JPS61117190A - Crucible for preparing crystal - Google Patents

Abstract

PURPOSE:To enable industrial prepn. of a single crystal having satisfactory quality by constituting material for members of a heat sink for holding a soln., for fixing a seed crystal, and for releasing latent heat, of a same material. CONSTITUTION:In the crucible for prepg. a single crystal used in a compound semiconductor preparation device for obtd. the single crystal, starting materials for the compound semiconductor crystal is sealed in an ampule, and the ampule is moved in an electric furnace having an optional temp. distribution. The cru cible consists of a heat sink part and a solution holding part, and a mechanism for fixing a seed crystal is provided to the soln. holding part. The whole body is constituted of a same material, most pref. sintered aluminum nitride. Sintered aluminum nitride has superior characteristics being dense and easily formable, having moreover a high heat conductivity. Furthermore, each member is coupled by screwing and there is no difference of heat conductivity between each mem ber since each member is made of a same material. Accordingly, there is no fear for causing damage due to thermal stress in the stage of using the members.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a crucible for crystal production used in the production of single crystals of compound semiconductors by a solution growth method.

[Conventional Technology] FIG. 5 is a schematic cross-sectional view of an apparatus used in a synthetic solute diffusion method, which is an example of a conventional compound semiconductor single crystal solution growth method. In FIG. 3, reference numeral 1 is a high temperature furnace, 2 is a low temperature furnace, 3 is a furnace core tube, 4 is an f-hybrid semiconductor raw material, 5 is a raw material solution, 6 is a crucible, 7 is an amble, 8 is a driving unit, 10 1 is a seed crystal, 11 is a heat sink, and 20 is a protrusion. This type of equipment basically consists of a high temperature furnace 1 and a low temperature P2
Generally speaking, these are spaced apart from each other.

A furnace core tube 5 is provided through the high-temperature furnace 1 and the low-temperature furnace 2, and a compound semiconductor raw material 4 is stored in the bottom of the f-core tube 3, and a raw material solution 5 and a gold-containing crucible 6 are placed at the high temperature. It is housed in the furnace 1 and is provided with an amble 7. The crucible 6 is held by a protrusion 20 in the angle. Furthermore, the amble 7 can be moved up and down by a driving unit 8. K$4 is a raw material with high vapor pressure such as phosphorus, which is vaporized in the low temperature furnace 2 and melted from the surface of the raw material solution 5. As the amble 7 gradually moves to the low temperature region, it melts from the bottom of the crucible 6. Crystals precipitate. A seed crystal 10 is installed at the bottom of the crucible, and a heat sink 11 is provided at the bottom of the crucible.

Conventionally, in order to grow a single crystal using this type of apparatus, a crucible configuration as shown in FIG. 4 has been used. Fourth
In the figure, numeral 9 is a crucible pipe (quartz is used), 10 is a seed crystal, 11 is a heat sink mainly made of carbon, 12 is a grown crystal, and 13 is a solution.The seed crystal is a unit with the same orientation. In order to obtain crystals with good reproducibility,
The heat sink is also used to release latent heat during crystal solidification to the bottom, stabilize the shape of the crystal growth interface, and maintain single crystal growth.

? , 11 are made of different materials because there has never been a high-quality material that is dense, has good thermal conductivity, and does not cause crystal contamination.

[Problem that the invention seeks to solve]

In the above method, the crucible pipe, the seed crystal, and the heat sink are fixed by rubbing together, and if the machining accuracy is poor, the seed crystal floats or liquid leaks. Furthermore, since the heat sink material requires high thermal conductivity, carbon is mainly used. However, since this material is porous and allows gas molecules to permeate through it, there are problems in that during use, the adsorbed impurities emit noise, contaminating the crystal, and cannot prevent the decomposition of AI# crystals and growing crystals that contain components with high vapor pressure. There was a point.

On the other hand, there is a method of inserting a dense plate-like material mainly made of glass between the seed crystal and the heat sink to suppress the decomposition of the crystal. However, such materials have a problem in that they have poor thermal conductivity, reducing the effectiveness of the heat sink.

In particular, in a dangerous device configuration using a crucible as described above,
Currently, high-quality single crystals cannot be obtained, and it is almost impossible to use them industrially.

An object of the present invention is to eliminate these drawbacks and to provide a crucible for producing crystals in which seed crystals can be fixed and which can produce high-quality single crystals on an industrial scale.

[Means for solving problems]

Present invention ↑ To summarize, the present invention relates to a crucible for producing crystals, in which a raw material for producing compound semiconductor crystals is sealed in an amble, and the amble is transferred to raw metal in an electric furnace having an arbitrary temperature distribution. In a crystal manufacturing crucible used in a compound semiconductor manufacturing device for obtaining crystals, the crucible has a mechanism for completely fixing the seed crystal at the bottom of the P1 solution holding part including a heat sink part and a solution holding part, and the whole is made of the same material. It is characterized by being

A feature of the present invention is that the heat sink members for holding the solution, fixing the seed crystal, and releasing latent heat are all made of the same material. Sintered aluminum nitride is particularly suitable as such a material. This material is dense, easy to mold, and has high thermal conductivity. That is, if aluminum nitride is used as the crucible material, all the crucibles in FIG. 4 can be made of the same material. In addition, each part has good workability and can be connected by screwing, and there is no difference in thermal conductivity, so there is no damage due to thermal stress during use. Furthermore, since aluminum nitride has a high melting point and is dense, there is no problem of crystal contamination and high purity crystals can be grown entirely.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The invention is not limited to these examples.

