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Indexed by:期刊论文

Date of Publication:2012-08-01

Journal:JAPANESE JOURNAL OF APPLIED PHYSICS

Included Journals:SCIE、EI、Scopus

Volume:51

Issue:8

ISSN No.:0021-4922

Abstract:The effects of low temperature electronic cyclotron resonance microwave hydrogen plasma pretreatment and post-annealing on the electrical properties of Ti and Ni contacts to 4H-SiC were investigated. The HPT improves the Ohmic behavior of Ti/4H-SiC contact significantly. In contrast, it remarkably enhances the rectifying behavior of Ni/4H-SiC contact. The properties of Ti Ohmic contact and Ni rectifying contact improve with increasing annealing temperature up to 400 degrees C. However, they are deteriorated above 400 degrees C. X-ray photoelectron spectroscopy measurements confirm that the surface Fermi level (E-F(s)) moves toward the conduction band edge by the HPT. It almost attains the bulk Femi level position after annealing at 400 degrees C with the surface states density (D-s) as low as 4.43 x 10(11) cm(-2) eV(-1). However, after annealing above 400 degrees C, E-F(s) moves back closer to midgap with an increase of D-s. The experimental results are found to obey the barrier height theory of Cowley and Sze. (c) 2012 The Japan Society of Applied Physics