Contact resistance measurement between single walled carbon nanotube and graphene using channel length scaling of transistor

Abstract

Both single wall carbon nanotube (SWNT) and graphene have exceptionally high carrier mobility, transmittance and flexibility. While some of SWNTs have semiconducting properties depending on their chirality and diameter, graphene has mainly superior metallic properties. Accordingly, with using SWNTs channel and graphene electrodes of transistor, it is realizable to fabricate all carbon based transistor which will be based on realizing flexible display. However, contact resistance between channel (SWNTs) and electrode (graphene) is critical factor which degenerates device performance as various types of transistors did. Precise measurement of contact resistance between graphene and one SWNT will be first step for solving contact resistance issue in all carbon based transistor. Accordingly, in this work, we primary measured contact resistance between one nanotube and graphene using channel length scaling of transistor. For this measurement, we fabricated perfect bottom gated aligned SWNTs transistors with graphene electrodes which have various channel length after growth of high quality monolayer graphene and perfectly aligned SWNT array. Measured values of contact resistance was 21.4kΩ (metallic-SWNT / graphene) and 83.6kΩ (semiconducting-SWNT / graphene), respectively. And then we suggested solutions for lowing contact resistance between them from theoretical analysis of measured values. In conclusion, we showed positive prospect for using graphene electrode in CNTFET in respect of contact resistance, which means that it can get closer to realization to fabricate high performance of all carbon based transistor.