SILICON CARBIDE SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD FOR SAME

摘要

A silicon carbide semiconductor device includes a drift layer of a first conductivity type, a source region of the first conductivity type, an active trench formed in penetration through the source region, a base region, a termination trench formed around the active trench, a gate insulating film formed on a bottom surface, a side surface of the active trench, a gate electrode embedded and formed in the active trench with the gate insulating film interposed therebetween, a protective diffusion layer of a second conductivity type formed in a lower portion of the active trench and a part of a lower portion of the termination trench and having a first impurity concentration, and a termination diffusion layer of the second conductivity type formed on an outside of the protective diffusion layer in the lower portion of the termination trench and having a second impurity concentration lower than the first impurity concentration.

主权项

1. A silicon carbide semiconductor device comprising:
a drift layer of a first conductivity type formed in an active region and a termination region being a surrounding region of said active region; a base region of a second conductivity type formed on an upper portion of said drift layer in said active region; a source region of the first conductivity type formed on an upper portion in said base region; an active trench formed in penetration through said source region and said base region in said active region; a termination trench formed to surround said active trench in said drift layer of said termination region; a gate insulating film formed on a bottom surface and a side surface of said active trench; a gate electrode formed in said active trench with said gate insulating film interposed therebetween; a protective diffusion layer of the second conductivity type formed in a lower portion of said active trench and a part of a lower portion of said termination trench and having a concentration of impurities of the second conductivity type which is a first impurity concentration; and a termination diffusion layer of the second conductivity type formed on an outside of said protective diffusion layer in said lower portion of said termination trench and having a concentration of impurities of the second conductivity type which is a second impurity concentration lower than said first impurity concentration.