Device parameters estimation of GFETs at temperatures below 300 K

Abstract

Low-temperature performance of four different graphene field-effect transistor (GFET) technologies previously reported in the literature is studied here by means of device transport parameters such as the intrinsic and extrinsic mobility degradation coefficients and the contact resistance. Model-based extraction methodologies are used for obtaining the parameter values. A mobility degradation-based transport model describes accurately the experimental ambipolar I-V data of devices with different gate lengths and at temperatures below 300 K with the extracted parameters. The temperature dependence of both the low-field and effective mobility, calculated based on the validated parameters, enables to obtain an insight on relevant scattering mechanisms at different device conditions, e.g., temperature and bias. From the extracted data it is suggested that, below a certain threshold temperature, the extrinsic mobility degradation improves, i.e., the gate control over the channel, for devices with low scattering mechanisms at room temperature than the ones with significant values of mobility degradation at 300 K.