Carbon-based materials like nanotubes and graphene are heavily investigated as future CMOS-like devices and in interconnect applications. While much of the interest has been devoted to the device aspects in competition to conventional CMOS transistors, the paper here will focus on some less known applications of carbon. Proposed and demonstrated are interconnect applications like highly conductive electrodes for capacitors, gate material or through-silicon vias (TSV), novel non-volatile memories, carbon-silicon Schottky diodes or superior sensors.