Semiconductor structures and fabrication method thereof

摘要

A method is provided for fabricating a semiconductor structure. The method includes providing a to-be-etched layer; and forming a hard mask layer on the to-be-etched layer. The method also includes forming a photoresist layer on the hard mask layer; and forming a patterned photoresist layer having openings exposing the hard mask layer by exposing and developing the photoresist layer. Further, the method includes forming sidewall spacers on side surfaces of the openings; and forming a patterned hard mask layer by etching the hard mask layer using the patterned photoresist layer and the sidewall spacers as an etching mask such that patterns in the hard mask layer have a substantially right angle at edge. Further, the method also includes forming to-be-etched patterns by etching the to-be-etched layer based on the patterned hard mask layer.

主权项

1. A method for fabricating a semiconductor structure, comprising:
providing a to-be-etched layer for making the semiconductor structure; forming a hard mask layer on the to-be-etched layer; forming a photoresist layer on the hard mask layer; forming a patterned photoresist layer having openings exposing the hard mask layer by exposing and developing the photoresist layer; forming sidewall spacers on side surfaces of the openings; forming a patterned hard mask layer by etching the hard mask layer using the patterned photoresist layer and the sidewall spacers as an etching mask such that patterns in the hard mask layer have a substantially 90 degree angle at edge, wherein, while etching the hard mask layer, the patterned photoresist layer and the sidewall spacers are also etched such that remaining sidewall spacers have a height greater than remaining patterned photoresist layer over the to-be-etched layer; and forming to-be-etched patterns by etching the to-be-etched layer based on the patterned hard mask layer.