The system has been found to give good results for preferential etching of . The etch rates for the low‐index planes of in this system have been investigated as a function of Br2 concentrations in .The order of the etch rate at 1% Br2 by weight has been found to be planes have been only slightl yetched. The A{111} planes have played an important role for the etched profiles produced by this etching system. A V‐shaped groove, a reverse mesa‐shaped structure, and a triangular prism‐shaped "bridge" have been formed by channels being etched on the {100} planes. The sizes of the V‐shaped groove and the "bridge" have been controlled by the width of the opening in the oxide mask. A channel etched groove in the B{111} planes has also exhibited crystal habit. Interesting etched profiles which are applicable for the design and fabrication of device structures are described.