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We developed and fabricated the world's highest resolution (18 megapixel, 1443 ppi) OLED on glass display panel. The design uses a white OLED with color filter structure for high density pixelization and an n-type LTPS backplane for faster response time than mobile phone displays. A custom high bandwidth driver IC was fabricated. We developed a foveated pixel pipeline appropriate for virtual reality and augmented reality applications, especially mobile systems.

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...

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We investigated the lateral distribution of the equilibrium carrier concentration ( n 0 ) along the channel and the effects of channel length ( L ) on the source-drain series resistance ( R ext ) in the top-gate self-aligned (TG-SA) coplanar structure amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs). The lateral distribution of n 0 across the channel was extracted using the paired gate-to-source voltage ( V GS )-based transmission line method and the temperature-dependent transfer characteristics obtained from the TFTs with different L s. n 0 abruptly decreased with an increase in the distance from the channel edge near the source/drain junctions; however, much smaller gradient of n 0 was observed in the region near the middle of the channel. The effect of L on the R ext in the TG-SA coplanar a-IGZO TFT was investigated by applying the drain current-conductance method to the TFTs with various L s. The increase of R ext was clearly observed with an increase in L especially at low V GS s, which was possibly attributed to the enhanced carrier diffusion near the source/drain junctions due to the larger gradient of the carrier concentration in the longer channel devices. Because the lateral carrier diffusion and the relatively high R ext are the critical issues in the TG-SA coplanar structure-based oxide TFTs, the results in this work are expected to be useful in further improving the electrical performance and uniformity of the TG-SA coplanar structure oxide TFTs.