FDTD SIMULATION OF IR EVANESCENT LIGHT FOR NANODEFECTS INSPECTION IN POLISHED SI WAFER SUBSURFACE

摘要

In order to reduce and control yield loss in the fabrication process of next generation LSI devices, nano-defects inspection technology for polished Si wafer surface is essential. This paper discusses the new inspection method of nanodefects in polished Si wafer subsurface by detecting infrared radiation (IR) evanescent light emerging on the surface. To verify the feasibility of this proposed method, computer simulations are performed by means of FDTD method directly solving Maxwell's equations based on the scanning Si probe model. The results show that the proposed method is effective for detecting nano-defects existing not only on Si wafer surface but also in the subsurface with high sensitivity.