The Ni-silicide of a sheet resistance of 7 (Omega) /(open square) can be formed at 230 degree(s)C on n⁺ a-Si:H and thus can be applied to gate and source/drain contacts for high performance TFTs. Because of its low resistance it is possible to make a self-alignment between gate and source/drain, which lead to a coplanar a-Si:H TFT having a low parasitic capacitance between them. The NiSi₂ precipitates can be formed on a-Si:H at around 350 degree(s)C and needlelike Si crystallites are grown as a result of the migration of the NiSi₂ precipitates though a-Si:H network. Amorphous silicon can be crystallized at 500 degree(s)C in 10 minutes in a modest electric field. The low temperature poly-Si TFT with a field effect mobility of 120 cm²/Vs has been demonstrated using the low temperature poly-Si.

We have developed a highly integrated liquid-crystal-on- silicon light valve for three-panel color projector. The silicon panel was designed and fabricated by a 0.35 micrometers , 3-metal and dual-voltage CMOS process with a spatial resolution of 1280 X 1024 pixels. The pixel pitch was 12 micrometers , the fill factor was 90% and the display area was 0.77' in diagonal. Eight-bit digital data drivers and gamma- correction circuitry were integrated into the silicon panel for true gray scale and full color representation. The display panel was assembled with a mixed twisted nematic and birefringence liquid crystal cell for high contrast at CMOS compatible voltage. Contrast ratio was typically 200:1 at 5.5 Vrms. In addition, silicon surface layers, liquid crystal materials, pixel structures and driving schemes were carefully optimized for the minimization of visual flicker. Flicker ratio of less than 3% was achieved at 60 Hz frame rate. The optical sub-system utilized a trichroic prism assembly for both color separation and recombination. With this trichroic prism assembly incorporating three silicon light valves, a compact and high-contrast SXGA video projector was demonstrated.

Polycrystalline silicon (poly-Si) has been obtained by low- temperature (< 500 degree(s)C), nickel-based, metal-induced crystallization (MIC) of amorphous silicon. Because crystallization outside of the nickel-covered regions is not only possible but also commonly utilized, the technique is more often called metal-induced lateral crystallization (MILC). Based on studies on the crystallization kinetics and material characteristics, a unified mechanism is proposed for MIC both under and outside of the nickel coverage. Conduction in MILC poly-Si is found to be anisotropic with respect to the MILC direction. While the material quality of MILC poly-Si is significantly better than that of solid- phase crystallized poly-Si, the performance of MILC poly-Si thin-film transistors (TFTs) is quite sensitive to and degraded by the inclusion of MIC/MILC interfaces in the device channel regions. When such interfaces are eliminated, excellent TFTs are obtained that can be used to realize high performance systems-on-panels, including sophisticated displays based on liquid crystals or organic light-emitting diodes. The application of MILC poly-Si is not limited to low-temperature electronics, it is found that high- temperature recrystallization results in MILC poly-Si with material quality approaching that of single-crystal Si. Re- crystallized MILC poly-Si has been used to realize high performance piezo-resistors and TFTs for integrated sensor applications.

We have investigated the laser crystallized LT poly-Si TFT characteristics in the overlapped area of excimer laser scans in the long axis direction. Continuous TFTs located at the edges of single scan and overlaps of two scans were used. Different laser energy densities were dual-scanned to study the characteristics of the TFTs in overlapped area. It was found that the laser with higher energy density dominates the TFT characteristics, and their characteristics in the overlapped area can be as good as those in the non- overlapped area. Based on these results, large uniform LT poly-Si panel can be fabricated by overlapping the laser scans in the long axis direction.

In this study, the effects of laser beam profiles were investigated on the crystallization of poly-Si films. `One Pulse' laser crystallized poly-Si was analyzed by SEM and alpha-step to distinguish the effects of non-uniform laser beam profiles. Surface smoothness of poly-Si films with various laser-overlapping ratios was also measured to investigate the effects of laser beam profiles. Then the relationship of TFT characteristics and laser overlapping ratios will be discussed.

