Medium Scale Integrated Circuits Using Carbon Nanotube Thin Film Transistors

Abstract

Medium scale integrated circuits with more than 100 carbon nanotube (CNT) thin-film transistors (TFTs) have been successfully fabricated. These are the largest CNT-based integrated circuits reported so far. Our fabrication technology features a buried back-gate architecture made by CNT growth using plasma-enhanced chemical vapor deposition, chemical doping and enhancement/depletion mode logic gates. High-speed operation with a switching time of 0.51 µs/gate demonstrated by a 53-stage ring oscillator, which has about two orders of magnitude higher switching speed than previous TFT integrated circuits, confirms the suitability of the present TFT technology for implementing CNT-TFT integrated circuits with various functions.