Regrowth of Germanium from Molten Indium or Lead

Abstract

A single crystal of n-type germanium was alloyed with indium on its (111) plane and the resulting regrown layer of p-type germanium was observed. When the specimen was cooled at an intermediate speed, dendritic crystal is produced on the flank of the pan-shaped regrown layer. In the case of cooling at very low speed, steps bounded by (111) plane are produced also on the flank. Any of these may be indicative of the growth due to screw dislocation. On the other hand, when the specimen was cooled rapidly, growth due to surface nucleation takes place on the bottom while dendritic growth due to screw dislocation is produced on the flank. As to a specimen made by alloying Pb–As alloy on a p-type germanium pellet and subsequently cooled at low speed, several layers of striations are observed on its cross-section. By this method, it is possible to make observations on the state in which misfit grain boundary is formed in the course of regrowth and also on the anomaly of regrowth produced around a blowhole and other foreign materials.