Biosensing characteristics of InAs nanowire transistors grown by MOCVD

We demonstrated the ion-sensitive field-effect transistors (IS-FETs) based on nanowires (NWs) with different diameters and doping concentrations to obtain the high sensitivity and various applications. The growth of the catalyst-free InAs NWs was carried out using a horizontal reactor MOCVD system (AIXTRON Inc.). A p-type Si (111) wafer (rho = 1 - 10 Omega-cm) was prepared for the NW growth. Here, NWs with diameters of around 50 similar to 150 nm were grown and the doping concentration also was changed around x +/- 10(16 similar to 18)/cm(2). IS-FETs with the grown InAs NWs were fabricated using the photolithography and the lift-off process. The gas sensing characteristics have been investigated through studying the gate response of the NW conductance in different ambient conditions.