US Government As Represented by the Secretary of the Army

Kevin E Mello

Toh-Ming Lu

Shyam P Murarka

Sabrina L Lee

Steven Robert Soss

A partially ionized beam (PIB) deposition technique is used to heteroepitally deposit a thin film of CoGe.sub.2 (001) on GaAs (100) substrates 14. The resulting epitaxial arrangement is CoGe.sub.2 (001) GaAs (100). The best epitaxial layer is obtained with an ion energy 1100 eV to 1200 eV and with a substrate temperature of approximately 280.degree. Centigrade. The substrate wafers are treated only by immersion in HF:H.sub.2 O 1:10 immediately prior to deposition of the epitaxial layer. Contacts grown at these optimal conditions display ohmic behavior, while contacts grown at higher or lower substrate temperatures exhibit rectifying behavior. Epitaxial formation of a high melting point, low resistivity cobalt germanide phase results in the formation of a stable contact to n-GaAs.

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Ballston Spa, NY, United States of America

Kevin E Mello