JPS59223296A - Raw material for producing sealed compound semiconductor crystal - Google Patents

Abstract

PURPOSE:To constitute a raw material from which a titled crystal can be produced with easy packing operation and decreased contamination with an impurity by putting a mixture composed of elements consstituting the compd. semiconductor crystal into a vessel consisting essentially of boron oxide. CONSTITUTION:>=1 Kind among IIb, IIIb group elements and >=1 kind among Vb, VIb group elements which are elements constituting a compd. semiconductor crystal for example, gallium 3 and arsenic 4 are put into a vessel 1 consisting of a material composed essentially of boron oxide and the vessel is closed with a cover consisting likewise of a material composed essentially of boron oxide. The veseel is heated for about 30min at about 400 deg.C in a vacuum and the vessel 1 is melt stuck to the cover 2. The gallium 3 in this stage melts to form gallium 3' mixed with the arsenic. Such material is kept housed in a vessel contg. inert gas and is used for producing the compd. semiconductor crystal.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is used when manufacturing a compound semiconductor crystal containing a volatile element by liquid confinement pulling method (hereinafter referred to as LKO method).
The present invention relates to a raw material for producing compound semiconductor crystals that is configured to have little impurity contamination and to facilitate filling operations.

(Prior Art) In general, the electrical characteristics of a compound semiconductor crystal are greatly influenced by the species and amount of elements (hereinafter referred to as impurity elements) that are intentionally or unavoidably mixed in, other than the elements that form the compound semiconductor. Therefore, in order to create an element with good characteristics with good reproducibility in a compound semiconductor crystal, it is necessary to avoid the contamination of impurity elements during crystal creation as much as possible. Although great care is taken to avoid contamination, conventional methods are not always sufficient.

Next, we will discuss the conventional method for producing raw materials for gallium arsenide, which is a representative compound semiconductor, and its drawbacks. The raw materials, gallium and arsenic, are refined and crystallized by their respective manufacturers, then weighed and placed in containers. Gallium, which hardly oxidizes at room temperature, is generally stored in a synthetic resin container into which an inert gas is introduced.

On the other hand, arsenic, which oxidizes significantly even at room temperature and becomes highly toxic arsenic oxide, is stored in a glass tube and then either melted part of the glass tube and vacuum-sealed, or placed in a screw-top glass container with a rubber backing. It is sealed with inert gas using the moon. Crystal manufacturers purchase and obtain raw materials sealed in these containers, and after opening the containers, weigh the desired amount of each and transfer them to a crystal manufacturing furnace, which is then installed in a crystal manufacturing furnace. . Finally, after putting the melt coating material (gOs) into the melting box, the lid of the furnace is closed, the inside of the furnace is evacuated, the temperature is raised, and the steps necessary for crystal production are carried out.

The work carried out by crystal manufacturers is not necessarily carried out in a clean atmosphere, and impurity elements (particularly Si and S present in the air as particulates) are present between the opening of the raw material container and its sealing in the furnace. , 0, 0, AJ, etc.). Furthermore, the quality of the crystals depends on the filling ratio of the raw materials, and it is necessary to prevent harmful raw materials from scattering, so careful weighing and handling are required. Handling must be prompt. Therefore, although this series of operations is normally carried out by skilled personnel, it is not possible to completely prevent the contamination of impurities and the scattering of toxic substances, and the amount of filling is not accurate, resulting in crystalline quality. There is a problem with sexual deterioration.

There is a desire to resolve the above-mentioned shortcomings of the conventional raw material processing method, but in addition, each container at the time of raw material purchase and the remaining raw materials that cannot be reused are hazardous substances, so special treatment is required. However, some improvements are desired from the viewpoint of resource saving.

An easily conceivable method is for the raw material manufacturer to weigh out the desired amount of two or more raw materials in the same container in a clean atmosphere, but it is difficult to find a suitable container. It has not been used industrially because it requires transfer to a crucible for crystal production and has few advantages.

(Object of the invention) The present invention is characterized in that a desired amount of raw materials necessary for synthesizing a compound semiconductor is sealed in a container mainly composed of boron oxide used as a liquid sealant, and its purpose is to It is an object of the present invention to provide a raw material with a new structure for manufacturing high-purity compound semiconductor crystals with reduced contamination, good reproducibility, no generation of harmful substances, and resource saving.

(Structure of the Invention) In order to achieve the above object, the present invention provides a mixture of one or more Ilb group elements and one or more Vb group elements and one or more Wb group elements, which are constituent elements of a compound semiconductor crystal. Or, a polycrystal made of the above element or a polycrystal made of the mixture and the above element is made of boron oxide (B
A raw material for producing a sealed compound semiconductor crystal, comprising a container with a desired shape and a lid made of a substance containing tOs as a main component, and the inside of which is housed in a vacuum or inert gas atmosphere. This is the gist of the invention.

Next, embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that the embodiments are merely illustrative, and it goes without saying that various changes and improvements may be made without departing from the spirit of the present invention.

