AVT-RIT-NSF partnership for the development of low voltage thin film phosphor for field emission display devices

This paper describes the development of a low voltage thin film phosphor material by an alliance between the Rochester Institute of Technology, Advanced Vision Technology Inc., a Rochester based small company and the National Science Foundation (NSF) through the NSF´s small business technology transfer (STTR) program. The overall goal of the Phase I program was to develop tantalum zinc oxide (TZO), a novel low voltage blue phosphor that can be deposited in thin film form and integrated with semiconductor device fabrication for flat panel display applications. A lower temperature process for depositing TZO thin films was achieved by rf sputtering from a ZnO-Ta mosaic target. A thorough investigation of the intrinsic blue luminescence showed that the mechanism responsible for luminescence in TZO is metal-to-ligand (Ta 5d ⁰-O 2p⁶) radiative transition. Saturated red and green colors were obtained by doping the TZO host lattice with Mn. An exhaustive study of processing parameters, such as annealing, etching, and subsequent deposition processes was done. Successful integration of the TZO phosphor using standard IC processing was realized in working field emission devices