HIGH VOLTAGE POWER MOSFET HAVING A VOLTAGE SUSTAINING REGION THAT INCLUDES DOPED COLUMNS FORMED BY TRENCH ETCHING AND DIFFUSION FROM REGIONS OF OPPOSITELY DOPED POLYSILICON

摘要

A kind of method being used to form power semiconductor is provided. This method starts from providing the substrate of first or second conduction type, and voltage sustaining region is formed on the substrate later. In voltage sustaining region by forming the epitaxial layer of at least one groove in deposit epitaxial layers in the first conductive type substrate. First polysilicon layer has the filling of the second dopant of the second conduction type in the trench. The epitaxial region of the second dopant doping is spread, and in the epitaxial layer of adjacent trenches. Second layer polysilicon has the subsequent filling of the first dopant of the first conduction type in the trench. The realization electrical contact compensation of the first and second dopant phase counterdiffusion in the second and first polysilicon layer is located in first and second layers of polysilicon. Finally, the upper area for forming at least one the second conduction type, voltage sustaining region is to limit knot therebetween.