Patent ID: 6727527
Filing Date: 2004-04-27
Classification: H01L

Abstract:
A power device comprising:a semiconductor substrate of first conductivity type, said semiconductor substrate including a front-side surface, a backside surface, and a scribe region, said substrate having a first well of second conductivity type whereon an active cell is defined, said first well having a first impurity type of a first mobility; a drain region of second conductivity provided proximate said backside surface, said drain region having said first impurity type and formed by diffusing said first impurity type into said substrate from said backside surface; and a continuous diffusion region of second conductivity type extending from said front-side surface to said backside surface, said continuous diffusion region including: a second impurity type of a second mobility that has been diffused vertically into the substrate from a selected location of said backside surface, said second mobility being higher than said first mobility, a lower portion of said continuous diffusion region corresponding to said selected location of said continuous diffusion region, an upper portion provided proximate said front-side surface of said substrate, and an intermediate portion provided above said lower portion but below said upper portion, said intermediate portion being formed at least in part by having said second impurity type being diffused into said substrate from said lower portion to said intermediate portion, wherein a concentration of said second impurity type is higher in said lower portion than that in said intermediate portion, wherein said second impurity type of said continuous diffusion region and said first impurity type of said drain region are diffused into said substrate together to form said continuous diffusion region and said drain region.