US 5,690,731 A · Method of growing single crystal

Abstract

A method of growing a crack-free single crystal is disclosed which comprises heating raw materials in a crucible to thereby obtain a melt of the raw materials, contacting a lower end of a seed crystal with the melt and pulling the seed crystal to thereby grow a single crystal, and wherein the melt of the crucible flows from its surface toward its inner part inside the crucible by convection at a position locating outside a region where the growth of the single crystal occurs. This flow control can be achieved by, for example, surrounding the crucible with a heat insulation refractory composed of a pair of semicylindrical refractories disposed so as to provide a circular cross section with differently sized gaps. In the above-mentioned method, the seed crystal may be rotated during a shoulder growth in which the single crystal has its diameter increased from that of the seed crystal to a target diameter at a rotation rate greater than that during a subsequent cylindrical body growth. Further, in the above-mentioned method, during the shoulder growth, the single crystal may have a solid-liquid interface configuration changed from a convex toward the melt to a flatness or a convex toward the seed crystal.

Claims11

Dependent claims

A method of growing a single crystal, comprising the steps of:

a) heating raw materials in a crucible to obtain a melt of the raw materials;
b) contacting a lower end of a seed crystal with a surface of the melt;
and
c) lifting the seed crystal to grow a single crystal, wherein the temperature in said crucible is regulated so that the melt flows from the surface of the melt toward the inside of the melt by convection within a region of said surface of the melt which is not in contact with said single crystal.

1 more element

Dependencies are inferred from the claim text.

Method of growing single crystal

Life of this patent

Method of growing single crystal

Life of this patent

Abstract

Claims11