Silicon nanowire field effect transistor made of silicon-on-insulator

In this study, a fabrication technique and the results of the investigation of a silicon nanowire-based field effect transistor (Si NWFET) that can be the backbone for the fabrication of a high-sensitivity field and charge sensor with nanoscale spatial resolution for uses in different branches of physics, biology and medicine, are presented. The NWFET was fabricated of silicon-on-insulator (SOI) material by electron-beam lithography and reactive ion etching. Special care was taken of the electrical insulation of lead-in (metal) contact wires to the drain and source of the transistor, both for a reduction in the current of the leak-age to the underlying silicon wafer and for preventing contact with a conducting medium during experiments in a liquid. The measurements of the transistor in wet solutions of various pH demonstrate the possibility of using such a SiNWFET as an ultrasensitive field/charging sensor.