INTEGRATED ELECTROCHEMICAL GATING OF CARBON NANOTUBE FETs FOR BIOSENSING APPLICATIONS

Carbon nanotubes have emerged as the leading candidate of electronic materials used for future nanoscale chemical and molecular sensors. Recently, nanotube field effect transistors (CNFETs) have been exploited as biodetectors of the thyroid hormone, triiodothyronine (T3). Although significant progress has been towards the development of actual nanotube based sensor devices, the next challenge is to integrate the devices into a single chip. Numerous gate configurations to CNFETs have been proposed, but few have been shown to be effective, and even fewer can be integrated to a chip. An electrolytic “tip” gate design has been shown to be more effective than the conventional backgate geometry. The drawback to the “tip” gate geometry lies in the fact that an external electrode is required to gate the devices. In this paper, a novel integrated gate design is proposed. Lithographically patterned electrodes on the chip surface are fabricated to effectively gate CNFET devices.