Papers by Author: Petr M. Lytvyn

Abstract: In this communication we present the results of study of new contact systems to GaN epitaxial layers grown on sapphire and n-type 6H-SiC monocrystals. The TiBx nanostructure phase has been used during manufacturing Ti – Al – TiBx – Au and TiBx contact systems. The n-GaN epitaxial layers of 1 µm thickness were grown on [0001] sapphire substrate by vapor-phase epitaxy. The n-type 6H-SiC monocrystals were grown by Lely method with the donor concentration of 2x1018 cm3. The layers of Ti, Al, TiBx and Au were deposited by magnetron sputtering followed by high-temperature annealing.

Abstract: An effect of electron beam annealing (EBA) on both surface morphology and characteristics of test Ti/n-6H-SiC contacts was investigated. It was found that the mean roughness of the n-6H-SiC surface decreased from 3.43 nm to 1.35 nm and the surface sheet resistance increased from 3.1 to 4.0 Ω/sq after EBA. The Ti/n-6H-SiC contacts formed on substrates after EBA exhibited ohmic properties, while the same contacts formed on the un-annealed samples were Schottky contacts with the barrier height of 0.63 eV and ideality factor of 1.92.