1/ f Noise model for 4H-SiC MOSFETs incorporating the nonuniform spatial distribution of oxide traps

Conventional noise models exhibit limited capability in characterizing the spatial distribution of oxide traps in 4H-SiC MOSFETs. To overcome this limitation, the present study considers the nonuniform distribution of oxide traps in the direction normal to the channel and employs a Gaussian profile to describe a trap distribution characterized by a localized concentration maximum. Based on this premise, a 1/f noise model that incorporates the nonuniform spatial distribution of oxide traps is developed for 4H-SiC MOSFETs. The proposed model is assessed using Sentaurus TCAD simulations and measured low-frequency noise spectra from practical 4H-SiC MOSFETs. Its applicability is further investigated under various bias conditions through comparisons with exponential- and uniform-distribution models, as well as through measurements on multiple devices. The results indicate that the proposed model effectively reproduces the 1/f noise characteristics of 4H-SiC MOSFETs and facilitates the estimation of model parameters related to the oxide-trap spatial distribution, including peak trap density, peak position, and distribution width, from the low-frequency noise power spectral density. Consequently, the proposed model offers a physics-based approach for characterizing the nonuniform spatial distribution of oxide traps in 4H-SiC MOSFETs.