Angular etching yields of polysilicon and dielectric materials in Cl{sub 2}/Ar and fluorocarbon plasmas

Journal Article · Tue Jan 15 04:00:00 EST 2008 · Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films

DOI:https://doi.org/10.1116/1.2821750· OSTI ID:21020898

Yunpeng, Yin; Sawin, Herbert H ^[1]

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1. Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

The angular etching yields of polysilicon in Cl{sub 2}/Ar plasmas, and dielectric materials (thermal silicon dioxide and low-k dielectric coral) in fluorocarbon plasmas, have been characterized in an inductively coupled plasma beam apparatus. The effects of ion energy, feed gas composition, and plasma source pressure are studied. The experimental results showed that these etching parameters had a significant impact on the resulting angular etching yield curve. In particular, the angular etching yield curve was more sputteringlike at low plasma source pressure and/or low effective gas percentage (Cl{sub 2} and C{sub 4}F{sub 8}), with a peak around 60 deg. -70 deg. off-normal ion incident angle. In contrast, ion-enhanced-etching-like angular curves, which dropped gradually with off-normal angle, were formed at high plasma source pressure and/or high effective gas percentage. Further analysis indicated that the effective neutral-to-ion flux ratio reaching the surface was the primary factor influencing the angular etching yield curve. More specifically, the angular etching yield curve had physical sputtering characteristics at low neutral-to-ion flux ratios; while etching process was really dominated by ion-enhanced etching at high ratios and the angular curve was ion-enhanced-etching-like. The polymer deposition effects are also discussed in this article.

• OSTI ID: 21020898
• Journal Information: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Journal Name: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films Journal Issue: 1 Vol. 26; ISSN 1553-1813
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CARBON FLUORIDES
CHLORINE
DEPOSITION
DIELECTRIC MATERIALS
ETCHING
IONS
PLASMA
SEMICONDUCTOR MATERIALS
SILICON
SILICON OXIDES
SPUTTERING
SURFACES
THIN FILMS