The etching behavior of the (100) and (110) faces was studied. The results revealed that HNO3 was a dislocation etchant for both faces. It was shown that the shapes of the etch pits were different for the 2 habit faces. The dependence of the etching rates, for (100) and (110) faces (lateral or vertical) upon the etchant concentration and temperature, were determined. It was shown that the faces resisted attack by the etchant in the direction of the normal to the surface, after 2h of etching, regardless of the concentration of the etchant. It was also shown that, before passivity arose, the variation in depth with etching time was linear in all cases.

A.Jain, A.K.Razdan, P.N.Kotru, B.M.Wanklyn: Applied Surface Science, 1995, 84[1], 65-73