High switching trench MOSFET

摘要

A shielded gate trench metal oxide semiconductor filed effect transistor (MOSFET) having high switching speed is disclosed. The inventive shielded gate trench MOSFET includes a shielded electrode spreading resistance placed between a shielded gate electrode and a source metal to enhance the performance of the shielded gate trench MOSFET by adjusting doping concentration of poly-silicon in gate trenches to a target value. Furthermore, high cell density is achieved by employing the inventive shielded gate trench MOSFET without requirement of additional cost.

主权项

1. A power semiconductor device comprising:
a plurality of gate trenches extending into a silicon layer of a first conductivity type; a gate electrode disposed in upper portion of each of said gate trenches and a shielded electrode disposed in lower portion of each of said gate trenches, wherein said gate electrode and said shielded electrode insulated from each other by an inter-electrode insulating layer; said gate electrode and said shielded electrode are doped poly-silicon layers wherein said gate electrode having doping concentration equal to or higher than said shielded electrode; said gate electrode connected to a gate metal through a gate electrode spreading resistance and said shielded electrode connected to a source metal through a shielded electrode spreading resistance; and said upper portion of said gate trenches surrounded by source regions of said first conductivity type and body regions of a second conductivity type in active area.