In this paper, we demonstrate a novel device structure of low-temperature polysilicon thin-film transistors (LTPS TFTs) for AMLCD applications with using excimer-laser crystallization (ELC). The device structure consists of a thin channel and a thick source/drain. This structure has its merit in the process of ELC and is capable of improving TFTs' electrical characteristics. During excimer laser irradiation, this kind of recessed structure is able to built up localized lateral thermal gradients in the regions near the steps and entice crystallization from the chiller thick source/drain regions toward the hotter thin channels. Because of the development of crystallization process, the average field-effect mobility of the devices can be increased to about 350 cm²/V.s, and the on/off current ratios exceed eight orders. In addition to improvement of device performance, the process window of ELC is broadened with the recessed structure.

In low temperature poly-silicon TFT's, the electrical characteristics are controlled by the inter- and intra-grain defects in the poly-silicon films. Hydrogen passivation is an effective way to reduce the density of these defects and can improve TFT's characteristics. In this study we investigated the characteristics of TFT's as a function of the hydrogenation time for two different hydrogenation techniques: H₂/Ar plasma and PECVD silicon nitride film deposition. It was found that the characteristics of TFTs could be greatly improved after a very short period of time by both hydrogenation processes. In the H₂/Ar RF plasma hydrogenation process, the characteristic parameters would be apparently improved within 30 min., and with only limited improvement after that. In the nitride hydrogenation process, the electrical characteristics of TFTs would be optimized within 5 min. of annealing, but started to degrade with loner annealing time. From these result, we concluded that the hydrogenation mechanism of these two techniques are very much different from each other.

Low Temperature Poly-Silicon (LTPS) TFT technology for LCD has been developed for a long time. Because of its higher mobility, scan driver and data driver could be fabricated on the glass panel to form a fully integrated display panel and reduce its cost. In this paper, new circuits for buffering the DAC in the data driver will be proposed. These circuits have the advantages of lower power and smaller area than the conventional ones. They all extend their full swing from 2 to 10 volts in 12 us and have 6-bit resolution at least. Furthermore, the circuits have no feedback system as the operational amplifier does, which is hard to design in the current LTPS technology.

The mass production of the color plasma display started from 1996. However, since the price of the panel is still expensive, PDPs are not in widespread use at home. It is necessary to develop the new and low-cost manufacturing technologies to reduce the price of the panel. This paper describes some of the features of new fabrication technologies of PDPs.

Several kinds of color PDPs have been converged to a single group of the surface-discharge color ac PDPs of which the reason will be described on the basis of the recent advanced ultraviolet-rays measuring systems. PDP Manufacturers completed to construct the first generation of mass production lines for color PDPs and now doing to accomplish the second generation of ones until 2001. Under the existing circumstances in Japanese PDP manufactures one of the most distinctive events in 1999 is amalgamating or cooperative motions between PDP manufacturers within or outside of Japan. The present paper will also describe the latest information about the processes and materials of which composed the advanced color PDPs.

Physical phenomena which take placed in an AC Plasma Display Panel cells are discussed in this paper.

A fully sealed field emission display (FED), indicator, using carbon nanotubes (CNTs) as emitters is examined. The CNTs chunk, synthesized by arc discharge, were crushed, mixed with conductive pastes and then screen-printed on glass for the cold cathode. And the anode plate, an ITO glass printed P15 phosphor, was separated from cathode using 90 micrometers spacers. The indicator display performed a turn-on voltage as low as 250 V, and the emission current density 2.2 mA/cm² under 300 V with brightness of 500 nits. The pixels, driven by open drain IC with 5 V gate voltage, showed the clock image which indicated the application of CNTs-FED. No significant degradation of this performance was observed during 1000 mins testing. The influence of printing condition and surface treatment process on the emission characteristics will also be discussed in this letter.

A carbon nanotube emitter with high uniformity, adhesion and emission current has been formed by screen printing. The raw carbon nanotubes (CNTs) chunk were crushed, purified, dispersed, mixed with organic additives and then screen printed on Ag electrode. After burning out the organic additives under two thermal cycles, the surface of CNTs emitters were treated. The treated emitters showed a better emission characteristic than untreated emitters.

