UDC 621.382.32
ANALYTICAL APPROXIMATION OF NUMERICAL CALCULATION OF QUASI FERMI LEVEL IN QUANTUM WELL VERSUS GATE VOLTAGE FOR COMPACT MODELING OF GaAs HEMT
A. A. Popov, Junior Researcher at 50ohm Lab, TUSUR, Tomsk, Russia;
orcid.org/0000-0001-6010-4459, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
The problem of deriving an analytical approximation for numerical calculation of quasi Fermi level versus gate voltage in the quantum well of AlGaAs/GaAs-based heterostructure is studied. The aim is to analyze the principles of deriving analytical approximation expressions in terms of the introduced assumptions for three gate voltage regions corresponding to different surface charge densities formed in a HEMT channel. Application of interpolation functions to infer the unified expression valid in the wide range of gate voltages is justified. To increase the approximation accuracy in low and high surface charge density regions, improvements to the existing expressions are proposed. Obtained analytical expression can be used to develop a physics-based surface potential compact model of GaAs HEMT.
Key words: HEMT, compact model, analytical approximation, quasi Fermi level, surface charge density, heterostructure, numerical solution, interpolation function.