Affiliation:
1. TEL Technology Center, America, LLC 1 , 255 Fuller Rd., Albany, New York 12203
2. SUNY Polytechnic Institute 2 , 257 Fuller Road, Albany, New York 12203
Abstract
This paper explores the use of a low temperature inductively coupled plasma discharge containing an NF3/Ar mixture for the isotropic, dry etching of TaN with selectivity to low-k dielectric; relying on radically based etch, without nonselective ion bombardment. With a clean chamber condition, no etch selectivity is found between TaN and the low-k dielectric, but when the chamber condition is manipulated by the addition of a plasma-deposited SiOx coating to the chamber wall, selectivity between TaN and the low-k dielectric is achieved. Deposition occurred on the low-k dielectric when the coating was applied to the chamber walls before etch, and while the TaN film etch rate did decrease with a coating applied, an etching regime was still observed. The coating was found to add significant atomic oxygen to the etch processes and decreased etching of the low-k dielectric. The deposition regime apparent for the low-k dielectric was made possible by the inability of the fluorine radicals to volatize silicon oxyfluoride compounds, causing deposition of a silicon oxyfluoride film on the low-k surface. The same etching inhibition was not observed on TaN, allowing selective etching.
Funder
TEL Technology Center, America
Subject
Materials Chemistry,Electrical and Electronic Engineering,Surfaces, Coatings and Films,Process Chemistry and Technology,Instrumentation,Electronic, Optical and Magnetic Materials