Fabrication of Organic Thin Film Transistors Using Low Temperature, Soluble Silicon Oxide as the Gate Dielectrics

Abstract

ABSTRACTIn this paper, a unique water-based, liquid phase deposited silicon oxide (LPD SiO2) is adapted to the fabrication process of the organic thin film transistor (OTFT). Through the use of this process, an OTFT with a silicon oxide gate insulator is successfully fabricated at 100°C or less. At this low process temperature, the SiO2 functions efficiently as a gate dielectric with the breakdown field being larger than 5 MV/cm, the leakage current being near 1 pA/um2 with a gate bias of 20 V and the surface roughness being less than 1nm. Due to the high quality silicon oxide, the oxide-gated OTFT shows the low threshold voltage (-1 ∼ -2V) and medium on/off current ratio (∼1000). Because this oxide is a water-based process, it is highly resistant to the following soluble semiconductor material and its solvent.