Patent ID: 6870199
Filing Date: 2005-03-22
Classification: H01L

Abstract:
1. A semiconductor device comprising: a semiconductor substrate of a lightly doped first conductivity type; a heavily doped region of a second conductivity type formed selectively in the semiconductor substrate; and an electrode formed on a surface of said semiconductor substrate, said electrode being in contact with said heavily doped region, said heavily doped region having a projecting region that extends beyond said electrode, wherein said semiconductor substrate comprises a first carrier lifetime region and a second carrier lifetime region, wherein the carrier lifetime in said first carrier lifetime region is shorter than the carrier lifetime of said second carrier lifetime region, wherein said first carrier lifetime region extends into at least a portion of said projection region of said heavily doped region and overlaps a portion of said electrode, and wherein said first carrier lifetime region includes a boundary area spreading nearly vertically between said heavily doped region and said semiconductor substrate, wherein said first carrier lifetime region has a portion having a width La that overlaps said electrode, the width La and a diffusion length Ls of carriers in said first carrier lifetime region are related to each other by the following relational expression: La>Ls.