Analytical model for the potential and electric field distributions of AlGaN/GaN HEMTs with gate-connected FP based on Equivalent Potential Method

A new physics-based modeling approach, Equivalent Potential Method (EPM), is first proposed in this paper to simplify the modeling progress of AlGaN/GaN HEMTs. The EPM indicates that charges in depletion region can be equivalent to the potential at passivation surface layer. Hereby, the depletion region can be seen as neutral, which therefore can be analyzed by using Laplace Equations other than the inherent Poisson Equations leading to much less modeling complexity. Especially, the corresponding iteration calculations can be significantly simplified with the elimination of various charge quantity. EPM provides an effective way to solve electric field and potential distributions with great concision and accuracy, especially important for AlGaN/GaN HEMTs with various charge layers to be concerned. By applying EPM, the analytical model shows good agreements with numerical results with acceptable discrepancies. The proposed simple analytical approach also offers effective guidance for field plates designing.