This study examined the effect of the thickness of interfacial indium-tin oxide (ITO) on the performance and bias reliability of zinc-tin oxide (ZTO) thin film transistors (TFTs). The 3.5-nm-thick ITO-inserted ZTO TFTs exhibited superior mobility (43.2 cm2/V s) to that of the ZTO only TFTs (31.6 cm2/V s). Furthermore, the threshold voltage shifts for the ZTO/ITO bi-layer device decreased from 1.43 and −0.88 V (ZTO only device) to 0.46 V and −0.41 V under positive and negative bias stress, respectively. This improvement can be attributed to a decrease in the interfacial trap density for the ITO-inserted ZTO device.

Titanium oxide ͑TiO x ͒ passivation layer was employed and optimized to stabilize the performance of the bottom gate amorphous indium-gallium-zinc oxide ͑a-IGZO͒ thin-film transistors ͑TFTs͒. A molybdenum/titanium ͑Mo/Ti͒ source-drain electrode was deposited on an a-IGZO layer, and the TiO x passivation layer was formed by oxidizing the Ti layer using oxygen plasma after etching the Mo layer. By increasing the oxygen plasma treatment time, the subthreshold slope and leakage current of the a-IGZO TFTs were improved to 0.78 V decade −1 and 0.3 pA, respectively, and the degradation of the TFT performance was not observed, even after thermal treatment at 280°C for 1 h.Recently, there has been a large demand for stable high mobility thin-film transistors ͑TFTs͒ to replace a-Si TFTs. Among several candidates, an amorphous InGaZnO ͑a-IGZO͒ has attracted great attention for use in active-matrix liquid-crystal displays ͑AM-LCDs͒ due to its ultrahigh definition ͑4K ϫ 2K͒, large size ͑over 90 in.͒, and 120 Hz driving scheme, and in active matrix organic light emitting diodes ͑AM-OLEDs͒ with uniform and stable TFTs of low cost. 1 The a-IGZO TFTs provide better uniformity and high mobility over 10 cm 2 V −1 s −1 due to the amorphous phase and electron transport through circular metal s orbital. 2-4 Even though a-IGZO exhibits superior characteristics, it is dependent on the properties of the passivation layer. The oxide TFT can degrade easily when the a-IGZO layer is exposed to H 2 and O 2 atmosphere, especially H 2 during plasma-enhanced chemical vapor deposition ͑PECVD͒ SiN x and SiO 2 film deposition and O 2 without a passivation layer. 5-8 The a-IGZO TFT characteristics vary with the atmosphere and the deposition conditions of the passivation layer. As a result, it is difficult to obtain a stable TFT, and the deposition conditions of the passivation layer must be carefully controlled. More recently, to prevent the degradation of the oxide semiconductor, Jeong et al. employed an etch stopper layer ͑ESL͒, which is formed and patterned before the source-drain ͑S/D͒ electrode formation, 7 but which requires more processes and mask steps.In this article, we introduced the fabrication of highly stable and high performance a-IGZO TFTs using a Mo/Ti S/D electrode, where the lower part of Ti was simultaneously used for the passivation layer of TiO x . The as-deposited Ti film was uniform over the whole substrate ͑370 ϫ 470 mm͒ with a thickness variation of ϳϮ10%. The Mo/Ti was used for the S/D electrode, and TiO x formed from Ti by oxygen plasma was the first passivation layer without any extra mask step and ESL deposition. The portion of TiO x formed from Ti was proportional to the oxygen plasma treatment time, and the effect of the TiO x protection layer on the device performance of a-IGZO TFTs was discussed in detail. Figure 1 represents the schematic cross-sectional view of an a-IGZO TFT with a TiO x passivation layer formed by oxygen plasma treatment. Mo/AlNd ͑500/2000 Å͒ deposited by dc magnetron sputtering on a Corning Eagl...

We have developed a new 15.0‐inch AMOLED display. An advanced Solid Phase Crystallization (a‐SPC) method was employed for the increase of uniformity and reliability of TFTs. A new pixel was proposed for the compensation of I×R voltage drop in power line and a symmetric driving scheme was also developed for the reduction of short term image sticking problem.

Abstract— A novel pixel circuit for electrically stable AMOLEDs with an a‐Si:H TFT backplane and top‐anode organic light‐emitting diode is reported. The proposed pixel circuit is composed of five a‐Si:H TFTs, and it does not require any complicated drive ICs. The OLED current compensation for drive TFT threshold voltage variation has been verified using SPICE simulations.

Flexible displays have attracted much attention as a future display due to highly rugged, lightweight, and extremely low power consumption. We have developed the flexible process technology for a mass production using the improved etching technology. F-DIET(Flexible Display using Improved Etching Technology) technology enables us to make a flexible display in standard AMLCD factories and to stably manufacture of flexible AMEPD and AMOLED.