METHOD FOR MANUFACTURING POWER SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for manufacturing a power semiconductor device is provided to be capable of prevent electric field crowding of a ring area and reducing chip size. CONSTITUTION: An epitaxial layer(12) is grown on a substrate(11). An oxide layer is formed on the epitaxial layer. A photoresist pattern is then formed on the oxide layer. The oxide layer is selectively etched by using the photoresist pattern as an etching mask. An etching process is performed on the epitaxial layer through the open portion of the oxide layer for forming a trench. A diffusion process is performed at the trench alone by using thermal diffusion material. The trench is filled with a CVD(Chemical Vapor Deposition) oxide layer(17). The CVD oxide layer is partially removed by carrying out a CMP(Chemical Mechanical Polishing) process. A P+ body(18) is formed in the active region of the epitaxial layer.