公开(公告)号：US20180068856A1

公开(公告)日：2018-03-08

申请号：US15643341

申请日：2017-07-06

申请人： Renesas Electronics Corporation

发明人： Kazuya HORIE ,  Katsuhiro UCHIMURA ,  Kazuhiro TOI ,  Masakazu NAKANO

IPC分类号： H01L21/28 ,  H01L21/3065 ,  H01L21/324 ,  H01L21/283 ,  H01L21/311 ,  H01L21/768 ,  H01L29/66

CPC分类号： H01L21/324 ,  H01L21/28035 ,  H01L21/28114 ,  H01L21/3065 ,  H01L21/31055 ,  H01L21/31116 ,  H01L21/32135 ,  H01L21/32155 ,  H01L29/66 ,  H01L29/66659 ,  H01L29/66727 ,  H01L29/66734

摘要： In manufacturing a trench type MOSFET, reliability of a semiconductor device is prevented from being degraded due to a short circuit or lowering of withstand voltage between a trench gate electrode and a source region.To achieve the above, poly-silicon films are formed inside a trench in a main surface of a semiconductor substrate and over the semiconductor substrate. Further, phosphorus is thermally diffused into each poly-silicon film from a phosphorous film over an upper surface of the poly-silicon film. Still further, a silicon oxide film formed in a surface layer of the poly-silicon film by the thermal diffusion process is removed by a first dry etching process using a fluorocarbon gas or a hydroxy-fluorocarbon gas. Then, by performing a second dry etching process using a Cl2 gas etc., an insulating film is exposed and, thereby, a trench gate electrode including the poly-silicon film is formed.