The surface quality of CdZnTe plays an important role in the performance of sensors based on this material. In this paper the effect of chemical etching on Cd 0.9 Zn 0.1 Te sensor performance was examined. Sample surfaces were treated with the same concentration 2% Br-MeOH for different etching times (30s, 2, 4, 6, 8min). The surfaces were characterized by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), and I–V Measurement. These results demonstrate that the best surface quality can be obtained by chemical etching for 30s. Under these experimental conditions, the surface composition Te/Cd+Zn approaches 1, the roughness is lower than 3nm, and the leakage current shows a value lower than 10nA.