Effect of Ar and N{sub 2} addition on CH{sub 4}-H{sub 2} based chemistry inductively coupled plasma etching of HgCdTe

Journal Article · Wed Jul 15 04:00:00 EDT 2009 · Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films

DOI:https://doi.org/10.1116/1.3147219· OSTI ID:22053508

Boulard, F; Baylet, J; Cardinaud, C ^[1]

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1. Institut des Materiaux Jean Rouxel (IMN), Universite de Nantes, CNRS, 2 rue de la Houssiniere, 44322 Nantes Cedex 3 (France)

Mercury cadmium telluride (MCT) CH{sub 4}-H{sub 2} based chemistry inductively coupled plasma (ICP) etching mechanisms are investigated. The effect of Ar and N{sub 2} addition in the mixture on plasma and MCT surface characteristics are studied by Langmuir probe, mass spectrometry, and x-ray photoelectron spectroscopy (XPS). In the authors' conditions, the HgTe faster removal than CdTe leads to the formation of a CdTe rich layer in the first 30 s of plasma exposure. Ion flux intensity and composition are only slightly influenced by N{sub 2} addition while a strong effect is shown on neutral species by the formation of NH{sub 3}, HCN, and the increase in CH{sub 3} radical density. At the opposite, Ar addition to the gas mixture leads to a total ion flux increase and promote CH{sub 3}{sup +} formation while small changes are observed on neutral species. In our low pressure and high density conditions, same order of magnitude of ion and neutral CH{sub 3} flux on MCT surface is found, suggesting a chemical contribution of CH{sub 3}{sup +} ions in MCT etching. This is confirmed by a strong correlation of the MCT etching yield versus total (neutral and ionic) CH{sub 3} flux. These results suggest that the etching is limited by the supply of CH{sub 3} to the surface.

• OSTI ID: 22053508
• 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: 4 Vol. 27; ISSN 1553-1813
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
AMMONIA
CADMIUM TELLURIDES
CORRELATIONS
ETCHING
HYDROCYANIC ACID
HYDROGEN
IONS
LAYERS
MASS SPECTROSCOPY
MERCURY TELLURIDES
METHANE
MIXTURES
PLASMA
RADICALS
SEMICONDUCTOR MATERIALS
SPUTTERING
X-RAY PHOTOELECTRON SPECTROSCOPY