High temperature rectifying contacts using heteroepitaxial ni films on semiconducting diamond

The first results pertaining to the fabrication of high-temperature rectifying contacts using heteroepitaxial Ni films deposited on natural p-type semiconducting diamond substrates are reported. The contact diodes were deposited at 500°C by the thermal evaporation of Ni from a W filament in ultra-high vacuum. The epitaxial nature of the deposited Ni layers has been established from an inspection of in situ low-energy electron diffraction (LEED) patterns. The Ni films exhibit excellent adhesion properties with the underlying diamond substrate. As evidenced by current-voltage (I-V) measurements stable rectifying characteristics for the Ni/diamond contacts were observed in the 25-400°C temperature range.