Mobility degradation under a high effective normal field in an inversion layer of 4H-SiC (0001) metal–oxide–semiconductor structures annealed in POCl3

Abstract

Mobility degradation under a high effective normal field (1 MV cm−1 < E eff < 2 MV cm−1) in an inversion layer of 4H-silicon carbide (SiC) (0001) metal–oxide–semiconductor field-effect transistors (MOSFETs) annealed in POCl3 is investigated by applying a negative body bias (0 V ≥ V BS ≥ −40 V). The effective channel mobility (μ eff) is proportional to E eff −2.3–−2.2 in the range 1 MV cm−1 ≤ E eff. On the basis of the obtained results, the authors propose that the mobility degradation in the high-E eff region is caused by strong surface roughness scattering in SiC MOSFETs with a very low interface state density.