The Study Of High Speed Mechanochemical Lapping Technology For Germanium Wafer

The solar cell based on Germanium substrates compare to silicon solar cell it have higher cell conversion efficiency, lower cost of electricity, better high temperature endurance performance and better resistance to radiation from the space. The solar cell have a very high quality requirements for the surface of the germanium substrate which was made of GaAs and other semiconductor material epitaxy on crystal germanium substrate. It is important to study the process of high-speed mechanochemical lapping on germanium wafer which it can enlarge the applications for single crystal Germanium and reduce the costs for the production.Lapping is a conventional technology often used for optical materials. But now few people do a research about lapping on single crystal Germanium wafer. So, on theory research, the relative movement between the lapping disk and the Germanium wafer was analyzed, the form of the lapping trace, the trace’s distribution character and the effecting factors were achieved. The mechanics math model was setup. After the mechanical analysis, the single crystal Germanium’s critical load and the theoretical surface roughness equation were derived. Finally, mechanical model of the material removal process were setup and the chemical reactions in this process were point out. On experiment research, an orthogonal high speed mechanochemical lapping with solid abrasives experiments were carried out.The abrasive’s size, lapping pressure, the spindle’s speed were taken as the main parameters, the roughness, surface removal rate and subsurface deformation depth were taken as the main results, the optical contour equipment and microscope were taken as the measuring tools, the deformed depth and characters under different lapping conditions were conducted, after analysis of its effectors, a proper high speed mechanochemical lapping with solid abrasives process planning for the Germanium wafer was established. All the work done before may provide some references of the future work.