公开(公告)号：US20220336611A1

公开(公告)日：2022-10-20

申请号：US17471859

申请日：2021-09-10

Applicant: Taiwan Semiconductor Manufacturing Co., Ltd.

Inventor： Fo-Ju LIN ,  Fang-Wei Lee ,  Chih-Long Chiang ,  Li-Te Lin ,  Pinyen Lin

IPC: H01L29/423 ,  H01L29/786 ,  H01L29/06 ,  H01L29/417 ,  H01L29/66 ,  H01L29/40 ,  H01L21/311

Abstract: The present disclosure describes a method to form a semiconductor device with air inner spacers. The method includes forming a semiconductor structure on a first side of a substrate. The semiconductor structure includes a fin structure having multiple semiconductor layers on the substrate, an epitaxial structure on the substrate and in contact with the multiple semiconductor layers, a gate structure wrapped around the multiple semiconductor layers, and an inner spacer structure between the gate structure and the epitaxial structure. The method further includes removing a portion of the substrate from a second side of the substrate to expose the epitaxial structure and the inner spacer structure, forming an oxide layer on the epitaxial structure on the second side of the substrate, and removing a portion of the inner spacer structure to form an opening. The second side is opposite to the first side of the substrate.