Semiconductor device having different source/drain junction depths and fabrication method thereof

Abstract

Structures and formation methods of a semiconductor device are provided. The method includes forming a first dummy gate structure across a first fin in a first transistor region of a semiconductor substrate and a second dummy gate structure across a second fin in a second transistor region of the semiconductor substrate. The method also includes selectively introducing atomic or ionic species into the second fin on opposite sides of the second dummy gate structure and etching portions of the first and second fins, so as to form first and second recesses. Each recess is in the respective fin on a side of the respective dummy gate structure. The first recess has a different depth than the second recess. The method further includes forming first and second source/drain features in the first and second recesses, respectively.