Analytical modeling for threshold voltage of enhancement mode GaN MESFET

Threshold voltage is an important aspect to determine the enhancement and depletion mode behavior of a MESFET device. An analytic framework of an ion implanted GaN MESFET device has been modeled with the purpose of obtaining and characterizing the device's threshold voltage and transconductance. This is developed in consideration of fabrication parameters including annealing effects, ion range, ion energy, and ion dose. By solving a one-dimensional Poisson equation, an analytical model was developed to determine the threshold voltage of GaN MESFETs using selective ion dose and substrate concentration. The results were simulated by using MATLAB program. The developed model will be useful to analyze device behavior between enhancement and depletion modes Ga MESFET and the study shows how the enhancement mode GaN MESFET device can be developed by precisely control of the ion doses and substrate concentrations.