SHALLOW TRENCH ISOLATION

摘要

A shallow trench isolation (STI) and method of forming the same is provided. The STI structure includes an upper insulating portion and a lower insulating portion, where the lower insulating portion includes a first insulator and an insulating layer surrounding the first insulator, the upper insulating portion includes a second insulator and a buffer layer surrounding the second insulator. Apart of the buffer layer interfaces between the first insulator and the second insulator, and the outer sidewall of the buffer layer and the sidewall of the first insulator are leveled.

主权项

1. A shallow trench isolation structure, comprising:
an upper insulating portion and a lower insulating portion in a trench of a substrate, wherein said lower insulating portion comprises a first insulator and an insulating layer on the sidewall and the bottom of said first insulator, said upper insulating portion comprises a second insulator and a buffer layer on the sidewall and the bottom of said second insulator, a part of said buffer layer interfaces between said first insulator and said second insulator, and the outer sidewall of said buffer layer and the sidewall of said first insulator are leveled.