Effects of Thermal Treatment on the Sensitivity of Polycrystalline Silicon Nanowire FET Biosensors

In this study, we developed polycrystalline silicon (poly-Si) nanowires by a sidewall spacer technique and employed them to fabricate nanowire field-effect transistor (NWFET) devices for biomedical sensing applications.The impact of post-fabrication thermal treatments on the electrical performance of the poly-Si NWFET biosensors was systematically investigated.Among the tested conditions, the devices treated at 400 ℃ in vacuum exhibited significantly enhanced electrical characteristics.These optimized biosensors were then used for solution pH detection, demonstrating high sensitivity and a clear linear correlation between drain current and pH.Furthermore, real-time pH sensing experiments confirmed the biosensors' capability to respond rapidly and accurately to changes in pH, highlighting both their sensitivity and response speed.Overall, the developed poly-Si NWFET biosensors show strong potential for advancing medical diagnostics by enabling early disease detection and supporting personalized healthcare strategies.