A study of critical factors for the development of aqueous-route based aluminium oxide dielectri

Abstract

Aqueous route method based on a metal aquo complex has attracted a lot of attention because it enables the solution-processed metal oxide thin film with high electrical properties to be prepared in low temperature fabrication condition. However, most studies have mainly focused on the development of metal oxide semiconductor thin film. For expansive application of the aqueous route based metal oxide films to various flexible fundamental devices, the systematic study for the development of metal oxide insulator film based on the aqueous route method is urgently required.

Here, I propose critical factors for developing high-quality metal oxide insulator thin films based on the aqueous route method. I found that the critical factors including precursor solution temperature and humidity during the spin-coating process strongly affect chemical, physical, and electrical properties of AlOx insulator thin films. Through the optimization of critical factors, an AlOx insulator thin film with a leakage current value approximately 105 times smaller and a breakdown voltage value approximately 2 ~ 3 times greater than un-optimized AlOx was realized. Finally, by introducing the optimized AlOx insulator thin film to solution-processed InOx TFTs, I successfully achieved InOx/AlOx TFTs with remarkably high average field-effect mobility of ~52 cm^2V^-1s^-1 and on/off current ratio of 106 at fabrication temperature of 250 °C.