公开(公告)号：US20230141093A1

公开(公告)日：2023-05-11

申请号：US18149130

申请日：2023-01-02

Applicant: Taiwan Semiconductor Manufacturing Co., Ltd.

Inventor： Han-Yu LIN ,  Jhih-Rong HUANG ,  Yen-Tien TUNG ,  Tzer-Min SHEN ,  Fu-Ting YEN ,  Gary CHAN ,  Keng-Chu LIN ,  Li-Te LIN ,  Pinyen LIN

IPC: H01L21/8234 ,  H01L21/3065

CPC classification number: H01L21/823431 ,  H01L21/3065 ,  H01L21/823418

Abstract: The present disclosure describes a semiconductor structure and a method for forming the same. The method can include forming a fin structure over a substrate. The fin structure can include a channel layer and a sacrificial layer. The method can further include forming a first recess structure in a first portion of the fin structure, forming a second recess structure in the sacrificial layer of a second portion of the fin structure, forming a dielectric layer in the first and second recess structures, and performing an oxygen-free cyclic etching process to etch the dielectric layer to expose the channel layer of the second portion of the fin structure. The oxygen-free cyclic etching process can include two etching processes to selectively etch the dielectric layer over the channel layer.