A Complete Analytical Model for MOS-HEMT Biosensors: Capturing the Effect of Stern Layer and Charge Screening on Sensor Performance

This letter presents analytical and technology computer aided design models for analyzing the performance of biohigh-electron-mobility transistor (HEMT) sensors. Unlike existing models for these sensors in the literature, where the biolayer is modeled as semiconductor or insulator layer with analyte-induced interface charge (i.e., surface potential), the model presented in this letter provides a better design insights by taking into consideration charge screening effect and impact of electric double layer (Stern layer) on device performance. The simulation case study is focused on prostate cancer detection using prostate-specific antigen (PSA) present in human serum as the target biomarker. Application specific validation of the model has been presented through demonstration of a MOS-HEMT PSA sensor design with sensitivity large enough to detect clinically relevant concentration of PSA in human serum (1ng/ml-4ng/ml).