Effect of High-K Dielectric Layer on 1/f Noise Behavior in Graphene Field-Effect Transistors

We report the 1/f noise characteristics at low-frequency in graphene field-effect transistors that utilized a
high- dielectric tantalum oxide encapsulated layer (a few nanometers thick) placed by atomic layer
deposition on Si3N4. A low-noise level of ~ 2.2  10-10 Hz-1 has been obtained at f = 10 Hz. The origin
and physical mechanism of the noise can be interpreted by the McWhorter context, where fluctuations in
the carrier number contribute dominantly to the low-frequency noise. Optimizing fabrication processes
reduced the number of charged impurities in the graphene field-effect transistors. The study has provided
insights into the underlying physical mechanisms of the noise at low-frequency for reducing the noise in
graphene-based devices.