Enhanced on-state performance trench IGBT with a self-aligned p base

This paper presents an enhanced on-state performance of a 3.3 kV Trench IGBT with a self-aligned p base. The self-aligned p base process is based on the use of a common nitride mask for trench etching and p base boron implantation and diffusion which eliminates an extra process mask. Furthermore, the self-aligned p base structure virtually suppresses the parasitic JFET effect present in high-voltage trench IGBTs and results in considerably enhanced on-state performance. Extensive numerical simulations using the MEDICI simulator have been carried out and the results show that by adopting self aligned p base process one can relieve the pressure resulted from processing very deep trenches in high-voltage trench IGBTs.