Os rectifying Schottky and ohmic junction and W/WC/TiC ohmic contacts on SiC

摘要

Metallic osmium on SiC (either beta or alpha )forms a contact that remains firmly attached to the SiC surface and forms an effective barrier against diffusion from the conductive metal. On n-type SiC, Os forms an abrupt Schottky rectifying junction having essentially unchanged operating characteristics to at least 1050 DEG C. and Schottky diodes that remain operable to 1175 DEG C. and a barrier height over 1.5 ev. On p-type SiC, Os forms an ohmic contact with specific contact resistance of <10-4 ohm-cm2. Ohmic and rectifying contacts to a TiC layer on a SiC substrate are formed by depositing a WC layer over the TiC layer, followed by a metallic W layer. Such contacts are stable to at least 1150 DEG C. Electrodes connect to the contacts either directly or via a protective bonding layer such as Pt or PtAu alloy.