CXX. Screw dislocations, etch figures, and holes

Abstract

Etch figures similar in appearance to those observed in the mineralogical technique are shown to result from the rapid chemical dissolution of growth spirals on silicon carbide. Each spiral resulting from an independent screw dislocation gives an etch figure. The etch figure produced by rapid dissolution, therefore, becomes a convenient means for indexing screw dislocations whether growth spirals are evidenced or not. Prolonged rapid dissolution of a crystal with a screw dislocation extending between opposite crystal faces results in a hole through the crystal at the site of the screw dislocation.