It was found that rectangular etch-pits developed on the (¯5¯1¯1)B planes of crystals which had been grown by using the Bridgman method. The pits had the same origin as pits which developed on the (100) plane. On the other hand, sharp triangular etch-pits with a vertical angle of 22º were produced on the (511)A plane. The shape of the pits was explained on the basis of the regular tetrahedron of the zincblende structure. The facets of the pits on (511)A and (¯5¯1¯1)B surfaces were (¯1¯1¯1)B-type polar planes.

H.Iwanaga, N.Shibata, A.Tanaka, Y.Masa: Journal of Crystal Growth, 1987, 84[3], 345-8