Synopsys, Inc.
EPITAXIAL GROWTH OF SOURCE AND DRAIN MATERIALS IN A COMPLEMENTARY FIELD EFFECT TRANSISTOR (CFET)

Abstract:

A method of performing epitaxial growth of a source and drain on levels of a complementary field effect transistor (CFET) is provided. The method includes depositing a first blocking material in a vertical channel of an unfinished CFET structure, oxidizing silicon at a surface of an upper level of the CFET to provide one or more SiO.sub.2 protective layers, etching away a portion of silicon from a lower level of the CFET to form a lateral recess that is exposed to the vertical channel, and performing silicon epitaxial growth in the lower level of the unfinished CFET structure. Further, after the silicon epitaxial growth on the lower level, the method includes depositing a second blocking material in the vertical channel to cover at least a portion of the silicon epitaxial growth in the lower level, removing the SiO.sub.2 protective layer, and performing epitaxial growth on the upper level.