JPS60145989A - Seed crystal - Google Patents

Abstract

PURPOSE:A hard to break seed crystal in the rectangular prism rodlike form consisting of substantially {100} face of face orientation and sides with {100} face of face orientation capable of growing an inorganic compound single crystal having the zincblend type crystal structure in high yield. CONSTITUTION:A seed crystal 1 in the rectangular prism rodlike form used for growing an inorganic compound single crystal having the zincblend type crystal structure, e.g. GaAs or GaP, by the Czochralski method. The face orientation of ends 2 for pulling up a single crystal in contact with a melt is substantially {100} face, and face orientation of the sides 3 thereof is {100} face or a face obtained by rotating the {100} face within 20 deg. therefrom about an axis perpendicular to the above-mentioned ends 2. Thus, a recess 4 formed for fixing on a seed holder is hardly broken by the formation of a fractured surface to improve the yield of single crystal growth.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on the Czochralski method (CZOChralski method).
i method, hereinafter referred to as "C2 method". ) related to seed crystals used in single crystal production.

Zincbleite type (GaAs, GaP, etc.)
Single crystals of inorganic compounds (nde) are often grown by the C2 method. In that case, it is a perspective view of a seed crystal that is first used as a seed crystal. / is a seed crystal,! is a seed crystal/
This is the end face of When growing a single crystal, the end face 2 comes into contact with the melt and pulls up the single crystal. The growth direction of the single crystal is the end face λ
It is determined by the surface orientation of, but usually the end surface! The plane orientation is (iooH plane, that is, the growth direction is selected to be the <10O> direction.The shape of the end face 2 is such that the seven sides are co-y
It is common to have a square shape of about mm. 3 is the side surface of the seed crystal. The hole is a recess provided as necessary to fix the seed crystal to the holder of the single crystal growth apparatus using the C2 method. The length of the seed crystal is usually 3”
It is about 0 to gotmn. Hiroshi Kobe is 10~ from 2 end
It is preferable to provide it at a position of 20 Trrm. Conventionally, as shown in seven examples in Figure 2, the side surface orientation of the seed crystal was (Il
o) side. That is, FIG. 2 is a perspective view illustrating the plane orientation of an example of a conventionally used seed crystal. In Figure 2,! and Z are the sides of the seed crystal. In the seed crystal shown in FIG.
was selected as (0//). 7 is a fracture surface to be described later;
That is, (lO/). λ and ≠ are the same as in FIG. (In this specification, the same reference numerals represent the same parts.) GaAs, GaP, In
In the zincblende crystals to which As, nP, etc. belong, (Il
The surface o) is the valve opening surface, and as a result, when an external force is applied, the valve tends to open and be easily damaged. In particular, in the conventionally used seed crystal described above, the valve opens at the (#)/) plane, forming a fracture surface indicated by 7 and breaking. When such a seed crystal was fixed to a seed holder, a concave part was emitted. In this case, the fracture surface 7 is the valve opening surface (10/)
, and the lines of intersection of the surface 7 and the side faces and t intersect with the sides sandwiched by the side faces and the sides, respectively, at an angle of jo.

The present inventors have arrived at the present invention as a result of extensive research aimed at developing seed crystals that are less likely to be damaged by external forces and improving the yield of single crystals.

The above-mentioned object of the present invention is to use a single crystal of an inorganic compound having a zincblende crystal structure by the C2 method, which has a rectangular parallelepiped rod shape and whose end face (2) has a substantially 4ioomolar orientation. ) plane, the plane orientation of the side surface (3) of the seed crystal is the (ioo) plane, or 2O from the (100) plane with the axis perpendicular to the end face (2) as the rotation axis.
This is achieved by seed crystals with planes rotated within 2.

FIG. 3 is a perspective view showing a specific example of a seed crystal according to the present invention.

In FIG. 3, when the end face 2 is a (10θ) plane, the side face ♂ is a (θθ/) plane, and the side face is a (010) plane. Although not shown in FIG. 3, the other side surface parallel to the side surface is a (007) plane, and the other side surface parallel to the side surface is an (oio) plane.

The plane orientation of the end face C of the seed crystal according to the present invention is substantially (10
0) Selected as side. In addition, essentially (iooH surface is (
ioo) refers to a surface that has an inclination within approximately 3°. The growth direction of a single crystal is determined by the plane orientation of the end face, but generally (
Since a /co) plane wafer is used, the above plane orientation is preferable.

In addition, the plane orientation of the side surface is the 4ioo) plane or the end plane λ
10o> direction (in the specific example shown in FIG. 3, (ioo, 1 direction)) (from the 100j plane,
A surface obtained by rotating within 200 degrees, preferably within 100 degrees, is suitable for drawing.

If it is outside the above range, the seed crystal will be easily damaged when fixed to a seed holder, which is not preferable. As a seed holder for fixing the seed crystal according to the present invention, Jitsukaisho, t7
-20327 is preferably used. In order to demonstrate the effects of the present invention, a seed crystal according to the present invention (the orientation of each plane of Yuake x j
A GaAs single crystal of II- was grown by the Cz method. As a result, there was no case in which the seed crystal was damaged out of 50 cases.

On the other hand, when a seed crystal having the plane orientation shown in FIG. 2 was used, breakage of the seed crystal occurred in 11.20 cases.

As is clear from the above explanation, when the seed crystal according to the present invention is used, there is almost no breakage of the seed crystal during the growth of the single crystal, and the yield of the single crystal can be significantly improved. .

[Brief explanation of drawings]

FIG. 1 is a perspective view of a seed crystal used in the O2 method. FIG. 2 is a perspective view illustrating the plane orientations of seven examples of conventionally used seed crystals. FIG. 3 is a perspective view illustrating the plane orientation of a specific example of a seed crystal according to the present invention. 2... End face, i.e. (/θ0) surface 3...
・・Side surface・・・・(00/) Side・・・・・・・
(Olo) side

Claims (1)

[Claims] The shape used when growing an inorganic compound single crystal having a zincblende crystal structure by the Czochralski method is a rectangular parallelepiped rod, and the plane orientation of the end face (2) is substantially (10
0) side surface of the seed crystal, the side surface of the seed crystal (3)
A seed crystal characterized in that its plane orientation is an (ioθ) plane or a plane rotated within 2O2 from a (10O) plane using an axis perpendicular to the end face (2) as the rotation axis.