Low-Frequency Noise Modeling of 4H-SiC Metal-Oxide-Semiconductor Field-Effect Transistors

Abstract

4H-silicon carbide metal-oxide-semiconductor field-effect transistors (4H-SiC MOSFETs) show 1/f low-frequency noise behavior. In this paper, this can be explained by the combination of the mobility fluctuation (Δμ) and the carrier number fluctuation (ΔN) theories. The Δμ theory believes that LFN is generated by the bulk defects, while the ΔN theory holds that LFN originates from the extraordinarily high oxide traps. For 4H-SiC MOSFETs, significant subthreshold noise will appear when only the ΔN theory attempts to model LFN in the subthreshold region. Therefore, we account for the high density of bulk defects (Δμ theory) and characterize the subthreshold noise. The theoretical model allows us to determine the bulk density of the trap states. The proposed LFN model is applicable to SiC MOSFETs and accurately describes the noise experimental data over a wide range of operation regions.