公开(公告)号：US20200052123A1

公开(公告)日：2020-02-13

申请号：US16056540

申请日：2018-08-07

Applicant: UNITED MICROELECTRONICS CORP.

Inventor： Yi-Liang Ye ,  Chun-Wei Yu ,  Yu-Ren Wang ,  Hao-Hsuan Chang ,  Chia-Wei Hsu

IPC: H01L29/78 ,  H01L29/06 ,  H01L29/66 ,  H01L21/02 ,  H01L21/324 ,  H01L21/762

Abstract: A method of rounding corners of a fin includes providing a substrate with a fin protruding from the substrate, wherein a pad oxide and a pad nitride entirely cover a top surface of the fin. Later, part of the pad oxide is removed laterally to expose part of the top surface of the fin. A silicon oxide layer is formed to contact two sidewalls of the fin and the exposed top surface, wherein two sidewalls and the top surface define two corners of the fin. After forming the silicon oxide layer, an annealing process is performed to round two corners of the fin. Finally, after the annealing process, an STI filling material is formed to cover the pad nitride, the pad oxide and the fin.