Effect of mechanical anisotropy on material removal rate and surface quality during polishing CdZnTe wafers

The mechanical characters of CdZnTe crystal were investigated by nanoscratch tests, and the effects of mechanical anisotropy on the material removal rate and surface quality were studied by polishing tests. There is a peak of frictional coefficient at the early stage of scratch, and increasing the vertical force will result in the increase of peak value correspondingly. The fluctuation phenomenon of frictional coefficient is generated at high vertical force. The lateral forces show the apparent twofold and threefold symmetries on (110) and (111) planes, respectively. To obtain high surface quality, low polishing pressure and hard direction (< 1̄10 > directions on (110) plane and < 112̄ > directions on (111) plane) should be selected, and to achieve high material removal rate, high polishing pressure and soft direction (< 001 > directions on (110) plane and < 1̄21̄ > directions on (111) plane) should be selected.