Etching of tungsten and tungsten silicide films by chlorine atoms

Journal Article · Mon Aug 01 00:00:00 EDT 1988 · J. Electrochem. Soc.; (United States)

DOI:https://doi.org/10.1149/1.2097848· OSTI ID:6593178

Fischi, D S ^[1]; Rodriques, G W ^[2]; Hess, D W ^[3]

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1. Air Products and Chemicals, Inc., Applied Research and Development, Allentown, PA (US)
2. Dept. of Chemical Engineering, Univ. of Wisconsin, Madison, WI (US)
3. Dept. of Chemical Engineering, Univ. of California, Berkeley, CA (US)

Thin films of tungsten and tungsten silicide were etched both within and downstream from a Cl/sub 2/ plasma discharge at 200 mtorr pressure and temperatures below 150/sup 0/C. When samples were positioned downstream from the discharge, etching proceeded solely by chemical reaction of the film with chlorine atoms. Without a discharge, molecular chlorine did not etch tungsten or tungsten silicide. Downstream and in-plasma tungsten etch rates were approximately equal at 110/sup 0/C, but the chlorine atom etch rate dropped more rapidly than the in-plasma etch rate as temperature decreased. The chemical reaction between chlorine atoms and the tungsten film was proportional to the gas phase Cl atom mole fraction. A pretreatment consisting of either a dilute hydrofluoric acid dip or a short plasma etch cycle was necessary for atom etching of tungsten silicide films. The etch rate of tungsten silicde in Cl/sub 2/ plamsas were approximately an order of magnitude higher and less temperature sensitive than those in the downstream (atom) configuration.

• OSTI ID: 6593178
• Journal Information: J. Electrochem. Soc.; (United States), Journal Name: J. Electrochem. Soc.; (United States) Vol. 135:8; ISSN JESOA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601* -- Other Materials-- Preparation & Manufacture
656001 -- Condensed Matter Physics-- Solid-State Plasma
656003 -- Condensed Matter Physics-- Interactions between Beams & Condensed Matter-- (1987-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ATOM TRANSPORT
CHLORINE
DIFFUSION
ELEMENTS
ETCHING
FILMS
HALOGENS
HYDROFLUORIC ACID
HYDROGEN COMPOUNDS
INORGANIC ACIDS
METALS
NEUTRAL-PARTICLE TRANSPORT
NONMETALS
PHASE STUDIES
PLASMA
PLASMA GUNS
RADIATION TRANSPORT
REFRACTORY METAL COMPOUNDS
SILICIDES
SILICON COMPOUNDS
SOLID-STATE PLASMA
SURFACE FINISHING
TEMPERATURE DEPENDENCE
THIN FILMS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
TUNGSTEN
TUNGSTEN COMPOUNDS
TUNGSTEN SILICIDES