SPECIFIC RESISTIVITY OF OHMIC CONTACTS TO N-TYPE DIRECT BAND-GAP III-V COMPOUND SEMICONDUCTORS

Contact resistivity curves are given in terms of intrinsic barrier height and doping level for ohmic contacts to n-type direct band-gap III-V semiconductor compounds, including Al(x)Ga1-xAs. The results are based on a rigorous treatment of carrier transport across the metal-semiconductor interface. They show that the resistivity behaves quite differently from what might be expected from the usual notion of the effects of doping and barrier height on the resistivity. As such, the results can be used as a useful guide in attempts to lower the contact resistivity.