US Patent 9490322 Semiconductor device with enhanced 3D resurf

A device includes a semiconductor substrate, source and drain regions in the semiconductor substrate and spaced from one another along a first lateral dimension, and a drift region in the semiconductor substrate and through which charge carriers drift during operation upon application of a bias voltage between the source and drain regions. The drift region has a notched dopant profile in a second lateral dimension along an interface between the drift region and the drain region.