White illumination characteristics of ZnS-based phosphor materials exited by an In_xGa_1-xN-based single quantum well-structure ultraviolet (UV) light-emitting diode (LED) have extensively been investigated. In order to evaluate white luminescence, two kinds of ZnS-based white phosphors have been employed. When an UV LED was operated at a current of 10 mA, chromaticity (x, y) color temperature (Tc) and general color rendering index (Ra) of the white luminescence are obtained to be (x,y) equals (0.29, 0.33), Tc equals 7700 K and Ra equals 70, respectively, for ZnS:Ag + (Zn,Cd)S:Cu,Al phosphors, whilst (x,y) equals (0.31, 0.34), Tc equals 6900 K and Ra equals 83, respectively, for white phosphor material including ZnS:Cu,Al, Sr and Y materials. The value of chromaticity slightly changed with increasing forward current of the UV light source. As a result, it is possible to obtain stable white luminescence spectrum. The dependence of the luminescence brightness on the thickness of phosphor shows a tendency to saturate for reflection brightness, but for transmission brightness its dependence has a peak due to light scattering effect. The reflection brightness was higher than the transmission brightness. It is revealed that the white luminescence light of stable chromaticity and high brightness using reflection light can be obtained.

The basic illumination characteristics of an efficient white LEDs lighting source, which is composed of cannon-ball type 10 cd-class InGaN-based white LEDs, are described. It is noted that the temperature and forward-bias current dependence under full wave rectification of AC 100 V gives a significant effect to both electroluminescence properties and luminous efficacy. We have obtained a maximum luminous intensity of 95000 cd/m² and a luminous efficacy of about 27 lm/W at an electric power of 20 W (at a constant current of 10 mA). The developed white LEDs lighting source indicates two injection electroluminescence peaks at 465 and 555 nm, which are originated from a blue LED and a YAG:Ce³⁺ phosphor, respectively. The illuminance distribution of the LED lighting source was analyzed using our `multi sources of LED light' theory. We have performed the design of a street lighting as the practical application using the 700 LEDs array lighting source.

Color integration in organic LEDs (OLEDs) on a substrate has always been a challenge due to the incompatibility of OLED materials with the conventional photolithography. In this paper, we report a process for the fabrication of large-area multicolor OLEDs of arbitrary patterns by combination of thermal-transfer printing and screen-printing. Thermal transfer printing is used to introduce color-tuning dyes into a thermally stable OLED polymer layer from a dye- dispersed polymer layer on the donor plate. Such a process permits controllable and uniform doping of a polymer layer over large areas. By using a patterned color donor plate, color integration in OLEDs could be accomplished with a single thermal transfer step. In this work, the source plate containing multicolor patterns is fabricated by screen- printing. The RGB color patterns were printed sequentially by using RGB inks prepared by dispersing nile red,C6 and perylene into a commercial screen-printing paste. Based on these printing approaches, we have successfully fabricated multicolor single-layer and heterostructure OLEDs.

An effective process of performing controllable doping of polymer films in organic light-emitting devices is reported. In this approach, a film to be doped is brought into direct contact with a dye-dispersed polymer donor film to permit direct dye-diffusion thermal transfer. Theoretical and experimental studies indicate that this doping process can be modeled by Fick's diffusion theory and that a desired dopant distribution from shallow to flat profiles may be obtained in a single transfer step by adjusting the diffusion conditions. Doped-polymer light-emitting devices made by this process and the conventional blending process exhibited same device characteristics. Along with patterned color donor plates, we demonstrated multicolor OLEDs of arbitrary patterns over large areas with a single thermal transfer step.

Many important innovations on LC display mode for wide- viewing angle color TFT-LCDs were reported within this several years, and recently the volume productions of LC monitors and LC TVs have been started using them. To realize good wide-viewing angle color TFT-LCDs, we have to design not only optical property of LC layer but also film polarizers and back lights. Typical wide-viewing angle LC display modes are classified into several categories and discuss their features.

