Method for forming lateral super-junction structure

摘要

A fabrication method to form a lateral superjunction structure in a semiconductor device uses N and P type ion implantations into a base epitaxial layer. In some embodiments, the base epitaxial layer is an intrinsic epitaxial layer or a lightly doped epitaxial layer. The method performs simultaneous N and P type ion implantations into the base epitaxial layer. The epitaxial and implantation processes are repeated successively to form multiple implanted base epitaxial layers on a semiconductor base layer. After the desired number of implanted base epitaxial layers is formed, the semiconductor structure is subjected to annealing to form a lateral superjunction structure including alternate N and P type thin semiconductor regions. In particular, the alternating N and P type thin superjunction layers are formed by the ion implantation process and subsequent annealing. The fabrication method of the present invention ensures good charge control in the lateral superjunction structure.

主权项

1. A method for forming a lateral superjunction structure, comprising:
providing a heavily doped semiconductor substrate of a first conductivity type; forming a lightly doped semiconductor layer of the first conductivity type on the substrate, the substrate and the lightly doped semiconductor layer forming a semiconductor base layer; forming a base epitaxial layer on the semiconductor base layer; performing N-type and P-type implantation into a first region of the base epitaxial layer to introduce both N-type and P-type dopants into the first region of the base epitaxial layer; repeating the forming a base epitaxial layer and the performing N-type and P-type implantation into the base epitaxial to form a plurality of implanted base epitaxial layers on the semiconductor base layer, the plurality of implanted base epitaxial layers forming a semiconductor structure having a first surface opposite the semiconductor base layer; and annealing the plurality of implanted base epitaxial layers to activate implanted dopants and to spread out the implanted dopants to form alternating N-type and P-type thin semiconductor regions in the semiconductor structure, wherein the alternating N-type and P-type thin semiconductor regions form the lateral superjunction structure, the alternating N-type and P-type thin semiconductor regions being formed in the first region and being formed parallel to the first surface of the semiconductor structure.