JPS6051698A - Arsenic compound single crystal growing apparatus - Google Patents

Abstract

PURPOSE:To provide a single crystal growing apparatus which is resistant to high temps. and capable of tightly sealing gaseous arsenic by using materials such as Mo (alloy), gas impermeable carbon, and oxides like alumina to form a tightly sealed vessel, and forming the vessel separable into two parts. CONSTITUTION:A gaseous arsenic sealing vessels 26 and 26' are formed of >=1 kind among Mo, Mo alloy, gas permeable carbon, SiN, and oxides like alunima. A sealing material 27 such as B2O3 is used for sealing a pulling shaft 29 and a crucible rotating shaft 38, and a sealing material 30 such as B2O3 is used for tightly sealing the opening part of the crucible 32. In addition a quartz rod or a quartz fiber 28 perforating through the vessel 26 is provided to observe the inside of the vessels 26 and 26'. The deformation of the vessels 26 and 26' is not recognizable with said structure, and the arsenic compound single crystal which is suitably used for a laser or an IC substrate can be easily manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an apparatus for growing an arsenic compound single crystal useful as a substrate for a laser or an IC.

Prior Art Conventionally, single crystal GaAs, which is an arsenic compound semiconductor, has been manufactured by the HB method or the LEC method, but each manufacturing method has its own drawbacks and is not in a satisfactory state.

In other words, as a substrate for laser or IC (
1oo) A circular surface with no defects is required, but H
In method B, an ingot with a <111> orientation is grown on a boat, and a circular wafer with a (100) orientation is obtained.
For this purpose, it must be cut at an angle of 54.7° to the crystal growth direction (and then punched into a circular shape).

Furthermore, although the LEC method allows growth in <100> orientation, it is difficult to stably produce ingots with few defects.

As a method to solve these problems, JP-A-55-8
No. 0796 proposes a method for growing a high dissociation pressure compound semiconductor single crystal for semiconductors by a double melt seal pulling method and an apparatus therefor.

This method is convenient because it can obtain circular wafers with (100) planes and wafers with a crystal defect density comparable to or lower than that of the HB method. Therefore, if pressure fluctuations occur while holding the quartz container at 1240°C, which is the melting point of gallium arsenide, the quartz container will be deformed. necessitated the development of arsenic sealed containers.

This will be explained in detail with reference to the drawings. FIG. 1 shows a conventional lifting device using an arsenic sealed container made of quartz. In the figure, 1 is a metal container, 2 is a quartz rotating crucible, 3 and 23 are after heaters, 4 is a lid that fits into the soil part, 5.22 is oxidation for sealing (iodine), 6 is a rotating shaft, and 7 is a main heater. , 8 is a high dissociation pressure compound, 9 is a rotating shaft, 10 is a graphite susceptor, 11 is a chuck, 12 is a seed crystal, 13 is an inert gas introduction system, 14 is an exhaust system, 15
is single crystal, 16 is boron oxide for coating, 17.24 is receiving 1
18 is a support stand, 19 is a drive stand, 20 is a furnace tube, 2
1 is the F section fitting lid. As a result of detailed temperature measurement in such a device, the internal observation part of the arsenic sealed container was 1050 to 1
If the temperature is limited to 150°C and there is no coating boronate on the melt, the observable area will be stuck at 1080-1150°C. In the 950-1080°C range, the inside of the quartz arsenic sealed container is galium arsenide. Furthermore, since the inside of the after-heater 3 is hidden, it was considered to be an inappropriate part for observation and was ignored. However, according to the detailed observation results of the present inventors, the inside of the quartz arsenic sealed container is transparent during the pulling operation in the temperature range of 610 to 950 degrees Celsius, and by changing the observation angle, I came to think that it would be useful as an internal observation part.

On the other hand, if a pressure difference occurs between the inside and the outside of the quartz furnace core tube 20, especially when the pressure on the outside becomes high, the furnace core tube 20 will collapse, making it impossible for the graphite septa 10 to rotate. In order to obtain large crystals, a large core tube is inevitably required, and the larger the core tube, the smaller the resistance to deformation, which reduces the pressure difference inside and outside the core tube. It becomes necessary. Naturally, in order to effectively seal arsenic into the quartz core tube 20, it is required to maintain a higher pressure on the outside of the core tube than on the inside, and this requirement cannot be met. Therefore, it was necessary to select a material that has higher temperature strength than quartz, can withstand arsenic gas, and can be sealed against arsenic gas.

