Forward thermionic field emission transport and significant image force lowering caused by high electric field at metal/heavily-doped SiC Schottky interfaces

摘要

We investigated the doping concentration dependence of the barrier height and forward carrier transport mechanism in Ni/SiC Schottky barrier diodes (SBDs) in the wide range of 6.8 x 10(15) -1.8 x 10(19) cm(-3). Forward current-voltage characteristics in heavily-doped SiC SBDs ( 2.6 x 10(17) cm(-3)) can be well reproduced by a thermionic field emission model. The barrier height decreased with increasing doping concentration and the barrier height drop in the most heavily-doped SBD (1.8 x 10(19) cm(-3)) was about 0.2 eV, which quantitatively agreed with the image force lowering of 0.18 eV caused by the high electric field. (c) 2020 The Japan Society of Applied Physics