Correlations between the electrical properties and interfacial reactions for the Co/GaAs, Co/Ge/GaAs, and Ge/Co/GaAs contact systems have been studied. Current-voltage and capacitance-voltage measurements show that for all three systems following heat treatments at temperatures not higher than 400°C, a rectifying contact was obtained. However, annealing in the temperature range of 450-600°C leads to an ohmic behavior; the lowest contact resistivity value (2.7×10-4 Ω cm2) was obtained for Co/Ge/GaAs following heat treatment at 500°C. The electrical properties of the contacts are correlated with modifications in the structure and composition of the metallization interfacing the GaAs as determined by Auger electron spectroscopy, transmission electron microscopy, and x-ray diffraction.
|Number of pages||3|
|Journal||Applied Physics Letters|
|State||Published - 1988|