Investigation of silicon lapping and polishing technique for micro-inertial device

The precision lapping and polishing Si wafer is presented. Three-step lapping Si wafer and two-step polishing Si wafer are adopted within this processing. The Al2O3 abrasive of 20 mu m, 9 mu m and 3 mu m is used to lap wafer, then precision polishing is done with lapping agent of CeO2 and SF1. The thickness of the Si wafer can be controlled accurately, the flatness can be controlled within 3 mu m, and the roughness can be controlled under mm. The stress can be decreased evidently, even the thickness of the Si wafer is thinned down to 60 mu m, it is still flat.