jig, it is desirable to have a structure in which the influence of this part does not directly affect the substrate when loading the substrate.

[Conventional technology]

2 are perspective views illustrating a conventional closed-tube type chipping crystal growth apparatus.

Figures 2 1 and 2 show growth jigs, each holding jig 21 (consisting of members 21A, 21B, and 21C).
FIG. 2 and FIG. 3 show the entire crystal growth apparatus in which these growth jigs are loaded into a quartz ampool 23.

In FIG. 2 1, a holding jig 21 made of quartz
The substrate holding parts 21A and 21B have a groove cut in the B part so as to support the substrate fixing jig 22 shown in FIG.

In FIG. 2, a substrate fixing jig 22 made of quartz attaches and fixes a CdTe substrate 26 as a substrate.

In FIG. 2, the growth jig to which the crystal substrate 26 is attached, the quartz inner tube 24 serving as a spacer, and the melt 25 are sealed in a quartz ampool 23 and inserted into a horizontal soaking furnace.

27 is a heater for the furnace.

In the crystal growth apparatus having the above structure, the parts where the quartz pieces rub against each other are the substrate holding parts 21A and 21.
B is part A that fits into the quartz ampool 23, and part B that inserts the substrate fixing jig 22 into the substrate holding parts 21A and 21B.

In this method, even if the outer diameter of the holding jig 21 is adjusted to the inner diameter of the quartz ampule 23 and the jig is carefully loaded to suppress the generation of quartz pieces in the A part, quartz pieces still occur in the B part. and adheres to the surface of the crystal substrate.

In addition, growth jigs are usually finished with a mirror finish and chamfered to prevent chips from occurring, but since each growth jig is cleaned with hydrofluoric acid, the quartz surface corrodes and becomes prone to chipping. Pieces are more likely to form.

[Problem that the invention seeks to solve]

In conventional crystal growth equipment, when loading the substrate fixing jig into the holding jig, quartz pieces adhere to the substrate, causing crystal defects such as non-growth in this area, and the surface of the growing crystal becomes uneven. Become.

[Means for solving problems]

The solution to the above problem is to use a holding jig consisting of two cylindrical substrate holding parts 1A and 1B that fit into the quartz ampoule 3, and a melt holding part 1C that connects the two and holds the melt material. 1, and a substrate fixing jig 2 to which a substrate 6 on which a crystal is to be grown is attached and held between the substrate holders 1A and 1B, each of the substrate holders 1A and 1B having 2 Divided members 1A-1, 1A-2, and 1B-
1, 1B-2, and the substrate fixing jig 2 is sandwiched and fixed between each member. This is achieved by the crystal growth apparatus according to the present invention.

[Effect]

Although quartz is a material that is prone to chipping, it is the most suitable material for closed-tube epitaxial growth jigs in terms of purity. Therefore, it is necessary to solve the problem of easy chipping by changing the structure of the jig.

In the apparatus of the present invention, when inserting the substrate fixing jig into the holding jig, the holding jig is divided into two parts and fixed by sandwiching them in two to prevent the quartz pieces from rubbing against each other.

There is no problem in fixing the holding jig divided into two parts because, with the substrate fixing jig fixed, it is placed in a quartz ampoule whose inner diameter matches the outer diameter of the holding jig.

As described above, quartz pieces are prevented from adhering to the substrate.

〔Example〕

1 and 2 are perspective views illustrating a closed tube type chipping crystal growth apparatus according to the present invention.

FIG. 1 shows growth jigs, including a holding jig 1 and a substrate fixing jig 2, respectively, and FIG. 1 2 shows the entire crystal growth apparatus in which these growth jigs are loaded into a quartz ampool 3.

In FIG. 1, a holding jig 1 made of quartz
consists of substrate holding parts 1A and 1B that hold a substrate fixing jig 2 made of quartz, and a melt holding part 1C that holds a melt material. Board holding part 1
A and 1B are members 1A-1 and 1A-, respectively.
2, and is divided into two into 1B-1 and 1B-2.

In this case, the holding method is as follows: members 1A-1, 1A-
2 and between 1B-1 and 1B-2, the substrate fixing jig 2 is inserted into the quartz ampoule 3 shown in FIG. 1 and 2.

The substrate fixing jig 2 attaches and fixes a CdTe substrate 6 as a substrate.

In FIG. 1, the growth jig with the substrate 6 attached thereto, the quartz inner tube 4 serving as a spacer,
The melt 5 is sealed in a quartz ampool 3 and inserted into a horizontal soaking furnace.

7 is a heater for the furnace.

In the crystal growth apparatus having the structure according to the present invention as described above, when the substrate fixing jig 2 is held on the holding jig 1, the quartz pieces do not rub against each other, and therefore, quartz pieces do not adhere to the surface of the crystal substrate. do not have.

Actual crystal growth is performed as follows.

Hg _1-x Cd _x Te on CdTe substrate with surface index (111)
(x is the mixed crystal ratio and when growing 0.2<x<0.3),
The melt (solution) uses Te as the solvent and HgCd as the solute.
Its composition is (Hg _1-x Cd _x ) _1-y Te _y (x, y are mixed crystal ratios)
Select a composition that has a saturation concentration at approximately 500°C.

While keeping the melt at a saturation temperature, the quartz ampoule is rotated to lower the furnace temperature with the CdTe substrate immersed in the melt, and the melt is deposited on the substrate.

After the growth is completed, the quartz ampoule is further rotated to separate the substrate from the melt.

[Effects of the Invention] As explained in detail above, in the crystal growth apparatus according to the present invention, when loading the substrate fixing jig into the holding jig, the quartz pieces do not adhere to the substrate, and therefore the quartz pieces do not adhere to the substrate. The occurrence of crystal defects such as non-growth due to adhesion can be prevented.

[Brief explanation of drawings]

1 and 2 are perspective views illustrating a closed tube type chipping crystal growth apparatus according to the present invention, and FIGS. 2 1 to 3 are perspective views illustrating a conventional closed tube type chipping crystal growth apparatus. In the figure, 1 is a holding jig, 1A and 1B are substrate holders, 1C is a melt holder, 2 is a substrate fixing jig, 3 is a quartz ampoule, 4 is a quartz inner tube, 5 is a melt, and 6 is a substrate. The substrate 7 is a furnace heater.

Claims (1)

[Claims] 1. A holding jig consisting of two cylindrical substrate holding parts 1A and 1B that fit into a quartz ampoule 3, and a melt holding part 1C that connects the two and holds the melt material. 1, and a substrate fixing jig 2 to which a substrate 6 on which a crystal is to be grown is attached and held between the substrate holders 1A and 1B, each of the substrate holders 1A and 1B having 2 Divided members 1A-1, 1A-2, and 1B-
1, 1B-2, said member 1A-1, 1A
A crystal growth apparatus characterized in that the substrate fixing jig 2 is sandwiched and fixed between 1B-2 and 1B-1 and 1B-2.