Abstract: In a compound semiconductor crystal growth process, the crucible (11) that contains the semiconductor melt is contacted on its opposite surface by a material (26) which, when melted, reacts with the crucible. The reacting material is melted along with the compound semiconductor material and thereafter reacts with the wall (24) of the crucible that contains the semiconductor melt. During the entire growth process, the wall is sufficiently thick to separate the reacting material from the compound semiconductor material, but is sufficiently thin that the reacting material significantly weakens its structural integrity. As a consequence, thermal stresses resulting from differential contraction of the compound semiconductor material and the wall during the cooling step are relieved by fracture of the crucible wall.

Abstract: In a VGF process for growing a large single crystal 16' in a crucible 11, the problem of stress forces caused by a freezing liquid encapsulant are solved by using a step or indentation 21 around the inner surface of the crucible 11 at or near the top of the single crystal 16' being grown. As a consequence, the newly-frozen single crystal (e.g., InP)conforms to the shape of the indented inner surface of the crucible and therefore has a pronounced bulge 22 near its top. The bulge of the frozen semiconductor crystal then nests against the indentation on the periphery of the crucible, thereby to prevent any liquid encapsulant from flowing between the crystal and the wall of the crucible.