Methods and structures for back end of line integration

摘要

Embodiments of the present invention provide a semiconductor structure for BEOL (back end of line) integration. A directed self assembly (DSA) material is deposited and annealed to form two distinct phase regions. One of the phase regions is selectively removed, and the remaining phase region serves as a mask for forming cavities in an underlying layer of metal and/or dielectric. The process is then repeated to form complex structures with patterns of metal separated by dielectric regions.

主权项

1. A method of forming a semiconductor structure, comprising:
depositing a first dielectric layer on a semiconductor substrate; depositing a first layer of direct self-assembly (DSA) material on the first dielectric layer; performing a phase separation of the first layer of DSA material into a first phase region and a second phase region; selectively etching one phase region of the first phase region and second phase region of the first layer of DSA material; forming cavities in the first dielectric layer; depositing a metal fill layer in the cavities of the first dielectric layer; depositing a second layer of DSA material over the metal fill layer; performing a phase separation of the second layer of DSA material into a first phase region and a second phase region; selectively etching one phase region of the first phase region and second phase region of the second layer of DSA material; forming cavities in the metal fill layer; and depositing a second dielectric layer over the metal fill layer and in the metal layer cavities.