Influence of ion mixing on the energy dependence of the ion-assisted chemical etch rate in reactive plasmas

Journal Article · Fri Sep 15 04:00:00 EDT 2006 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2349544· OSTI ID:20884727

Stafford, L; Pearton, S J; Margot, J ^[1]

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1. Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States)

Recently, Stafford et al. [Appl. Phys. Lett. 87, 071502 (2005)] have shown that in contrast to the etch yield on a saturated surface, the ion-assisted chemical etch rate cannot universally be modeled by a simple square-root energy dependence. This results from the surface coverage by reactive neutral species being also a function of the ion energy. In this work, we further point out that depending on the plasma-material combination, the etch rate can exhibit two regimes that are characterized by different dependences on the ion energy. While these results are inconsistent with currently available models, we show that they can be interpreted by taking into account ion mixing effects on the desorption rate of volatile reaction products involved in the model of Stafford et al. Application of this rate model to the etching of Si, SiO{sub 2}, HfO{sub 2}, and ZrO{sub 2} in chlorine and fluorine plasma chemistries provides an excellent description of the simultaneous dependence of the etch rate on ion energy and on ion and reactive neutral fluxes.

• OSTI ID: 20884727
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 6 Vol. 100; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHLORINE
DESORPTION
ENERGY DEPENDENCE
ETCHING
FLUORINE
HAFNIUM OXIDES
PLASMA
REACTION KINETICS
SEMICONDUCTOR MATERIALS
SILICON
SILICON OXIDES
VOLATILITY
WALL EFFECTS
ZIRCONIUM OXIDES