A study was made of the contact properties of a AuBe eutectic and a AuBeNi alloy on p-type GaP. The specific contact resistance varied from 1 × 10-3 to 7.5 × 10-5 ω cm2 in the acceptor concentration range of 9 × 1016 to 2 × 1018 cm-3. In the sintering temperature range resulting in good ohmic behaviour and low contact resistance the AuBe contacts do not form drops, whereas the AuBeNi contacts became molten; even after melting they wetted the surface of the GaP well. At the temperature of sintering Be diffuses from the contact into the GaP. The diffusion of Be gives rise to an additional acceptor concentration of 5 × 1018 to 1 × 1019 cm-3 beneath the contact surface. Taking this into consideration the concentration-specific contact resistance relationship appears to support a field emission FE conduction mechanism.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry