Yutaka Onozuka

A wafer-level heterogeneous technology integration for flexible pseudo-SoC

The MEMS-LSI integration technologies that have been reported are mainly implemented for monolithic integrated System on Chip (SoC) by applying the advantages of process compatibility between MEMS and CMOS LSI [1]. However, it has been impossible to integrate them in the case that MEMS and standard CMOS processes are incompatible. Furthermore, many MEMS-LSI integration technologies applying System in Package (SiP) technology with the interposer substrate to realize electronics devices have been reported. However, using SiP technology, it has not been possible to achieve high integration density comparable to that of monolithic integrated SoC because the interposer substrate occupies a large area in SiP. Accordingly, development of an advanced MEMS-LSI integration technology to realizing highly integrated SoC incorporating MEMS devices is required [2].

Preparation of Pb(Zr, Ti)O3 Thin Films on Glass Substrates.

Lead-zirconate-titanate (PZT) thin films were prepared on non-alkaline glass substrates widely used in liquid crystal display (LCD) devices, by plasma-assisted magnetron RF sputtering with an immersed coil. After preparation of the PZT thin film, the glass was available for use in LCD device processing. No mutual diffusion of the elements was recognized between the glass substrate and the bottom electrode. The PZT layer had a dense film structure with rectangular and columnar grains, and only its perovskite phase was crystalline. PZT thin films on a glass substrate had leakage current densities of about 10-8 A/cm2, acceptable hysteresis loop shapes with the remanent polarization (Pr) of 45 µC/cm2 and the coercive field (Ec) of 90 kV/cm. Ferroelectric properties on a glass substrate almost conform with those on a Si-based substrate.

Preparation of Pb(Zr, Ti)O3 Thin Films by Plasma-Assisted Sputtering

A novel plasma-assisted RF magnetron sputtering system with an immersed coil antenna between a target and a substrate was applied for preparing Pb(Zr, Ti)O3 (PZT) thin films. The antenna enabled the generation of inductively coupled plasma (ICP) independently of the target RF source. The plasma assisted by the antenna resulted in the changes of ion fluxes and these energy distributions irradiating to the substrate. The crystalline phase of the deposited PZT thin films was occupied by the perovskite phase depending on the antenna power. In addition, a high deposition rate, modified uniformity of film thickness, and a dense film structure with large columnar grains were obtained as a result of effects of the assisted plasma. The application of the plasma-assisted sputtering method may enable the preparation of PZT thin films that have excellent properties.

A wafer-level system integration technology for flexible pseudo-SOC incorporates MEMS-CMOS heterogeneous devices

A flexible pseudo-SoC which integrates electrostaticMEMS and its driver CMOS-LSI for mobile electronics device applications has been developed. From the experiments, the pseudo-SoC process has succeeded to form a fine-pitch on-chip global layer on the MEMS and CMOS-LSI embedded in the epoxy resin and to realize total thickness of 100µm. This paper reports the pseudo-SoC that overcomes the limitation of system integration and provides the complementary advantages of SiP and SoC within the results of a highly-integrated flexible pseudo-SoC incorporating electrostatic MEMS and its driver CMOS-LSI for mobile electronics applications.

A Low‐Power, Image‐Memory LCD using Ferroelectric Film with Gray‐Scale Capability

A novel image-memory LCD using ferroelectric film for memory elements with gray-scale capability and ultra-low-power consumption has been proposed. We have demonstrated the operation of image-memory function by using an LC cell with discrete ferroelectric devices. A gray-scale image without any power consumption for more than several seconds has been obtained.

33.1: A 3.2‐in. LCD Panel using Amorphous Silicon TFT Formed with Novel Selective and Dispersive Transfer Technique

A novel formation process for TFT using our proposed novel selective transfer technique, which enables low cost TFT fabrication on a large and flexible substrate, is proposed. This technique is used to fabricate a 3.2-inch LCD Panel using amorphous silicon TFT transferred on glass substrate for the first time.

Low-Power Operation of an Image-Memory LCD using Ferroelectric Film

Abstract The authors have proposed an image-memory LCD using ferroelectric thin film for memory elements to achieve ultralow power consumption. Memory operation with gray-scale levels was confirmed by using an equivalent circuit model of the LCD consisting of a discrete ferroelectric device. The reduction in power consumption is related to hold time and the ferroelectric characteristics.

Photolithographic pattern transformation by backside exposure in a-Si:H thin-film transistor liquid crystal displays

Resist pattern transformation by backside exposure, which is a key process for a self-alignment technique is investigated. The light intensity and a-Si:H thickness markedly affect the pattern transformation, while the effect of gate insulator thickness is small. Numerical simulations based on Fresnel diffraction showed fairly good agreement with the experimental results.

A lens-free single-shot fluorescent imaging system using CMOS image sensors with dielectric multi-layer filter

This paper reports a lens-free single-shot fluorescent imaging system based on CMOS image sensors, for monitoring the shape of a single cell in the cluster during culture in parallel. By directly depositing a dielectric multi-layer filter to eliminate excitation light on a CMOS image sensor, the spatial resolution of smaller than 10 μm was achieved, which is small enough to distinguish fluorescent characteristics for single cell level. As one of the typical demonstrations, rat primary neurons and human colon cancer cells stained with Hoechst® 33342 were observed and their individual nuclei were distinguished in the fluorescent image.

LP‐4: Late‐News Poster: Reflective Color Image‐Memory LCD Using Ferroelectric Film on LC Glass Substrate

A 2.8″-diagonal reflective image-memory LCD using ferroelectric film for memory elements, which enables ultra-low-power consumption, is fabricated on a glass substrate for the first time. The asymmetrical feature of the hysteresis loop is improved by symmetrical ferroelectric capacitor configuration, and achieved an image-memory color LCD with good quality.