Abstract: A SiC die with Os and/or W/WC/TiC contacts and metal conductors is encapsulated either alone or on a ceramic substrate using a borosilicate (BSG) glass that is formed at a temperature well below upper device operating temperature limits but serves as a stable protective layer above the operating temperature (over 1000° C., preferably >1200° C.). The glass is preferably 30-50% B2O3/70-50% SiO2, formed by reacting a mixed powder, slurry or paste of the components at 460°-1000° C. preferably about 700° C. The die can be mounted on the ceramic substrate using the BSG as an adhesive. Metal conductors on the ceramic substrate are also protected by the BSG. The preferred ceramic substrate is AlN but SiC/AlN or Al2O3 can be used.

Abstract: Ohmic and rectifying contacts to a TaC layer on an n-type or p-type area of an SiC substrate are formed by depositing a WC layer over the TaC layer, followed by a metallic W layer. Such contacts are stable to at least 1150° C. Electrodes connect to the contacts either directly or via a protective bonding layer such as Pt or PtAu alloy through a dielectric layer.

Abstract: Ohmic and rectifying contacts to a TaC layer on an n-type or p-type area of an SiC substrate are formed by depositing a WC layer over the TaC layer, followed by a metallic W layer. Such contacts are stable to at least 1150° C. Electrodes connect to the contacts either directly or via a protective bonding layer such as Pt or PtAu alloy through a dielectric layer.

Abstract: A SiC die with Os and/or W/WC/TiC contacts and metal conductors is encapsulated either alone or on a ceramic substrate using a borosilicate (BSG) glass that is formed at a temperature well below upper device operating temperature limits but serves as a stable protective layer above the operating temperature (over 1000° C., preferably >1200° C.). The glass is preferably 30-50% B2O3/70-50% SiO2, formed by reacting a mixed powder, slurry or paste of the components at 460°-1000° C. preferably about 700° C. The die can be mounted on the ceramic substrate using the BSG as an adhesive. Metal conductors on the ceramic substrate are also protected by the BSG. The preferred ceramic substrate is AlN but SiC/AlN or Al2 O3 can be used.