High-Quality Solution-Processed Metal-Oxide Gate Dielectrics Realized With a Photo-Activated Metal-Oxide Nanocluster Precursor

Abstract

High-quality solution-derived amorphous alumina ( ${a}$ -Al2O3) dielectric has been achieved with [Al $_{\textsf {13}}{(}\mu _{\textsf {3}}$ -OH ${)}_{\textsf {6}}{(}\mu $ -OH)18 (H2O)24](NO3)15(Al-13 nanocluster) as a precursor and a local structure-controllable activation process via deep-UV-induced photochemical activation. The synergetic combination of an Al-13 nanocluster precursor and high-energetic photochemical activation enables the formation of highly dense ${a}$ -Al2O3 thin films via an efficient dissociation and rearrangement of the nanocluster skeleton. The electrical characteristics of the nanocluster-based ${a}$ -Al2O3 thin films were investigated in terms of their operative electronic conduction mechanism by comparing conventional nitrate-based and vacuum-deposited films. From these results, it was found that the leakage current density of solution-processed ${a}$ -Al2O3 layers is largely affected by their precursor structures. Finally, to demonstrate the versatility of the high-quality nanocluster-based ${a}$ -Al2O3 dielectrics, carbon nanotube and metal-oxide thin-film transistors were fabricated on low thermal budget stretchable and rigid substrates, respectively.