JPS5891096A - Growing device for single crystal - Google Patents

Abstract

PURPOSE:To produce a single crystal with less crystal defects and with good reproducibility by controlling a heating furnace dividely to many pieces and constituting the sloped temp. region in temp. distributions movably in an axial direction at a specified speed by electrical control. CONSTITUTION:A heating furnace 11 is divided to n pieces of heaters 121-12n in an axial direction, to which respectively independent controllers 131-13n are attached, so that the temps. of the respective heaters are controlled. The controllers 131-13n are connected to one unit of controller 14. The controller 14 controls the setting of the controllers 131-13n thereby controlling the temp. distributions over the entier part of the furnace 11 to prescribed programs. The curve of the temp. distributions to be set when a single crystal 3 grows to the position of a dotted line 15 is shown by the dotted line in the right figure. While the controller 14 maintaines the temp. TH in the specified temp. region and temp. below TI constant during this growth period, the controller shifts the sloped temp. region TM to an axial direction at a specified speed to T'M.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for preparing compound semiconductor single crystals using a solute synthesis diffusion method (hereinafter referred to as
It is called SSD method-i! -) This invention relates to a single crystal growth apparatus for IcJI growth.

Conventionally, in order to manufacture single crystals of compound semiconductors by the SSD method, a single crystal growth apparatus such as the example shown in FIG. 1 has been used. In the figure, a compound seed crystal 2 is placed on the bottom of a crucible 1, and a solvent metal 4, which is the first component of the compound, is placed on top of it.
A gold case is placed, and the compound powder 5 is placed on top of it. This crucible 1 is housed in a quartz container 6 (growth capsule), and a crucible 8 containing a second component 7 of the compound is housed in the quartz container 6. 9 is a furnace tube.

When the entire quartz container 6 is housed in a heating furnace 10 and heated to a temperature distribution as shown on the right, the second component 7 is supplied in the form of vapor to the first component solvent metal 4, and from the seed crystal 2. A high quality compound single crystal 3 is grown.

Furthermore, it is said that by controlling the vapor pressure in accordance with the growth temperature, it is possible to control the stoichiometric composition (stoichiometry) of the compound semiconductor, resulting in better single crystals.

For this reason, a method is used in which the quartz container 6 is moved as the crystal grows, or the heating furnace IO is moved as the crystal grows.

These methods are susceptible to mechanical disturbances from the outside due to mechanical movement of the furnace or quartz container, and twins and
Crystal defects such as dislocations were likely to occur, and there were problems with reproducibility.

In addition, it requires a mechanical drive system, which has the disadvantage of complicating the device.

The present invention was made to solve the above-mentioned problems, and it is possible to control the heating furnace by dividing it into many parts, and to move the inclined temperature region of the temperature distribution in the axial direction at a constant speed by electrical control. By configuring this structure, it is possible to control the stoichiometric composition of a compound semiconductor without mechanical movement of parts, and to provide a single crystal growth device that can produce high-quality single crystals with few crystal defects with good reproducibility. This is what I am trying to do.

The present invention provides an apparatus for total growth of a single crystal by a solute synthesis diffusion method, in which a heating furnace includes a heater divided into a large number of parts in the axial direction, and an independent temperature controller for controlling the temperature of each of the divided heaters. , comprising a controller that controls the settings of each of the temperature controllers that control the temperature distribution of the entire heating furnace, and the gradient temperature region in the temperature distribution that has a constant temperature region and a gradient temperature region set by the controller. This single crystal growth apparatus is characterized by being configured to be movable in the axial direction at a constant speed with a constant inclination.

The single crystal grown by the apparatus of the present invention is N- of the periodic law S.
It may be made of a group V, group 11-2, group IV-IV compound semiconductor, or a mixed crystal thereof.

Hereinafter, the present invention will be explained by examples using the drawings.

FIG. 2 is a longitudinal sectional view showing an embodiment of the device of the present invention and a diagram showing its temperature distribution. In the figure, the same reference numerals as in FIG. 1 indicate the same parts. In the figure, the furnace core tube 9
The inner device is similar to that in FIG.

The heating furnace 11 includes a large number (n) of heaters 12 in the axial direction,
．． It is divided into 12゜・・・・・・12. Individual split heaters 12. ~12. V- are independent temperature regulators 18. ．． 13 degrees, .

Further, the temperature regulators 181 to 13° are connected to one controller 14. The controller 14 controls each temperature regulator 13. ．． 132
・・・・・・・・・13. This controls the temperature distribution of the entire heating furnace according to a predetermined program.

