Study on NO Passivation on the Near Interface Electron and Hole Traps of n-Type 4H-SiC MOS Capacitors by Ultraviolet Light
The characteristics of near interface electron and hole traps in n-type 4H-SiC MOS capacitors with and without nitric oxide (NO) passivation have been systematically investigated. The hysteresis of the bidirectional capacitance-voltage (C-V) and the shift of flat band voltage (Vfb) caused by bias stress (BS) with and without ultraviolet light (UVL) irradiation are used for studying the influence of near interface electron traps (NIETs) and near interface hole traps (NIHTs). Compared with Ar annealed process, NO passivation can effectively reduce the density of NIETs, but induce excess NIHTs in the SiC MOS devices. What’s worse is that part of the trapped hole cannot be released easily from the NIHTs in the NO annealed sample, which may act as the positive fixed charge and induce the negative shift of threshold voltage.
Robert Stahlbush, Philip Neudeck, Anup Bhalla, Robert P. Devaty, Michael Dudley and Aivars Lelis
Y. F. Jia et al., "Study on NO Passivation on the Near Interface Electron and Hole Traps of n-Type 4H-SiC MOS Capacitors by Ultraviolet Light", Materials Science Forum, Vol. 924, pp. 449-452, 2018