Note that FIGS. 1 and 2 are cross-sectional views of a crucible structure showing one embodiment of the present invention.

Example 1 FIG. 1 shows an example of the crucible for single crystal growth of the present invention. 10 is a seed crystal, 12 is a grown crystal, 15 is a solution, 14 is an aluminum nitride crucible body, and 15 is an inner pipe made of aluminum nitride. The inner pipe 15 prevents the seed crystal from floating and makes it easy to take out the crystal after it has been grown.

The crucible is 100 pieces in diameter 10, 200 gourds in depth 100,
The heat sink length is about 150m and the protrusion inside the amble is 2.
0 keeps it in the optimal position. Next, the single crystal growth method used in the present invention will be explained using an rnP crystal as an example. The equipment other than the crucible is the same as in FIG. 3.

First, a 111〉-oriented seed crystal with a thickness of 4 m close to the inner diameter of the crucible is inserted and fixed to the inner pipe.In this way, since the seed crystal is fixed with the inner pipe, the accuracy of the outer diameter machining of the seed crystal is It's not a problem. Next, 100-2001 engineering n
A crucible was loaded with about 20 wt % of N-P crystals.

The purpose of loading the InP crystal is to prevent the seed crystal from dissolving into the solution. 50-100t of P at the bottom of the amble
The crucible is held by a protrusion inside the amble.

After sealing the ambule at a vacuum level of 2 x 10''6 torr, it was placed in an electric oven and heated. The installation conditions for the crucible were 950°C at the bottom of the crucible, and the temperature gradient before and after that was 50°C/c11M. Also, make sure that the temperature at the bottom of the amble is 450℃. At this temperature, the P vapor pressure in the amble is approximately 2 atmospheres. P vapor dissolves in In liquid and In-P
The solution and 1 to 5 reach the seed crystal. Near the aiM crystal, the temperature of the upper liquid level is also kept low at 9th P.
When the concentration reached saturation, nP was crystallized on the seed crystal with the same orientation. Furthermore, while rotating at about 5 rpm, I pulled it down at a speed of 10,.../day.
A long (approximately 100 m) single crystal extending in the 11> direction was obtained.

Example 2 FIG. 2 shows an example of the single crystal growth crucible fJX2 of the present invention. Reference numeral 10 denotes the crystal nPs, 12 the grown nPs crystal, and 12 the grown nPs crystal.
P single crystal, 15 is an In-P solution, 16t [1fts] crucible pipe made of aluminum, 17 is a heat sink made of electrified aluminum Ecum, and 18 is a friend screw machined into 16.17.

That is, 16 and 17 are connected by screws. The difference from Example 1 is that an inner pipe is not required and that the outer dimensions of the seed crystal can be varied.

The results of crystal growth were the same as in Example 1.

〔Effect of the invention〕

As explained above, the crucible of the present invention can be constructed of the same material, and the problems of seed crystal floating, liquid leakage, crucible damage, and seed crystal decomposition can be solved.

Furthermore, it has been revealed that there is no problem of crystal contamination, and high purity crystals can be obtained. In particular, when aluminum nitride is used, this material has mechanical strength and can withstand cleaning with acids and the like, so it has the advantage of being able to be used repeatedly as a crucible.

Although the crucible for producing crystals of the present invention can be widely applied to single crystal growth using the solution growth method, the next crucible is most suitable for the growth of compound semiconductor crystals such as nP, ()aAs, and GaP, which require high purity crystals. It is.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIGS. 1 and 2 are cross-sectional views of a crucible structure showing one embodiment of the present invention, and FIG. 3 is a schematic cross-sectional view of an example of a crystal growth apparatus using a conventional solution growth method. FIG. 4 is a cross-sectional view of a crucible structure with a seed crystal used for conventional single crystal growth. 1: High temperature furnace, 2: Low temperature furnace, 3: Furnace core tube, 4: Compound semiconductor raw material, 5: Raw material solution, 6: Crucible, 7: Amble, 8
ni driving unit, 9 niru pot pipe, 10: seed crystal, 11: heat sink, 12: g long crystal, 15
: Solution, 14: Aluminum nitride crucible body, 15: Inner pipe, 16: Aluminum nitride crucible pipe, 17
:! Aluminum heat sink, 18: Screw part, 2
0: Protrusion

Claims (1)

[Scope of Claims] 1. A crystal manufacturing device used in a compound semiconductor manufacturing device in which a raw material for compound semiconductor crystal manufacturing is sealed in an amble and the amble is moved through an electric furnace with an arbitrary temperature distribution to obtain a single crystal. A crucible for crystal production, characterized in that the crucible comprises a heat sink part and a solution holding part, has a mechanism for fixing a seed crystal at the bottom of the solution holding part, and is entirely made of the same material. . 2. The crucible for producing crystals according to claim 1, wherein the crucible material is aluminum nitride.