Method for forming a stacked transistor device

Abstract

The present disclosure relates to a method for forming a stacked transistor device comprising a lower NSHFET structure and an upper FinFET structure including: forming a fin structure comprising: a lower device sub-stack comprising a number of lower channel nanosheets, a middle insulating layer, an upper device sub-stack comprising an upper channel layer, and a capping layer; forming a process layer embedding the fin structure; subsequent to forming the process layer, removing the capping layer from the fin structure to define a gap exposing the upper device sub-stack; forming spacer layers on opposite side surfaces of the gap to form a reduced-width gap; splitting the upper channel layer by etching back an upper surface thereof via the reduced-width gap to form two upper channel fins; subsequent to forming the upper channel fins, removing the spacer layers; and thereafter: forming a gate structure; and forming source and drain regions for the lower channel nanosheets and the upper channel fins.