Delicate dry clean

Abstract

A method of selectively removing fluorocarbon layers from overlying low-k dielectric material is described. These protective plasma treatments (PPT) are delicate alternatives to traditional post-etch treatments (PET). The method includes sequential exposure to (1) a local plasma formed from a silicon-fluorine precursor followed by (2) an exposure to plasma effluents formed in a remote plasma from a fluorine-containing precursor. The remote plasma etch (2) has been found to be highly selective of the residual material following the local plasma silicon-fluorine exposure. The sequential process (1)-(2) avoids exposing the low-k dielectric material to oxygen which would undesirably increase its dielectric constant.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS[0001]This application claims the benefit of U.S. Prov. Pat. App. No. 61 / 823,995 filed May 16, 2013, and titled “DELICATE DRY CLEAN” by Zhu et al., which is hereby incorporated herein in its entirety by reference for all purposes.STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT[0002]NOT APPLICABLEREFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISK[0003]NOT APPLICABLEBACKGROUND OF THE INVENTION[0004]Integrated circuit fabrication methods have reached a point where many hundreds of millions of transistors are routinely formed on a single chip. Each new generation of fabrication techniques and equipment are allowing commercial scale fabrication of ever smaller and faster transistors, but also increase the difficulty to make even smaller, faster circuit elements. The shrinking dimensions of circuit elements, now well below the 50 nm threshold, ha...

AI Technical Summary

Benefits of technology

The patent describes a method to selectively remove fluorocarbon layers from overlying low-k dielectric material using plasma treatments. This method avoids exposing the low-k material to oxygen which could increase its dielectric constant. The process involves sequential exposure to a local plasma formed from a silicon-fluorine precursor followed by an exposure to plasma effluents formed in a remote plasma from a fluorine-containing precursor. The method can provide a controlled and selective way to remove protective layers without damaging the low-k materials during semiconductor device manufacturing.

Problems solved by technology

These protective plasma treatments (PPT) are delicate alternatives to traditional post-etch treatments (PET).

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