JPH06157189A - Single crystal growth equipment - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide an apparatus for easily growing a single crystal film having a uniform thickness in growing a single crystal film using a liquid phase epitaxial method. [Structure] A through-hole 15 is provided in a rotary elevator 14 for a substrate 6, and a substrate holder 13 connected to the through-hole 15 sucks and holds the substrate 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single crystal growing apparatus.

[0002]

2. Description of the Related Art The growth of a magnetic garnet single crystal film using a liquid phase epitaxial method has been carried out by using an apparatus having a structure shown in FIG. First, a platinum crucible 1 is filled with a magnetic garnet component and a flux component, which are weighed to have a predetermined composition, and heated by a heater 2 to melt. A non-magnetic garnet single crystal substrate 6 held by a platinum holder 5 attached to one end of an alumina rod 4 is immersed in a melt 3 melted at a high temperature, and the non-magnetic garnet single crystal substrate 6 is rotated by a rotary elevator 7. The magnetic garnet single crystal film 8 was epitaxially grown on the non-magnetic garnet single crystal substrate 6 while rotating.

[0003]

However, in the conventional structure as described above, a part of the platinum holder 5 wraps around the lower portion of the non-magnetic garnet single crystal substrate 6 to form a three-point claw for supporting. When the magnetic garnet single crystal substrate 6 is rotated, the portion of the nail at the tip of the platinum holder 5 immersed in the melt 3 disturbs the flow of the melt 3. Since the growth conditions of the single crystal film are very delicate, if the flow of the melt 3 is disturbed during the growth of the magnetic garnet single crystal film 8, the growth film thickness varies,
There is a problem that cracks and other defects are created on the magnetic garnet single crystal film 8 and cause defective products.

The present invention is intended to solve such a problem, and an object thereof is to easily grow a single crystal film having a uniform film thickness in growing a single crystal film using a liquid phase epitaxial method. is there.

[0005]

In order to solve this problem, the present invention provides a rotary elevator with a through hole, and a substrate holder connected to the through hole sucks and holds the substrate.

[0006]

With this structure, firstly, the substrate holder is not immersed in the melt, so that the flow of the melt is not disturbed during the rotation of the substrate, and a uniform single crystal film can be grown. Secondly, since the suction force can be constantly exerted during the growth of the single crystal film, it is possible to prevent an accident such as the dropping of the substrate during the growth.

[0007]

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention. In FIG. 1, 1 is a platinum crucible, 2 is a heater, 3 is a melt, 6 is a substrate for growing a single crystal, 13 is a substrate holder, 14 is a rotary elevator, 15 is a through hole, 16 is a pipe,
Reference numeral 17 is a suction pump, and 8 is a single crystal film.

First, yttrium oxide (Y ₂ O ₃ ) which is a magnetic garnet component, gadolinium oxide (Gd ₂ O ₃ ),
And iron oxide (Fe ₂ O ₃ ) and bismuth oxide (Bi ₂ O ₃ ), lead oxide (PbO), and boron oxide (B ₂ O ₃ ) which are flux components are weighed to a predetermined composition ratio, and the raw materials It is a mixture. This raw material mixture is filled in a platinum crucible 1 and heated to about 1000 ° C. by a heater 2 to melt the raw material mixture, and then this melt 3 is melted at a crystal growth temperature (600 to 900).
C.) and slowly maintain the temperature for a while to stabilize the melt temperature.

On the other hand, a single crystal substrate (hereinafter referred to as substrate) 6
Is a non-magnetic garnet single crystal calcium-magnesium-zirconium-substituted gadolinium-gallium-garnet (hereinafter referred to as Ca-Mg-Zr-substituted GGG) single crystal cut into a disk shape with a diameter of 75 mm and a thickness of 0.5 mm. Then
A mirror surface of both sides is used. Substrate holder 13
Is the same material as the substrate 6, Ca-Mg-Zr-substituted GG
After being processed into a cylindrical shape using G, the inside is cut off and the end surface is polished to a mirror surface.

The rotary elevator 14 of the single crystal growing apparatus used here is provided with a through hole 15 at its center, and the through hole 15 is further connected to a suction pump 17 by a pipe 16. The substrate holder 13 is fixed by connecting it to the center of the rotary elevator 14 with its rotation axis aligned.

Next, the substrates 6 are brought into close contact with the substrate holder 13 by aligning their respective central axes, and then the suction pump 17 connected to the rotary elevator 14 is operated. Then, the substrate 6 can be sucked and held by the substrate holder 13 by the suction force. The substrate 6 is the rotary elevator 1 as it is.
Slowly descend by 4 and immerse in the melt surface for 10
The bismuth-substituted yttrium-gadolinium iron garnet (hereinafter referred to as BiYGdIG) single crystal film 8 is grown on the substrate 6 while being rotated at 0 rpm for 2 to 10 hours.

The BiYGdIG single crystal film 8 thus obtained had a thickness of 50 to 300 μm, and no cracks or other defects were observed. The film thickness difference depending on the location within the 75 mm disc is 50
1μm for μm thickness, 5μ for 300μm thickness
m, and a single crystal film having a uniform film thickness could be obtained.

Although the crystal growth method by the liquid phase epitaxial method is taken up in the present embodiment, it can be applied to other crystal growth methods (for example, pulling method) using a substrate or a seed crystal.

Further, although the single crystal film 8 is made of magnetic garnet and the substrate 6 is made of non-magnetic garnet in the present embodiment, other materials such as garnet of other composition, lithium niobate and lithium tantalate can be used. Needless to say.

[0016]

As described above, according to the present invention, first, a single crystal film is grown while adsorbing and holding the substrate by the substrate holder, so that the substrate holder is not immersed in the melt. . Therefore, the flow of the melt is not disturbed during the rotation of the substrate, and uniform growth of a single crystal film can be realized. Second
In addition, since the suction force can be constantly exerted on the substrate during the growth of the single crystal film, it is possible to prevent an accident such as dropping of the substrate during the growth.
Thirdly, since the substrate holding jig used for growing the single crystal film is made of the same material as the substrate, the thermal expansion coefficients of the substrate and the jig can be made equal to each other. The reduction can be realized. if,
If there is a large difference in the coefficient of thermal expansion between the substrate and the substrate holder, both the substrate and the substrate holder must be used in a wide range from room temperature to about 900 ° C. What is held as a result is displaced and eccentrically rotated due to the difference in thermal expansion, and as a result, turbulent flow occurs and the grown film thickness becomes non-uniform. Further, when the displacement due to the thermal expansion does not occur because the holding force by suction is large, stress due to the difference in thermal expansion dimension is applied to the substrate,
If the substrate is thin, cracks will occur.

The entire substrate holder does not have to be made of the same material as the substrate, but may be made of the same material only in the vicinity of the portion in contact with the substrate.

[Brief description of drawings]

FIG. 1 is a block diagram of a single crystal growth apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional example

[Explanation of symbols]

 1 Platinum crucible 2 Heater 3 Melt 4 Alumina rod 5 Platinum holder 6 Substrate 8 Single crystal film 13 Substrate holder 14 Rotary elevator 15 Through hole 16 Pipe 17 Suction pump

Claims (2)

[Claims] 1. A single crystal growing apparatus using a liquid phase epitaxial method, wherein a rotary elevator is provided with a through hole, and a substrate holder connected to the through hole sucks and holds the substrate. apparatus. 2. The single crystal growing apparatus according to claim 1, wherein a portion of the substrate holding jig which is in contact with the substrate is formed of the same material as the substrate.