POS5-1183
Preparation and Thin Film Properties of a Solution-Based TiO2- Polyimide Nanocomposite for High-k Dielectric
When and Where
Nov 30, -0001
00:00 - 00:00
Presenter(s)
Han Byul Choi (Kyungsung Univ.)
Co-Author(s)
Abstract
Organic thin film transistors (OTFTs), which are appropriate for flexible and lightweight devices compared with traditional inorganic electronics, have considerable potentials for printable electronics. However, there are several challenges regarding OTFTs, such as a high operating voltage induced by the low charge carrier mobility of organic semiconductors and the low dielectric property of the organic gate dielectric. To operate at low voltage, OTFTs must have an organic insulator with a high dielectric constant. However, polymer materials are not suitable for use in low voltage applications due to their low dielectric constant. In order to overcome this problem, various nanocomposite dielectrics including inorganic nanoparticles with a high dielectric constant, have been studied. However, nanocomposite dielectrics in OTFTs have not been shown to have a surface that allows well-aligned organic semiconductor growth, resulting in a low on/off ratio and low carrier mobility in the low voltage range. Furthermore, according to the increase of inorganic particles in nanocomposite materials, the dielectric layer shows high leakage currents because high-k materials can generate a high leakage current path. To overcome such problems, we report on a novel solution-based TiO2-polyimide composite dielectric based on TiO2 precursor as a dopant in cross-linkable polyimide (PI). Soluble polyimide (DOCDA-6FHAB) was synthesized using the monomers, 5-(2,5-dioxytetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride (DOCDA) and 5,5'-(perfluoropropane-2,2-diyl)bis(2-aminophenol) (6FHAB). And then, we introduced TiO2 precursor to make a high dielectric constant polyimide nanocomposite layer. Polyimide nanocomposite bilayer film showed high dielectric constant (6.15) and low leakage current density (1.05x10-5 A/cm2 at 1 MV/cm) in metal-insulator-metal (MIM) devices. Detailed synthetic routes of polyimide and nanocomposite film fabrication condition will be presented.
