Process for producing compound semiconductor single crystal
View Patent ↗A process for producing compound semiconductor single crystal, comprises the steps of: putting a compound semiconductor raw material into a crucible, setting the crucible in a vertical type of heating furnace to heat and melt the raw material by a heater, promoting a nucleation on a surface of a raw material melt by leaving a solid raw material in a part of the raw material melt, solidifying the raw material melt gradually from the surface of the raw material melt without a seed crystal, and growing a crystal by using a nucleus generated by the nucleation.
1. A process for producing compound semiconductor single crystal, comprising the steps of:
a) placing a compound semiconductor raw material into a crucible;
b) encapsulating the raw material;
c) setting the crucible in a vertical type of a heating furnace to heat the raw material;
d) melting the raw material;
e) promoting a nucleation on a top surface of a raw material melt;
f) solidifying the raw material gradually from the surface of the raw material melt without a seed crystal; and
g) growing a crystal by using a nucleus generated by the nucleation,
wherein a solid raw material is left in a part of the raw material so as to prevent the raw material melt from being supercooled.
2. The process of claim 1 , wherein the raw material is ZnTe or CdTe.
3. The process of claim 1 , wherein B 2 O 3 is used to encapsulate the raw material.
4. The process of claim 1 , wherein nucleation occurs on a top surface of raw material melt.
5. The process of claim 1 , wherein nucleation occurs on a surface adjacent to the raw material melt.
6. The process of claim 1 , wherein a temperature of the surface of the raw material melt is lower than a temperature of other part of the raw material in the promoting step.
7. The process of claim 3 , wherein the top surface is a boundary between the raw material melt and the B 2 O 3 .
8. The process of claim 1 , wherein the solid raw material is left on the bottom of the crucible.
9. The process of claim 1 , wherein in the melting step, said raw material is caused to melt under conditions under which said raw material has a temperature distribution whereby a bottom-most portion of said raw material in said crucible is maintained in a solid state and the remaining portion is in the melt state.