Fabrication of electrolyte-gate nanocrystalline diamond-based field effect transistor (NCD-EGFET) for HIV-1 Tat protein detection

In this paper, we reported on the fabrication process of electrolyte-gate field effect transistor using nanocrystalline diamond as a sensing transducer. The fabrication procedure was begin with the growth of nanocrystalline diamond thin film on silicon/silicon dioxide (Si/SiO2) substrate using microwave plasma-enhanced chemical vapour deposition (CVD). Then the photolithography process was performed in order to design and pattern the field effect transistor device with the active gate channel of 60 m length and 20 m width. Each device consists of three active gate channel which connecting to three different pairs of source and drain contact. The surface morphology of fabricated NCD-EGFET was characterized using Scanning Electron Microscope to clarify the active gate channel of the device and the grain size of nanocrystaline diamond. The current-voltage (I-V) measurement of the device were carried out to study the electrical behaviour for HIV-1 Tat protein detection via RNA aptamer as sensing probe.