Kunihiro Shiota

16.2: A Parallel Digital‐Data‐Driver Architecture for Low‐Power Poly‐Si TFT‐LCDs

A parallel digital-data-driver architecture has been developed to reduce power consumption in low-temperature poly-Si TFT-LCDs. It features low-power 3V-interface level shifters and 198 serial/parallel converters driven in parallel at a clock frequency of 62.5 kHz. Total power consumption in a 2.4-in., 41K(176 × 234)-pixel TFT-LCD with integrated 6b DACs is 12 mW at a 30-Hz frame frequency.

High crystallinity poly-SixGe1-x at 450°C on amorphous substrates

The composition variation and strutural properties of poly-SiGe thin films prepared by Reactive Thermal chemical vapor deposition (CVD) with Si2H6 and GeF4 were investigated. Deposition of the films at 450° C was carried out with various gas flow ratios of Si2H6 to GeF4 on amorphous substrates such as glass plates and oxidized silicon wafers. The structural profiles of films were characterized by X-ray diffraction (XRD) and Raman scattering spectroscopies, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). All films show high crystallinity and (220) prefered orientation. The mole fractions of Si in the Six Ge1-x films were estimated to be from 0.95 to 0.05 for x, using Vegards law for the XRD peaks. Crystallinity in the Si-rich films was affected by growth rate and was greatly improved at lower growth rates. TEM observation revealed that high crystallinity was well established, even in poly- Si0.95Ge0.05 film, owing to direct polycrystalline layer growth on the substrate surface.