JPS63134594A - Production of single crystal of iii-v compound semiconductor - Google Patents

Abstract

PURPOSE:To contrive to form high-quality single crystal of compound semiconductor in setting an ampule having a sealed boat in a crystal growing furnace and forming single crystal of III-V compound semiconductor, by laying a group V element to compensate pressure in the ampule and a heat shielding plate in the ampule. CONSTITUTION:An ampule 2 having a sealed boat 1 is set in a crystal growing furnace, a group III element and a group V element in the boat 2 are subjected to eutectic melting in a ratio of chemical equivalent, the boat is controlled in such a way that temperature distribution 9 produced in the boat 2 is transferred in the lengthwise direction and seed crystal 4 set at the end of the boat 2 is brought into contact with melt 3 to gradually form single crystal 5. The above-mentioned constitution is provided with the following constitution. Namely, at the end on the opposite side to the boat 2 in the ampule 1, a group V element 6 to compensate the pressure in the ampule 1 constant by its vapor pressure and a heat shielding plate 7 is set between the group V element 6 and the boat 2 so that radiation heat radiating from a high-temperature part 10 to the group V element 6 is shielded and reduction in the pressure compensating function is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a group III-V compound semiconductor single crystal.

[Prior art] Gallium phosphorus (GaAs), indium phosphide (In
Regarding the manufacturing method of ■-v group compound semiconductor single crystals such as P) and indium-1-sol (InAs), for example, the horizontal Bridgman method (H-method) and JP-A-58-15659
The temperature gradient method (GF method) disclosed in Japanese Patent No. 9 is known.

Although there are differences in the transfer method between the boat containing the melt and the heating furnace that heats it, these methods can basically be said to be the same method. The group elements are eutectic in a chemical equivalent ratio, and the boundary between the same phase and liquid phase is moved in the longitudinal direction of the boat while keeping the temperature gradient formed in the direction of the boat constant, gradually starting from the seed crystal. Single crystals are produced by crystallization.

[Problems to be solved by the invention] When using the above-mentioned manufacturing method, in order to maintain the composition based on the stoichiometry of the crystal, a group V element is inserted into the ampoule and its dissociation is performed. It is necessary to create a state in which the pressure is equal to the w4 separation pressure of the group Ⅰ element at the melting point of the compound semiconductor.

Taking the case of GaAS as an example, the melting point of GaAS is 1238
Since the dissociation pressure of AS at 610'C is approximately 1 atm, it is necessary to maintain the inside of the ampoule at 1 atm. This is because the vapor pressure of AS at a temperature of 610'C is 1 atm. By placing As inside the ampoule and heating it to 610° C., the AS acts as a pressure compensating element and the pressure inside the ampoule is kept constant.

However, if things continue as they are, since the ampoule and other containers are made of quartz and have good thermal conductivity, high-temperature radiant heat near the melt will pass through the ampoule and have a thermal effect on the AS, and this effect will change as the crystal solidifies. Therefore, the temperature around As fluctuates and A
This means that the effect of S as a pressure compensation element cannot be achieved. This phenomenon occurs in both the above-mentioned HB method and GF method, and is therefore an undesirable phenomenon.

An object of the present invention is to provide a method for producing a single-crystalline compound semiconductor of group 1-V compound, which reduces the influence of radiant heat generated from a high-temperature section and allows stable growth of the single crystal.

[Means for Solving the Problems] The present invention includes installing an ampoule in which a boat is enclosed in a crystal growth furnace, and eutecticizing a group (I) element and a group V element in a chemical equivalent ratio in the boat. , Control is applied so that the temperature distribution generated in the boat moves in the length direction, and the seed crystal provided at the end of the boat is bonded to the melt to gradually produce a single crystal. - A method for manufacturing a group V compound semiconductor single crystal, in which a group V element is disposed at the end of the ampoule opposite to the boat, and the vapor pressure thereof compensates for the pressure in the ampoule to be constant; A heat shielding plate is provided between the V group element and the boat to block radiant heat radiated from the high temperature part of the boat to the V group element and prevent a decrease in the pressure compensation function. This goal was achieved by removing the effects of radiant heat and ensuring stable crystal growth.

[Function] In the method for producing a group I[[-V compound semiconductor single crystal of the present invention, a boat is enclosed in a long ampoule, and a group I element and a group V element are mixed in the boat using chemical procedures. eutectic in proportion,
A seed crystal is provided at the end of the boat, and a group V element is provided at the end of the ampoule on the opposite side of the boat, which acts to keep the pressure within the ampoule constant due to its vapor pressure. It is installed in a furnace and controlled to form a temperature gradient in which the temperature near the boat is high and the area near the V group element is low, and the seed crystal and melt are joined to gradually grow a single crystal. However, if the radiant heat generated in the above-mentioned high temperature section is added to the V group element, the temperature of the V group element will rise and the pressure compensation function will be lost. A heat shield plate is installed between the element and the boat to block radiant heat.This allows the pressure inside the ampoule to remain constant without fluctuation during single crystal formation, making it possible to produce high quality single crystals. It has become possible.

