LOW-TEMPERATURE EPITAXIAL-GROWTH OF COGE2(001) GAAS(100) FILMS USING THE PARTIALLY-IONIZED BEAM DEPOSITION TECHNIQUE/

The partially ionized beam (PIE) deposition technique was used to depo sit CoGe2(001) thin films heteroepitaxially on GaAs(100) substrates. T he epitaxial arrangement is CoGe2(001)/GaAs(100). It is found that the best epitaxy was obtained with an ion energy around 1100 eV and with a substrate temperature of 280 degrees C. The wafers were treated only by immersion in HF:H2O 1:10 immediately prior to deposition. Contacts grown at the optimal epitaxial formation conditions displayed Ohmic b ehavior, while contacts grown at higher or lower substrate temperature s had rectifying behavior. Epitaxial formation of CoGe2, a high meltin g point, low resistivity cobalt germanide phase, offers the possibilit y of forming a stable contact to n-GaAs. (C) 1996 American Institute o f Physics.