Pyro­ lyzed photoresist thin film: effect of electron beam patterning on DC and THz conductivity

Abstract

Pyrolyzed photoresist films (PPFs), which are formed via vacuum annealing of a photoresist without a catalyst, can be employed for fabrication of graphitic nanostructures by using conventional lithographic techniques. Such approach allows for reduction of technological steps required for fabrication of conductive micro- and nanoelectrodes for different applications. However, the operation frequency range of PPF electrodes is still unknown. Here, we report the results of the comparative study of PPF structures fabricated by electron beam lithography prior and after the annealing process with preference to the first approach. By performing the comparative measurements of PPF transport properties we found that both pre-and post-processed PPFs possess the same conductivities at dc-current and in the frequency range from 0.2 to 1.5 THz. Moreover, we achieved the sheet resistance of 150 nm thick PPFs as low as 570 Ω/sq, which is comparable to that of commercially available chemical vapour deposited (CVD) graphene. These findings open a path for a simple, reproducible and scalable fabrication of graphitic nanocircuits, nanoresonators and passive components suitable for applications in frequencies up to few terahertz.