International Business Machines Corporation

Satya P Bhatia

Sampath Purushothaman

Hormazdyar M Dalal

Harsaran S Bhatia

Umar M Ahmad

William H Price

Douglas A Grose

Harasaran S Bhatia

Cyril P De Vries

A thin-layer metallization structure in which the final gold layer is deposited by evaporation with the surface onto which it is evaporated maintained at an elevated temperature. By evaporating the uppermost gold layer of the structure at an elevated substrate temperature, the gold atoms have a higher mobility, causing the deposited gold to spread over the edge of the structure and cover the otherwise exposed edges, including the edge at the copper interface.

Process for corrosion free multi-layer metal conductors

A Schottky barrier diode and ohmic contact metallurgy which is especially suited for shallow-junction bipolar semiconductor devices. The metallurgy comprises a thin layer of an at least 95 atomic % pure Schottky metal disposed in the contact openings on a shallow-junction semiconductor device to a thickness of less than 850 angstroms. An electrically conducting barrier layer is then disposed over the thin Schottky metal layer, with the barrier layer being of a material which does not react with either the Schottky metal or the semiconductor material in the contact openings to thereby prevent semiconductor material from diffusing past the barrier layer. An electrical contact layer is then deposited over the barrier layer. The doping of the semiconductor material in the individual contact openings determines whether an ohmic contact or a Schottky barrier diode is formed. The resulting ohmic contact metal and Schottky barrier metal do not penetrate through to the shallow junction of the semiconductor device. Additionally, the Schottky barrier diodes maintain a desired barrier height despite repeated heat treatments.

Schottky diode and ohmic contact metallurgy

Growing community of inventors

Wappingers Falls, NY, United States of America

Satya P Bhatia