Manufacturing methods for accurately aligned and self-balanced superjunction devices

A method for manufacturing a semiconductor power device on a semiconductor substrate supporting a drift region composed of an epitaxial layer thereon, the method comprising:

• 1) forming a first hard mask layer on top of a first epitaxial layer followed by applying a first implant mask to open a plurality of first set of implanting windows then carrying out an ion implant with dopant ions of a first conductivity type to form a plurality of dopant regions of the first conductivity type in the first epitaxial layer;
• 2) forming a second hard mask layer filling in the first set of implanting windows followed by planarization of the second hard mask layer and removing of the first hard mask layer to form a second set of implanting windows then carrying out an ion 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 first conductivity type doped regions and the second conductivity type doped regions being arranged alternately to each other;
• and
• 3) repeating the step 1) and step 2) by applying the same first and second implant masks to form a plurality of epitaxial layers and implanting each of the epitaxial layers to form the dopant regions of the alternating first and second conductivity types adjacent to each other in each of the epitaxial layers.

A method for manufacturing a semiconductor power device on a semiconductor substrate supporting a drift region composed of an epitaxial layer thereon, the method comprising:

• 1) forming a first hard mask layer on top of a first epitaxial layer of a first conductivity type followed by applying a first implant mask to open a plurality of 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;
• 2) removing the first hard mask followed by forming a second epitaxial layer of the second conductivity type then forming a second hard mask layer on top of the second epitaxial layer followed by applying a second implant mask to open a plurality of second set of implanting windows to carry out an implant with dopant ions of the first conductivity type in the second epitaxial layer to form a plurality of dopant regions of the first conductivity type, each of said plurality of dopant regions of the first conductivity type being located laterally between two of said dopant regions of the second conductivity type in the first epitaxial layer;
• and
• 3) repeating the step 1) and step 2) by applying the same first and second implant masks to form a plurality of epitaxial layers of alternating conductivity types with dopant regions of opposite conductivity type of the epitaxial layer.