Preannealing Effect on Mobility of N-/Al-Coimplanted and Over-Oxidized 4H-SiC MOSFETs
The authors investigated the effect of preannealing on N-/Al-coimplanted and over-oxidized Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs). The preannealing process causes a decrease of the Hall mobility and the effective mobility, and an increase of the interface state density. Secondary ion mass spectroscopy (SIMS) measurements revealed that the N concentration at the SiO2/SiC interface in preannealed samples is lower than in not-preannealed samples, which might be the reason for in the increase of the interface state density. In MOSFETs without preannealing, more N atoms are piled up at the SiO2/SiC interface, leading to the lower interface state density and higher mobility.
Anton J. Bauer, Peter Friedrichs, Michael Krieger, Gerhard Pensl, Roland Rupp and Thomas Seyller
Y. Nanen et al., "Preannealing Effect on Mobility of N-/Al-Coimplanted and Over-Oxidized 4H-SiC MOSFETs", Materials Science Forum, Vols. 645-648, pp. 487-490, 2010