Design and Analytical Assessment of Non-Ideal Ion-Sensitive β-MIS-(AlGa) 2 O 3 /Ga 2 O 3 High Electron Mobility Transistor.

In this work, for the first time, we have investigated an analytical model for β-MIS-(AlGa)2O3/Ga2O3 ion-sensitive FET by using commercial Silvaco and MATLAB tools for non-ideality behavior around the isoelectric point. Gouy-Chapman-Stern theory is used to analyze the electrical double layer with the electrolyte. Al2O3 is used as a dielectric between (AlGa)2O3 and electrolyte. The pH sensor detects the variation in hydrogen ion concentration in the aqueous solution. Different electrolyte concentrations (1 mM, 0.01 M, 0.1 M) are used in aqueous solution to find sensitive parameters such as surface potential, charge density, Alpha, βint, Cdiff and CDL for different pH values. Changes in surface potential and other sensitive parameters affect the intensity of 2DEG at the interface of (AlGa)2O3 and Ga2O3 in β-MIS-(AlGa)2O3/Ga2O3 HEMT. The behavior of pH- sensitive parameters are also discussed before and after the isoelectric point. Variation in electrolyte concentration shows that lower electrolyte concentration has high sensitivity. Effects of variation of pH on potential, H+ and OH− concentration with bulk distance have also been discussed. Transfer characteristics, threshold voltage, ION/IOFF of β-MIS-(AlGa)2O3/Ga2O3 HEMT have been investigated for different pH values. Threshold voltage increases with pH when pH moves from acidic to basic medium. [ABSTRACT FROM AUTHOR]