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

Abstract

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 Si 3 N 4 . 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.

Graphene–oxide interface for optoelectronic synapse application

“…Figure S3 shows the transfer characteristics of 6 different devices. In order to calculate the mobility, we fit the plot using the model 27 , 38 :

Figure 1 Graphene/Ta 2 O 5 /graphene ( a ) device schematic (not to scale). ( b ) R vs. V G for bottom ( R BG ) and top ( R TG ) graphene in dark and under illumination of 405 nm wavelength.

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“…Single-layer graphene absorbs only ~ 2.3% in visible and infrared regions and because of the zero band-gap behavior on the energy diagram, it leads to short lifetime of exciton in pure graphene; the high carrier mobility (electrons and holes) comes with the price of low light absorption, which gives low responsivity values ( ) 24 , 25 . Due to the semimetallic nature of graphene, a standard graphene field effect transistors with a graphene channel between two electrodes, can result in high dark current approaching the microampere regime which is an obstruction on many applications because of the increase in shot noise 26 , 27 . Hybrid graphene-quantum dot structures 26 , 28 , 29 , artificial nanostructures on graphene 30 and functionalization of graphene 31 have been used to increase the carrier lifetime in graphene-based photodetectors.…”

Disordered Structures and Dielectric Properties of Ni-Doped Bismuth Magnesium Niobate Pyrochlores

“…With the development of the microwave agile devices, it requires dielectric tunable materials to have large dielectric constants, low dielectric loss, and good temperature stability. − Additionally, their peculiar dielectric tunable property makes them more flexibility for potential applications in electronics such as high-k transistors and high performance photodetection. − Low dielectric loss contributes to a high quality factor, and a near-zero temperature coefficient of the dielectric constant stands for the good temperature stability, which is in favor of working stability. Bi 1.5 MgNb 1.5 O 7 (BMN) pyrochlores show attractive properties due to their medium dielectric constant of 86–195, low dielectric loss of 0.0007–0.002, and a reasonable temperature coefficient of −550 ppm/°C. − The dielectric properties of cubic pyrochlores are greatly depending on the structure.…”

Effect of boron nitride defects and charge inhomogeneity on 1/f noise in encapsulated graphene

“…The physical mechanism of 1=f noise in graphene has been explained using the Hooge's mobility fluctuation [37][38][39][40][41] or the McWhorter charge number fluctuation method 42,43 or both. Furthermore, both these mechanisms are correlated.…”