The Role of Fluorine Chemistry in Anisotropic Etching of Dielectric Materials

Published

October 12, 2021

Author(s)

B Ji, S A. Motika, P R. Badowski, S Dheandhanoo, C Timmons, D E. Hess, Eric C. Benck, Y Ye

Abstract

Fluorine-containing compounds have for many years been utilized to etch dielectric materials such as silicon oxide. Maintaining the balance between the removal rate of material from the trench bottom and formation of the protective sidewall film is critical in assuring desired etch features and critical dimensions. Soon anisotropic etching will be employed not only to form features less than 100 nm in size, but to produce them in a variety of new dielectric materials. This is driving a need for new etching gas chemistries to meet this challenge. As part of our product development efforts we performed a fundamentals study to better understand the relationship between etch gas compounds and the species formed within both capacitively and inductively coupled plasmas. We report here on our work comparing c-C₄F₈, a widely used etching gas, to two new etchants C₄F₆ and C₅F₈. UV Absorption Spectroscopy, Sub-millimeter Wave Absorption Spectroscopy, Optical Emission Spectroscopy, Mass Spectrometry, and X-ray Photoelectron Spectroscopy were employed to evaluate the gas phase and surface chemistries of these etching molecules.

Citation

Abstracts Of Papers Of The American Chemical Society

Pub Type

Journals

Keywords

dielectric etch, fluorocarbon, plasma

Citation

Ji, B. , Motika, S. , Badowski, P. , Dheandhanoo, S. , Timmons, C. , Hess, D. , Benck, E. and Ye, Y. (2021), The Role of Fluorine Chemistry in Anisotropic Etching of Dielectric Materials, Abstracts Of Papers Of The American Chemical Society (Accessed December 27, 2024)