We invented a new two-domain TN/LCD with excellent viewing performance with identical, symmetrical 160 degree(s) (+/- 80 degree(s)) viewing cone in all four major viewing zones. The display also showed excellent color tracking and no gray scale reversal. Each sub-pixel is twisted nematic (TN) based with the LC alignments oriented in the horizontal and vertical directions. This is different from the conventional TN/LCD where the LC alignments are oriented in the two diagonal directions. In this special two-domain TN/LCD, the two sub-pixels show complementary asymmetrical horizontal and vertical viewing zones. Thus the combined two-domain effects show symmetrical and identical optical performances in the four major viewing zones. The viewing angle and display performances can be further improved by optical compensation films, in particular, the combination of types A and C films to enlarge the viewing angles in the diagonal viewing directions.

We have compared the performance of wide-viewing angle technology using interdigital electrodes, which are in-plane switching (IPS), fringing field switching (FFS) and finger on plane (FOP). What we have found is that IPS has the fastest response, FOP has the largest process window, and FFS can provide the similar transmittance as FOP but with more difficult process. The basic properties of these technologies will be reviewed in this paper.

We report the results obtained from the studies of polymer- stabilized cholesteric texture films. Two sets of samples were fabricated. The first set were fabricated by adding various ferroelectric liquid crystal (SmC*) dopant concentrations in the mixtures. The second were fabricated using a dual-frequency liquid crystal. The experimental results obtained from the first set show that adding a small amount of SmC* could significantly improve the cells' electro-optical characteristics. Both the driving threshold voltage and the rise time were decreased, while the hysteresis width was increased. The result from the second set shows there exists a pronounced hysteresis effect in the transmission versus frequency curve at a given applied voltage. The hysteresis width is increasing as the applied voltage is increasing. A display mode is proposed based on this bistable feature.

A reflective TFT-LCD with an internal asymmetric diffusive micro slant reflector (DMSR) is developed to enhance the light efficiency. The DMSR structure is optimized to obtain a desired light distribution cone with asymmetric characteristics. In this paper, we will compare the optical properties of a reflective TFT-LCD panel with a DMSR structure and those of a reflective LCD with symmetric bump structure reflector.

Based on a novel concept that intensive optical field may improve alignment of polymer films photopolymerized by linearly polarized laser light, we investigated effects of instantaneous intensity of the laser light and viscosity of the films on alignment of liquid crystals on the photopolymerization-induced anisotropic films. The intensity and the viscosity are the two essential factors related intimately to magnitude and relaxation time of the reorientation Kerr effect. The experiments demonstrated that the increase in the intensity and the decrease of the viscosity improved the photopolymerization-induced orientation of the films. Based on the photochemical points, we discussed causes of the improvement.

Three types of 5-mask TFT array process have been compared and analyzed their characteristics including TFT performance, process window, etc. Results showing here indicate that a 5-mask TFT manufacturing process can be optimized with low cost, high production yield and high performance. These properties let the reduced mask TFT array process reveal a much higher potential in mass production.

The two-step-exposure (TSE) technology has been developed in application for combination the active layer with metal II layer. And this TSE technology has been applied in our Reduced-Mask process (five-mask) for cost reduction. The result shows that this amorphous-silicon thin-film transistor with four-photolithography process has great potential in mass production.

Mismatch between outer lead bonds (OLBs) of a tape automated bonding (TAB) and a glass panel during fabrication is studied using the finite element method. A 2D finite element model for the TAB-on-Glass (TOG) connector is presented for determining the deformation of the connector. The deformation of the TOG connector induced by residual thermal stresses are determined via a two-stage approach. At the first stage, the TOG connector is under heat and pressure. The anisotropic conductive film (ACF) in-between the TAB and glass panel is assumed to be in a melting condition so that both TAB and glass panel can expand freely. At the second stage, the connector is cooled down to room temperature and the ACF becomes solidified. The deformations of the connector at the two stages are determined in the finite element analysis in which the temperature dependence of material properties is considered. Effects of particular parameters on the mismatch between the OLBs are studied by means of a number of numerical examples. A method for compensation design of the lead locations of the OLBs is proposed. It has been shown that the compensation design can produce results that will avoid the occurrence of unwanted mismatch.

Chip-on-film is a new technology after tape-automated- bonding (TAB) and chip-on glass (COG) in the interconnection of liquid crystal module. The thickness of the film, which is more flexible than TAB, can be as thin as 44 micrometers . It has pre-test capability, while COG hasn't. It possesses great potential in many product fabrication applications. In this study, we used anisotropic conductive film as the adhesive to bind the desired IC chip and polyimide film.

