JPH0316988A - Production device of single crystal of compound semiconductor - Google Patents

Abstract

PURPOSE:To stabilize state of solid-liquid interface, to make a melt side convex and to obtain high-quality single crystal by equipping a cooling means from part of a melt forming furnace at least to an interface control furnace above a growth furnace. CONSTITUTION:A horizontal boat 2 provided with a compound semiconductor raw material 6 and a seed crystal 3 is placed at one end of a quartz ampule 1, a constituent element 7 having higher volatility among constituent elements of the compound semiconductor is laid at the other end and the ampule 1 is sealed in vacuum. Then the ampule 1 is set in a supporting tube 13 and introduced into a growth furnace consisting of a cooling means 14 from part of high-temperature furnaces 8 and 11, a melt forming furnace 9, an interface control furnace 10, a low-temperature furnace 12 and equipped with a cooling means from part of the furnace 9 at least to the furnace 10. The raw materials 6 and 7 in the boat are reacted under heating by the furnaces 8-12, temperature in the furnace 9 is raised to 1,260-1,280 deg.C to form a melt zone 5, the furnace body is moved, the seed crystal 3 is brought into contact with the melt zone 5, the seed is immersed, then the furnace body is moved in the opposite direction to grow compound semiconductor single crystal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a compound semiconductor single crystal manufacturing apparatus using a horizontal zone melting method.

[Prior Art] Several methods are known for manufacturing single crystals of compound semiconductors such as gallium arsenide (GaAs). When producing GaAs single crystals by controlling the temperature of . The method disclosed here is particularly effective when growing single crystals using the temperature gradient (GF) method, and good single crystals can be obtained by making the length of the heat dissipation part the same as the length of the crystal. be able to.

[Problems to be Solved by the Invention] As mentioned above, when producing a GaAs single crystal using the GF method, there is a heat dissipation part of the same length as the length of the crystal in the upper part of the boat of the growth furnace. A good single crystal can be obtained by providing a so-called horizontal Bridgman (H
When growing a single crystal using method B), the position of the solid-liquid interface is always approximately the same in the longitudinal direction of the growth furnace, even if the furnace moves, for example. On the other hand, when growing single crystals using the zone melt (ZM) method, the melt forming furnace that forms the peak temperature and the interface control furnace that forms the solid-liquid interface are placed close to each other. The temperature of the forming furnace influences the temperature of the interface control furnace. Therefore, in the ZM method, it has been observed that unless the position and length of the heat dissipation means are set appropriately, the heat dissipation effect is not achieved and the solid-liquid interface becomes concave with respect to the growth direction, resulting in unstable crystal growth.

An object of the present invention is to provide a compound semiconductor single crystal manufacturing apparatus that can stably grow a single crystal using the horizontal ZM method.

[Means for solving departmental problems] The present invention provides a horizontal board 1 for accommodating raw materials for compound semiconductors.
In addition, a quartz ampoule is provided in which the more volatile component of the compound semiconductor is placed in a predetermined position and vacuum-sealed, and a quartz ampoule is provided on the outer periphery of the quartz ampoule to contain the compound semiconductor raw material. A high-temperature furnace that accelerates the temperature to a temperature below the melting point of the raw material, a melt forming furnace that forms a peak value at the temperature inside the port, an interface control furnace that forms a solid-liquid interface during the growth of the single crystal, and the highly volatile constituent elements. In a compound semiconductor single crystal production apparatus having a long furnace constituted by a heating vapor pressure h11 compensation furnace, a cooling means is provided above the growth furnace from a portion of the melt forming furnace to at least the interface controlled furnace. It was established.

[Function] In the compound semiconductor single crystal manufacturing apparatus of the present invention, when manufacturing, for example, a GaAs single crystal by the horizontal ZM method, interface control is performed so that a solid-liquid interface is formed from a position that shapes the temperature peak value of the melt forming furnace. Since a cooling means such as a heat absorbing hole or a water cooling force is provided across the furnace, this heat absorbing effect stabilizes the state of the solid-liquid interface and makes the melt side convex, making it possible to obtain high quality LLI crystals. I can do it.

3 [Example] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory view showing a one-length embodiment of the compound semiconductor single crystal production apparatus of the present invention, with FIG. 1(a) showing a sectional view and FIG. 1(b) showing a plan view. Figure CC) is a temperature distribution diagram in the furnace, where the horizontal axis represents the length of the growth furnace and the vertical axis represents the temperature T.

In Figure 1, 1 is a quartz ampoule, 2 is a quartz boat,
3 is a seed crystal, 4 is a GaAs single crystal, 5 is a GaAs melt zone, 6 is a polycrystal, 7 is As, 8 is a high temperature furnace, 9
10 is an interface control furnace that controls the solid-liquid interface; 11 is a high-temperature furnace; 12 is an As
7 is a low temperature furnace for heating, 13 is silicon carbide (S i C)
14 indicates a heat radiation hole. Further, A indicates the position where the temperature T peaks, B indicates the position of the solid-liquid rising surface, C indicates the distance from point A to point B, and 1 indicates the length of the eight-hole hole 14.

