부산대학교 도서관

The interest in amorphous oxide semiconductors (AOS) thin-flim-transistors (TFTs) for applications in flat panel displays (FPDs) has generated a considerable number of experimental and theoretical studies. In particular, amorphous indium–gallium–zinc–oxide (a-IGZO) TFTs are now considered as the most favorable technology for designing integrated circuits used in display applications because of its many advantages, which include higher mobility than hydrogenated amorphous silicon (a-Si:H) and superior scalability with a low production cost compared to the low-temperature polycrystalline silicon (LTPS). In this thesis work, the use of a-IGZO TFTs in circuits is explored torwads high speed switching and digital-to-analog converter for integrated gate driver.Owing to bulk-accumulation (BA), dual-gate (DG) a-IGZO TFTs with top- and bottom-gates electrically tied together (DG-driving) exhibit higher ION, smaller sub-threshold swing (SS) and uniformly near zero-volt turn-on voltage (VON) compared to single-gate (SG) TFTs. This BA TFTs are applied here to achieve high speed switching circuits. The driving and load TFTs of inverters are first chosen between SG and DG TFTs, followed by the optimization of the TG offset length to take full advantage of BA. The high speed circuits are also realized on flexible polyimide substrate, which remain functioning well under tensile mechanical strain induced by a bending radius down to 2 mm.4 bit digital-to-analog converter (DAC) is designed, simulated, and fabricated, which turns out to have decent precision with integral nonlinearity (INL) of ±0.6 LSB and differential nonlinearity (DNL) < ±0.5 LSB. To improve the performance of DAC and potentially apply to actual integrated display drive circuits, a compact design with dencent performance is provided.