Evidence for Vacancy Clusters in Dislocation‐Free Ge

摘要

This note reports evidence for the existence of vacancy aggregates in Ge crystals. When dislocations are absent over volumes of the order of cubic centimeters the crystal etches much more rapidly than when dislocations are present. This enhanced etching behavior can be eliminated by appropriate heat treatment at 800°C. Ridges of normal etching rate have been observed traversing the rapidly etched areas in 〈110〉 directions. Etch figures, usually spiral dislocations, are always associated with these ridges. Ridges are not observed in completely dislocation‐free crystals.