[Example] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory diagram of an embodiment of the method for producing a semiconductor conductor single crystal of a ①-V group compound according to the present invention.

In the figure, 1 is a quartz ampoule, 2 is a boat, 3 is a melt of the ■-V group compound inside the boat 2, 4 is a seed crystal provided at the end of the boat 2, and 5 is at the tip of the seed crystal 4. A grown single crystal is shown. 6 is a group V element such as AS, whose vapor pressure compensates for the pressure within the entire ampoule. 7
8 is a heat shielding plate, and 8 is a quartz glass that covers the heat shielding plate 7. 9 represents a temperature distribution curve, which is given by the control of the crystal growth furnace, and moves in the direction of arrow A or B. 10 indicates a high temperature region, and 11 indicates a low temperature region. 12 indicates the temperature control point of the V group element AS6.

In this embodiment, when manufacturing a former-V group compound semiconductor single crystal, the ampoule 1 is inserted into a crystal growth furnace to control the temperature of each part. The area of the group Ⅰ element 6 is controlled to be a low temperature region 11.

(2) Ga and ΔS are used as raw materials for group V elements, but the melting point of GaAS is 1238° C., and at such a high temperature, the ampoule 1 is made of quartz glass and is likely to soften and deform.

Now, if the temperature distribution curve 9 is moved in the direction of arrow B so that the melt 3 and the seed crystal 4 are joined to grow a single crystal, the high temperature region 10 will gradually approach the group V element 1As6. .

In this case, if the heat shield plate 7 is not installed, As6 will be completely sublimed by the radiant heat of the high temperature region 10, and the internal pressure of the ampoule 1 will be upper bound, causing the ampoule 1 to expand and deform. However, if the shield plate 7 is installed If so, the radiant heat reaching As6 from the high temperature region 10 will be shielded by the heat shielding plate 7 and the As
6, and the quality of As6 hardly changes, so the air pressure inside the ampoule 1 also hardly changes, so the expansion deformation of the ampoule 1 does not occur, and a high quality single crystal is produced. .

The heat shield plate 7 is made of silicon carbide (S i C), which is opaque, has excellent heat resistance, and has no reactivity with quartz glass. It is covered with glass 8.

Since it is covered with quartz glass 8, cleaning and drying of the device can be easily carried out when it is transferred to a vJ building.

As6 is provided with a thermal lightning pair at the control point 12, and the temperature is controlled by this thermal lightning pair, but if the heat shield plate 7 is not provided, the effect of the control will not be achieved because the influence of radiant heat in the high temperature area 10 will be large. If this is not possible, the As6 will sublimate, but the effect of the heat shield plate 7 allows for stable control.

As described above, by using this embodiment, the following effects can be obtained.

(1) Since the radiant heat applied to the V group element installed as a pressure compensation inside the ampoule can be blocked, sublimation of the V group element can be prevented and the pressure inside the ampoule can be maintained at a constant pressure.

(Since the pressure inside the ampoule can be kept constant during the production of two crystals, a high quality compound semiconductor single crystal can be obtained.

(3) Since sublimation of the Vi element can be prevented, there is no deformation of the ampoule, and the ampoule can be reused to reduce cost.

[Effects of the Invention] According to the present invention, it is possible to provide a method for producing a -V group compound semiconductor single crystal, which reduces the influence of radiant heat generated from a high temperature section and stably grows a single crystal.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an embodiment of the method for manufacturing a III-V group compound semiconductor single crystal of the present invention. 1: Ampoule, 2: Boat, 3: Melt, 4: Seed crystal, 5: Single crystal, 6: Group V element, 7: Heat shield plate, 8: Quartz glass, 9: Temperature distribution curve, 10: High temperature region, 11: Low temperature region.

Claims (1)

[Claims] (1) An ampoule containing a boat is installed in a crystal growth furnace, and in the boat, Group III elements and Group V elements are eutecticized at a chemical equivalent ratio, and the temperature distribution generated in the boat is adjusted in the length direction. A method for producing a III-V compound semiconductor single crystal, in which a seed crystal provided at an end in the boat is joined to the melt to gradually produce a single crystal, A group V element whose vapor pressure compensates for the pressure inside the ampoule to be constant is arranged at the end of the ampoule opposite to the boat, and heat is created between the group V element and the boat. A method for manufacturing a III-V group compound semiconductor single crystal, characterized in that a shielding plate is provided to block radiant heat radiated from a high-temperature part of the boat to the group V element, thereby preventing a decline in the pressure compensation function.