Electron cyclotron resonance plasma etching of undoped and tellurium doped GaSb (100) samples using a combination of (Cl-2/BCl3/CH4/Ar/H-2) gases has been demonstrated. Etch rates up to about 5000 (A) over circle /min at room temperature with sharp sidewalls, low surface roughness, and no undercutting have been evinced. The etch rate obtained using the reported gas mixture is approximately two times the etch rate using existing methane based recipes and comparable to chlorine etches. (C) 2003 American Vacuum Society.