A novel high performance enhanced-planar IGBT with P-type buried layer

A novel high performance enhanced-planar IGBT with p-type buried layer (PBL-EPIGBT) is proposed in this paper. The p-type buried layer (PBL) is placed outside the n-type carrier stored (N-CS) layer and encompasses it partially. Compatible with the conventional EPIGBT technology, the PBL of the proposed structure can be formed by ion implantation and diffusion before the formation of the N-CS layer. Since additional bulk electric field modulation introduced from the charges in the PBL, the negative impact of the positive charges in the N-CS layer on the breakdown voltage (BV) is addressed effectively. The proposed structure breaks the limitation of the doping concentration of the N-CS layer (N
N-CS
) on the BV and hence, a higher N
N-CS
can be used for the proposed PBL-EPIGBT structure with almost constant BV. As a result, in comparison with the conventional EPIGBT without a PBL, the novel structure offers not only high BV, but also improved E
off
-V
ce(on)
trade-off characteristics.