97‐2: Late‐News Paper: Development of High‐Mobility Indium‐rich IGZO TFT Device for IT OLED Display

High‐end MNT, NBPC OLED displays require high resolution and high‐speed driving characteristics. In addition, as an OLED backplane, a high mobility and excellent reliability characteristics of TFT are required. We have developed high mobility devices by using Indium (In‐) rich a‐IGZO. In the In‐rich a‐IGZO TFT process, a relatively large amount of oxygen is used compared to conventional a‐IGZO (In:Ga:Zn 1:1:1) in order to control the variation of the threshold voltage (VTH) caused by high carrier concentration. However, the increase in excess oxygen leads to a decrease in reliability, making it even more difficult to satisfy both VTH dispersion and reliability at the same time. We have developed a‐IGZO TFTs that have excellent reliability characteristics while satisfying VTH dispersion and mobility by controlling the vertical and lateral distribution of oxygen and hydrogen. Furthermore, it has been confirmed that the 27‐inch QHD OLED monitor, which incorporates high‐mobility a‐IGZO TFTs, satisfies the product reliability characteristics.