Gan Buffer Design: Electrical Characterization and Prediction of the Effect of Deep Level Centers in Gan/algan Hemts

GaN buffer deep level centers are studied coupling measurements and device physics simulations. The impact of Feand C-doped samples on low frequency device transconductance and noise is presented. The Felevel found at 0.7 eV below the GaN conduction band results in low frequency generation-recombination noise and transconductance dispersion. The agreement with the model shows that the buffer can now be reliably simulated and used to investigate the impact of other deep level traps, such as carbon, that cannot be easily measured due to their deep position in the GaN bandgap.