Analytical Modeling and Simulation-Based Investigation of AlGaN/AlN/GaN Bio-HEMT Sensor for C-erbB-2 Detection

Abstract

Resolution of HEMT sensors needs to be improved to make feasible the precise detection of antigens from body fluids like saliva instead of blood. For enhancing sensitivity and long-term stability, a systematical study of the device becomes mandatory which is impossible without the aid of an analytical model. Presented through this work is a mathematical model developed for high frequency AlGaN/AlN/GaN HEMT with focus on its sensing performance. The HEMT application as a bio transistor for detection of c-erbB-2 protein, the breast cancer biomarker is being focused and the sensitivity analysis is done. The model developed has been compared and verified with simulation using Silvaco ATLAS TCAD. The analytical model for the device has been developed by the rigorous induction and expansion of Poisson’s equation. Numerical model for charge equivalent in c-erbB-2 also have been developed and device sensing is analyzed for varying quantities of c-erbB-2 in both saliva and serum. Enhanced sensing potentials over the existing bio-HEMT sensors have been observed in device incorporating the AlN interlayer and modification of epitaxial design. The impact of gate length on sensitivity has also been analyzed and devices of gate length $1~\mu \text{m}$ and $5~\mu \text{m}$ yields sensitivity of 2.5mA/mgL−1 and 0.72mA/mgL−1, respectively.