Patent ID: 7947432
Filing Date: 2011-05-24
Classification: G03F

Abstract:
1. A pattern formation method comprising steps of: (a) forming a lower layer film on a film to be etched, the film to be etched being formed on a substrate; (b) forming an intermediate layer film on the lower layer film; (c) forming a first resist pattern by forming a first resist film on the intermediate layer film, exposing the first resist film through a first photomask having a first pattern and developing the exposed first resist film; (d) forming a first intermediate layer pattern by etching the intermediate layer film with the first resist pattern used as a mask in order to transfer the first resist pattern to the first intermediate layer so that the first intermediate layer pattern includes a pattern of the first resist pattern; (e) removing the first resist pattern; (f) forming a second resist pattern by forming a second resist film on the lower layer film and the first intermediate layer pattern, exposing the second resist film through a second photomask having a second pattern and developing the exposed second resist film after the step (e); (g) forming a second intermediate layer pattern by etching the first intermediate layer pattern with the second resist pattern used as a mask in order to transfer the second resist pattern to the first intermediate layer pattern so that the second intermediate layer pattern includes patterns of the first resist pattern and the second resist pattern; (h) removing the second resist pattern; (i) forming a lower layer pattern in a shape of the first pattern and the second pattern by etching the lower layer film with the second intermediate layer pattern used as a mask after the step (h), wherein: in the step (f), the second resist pattern is formed so as to be in contact with a part of an upper surface of the lower layer film opposite to a surface being in contact with the film to be etched and a part of an upper surface of the first intermediate layer pattern opposite to a surface being in contact with the lower layer film, and the lower layer pattern is used as a mark for dry etching the film to be etched.