US Patent 10388569 Formation of stacked nanosheet semiconductor devices

A method of fabricating a stacked semiconductor device includes forming nanosheet stacks including silicon layers and silicon germanium layers on a substrate. The method includes growing a first epitaxial layer on a source and drain and depositing an interlayer dielectric on the first epitaxial layer. The method includes etching the interlayer dielectric to expose the first epitaxial layer. The method includes etching a portion of the first epitaxial layer and growing a second epitaxial layer on the first epitaxial layer and etching the interlayer dielectric and depositing a first liner in a recess left by the etching, forming a pFET. The method includes etching a portion of the first liner and removing the second epitaxial layer leaving a portion of the first epitaxial layer exposed and depositing a second insulator layer on the first epitaxial layer, forming an nFET. The pFET and nFET are disposed adjacent to one another vertically.