The solid line temperature distribution curve in the right figure is a diagram showing the temperature distribution of the entire heating furnace that is set when the single crystal 3 is grown as shown in the left figure. TI is the high temperature side temperature T1. is the lower temperature,
TM is the temperature gradient region.

Further, T1 is the lowest temperature of the gradient temperature region TM, and T2 is the high temperature constant temperature region.

The temperature distribution curve to be set when the single crystal 3 has grown to the position indicated by the dotted line 15 is the curve shown by the dotted line in the figure on the right. That is, during this growth period, while keeping the constant temperature region temperature T1□ and the temperature below T1 constant, the ramped temperature region T
M'ff may be moved in the axial direction at a constant speed If (crystal growth rate) to h'. Temperature TI.

5- Breaking point T2. The temperature T6 similarly moves in the axial direction, T,'.

T2' and T6'.

Such temperature distribution manipulation can be easily carried out by programming the controller 14, and the valley temperature controller +3. ,1
Each heater 12 by 3□・・・・・・13o
．． , 122...12n.

In this case, since there is no need to change the constant temperature range except for the gradient temperature range TM, a separate heater can be used.

Note that the valley temperature regulators 131 to 13. A microcomputer controls one or both of the controller 14 and the controller 14.
Control is easy if done using .

Thus, in the present invention, by moving the temperature distribution by static electrical operation, single crystal growth is always performed under an appropriate temperature distribution, so that the vapor pressure can be controlled in accordance with the growth temperature. Since the stoichiometric composition of the compound semiconductor can be controlled, defects such as twins and dislocations can be prevented, and high-quality single crystals with few defects can be manufactured with good reproducibility.

6- Acting child Siri.

An InP single crystal was grown using a single crystal growth apparatus and temperature distribution as shown in FIG.

An InP seed crystal with a diameter of 12 mm and a diameter of 1 cm was fixed on the 471 side of a crucible 2 with an inner diameter of 10 πm and a depth of 30 mm, and In metal was placed on top of it as a solvent metal 4 and I as a compound powder.
nP powder was put therein, and P was put in crucible 8.

Temperature T1□=900℃, T+” 800℃1T6=8
50℃.

T1, = 400°C, the temperature gradient of the gradient temperature region TM is 20°C/Cm, and the gradient temperature region TM is 2 m above.
By moving at a speed of yny days, an InP single crystal with a weight of 52 was obtained.

The obtained single crystal was a high quality InP single crystal with no deviation in stoichiometric composition, no twins, and extremely few dislocations.

As described above, in the single crystal growth apparatus used in the solute synthesis diffusion method of the present invention, the heating furnace has a heater divided into many parts in the axial direction, and an independent heater that controls the temperature of each of the divided heaters. It is equipped with a temperature regulator and a controller as described above that controls the temperature distribution throughout the heating furnace, and is set and movable by the controller. This can be done by static electrical operation without mechanical movement of parts, so there is no mechanical disturbance like in the past, and twinning,
Since crystal defects such as dislocations are prevented and the stoichiometric composition of the compound can be controlled, there is an advantage that high-quality compound semiconductor crystals with few crystal defects can be manufactured with good reproducibility.

In addition, as mentioned above, in the device of the present invention, the temperature distribution only needs to be moved through the gradient temperature region, so the device is simple and
It has the advantage of being easy to move.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an example of a conventional single crystal growth apparatus and a diagram showing its temperature distribution. FIG. 2 is a longitudinal sectional view showing an embodiment of the device of the present invention and a diagram showing its temperature distribution. 1.8... Crucible, 2... Seed crystal, 3... Single crystal, 4... Solvent metal, 5... Compound powder, 6... Quartz container, 7... Second component , 9...Reactor core 1! , 10.
II...Heating furnace, 121+12□,...12
．． ...heater, 13. , 132. Group...13o...
・Temperature regulator, 14... Controller, 15... Dotted line, T,
,T,',...gradient temperature region, TL...lower temperature side,
TM...Gradient temperature region. -9= Figure 71

Claims (2)

[Claims] (1) In an apparatus for growing a single crystal by a solute synthesis diffusion method, a heating furnace includes a heater divided into a large number of parts in the axial direction, and an independent temperature regulator that controls the temperature of each of the divided heaters; It is equipped with a controller that controls the settings of each of the temperature controllers that control the temperature distribution of the entire heating furnace, and the gradient temperature region in the constant temperature region and the gradient temperature region overall digit temperature distribution set by the controller, 1. A single crystal growth apparatus characterized in that it is configured to be able to move in an axial direction at a constant speed while maintaining a diagonal position. (2) The single crystal growth apparatus according to claim 1, wherein the valley temperature regulator and/or the controller are controlled by a microcomputer.