High-mobility high-reliability low-RC-delay oxide TFTs have been developed. Their performances are good enough for AMOLED displays even for the large-sized super-high-resolution, or high-frame-rate displays. In this paper, the status of oxide-TFT development and the issues for the mass-production of next-generation AMOLED displays will be discussed, and three types of AMOLED displays using different oxide materials and TFT structures will be demonstrated.

We developed a novel self-aligned top-gate oxide TFT for AM-OLED displays. Our developed Al reaction method to obtain source/drain regions is effective to fabricate a short channel and highly reliable TFT. A 9.9-inch diagonal qHD AM-OLED display was demonstrated to provide applicable solution for a large-sized and ultra-high definition OLED mass production.

Enhancement to the elevated-metal metal-oxide (EMMO) thinfilm transistor (TFT) architecture employing annealinginduced source/drain regions is presently reported, thus further extending the advantage of EMMO over the conventional TFT architectures. The enhancement includes: a 3-mask process resulting in a reduced mask-count, hence manufacturing cost; a bottom-gate self-aligned process resulting in reduced parasitic overlap capacitance, hence signal delay; and a 300o C process, with the lower temperature offering better compatibility with a wider range of flexible substrates.

We developed highly reliable oxide semiconductor TFT for AM-OLED displays. Passivating films, source/drain metals, and the TFT structure were optimized with an eye to improving device reliability to provide a lifetime over 10 years. An 11.7-inch diagonal qHD AM-OLED display was demonstrated to provide applicable solution for a large size OLED and an ultra-high definition LCD TV mass-production.