Ohmic Contacts on N-Type Hg0.4Cd0.6Te.

The electrical characteristics of In, Sn, Au and Pt contacts on n-type Hg0.4Cd0.6Te formed in the presence and absence of prior In2+ implantation have been examined. Measurements of specific contact resistance made using a Transmission Line Model have shown that the unimtlanted In/Hg0.4Cd0.6 and Sn/Hg0.4Cd0.6 junctions gave values of {ie155-1} to {ie155-2} ohm.cm2. Auger sputter profiles of the asdeposited In/Hg0.4Cd0.6 and Sn/Hg0.4Cd0.6 interfaces have shown a significant in-diffusion of the metal overlayer. The influence of shallow In2+ implantation prior to metallization was an increase in pc which occurred above a dose of 1013 ions/cm2. In contrast, Pt and Au formed Schottky barrier diodes on n-type Hg0.4Cd0.6 with ob=0.69eV for Pt and ob=0.79eV for Au. With prior In2+ implantation, both Pt and Au contacts exhibited an ohmic behaviour with {ie155-3} ohm.cm2. These results have significance in the fabrication of devices for 1.0 -2.5μm optical communications.