2D RF Electronics: from devices to circuits - challenges and applications

Abstract

We developed process technologies dedicated to high frequency graphene field-effect transistors (GFETs). We used graphene from different sources (graphene growth directly on silicon carbide (SiC) substrate by chemical vapor deposition (CVD) technique [1], CVD graphene growth on Cu foil and transferred on Si02/Si substrate [2]) to realize two GFET structures (top gate and back gate transistors). After fabrication, we have explored the high frequency performances of GFETs including noise performances. The performances of GFET achieved are comparable to the state of the art with the gate length. The noise parameters of the transistors are mandatory for circuit design (linear application such as amplifier). These parameters limit the performances of the device when small signals are considered. The effort was made here to measure the noise parameters of GFET $(\mathrm{NF}_{\min}, \mathrm{R}_{\mathrm{n}}, \Gamma_{\mathrm{opt}})$ . It is well known that these parameters depend both on intrinsic properties of the graphene material (noise generated in the channel under the gate), as well as extrinsic parameters related to the technological process (mainly noise generated by access resistances, …). Based on the reliability of the process, RF circuits were designed and fabricated. These circuits demonstrated the potential to achieve high performances in the field of linear circuit such as amplifiers, and non-linear circuits such as mixers.