Organic Thin Film Transistor Memories with Carbon Nanodots Fabricated by Focused Ion Beam Chemical Vapor Deposition

Abstract

Metal‐insulator‐semiconductor field effect transistor (MISFET) structures with a nanocrystal carbon (nc‐C) embedded in SiO2 thin films using a focused ion beam chemical vapor deposition (FIB‐CVD) system with a precursor of low energy Ga+ ion and carbon source to fabricate organic thin film transistor (OTFT) memories. The crystallinity of nc‐C was investigated by Raman spectroscopy and atomic force microscopy (AFM). Raman spectra indicate the evidence of crystallization of nc‐C after annealed at 600 degree celcius by the sharp peak at 1565 cm−1 in graphite (sp2), while no peak of diamond (sp3) could be seen at 1333 cm−1. The AFM images showed the nc‐C dots controlled with diameter of 100 nm, 200 nm and 300 nm, respectively. The above results revealed that the nc‐C dots had sufficiently stick onto SiO2 films. The characteristic of the OTFTs operated at negative gate bias shows the p‐channel enhancement behavior, and shows the most saturation behavior.