Fabrication of field-effect transistors with transfer-free nanostructured carbon as the semiconducting channel material

Abstract

Carbon nanostructures used as the active channel material in field effect transistors (FETs) are appealing in microelectronics for their improved performance, such as their high speed and low energy dissipation. However, these devices require the incorporation of nanostructure transfer steps in the fabrication process flow, which makes their application difficult in large scale integrated circuits. Here we present a novel method for the fabrication of FETs with nanostructured carbon in the channel with p-type semiconducting properties and intermediate drain-source current (IDS) on/off ratio. The method is based on the use of Ni nanoparticles in the source-drain gap region as the seed material for the formation of carbon nanostructures in the FET channel. FETs without Ni nanoparticles in the channel showed no modulation of IDS as a function of gate voltage. The device fabrication process does not require any carbon nanostructure transfer steps since it directly forms carbon nanostructures electrically connected to the device’s source and drain electrodes via electron-beam evaporation of carbon and conventional lithographic processes. Since all device fabrication steps are compatible with existing Si technology processes, they are capable of being further optimized following process development protocols practiced by the semiconductor industry.