The Schottky limit and a charge neutrality level found on metal/6H-SiC interfaces

• Published in: Surface science Vol. 494; no. 3; pp. L805 - L810
• Main Author: Hara, Shiro
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.12.2001; Amsterdam Elsevier Science; New York, NY
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in interface structures; Etching; Evaporation and sublimation; Exact sciences and technology; Interface states; Metal-semiconductor-metal structures; Metal–semiconductor interfaces; Oxidation; Physics; Schottky barrier; Silicon carbide; Surface electronic phenomena (work function, surface potential, surface states, etc.); Surface electronic phenomena (work function, surface potential, surface states, etc.); Silicon carbide; Metal–semiconductor interfaces; Oxidation; Etching; Interface states; Evaporation and sublimation; Schottky barrier; Schottky barriers; n-type conductors; Interface electron state; Silicon carbides; Experimental study; Photoelectron spectroscopy; Electronic structure; Transmission electron microscopy; Semiconductor-metal boundaries; Platinum; Transition elements; Crystal faces; Barrier height
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/S0039-6028(01)01596-5

We report the Schottky limit and a charge neutrality level (CNL) experimentally demonstrated at metal/6H-SiC(0 0 0 1) interfaces. An interface with the Schottky limit was formed by dipping SiC surfaces in boiling pure water before metallization. The total density of interface states, D it, was a drastically small value of 4.6×10 10 states cm −2/eV, indicating the density of the metal induced gap states was less than this value. In contrast, at incompletely passivated interfaces without the boiling water dipping process, a broad continuum of interface states with D it of 2.8×10 13 states cm −2/eV was observed with the CNL located at 0.797 eV from the conduction band minimum. The origin of these interface states was found to be in the disordered interface layers.