Semiconductor structure and process thereof

摘要

A semiconductor structure includes a substrate, a recess and a material. The recess is located in the substrate, wherein the recess has an upper part and a lower part. The minimum width of the upper part is larger than the maximum width of the lower part. The material is located in the recess.

主权项

1. A semiconductor process, comprising:
providing a substrate; forming a recess in the substrate, wherein the recess has a first sidewall and the first sidewall is a straight sidewall; filling an isolation material in the recess and exposing a part of the recess; performing an etching process to laterally etch the exposing part of the recess, the result being the recess comprises an upper part and a lower part, wherein the upper part has a second sidewall and the lower part has the first sidewall being formed simultaneously, and a first projection line substantially coplanar and parallel to the first sidewall of the lower part of the recess intersects at a first point with a second projection line substantially coplanar and parallel to a top surface of a pad nitride layer formed above the substrate, whereby the second sidewall at the upper part of the recess has one end thereof formed at the first point, and the other end of the second sidewall forms the turning point; and filling the isolation material in the recess after the etching process is performed.