INTEGRATED CIRCUIT CONTACT STRUCTURE

摘要

A multi-layer contact structure is described for providing ohmic contact to a shallow semiconductor region (12) forming a PN junction with a silicon semiconductor body (10). The multi-layer structure includes a layer of polycrystalline silicon (22) doped with an impurity of the same conductivity type as that of the semiconductor region (12). A first layer (26) of a refractory metal is deposited over the polycrystalline silicon layer (22) to provide an electrically stable interface therewith. A second layer (28) of another refractory metal is deposited over the first refractory metal layer and serves to protect the shallow PN junction against current leakage failure. A third layer (34) of interconnect metal such as aluminium is deposited over the refractory metal layer.