Study on the influence of ambient temperature on surface/subsurface damage of monocrystalline germanium lapping wafer

The surface and subsurface damage of monocrystalline germanium wafer directly affect the performance and life of the product, so it is necessary to reduce the occurrence of damage during the lapping and polishing process. The changes in ambient temperature and temperature in the process will affect the shape precision of the workpiece, and also influence the surface of the material and the quality of subsurface. In this paper, the angle polishing method was used to measure the subsurface damage of germanium wafer. The effects of different processing ambient temperature on the surface and subsurface damage of germanium wafer after lapping were compared and analyzed. The results show that compared with normal processing, the surface topography of germanium after low temperature lapping is flatter, less surface pits, more and more narrow shallow cracks, and less cracks on both sides of the cracks. The subsurface damage depth can be reduced effectively by low temperature processing. The shapes of subsurface crack are mainly line, herringbone, and dendrimer. (C) 2018 The Authors. Published by Elsevier Ltd.