GaN HEMT trap-induced variability through concurrent noise and AC TCAD modelling

In this work we exploit an in-house code implementing the drift-diffusion model coupled to trap rate equations to investigate the effect of Fe-induced buffer traps on the noise and AC behavior of GaN HEMTs. The model, exploiting a Green's function approach, shows that the noise frequency behavior is mainly due the trap equation Green’s Functions. Local noise sources are concentrated below the channel, extending in the buffer region. Statistical variation/uncertainty in the trap parameters significantly affect both the low frequency noise spectra and the Y parameters. We show a significant correlation between these quantities. The proposed analysis demonstrates that the developed code represents a promising tool to assist both the identification of trap parameters from experimental data, and to extract compact device models.