Nobuyoshi Saito

4.1: Low-Temperature-Processed IGZO TFTs for Flexible AMOLED with Integrated Gate Driver Circuits

We have reduced threshold voltage shift of IGZO TFTs processed at 200°C under bias-temperature stress of Vg = 20 V at 70°C for 2000 s to 0.22 V by optimizing IGZO deposition and annealing conditions. A flexible AMOLED display with integrated gate driver circuits has been demonstrated.

Barium ferrite tape for DAT magnetic contact duplication

The coercivity and perpendicular orientation effects on duplication performance for the Ba-ferrite slave tape are studied by means of a DAT (digital audio tape) performance measurement on DAT recorders and anhysteretic magnetization process measurement for the slave tapes. Environmental stability for the duplicated Ba-ferrite tapes is also described. It is shown that perpendicularly oriented Ba-ferrite slave tapes, with relatively low coercivity values of around 600-700 Oe, enable a high-speed magnetic contact duplication of 76 kFRPI DAT signals to be practical. A sufficiently low error rate and high environmental stability are demonstrated for the Ba-ferrite tapes. The magnetization mechanism involved in the duplication process is analyzed in terms of anhysteretic remanent magnetization. >

67.3: Electrochemical Reaction Display with Dual Reflective and Emissive Modes

We have developed an electrochemical reaction display (ECRD) that can be operated in dual reflective and emissive modes in an entire pixel area of a single device. The ECRD utilizes electrochromic (EC) and electrogenerated chemiluminescence (ECL) reactions. These two electrochemical reactions can be controlled independently by adding a luminescent molecule to a liquid electrolyte of an EC cell with three electrodes. In the reflective mode, the ECRD cell exhibits high reflectance (47%) and high contrast ratio (6:1). In the emissive mode, the cell can show luminescent moving images because of the fast response time (10 ms).

Origin of High Mobility in InSnZnO MOSFETs

The origins of higher mobility characteristics of InSnZnO MOSFETs than those of conventional InGaZnO MOSFETs were investigated. Comprehensive analyses of temperature and surface carrier concentration (N_{s}}) dependence of mobility revealed the aspects of potential profile around mobility edge (E_{c}}) in InSnZnO MOSFET. Incorporated Sn atoms were found to increase the potential fluctuation around E_{c}} at low N_{s}} compared to conventional InGaZnO MOSFET, but enhance the overlapping of electron orbitals of cations with In atoms, which results in mobility improvement by band transport.

High-mobility and H 2 -anneal tolerant InGaSiO/InGaZnO/InGaSiO double hetero channel thin film transistor for Si-LSI compatible process

We demonstrate a high-mobility and H2-anneal tolerant InGaSiO/InGaZnO/InGaSiO double heterochannel (DH) TFT for 3D-LSI applications. A novel oxide semiconductor (OS) material, InGaSiO (Si/In ratio > 0.47) was found to exhibit semiconductor property even after H<inf>2</inf> annealing at 380^°C, whereas a conventional InGaZnO layer changed into a metallic one. Moreover, the DH channel TFT was operated in an enhancement mode and achieved a high mobility of 30 cm²/Vs after the H<inf>2</inf> annealing.