Crystallographic Polarity and Etching Behavior of ZnSe

The crystallographic polarity of ZnSe has been identified uniquely by employing X-ray diffraction techniques. The X-ray identification has been correlated with the etch-pit figures formed on the (111)Zn and () Se surfaces. When etched with the K₂Cr₂O₇-H₂SO₄ solution, the (111) surface is highly polished, while the () surface forms triangular pyramidal shaped pits with positive orientation. Subsequently etched with the NaOH solution, triangular pyramidal shaped pits with negative orientation are formed on the (111) surface, and the positively oriented pits on the () surface formed by the K₂Cr₂O₇-H₂SO₄ solution develop into negatively oriented pits in triangular pyramidal shape and in addition, triangular pits with flat bottom are formed on the () surface. A similarity in etching behavior has been found between the ZnSe crystals grown from the melt and grown by sublimation techniques.