The present invention has been developed through many years of research, and has shown that there is extremely little reaction with compound semiconductor raw materials or their melts. It was devised based on the development of a technology for manufacturing containers of various shapes made of a substance whose main component is boron oxide, which is used as a melt coating agent in the LiC method. Hereinafter, in the case of synthesis of gallium arsenide crystal, which is a representative compound semiconductor, the raw material for manufacturing the sealed compound semiconductor crystal of the present invention and a specific crystal synthesis example using the same will be described in Section 1.2.
It will be explained in detail using Figures 3.4 and 5. In each figure, 1 is a container made of a substance whose main component is boron oxide, 2
is also a lid made of a substance whose main component is boron oxide,
3 is gallium, 4 is arsenic, 5 is aluminum laminate, 6 is a pyrolytic boron nitride ring, and 7 is a carbon susceptor. Figure 1 shows the oxidation of the raw material reservoir for manufacturing the sealed compound semiconductor crystal of the present invention. An example of the shape of a container and a lid made of a substance containing boron as a main component is shown. The outer diameters of the container 1 and the lid 2 for crystal production are, for example, 2 to 3 times smaller than the inner diameter of the container 6 shown in Figure M5. FIG. 2 shows a state in which gallium 3 and arsenic 4 are contained in the container shown in FIG. 1 and the container is covered. FIG. 3 shows an embodiment of the present invention, in which a container containing raw materials similar to the state shown in FIG. 2 is placed in a vacuum for 40 minutes.
0° (heated for 330 minutes to fuse container 1 and lid 2. In this case, gallium 3 has a melting point of .

Since the temperature is 29°C, it will once melt and become gallium-3 in an arsenic-mixed state. In this example, since gallium and arsenic are sealed in a vacuum, it goes without saying that no impurities are mixed in when handling this raw material. However, since boron oxide is a hygroscopic substance, when storing it for a long time or moving it to another location, it must be stored in a container that can be stored in a vacuum or an inert gas atmosphere.

Next, a specific example of synthesis of gallium arsenide using the raw materials of the present invention will be described with reference to FIGS. 4 and 5. FIG. 4 shows another embodiment of the present invention, in which a container containing the raw materials in the state shown in FIG. 2 in a clean atmosphere is once replaced with an inert gas, and then an aluminum laminate 5 is used to prepare It was sealed with true nitrogen using the method described above. After being stored in this state for about one month, the seal with the aluminum laminate 5 was opened, and the crystal manufacturing crucible 6 in the crystal manufacturing furnace prepared in advance was installed as shown in FIG. After that, after closing the lid of the furnace, keep the inside of the furnace in vacuum and turn the temperature around 400 DC.
After holding for a time, argon gas of about 80 atm was introduced into the furnace, and the temperature was raised to about 1300'O in about 10 minutes while maintaining the inside of the furnace at 80 atm. During this treatment, the synthesis of gallium arsenide started at the same time as the temperature of the carbon susceptor 7 reached approximately 820'0, but before that, the container 1 and the lid 2
is the effect of softening and melting liquid sealants in conventional synthesis methods,
In other words, it turned into a liquid state and covered the upper surface of the raw material, which was effective in preventing the evaporation of arsenic. After another 20 minutes, the synthesized gallium arsenide completely turned into a melt, and then the pressure inside the furnace was lowered to 4 atmospheres, and a single crystal of gallium arsenide was produced by the usual method. The obtained crystal has 0,0,Si,8,AJ! It was a good crystal with few impurities such as.

(Effects of the Invention) As explained above, by using the raw material according to the present invention, the work performed by the crystal manufacturer can be simplified to 117 times,
In addition, since the raw materials gallium and arsenic are sealed in a vacuum or inert gas from beginning to end, or stored in a container with a lid, there is an advantage that contamination with impurities is prevented. In addition, there are no toxic substances derived during the handling of raw materials, which is the case with conventional methods, and there is no scattering, so the work is safe.
Furthermore, there is an advantage that resources are saved because no unnecessary containers are required and there is no loss of weighing of raw materials. At the same time, the preparation of the raw material according to the present invention is generally carried out by a specialized raw material supplier, and in this case, the raw material can be weighed carefully in a clean atmosphere, which improves the reproducibility of crystal quality. There is also the benefit of getting better.

The case of gallium arsenide, which is a representative compound semiconductor, has been described in detail above, but other compound semiconductors that have the same drawbacks regarding the filling method of raw materials, that is, one or two of the nb and wb group elements that are constituent elements of compound semiconductor crystals. It goes without saying that the present invention is also effective for polycrystals made of the above elements, mixtures with one or more of the Vb and Wb group elements, or polycrystals made of the above mixtures and the above elements.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment of a container and a lid forming a part of the present invention, FIG. 2 is a cross-sectional view of a container filled with raw materials for explaining the embodiment, and FIGS. 3 and 4 are FIG. 5 is a cross-sectional view of a part of the inside of a crystal manufacturing furnace when gallium arsenide is synthesized using the raw materials of the present invention. 1... Container, 2... Lid, 3... Gallium, 4...
... Arsenic, 5... Aluminum laminate, 6... Crucible, 7... Carpon susceptor patent applicant Figure 1

Claims (2)

[Claims] (1) mb, m which are constituent elements of compound semiconductor crystal
A polycrystal consisting of one or more of the b-koji elements and one or more of the vb and wb group elements, or a polycrystal consisting of the above-mentioned element, or a polycrystal consisting of the mixture and the above-mentioned element, contains boron oxide (B203) as the main ingredient. 1. A raw material for producing a sealed compound semiconductor crystal, comprising a container and a lid of a desired shape made of a substance as a component, and the inside of which is housed in a vacuum or an inert gas atmosphere. (2) mb, m which are constituent elements of compound semiconductor crystal
A container and a lid containing a mixture of one or more B group elements and one or more VB and WB group elements and/or polycrystals made of the above elements in a vacuum or an inert gas atmosphere. The raw material for manufacturing a sealed compound semiconductor crystal according to claim 1, wherein the raw material is further hermetically sealed in a vacuum or inert gas with another seal.