Patent ID: 6936908
Filing Date: 2005-08-30
Classification: H01L

Abstract:
1. A power device, comprising: a gate electrode, a source electrode, and a drain electrode provided within an active region of a semiconductor substrate of first conductivity type; and a vertical diffusion region of second conductivity provided at a periphery the active region, the vertical diffusion region extending continuously from a top surface of the substrate to a bottom surface of the substrate, the vertical diffusion region including: an upper portion having a first depth, and a lower portion having a second depth that is substantially greater than the first depth, wherein the upper portion primarily comprises of an impurity of first type and the lower portion comprises of an impurity of second type different from the impurity of first type, wherein the impurity of first type has a first diffusion rate and the impurity of second type has a second diffusion rate, the second diffusion rate being greater than the first diffusion rate, wherein the impurity of first type is boron, and wherein the impurity of second type is aluminum.