Development of High Performance　Flexible Amorphous Oxide Semiconductor Thin-Film

Amorphous oxide semiconductor (AOS) e.g. InZnO, ZnSnO, InZnSnO, InGaZnO, thin-film transistors (TFTs) have been received considerable attention for promising applications in active matrix liquid crystal displays, organic light emitting diodes and flexible displays, because they offer high electron mobility, high optical transparency, wide band gap, low temperature and low-cost fabrication process in comparison with the amorphous and polycrystalline Si layers used for the channels of TFTs. The representative InGaZnO channel layer generally has a low field-effect mobility in TFTs. Nevertheless, an even higher mobility will be required for future applications in displays or integrated gate driver circuits. Due to the gallium atom acting as the carrier suppressor in InGaZnO system, this atom replaced by the tin atom could be achieved higher carrier concentration, thus leading to a higher electron mobility of ａ-InZnSnO TFTs. The electron transport through extensive s-orbital overlap between In3+ and Sn4+ ions can provide better conducting behavior of an ａ-InZnSn layer. In this proposal, the author will develop four AOS (InGaZnO, InZnO, ZnSnO, and InZnSnO) TFT flexibles using six rare-earth (RE) oxide films (Pr2O3, Er2O3, Yb2O3, PrTixOy, ErTixOy, YbTixOy) /Pb(ZrTi)O3 (PZT) stacked gate dielectrics for flexible panel applications within 3 years. In the first year, we develop the high quality of high-ｋ Pr2O3, Er2O3, Yb2O3, PrTixOy, ErTixOy, YbTixOy/PZT stacked gate dielectrics for AOS TFT applications. The structural and electrical characteristics of Pr2O3, Er2O3, Yb2O3, PrTixOy, ErTixOy, YbTixOy/PZT stacked gate dielectric films prepared under different Ar/O2 flows and film thicknesses and annealed at different temperatures were investigated. In the second year, by using low-temperature sputtering system, deposition conditions such as sputtering gas-pressure and deposition temperature, will be used to change four InGaZnO, InZnO, ZnSnO, and InZnSnO properties in the flexible panels. We explore the structural and electrical characteristics of InGaZnO, InZnO, ZnSnO, and InZnSnO TFT flexible devices using Pr2O3, Er2O3, Yb2O3, PrTixOy, ErTixOy, YbTixOy/PZT stacked gate dielectrics. In the third year, the electrical reliabilities of InGaZnO, InZnO, ZnSnO and InZnSnO TFT flexible devices using Pr2O3, Er2O3, Yb2O3, PrTixOy, ErTixOy, YbTixOy/PZT stacked gate dielectrics are studied under positive/negative bias stress (PBS/NBS), light stress (LS), positive/negative bias-light stress (PBLS/NBLS), positive/negative-bias temperature instability (PBTI/NBTI), and high temperature/moisture effect.

Project ID:PB10708-2116
External Project ID:MOST107-2221-E182-044