Masanori Yuki

A full-color LCD addressed by poly-Si TFTs fabricated below 450 degrees C

Poly-Si thin-film transistors (TFTs) fabricated with a maximum processing temperature of 450 degrees C by means of laser-induced crystallization of a-Si are discussed. These devices show high mobilities (50 cm/sup 2//V-s), low threshold voltages (2 V), low off current (10/sup -12/ A), and high reliability. A 3.5-in.-diagonal full-color liquid-crystal display addressed by these poly-Si TFTs is presented. >

Low Temperature Polysilicon TFTs by Non-Mass-Separated Ion Flux Doping Technique

A low temperature and hi8h throughput self aligned poly-Si TFT fabrication process has been developed. The process includes two key techniques. The first one is a laser induced crystallization of a-Si, occurring in the solid phase, using a high beam scanning speed. The second is a large diameter ion flux doping without nass separation. The maximum processing temperature is 450t, which is sufficiently low to use inexpensive glass substrates. With this process, exeellent poly-Si TFT characieristics of Ion/Ioff>106 and 4 ru=40em2/ys were obtained.

Low temperature fabrication of poly-Si TFT by laser induced crystallization of a-Si

Abstract Poly-Si TFTs were fabricated by means of laser-induced crystallization of PECVD a-Si in which the maximum process temperature was 450°C. These devices showed high field effect mobilities (50cm2/Vs), low off current (10–12A), and high reliability. A 3.5-in diagonal full-color LCD addressed by these poly-Si TFTs was fabricated and produced beautiful video images.

A full colour LCD addressed by poly Si TFTS fabricated at low temperature below 450 degrees C

A process below 450 degrees C has been developed for poly-Si thin-film transistor (TFTs). The devices have higher mobility ( approximately 50 cm/sup 2//V-s) and higher reliability than a-Si TFTs. A 3.5-in. full-colour liquid-crystal display addressed by these poly-Si TFTs is described.<<ETX>>

Low-Temperature Polysilicon Thin Film Transistors by Non-Mass-Separated Ion Flux Doping Technique

A low-temperature, high-throughput self-aligned poly-Si TFT fabrication process has been developed. The process includes two key techniques. The first one is a laser-induced crystallization of a-Si occurring in the solid phase using a CW Ar+ laser beam with high scanning speed, which was previously reported. The second is large-diameter ion flux doping without mass separation. The maximum processing temperature is 450°C, which is sufficiently low for use of inexpensive glass substrates. With this process, excellent poly-Si TFT characteristics of Ion/Ioff>106 and µFE=40 cm2/(V s) were obtained.

Low-leakage current polysilicon TFTs for LCD pixel addressing

The leakage current characteristics of low-temperature polysilicon TFTs (thin-film transistors) below 450 degrees C have been investigated. It was confirmed that the laser-induced crystallized polysilicon with temperature below 450 degrees C has good physical properties and device characteristics in TFT, equal to those of polysilicon with a process temperature of around 600 degrees C. Reduction of leakage current at higher signal voltage could be achieved by the optimization of the geometrical structure with the laser-induced crystallized polysilicon TFT. The low leakage current characteristics at the higher signal voltage may enlarge the applicable field in the higher-performance display. For example, these improved characteristics make it possible to apply higher voltage for addressing pixels of normally white TN and LC (liquid crystal) polymer composite mode.<<ETX>>

Material approach for the reduction of crosstalk in simple matrix LCDs

For the Vth drop of an LC (liquid crystal) cell in the lower frequency range, which is related to the crosstalk in simple matrix LCDs (LC displays), it was shown by calculation and experiment that the resistivities of the LC and aligning layer are important factors and both values are required to be more than 1*10/sup 11/ Omega -cm for the flat frequency dependence of the Vth. The flat frequency dependence of the Vth can be realized by making the resistivities of the LC and aligning layer sufficiently high. By using this method, the crosstalk caused by the frequency dependence of the Vth can be eliminated, even when the polarities of the pixel driving waveform are inverted in much longer cycles. Crosstalk-free and low-power-consumption LCDs can be realized by combining the driving method of Y. Kaneko et al. (1990).<<ETX>>

LP-A: Late-News Poster: A Low-Temperature Poly-Si TFT Reflective XGA Array for LCPC Light Valve

A 2 inches in diagonal low temperature poly-Si TFT reflective XGA array with driver integration was fabricated by Ar+ laser annealing method. An opaque organic film was used for a planarization layer of reflective electrodes as well as a light shield layer to the array. We applied the array to LCPC (Liquid Crystal / Polymer Composite) light valve and obtained a high resolution image.