Effect of surface preparations on contact resistivity of TiW to highly doped n-InGaAs

We report the effects of UV-ozone oxidation, oxide removal etch chemistry (dilute HCl or concentrated NH 4 OH), semiconductor doping, and annealing on the contact resistivity (rho c ) of Ti 0.1 W 0.9 refractory alloy to n-type InGaAs. The semiconductor surface was oxidized through exposure to UV-ozo...

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Bibliographic Details
Main Authors: Jain, V., Baraskar, A.K., Wistey, M.A., Singisetti, U., Griffith, Z., Lobisser, E., Thibeault, B.J., Gossard, A.C., Rodwell, M.
Format: Conference Proceeding
Language:English
Subjects:
Annealing
Chemistry
Conductivity
Indium gallium arsenide
Oxidation
Semiconductor device doping
Sputter etching
Sputtering
Surface treatment
Titanium alloys
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Summary:We report the effects of UV-ozone oxidation, oxide removal etch chemistry (dilute HCl or concentrated NH 4 OH), semiconductor doping, and annealing on the contact resistivity (rho c ) of Ti 0.1 W 0.9 refractory alloy to n-type InGaAs. The semiconductor surface was oxidized through exposure to UV-ozone, then subsequently etched by either dilute HCl or concentrated NH 4 OH before TiW contacts were deposited by blanket sputtering. InGaAs samples doped at 5 times 10 19 cm -3 , treated with 10 minutes of UV-Ozone then one minute dilute HCl exhibited rho c of (1.90 plusmn 0.35) times 10 -8 Omega-cm 2 . The contacts are thermally stable at least to 400 degC where after one minute anneal, rho c reduced to (1.29 plusmn 0.28) times 10 -8 Omega-cm 2 . TiW contacts on samples having same active dopants, with no UV-ozone oxidation and only 10 seconds of concentrated NH 4 OH etch exhibit rho c of (2.49 plusmn 0.40) plusmn 10 -8 Omega-cm 2 .
ISSN:1092-8669
DOI:10.1109/ICIPRM.2009.5012438