Dual-Segment AlGaN/GaN MOS HEMTs: A Simulation study on pH sensitivity Enhancement and Performance Optimization

In this work, the effect of pH variation on dual segment GaN/AlGaN/AlN/GaN MOS HEMTs channel potential, conductance and conduction band energy profile has been demonstrated through a comprehensive simulation study. For simulating the behavior of electrolyte solution, a semiconductor material’s properties were adjusted. This adjustment enabled a more precise simulation of the device's performance in environments rich in electrolytes by balancing the interface charge density at the oxide-semiconductor boundary with modifications to the charge density at this interface. The optimization of gate oxide thickness on the voltage and current sensitivity has been analyzed by using SILVACO simulation tool. The maximum threshold voltage sensitivity SV<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">tr</inf> and current sensitivity SI<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">D</inf> achieved for gate oxide thickness toxide = 5 nm are 0.102 V/pH and 0.019 Amp/pH respectively. This dual segment configuration with minimum gate oxide thickness provides better electrostatic control and boost chemical stability.