Patent ID: 8785306

Claim:
A method for manufacturing a semiconductor power device on a semiconductor substrate supporting a drift region thereon composed of a first epitaxial layer of a first conductivity type, the method comprising: 1) forming a first hard mask layer on top of the first epitaxial layer 2) applying a first implant mask to open a plurality of a first set of implanting windows then carrying out an implant with dopant ions of a second conductivity type to form a plurality of dopant regions of the second conductivity type in the first epitaxial layer, the second conductivity type being opposite to the first conductivity type; 3) applying a second implanting mask to block a selected set of implanting windows among the first set of implanting windows for implanting dopant ions of the first conductivity type to form a plurality of dopant regions of the first conductivity type in the first epitaxial layer followed by removing the second implant mask and the first hard mask and then followed by forming a second epitaxial layer of the first conductivity type on top of the first epitaxial layer; and 4) repeating the step 1) to step 3) by applying the same first and second implant masks to form a plurality of epitaxial layers each having dopant regions of alternating conductivity types vertically aligned according to the first and second implant masks.