Purpose In view of the above points, the present invention has been developed to obtain a melting point of 1, which is the melting point of gallium arsenide.
There is a method C that provides a container that can withstand high temperatures of 240° C. or higher, can withstand arsenic gas and hermetically seal the arsenic gas, and allows the inside to be observed from the standpoint of crystal growth.

Structure The present invention provides an apparatus for pulling an arsenic compound single crystal while controlling the pressure of arsenic gas sealed in a container, in which the container is made of molybdenum or molybdenum alloy, gas-impermeable carbon, silicon nitride, alumina-based oxide, or zirconia. middle one
This is a 16 arsenic compound single crystal growth apparatus characterized by being composed of one or more seeds and being able to be divided into two.

The device is also equipped with at least one of the following: a quartz window for internal observation, a quartz rond for passing through the container, or a fiber scope.

Furthermore, a boron oxide holding section is provided in the top container of the above-mentioned two-part container, and the lower end of the upper container is immersed in the boron oxide to seal the arsenic gas. This is a device that can be separated at will by motion.

As mentioned above, in order to effectively seal arsenic inside the reactor core tube, it must not change even if it comes into contact with arsenic gas at 01,250°C, and it must not deform even if a pressure difference is created between the inside and outside of the arsenic sealed container at 01,250°C. It is important to select a material that satisfies the following requirements: ■ It does not break when the sealing material 8203 solidifies; ■ It can be processed into a closed structure that seals out arsenic gas; ■ It does not allow arsenic gas to pass through. In the present invention, it has been found that molybdenum or molybdenum alloys, gas-impermeable gas bubbles, silicon nitride, alumina-based oxides, and zirconia are suitable materials for such purposes;
These materials have the property of not breaking even when they come into contact with boron oxide, which is used as a sealing material, so they can be used repeatedly. The container is divided into two parts and sealed with boronic oxide, which is advantageous for charging raw materials and taking out the crucible and crystals. Since it is not possible to satisfy both sealing and removal using the conventional sliding f' method for large containers used for making large I products, the present invention employs a sealing method using boron oxide.

In addition, by using a quartz rod or an iverscope for internal observation and setting the temperature of the tip to 610 to 950°C, it is possible to observe a clear image without adhesion of arsenic or potassium arsenide. There was found.

The embodiment will be described below based on FIG. 2. In the figure, 25 is an electric furnace for controlling arsenic pressure; 26. ．． 26 is an arsenic gas sealed container, 27 is a shaft seal made of boron oxide, 28 is a quartz lot or quartz filter for internal observation, and 29 is a pulled shirt 1 to . 30 is boron oxide for sealing arsenic gas, 31 is a heater, 32 is a crucible, 33 is an arsenic compound melt, 34 is an arsenic compound single crystal, 35 is a pedestal, 36 is an inert gas introduction system, 37 is a vacuum exhaust system, 38 is crucible rotation @.

Example 1 Special gas-impermeable carbon was used as the arsenic gas sealed containers 26 and 26', and boron oxide 2 for shaft sealing was used for the shaft seals of the pulling shafts 11 to 29 and the crucible rotating shaft 38.
7 was used.

Boron oxide 30 for sealing arsenic gas is used to seal the opening larger than the crucible, which is necessary to take out the crucible 32.

In this sealing means, the arsenic gas sealed container 26-(
The seal can be freely sealed by turning the lower chamber upward. Furthermore, the structure is such that the crucible 32 can be moved up and down independently of the arsenic gas sealed container 26, 26=.

In the crucible 32 of such a device, Ca As 2 K+1,
As150. The arsenic compound single crystal 34 was pulled up by charging S i 006 g, and the EPD and carrier concentration of the wafer were measured. EPD is E for center part 40φ
P D 2000/c+u or less, outside of that is 20
It was about 00-10000/c duck 2. On the other hand, the carrier concentration was 1×10 8 /C1 or more, and inbo 1- was grown which could be used satisfactorily as a substrate for a semiconductor laser.

No deformation was observed in the tube, and it could be used repeatedly.

Furthermore, the inside of the container could be clearly observed using the quartz rod 28 for internal observation.

Example 2 A glass-impermeable alumina-based oxide was used as the cover for the arsenic gas sealed container 26.26, and the structure was the same as in Example 1.

Also, a crucible 32 for holding the arsenic compound melt 33
After using PBN and charging Qa + AS IKg, directly synthesizing it in an arsenic gas sealed container, Ga AS
A single crystal was pulled.