When using this device to produce GaAs single crystal, put 2000 g of Ga as a raw material and a weighing crystal 3 into a quartz bowl 1-2, place it on one end of a quartz ampoule 1, and place As7 on the other end. 1 quartz ampoule with 2200g
Vacuum seal. This quartz ampoule 1 is set in the support tube 13 and placed in a high temperature furnace 311. Heating is performed using a melt forming furnace 9, an interface control furnace 10, and a low temperature furnace 12. At this time, the same figure (
As shown in c), the temperature of the low-temperature furnace 12 is set to 610°C, the pressure inside the quartz ampoule 1 is kept at 1 atm of As pressure, and in this state, the temperature of the furnaces 8 to 11 is raised to 1200°C to quartz. A synthesis reaction is carried out using Ga and As in Bo 1 and 2.

Then, the temperature of Mel I/forming furnace 9 was set to 1260°C to 128°C.
After raising the temperature to 0° C. to form a GaAs melt zone 5, the furnace body is moved to bring the seed crystal 3 into contact with the melt zone 5 to perform seeding. Next, the furnace body is moved in the opposite direction to the previous case at a speed of 5 to 10 cm/hour to elongate the GaAs single crystal, and then cooled to room temperature at a temperature of about 100°C/g to form a single crystal. .

Approximately 4150 g of qi crystal of GaAs can be obtained in this manner. In this case, Table 1 shows the results obtained by observing the shape of the solid-liquid interface while changing the length 1 of the heat dissipation hole 14.

The table shows the length of the heat dissipation hole for the case where the heat dissipation hole 14 is installed only in the interface controlled furnace 10 and the case where it is installed in common to both the interface controlled furnace 10 and the melt forming furnace 9 (Fig. 1(b)). 1 and the shape of the solid-liquid interface.As is clear from the table, when the heat radiation hole 14 is installed only in the interface control furnace 10, the shape of the solid-liquid interface will change even if the heat radiation hole 14 is lengthened to 150IllIII. Good crystal height cannot be obtained because the surface remains concave. On the other hand, when the heat radiation hole 14 is installed so as to span both the melt forming furnace 9 and the interface control furnace 10,
It can be seen that by making the length 1 of the heat radiation hole 14 longer than the distance C=801IIIll from the temperature peak position A to the solid-liquid interface position B, the solid-liquid interface shape becomes convex and good growth can be obtained.

7 As shown in the same table, in order for the solid-liquid interface shape to be slightly convex or convex and for stable growth of a single crystal, it is necessary to set it to 100 mm or more. 10011 in the opposite direction of single crystal 4 from value position A
Extend by 1111 or more and extend by 1001 or more in the direction of single crystal 4 from the solid-liquid interface position B to J'-2 including C-80mm.
If it is 80 m+ or more, even better results can be obtained.

In the above case, the long furnace is a resistance-heating electric furnace that is commonly used, but the same applies to other high-frequency heating furnaces and gold image furnaces (high-power infrared furnaces). I can do it.

[Effects of the Invention] As described above, according to the present invention, the following effects can be obtained.

(1) The dopant concentration in the length direction of the crystal is uniform, and a single crystal with stable and uniform properties can be obtained.

(2) When applied to a chromium (Cr) doped semi-insulating substrate, it is possible to reduce variations in the Cr concentration within the ingot and obtain good characteristics.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the compound semiconductor single crystal manufacturing apparatus of the present invention. 1: Quartz ampoule, 2: Quartz boat, 3: Seed crystal, 4: GaAs single crystal, 5: GaAs melt zone, 6: Polycrystal, 7: As, 8, 11: High temperature furnace, 9: Melt forming furnace, 10 ; Interface controlled furnace, 12: Low temperature furnace, 14. Heat radiation hole.

Claims (1)

[Claims] 1. A horizontal boat containing raw materials for a compound semiconductor, a quartz ampoule in which the more volatile constituent elements of the compound semiconductor are placed at predetermined positions and vacuum sealed; a high-temperature furnace that heats the compound semiconductor raw material to a temperature below the melting point of the raw material, a melt forming furnace that forms a peak value at the temperature inside the boat, an interface control furnace that forms a solid-liquid interface during the single crystal growth, and the volatilization furnace. In a compound semiconductor single crystal manufacturing apparatus having a growth furnace constituted by a vapor pressure compensation furnace for heating constituent elements with high properties, above the growth furnace, extending from a portion of the melt forming furnace to at least the interface control furnace. A compound semiconductor single crystal manufacturing apparatus characterized by being provided with a cooling means.