Physical model for drift in carbon nanotube based ZrO2 gate dielectric ion sensitive field effect transistor

Abstract

In this paper, a physical model for the drift behavior of carbon nanotube based ion sensitive field effect transistor (CNTISFET) with high-κ dielectric material ZrO2 as gate oxide is presented. Drift has been modeled as the threshold voltage instability with time based on hopping transport mechanism, also known as the dispersive transport. The exposure of ZrO2 surface to electrolyte solution leads to chemical modification of the surface and the resultant capacitance of the insulator changes with time. Thus, the threshold voltage of the device varies with time. The model has been verified with experimental drift characteristic results and a good fit was obtained.