A semi-insulating crystal was obtained in which the front EPD of this crystal was approximately 3000/cm2 and the back EPD was approximately 7000/cm2.

Effects The present invention is as described above, and it becomes possible to store a large-diameter arsenic compound using a large-diameter container, and it is possible to easily produce materials useful as substrates for lasers or ICs.

FIG. 1 is a sectional view of an example of a conventional single crystal growth apparatus, and FIG. 2 is a sectional view of an embodiment of the present invention.

1... Metal container, 2... Quartz rotary crucible, 3 and 23... After heater, 4... Upper fitting lid, 5.22... Boron oxide for sealing, 6...・Rotating pull-up shaft, 7... Main heater, 8.
... High dissociation pressure compound, 9 ... Rotating shaft, 10 ... Graphite 1 Lupta, 11 ... Chuck, 12 ... Seed crystal, 1
3... Inert gas introduction system, 14... Exhaust system, 15.
...Single crystal, 16...Boron oxide for coating, 17.24
...The receiver is a plate, 18...Support stand, 19...Drive stand,
20... Furnace core tube, 21... Lower fitting lid, 25... Electric furnace for arsenic pressure control, 2G, 26-... Arsenic gas sealed container, 27... Si1
r71 ~ Boron oxide for sealing, 28... Quartz rod or quartz fiber for internal observation, 29... Pulling shaft, 30... Boron oxide for arsenic gas sealing, 31... Heater, 32... Crucible, 33... Arsenic compound melt, 34... Arsenic compound single crystal, 35... Pedestal, 3G.
...Inert gas introduction system, 37...Vacuum exhaust system, 38.
...Crucible rotating shaft, Patent applicant: New Technology Development Corporation and 2 other agents, Patent attorney: Hide Komatsu, Takesai, 1 drawing, 1,100 sales, 11 books (self-motivated), September 1980, 220, Commissioner of the Japan Patent Office, Kazuo Wakasugi. 1. Indication of matter A'1 1982 Patent Application No. 157883
No. 2, Title of the invention: Arsenic compound single crystal growth device 3, Relationship with the person's case overturning the amendment Name of patent applicant Title: New Technology Development Corporation Detailed explanation column of Komei in 11th store.

(1) On page 5 of the specification, line 4, ``inside'' is changed to ``inside''.

(2) Correct “potassium” on page 8, lines 6 to 7tj as “gallium J”.

(3) The 12th line “Quartz 1~” is “Quartz [kotsuto]”
I am corrected.

(4) rcaAsj on page 9, line 11 is 1-GaA5J
I am corrected.

(5) In the 9th line, ``32 Toshiha'' is corrected to ``132 Doshiha''.

Handbook No. 111 (Spontaneous) August 30, 1980 El Special Edition '1 Director General Manabu Shiga 1, Indication of the incident 1983 Patent Application No. 157883 2, Name of the invention Arsenic compound single crystal growth Apparatus 3, Person who makes the amendment
Rito H17 (Telephone 586-8854> Address Akasaka Office Heights, 4-13-5 Akasaka, Minato-ku, Tokyo Name (7899) Riju Iri Hide Komatsu Gji,
? ili regular instruction El (=l (spontaneous) 6, pair of amendments Bli,iE
O'1 content column.

7. Contents of the amendment (1) Change the description No. 9, line 17, r1X108J to “1×1
018”, corrected.

(2) On page 10, line 6, ``Glass'' is corrected to ``1 gas''.

(3) On the 9th line of the same page, ``32 toshiha'' is corrected to ``32 doshiha''.

(4) In the amendment submitted on September 22, 1982, paragraph (5) in the 7° amendment content column is withdrawn.

Claims (3)

[Claims] (1) A device is used to pull up an arsenic compound single crystal while controlling the pressure of arsenic gas sealed in a container. middle one
An apparatus for growing an arsenic compound single crystal, characterized in that it is composed of one or more seeds and can be divided into two. (2) The apparatus for growing an arsenic compound single crystal according to claim 1, comprising at least one of a quartz window or a fiber scope passing through the container. (3) A boron oxide holding part is provided in the two-part container,
Arsenic compound semiconductor/single crystal growth apparatus according to claim 1, wherein the arsenic gas is sealed by immersing the lower end of the upper container in the boron oxide, and can be separated at will by vertical movement of the container. .