Based on the multibubble sonofluorescence display principle of the aqueous luminol-alkaline solution, two experimental applications, displaying the ultrasonic cavitation field and confirming the temperature distribution characteristic of the ultrasonic fountain are introduced.

This paper described the theoretical basis of extreme value orientation in detail, which is used to examine the dimension of hole and axle with double point one coordinate measure instrument, and it's quality and feature and calculation method of survey error on dimension, which is caused by turn back point error. The paper also provide a practical chart, which is used to revise at the same time also introduced the study method which is designed by author.

At present, the way to test plane level of terrace are all indirect survey methods at first, author choose some survey sections and get dates from these sections according to stipulation with survey method and then proceeding the dates, through which can strive the plane level error. The plane level dates calculated with these dates can't make an overall plane level assessment to the terrace, especially to the partial position so, it can't be described in detail on all terrace because of not been survived usually. Author all the error and plane level in the partial range the partial plane level, its assessment is very important to control the microcosmic quality. The paper also discuss the theory issue on speckle method and plane fluctuate capacity method with exist for a long term.

We report a study of the circular-shaped and rectangular- shaped focus-gate Field Emission Devices (FED) structure. In this work, we have developed a simulator of FED based on the Finite Difference Method. The major element of this simulator is a modified Fowler-Nordheim field emission model. We evaluate the performances of the circular-shaped and rectangular-shaped focus-gate FED structures by using this simulator. Results reveal that the circular-shaped focus-gate FED structure has more collector current. Also, the focusing characteristics of electron beam are improved.

In thin-film-transistor LCD, aperture ratio is an important parameter of transmittance. In this paper, we describe the relation between aperture ratio and reverse tilt domain. We conclude that we can control the magnitude of reverse tilt domain by changing rubbing density, pile impression, cell gap and altitude of TFT. Consequently, relatively large aperture ratio could be obtained by decreasing the area of black matrix.

Alignment of liquid crystal induced by rubbing is not only interesting in physical chemistry but also important as a fundamental technology of mass production of liquid crystal devices. A detailed investigation on the influences of various rubbing parameters and temperature on the polyamide film has been carried out to study the temporal behavior of the pretilt angle. We also use the Taguchi Method of the Quality Engineering to prove the evaluated value and experimental value of the pretilt angle. The possibility of using the method as in-line control parameters of the alignment process in an actual LCD production facility is considered.

Color LCD (Liquid Crystal Display) has been widely used for personal computers (PC) and video monitors because of its light weight, small volume, low power consumption and so on. Color reproduction for LCD panels are different from that of CRT (Cathode Ray Tube) display. This study describes the difference of color gamuts in different luminance level and the accuracy of color between CRT and LCD. In the present study, the reproduction color gamuts on the chromaticity diagram are measured in three types of displays, including two CRT types (BARCO Reference Calibrator Plus and ViewSonic PT775) and one LCD type (NEC MultiSync LCD 200).

InGaN/GaN double heterostructure and multiple quantum wells (MQW) light-emitting diodes were grown by metalorganic vapor phase epitaxy. Band gap narrowing of the PL spectra for the InGaN/GaN MQW LEDs can be observed at room temperature. In addition, the emission wavelength of EL and PL spectra for the MQW blue LEDs exhibit a blue-shift phenomenon when increasing the injection current and laser power, respectively. This luminescence behavior can tentatively be understood as a competition between a spectral red-shift mechanism of piezoelectrically-induced quantum-confined Stark effect and a blue-shift mechanism of band-filling and charge screening effects.

Diamond maybe is an ideal electron emission material for field emission display because of its low work function and better chemistry stability. In this research, complex diamond conduct ceramic thin film is fabricated by using Ag- Bi-Pb-B-O base in organic conduct paste and diamond grains. The research aim is to find a method for making large area diamond-base electron emission material. Field emission performances of complex diamond ceramic are studied, too. The turn-on voltage and maximum stable emission current of material are 300 V and 760 (mu) A, respectively. The material also shows better emission stability at low vacuum pressure. The emitting center view is employed to explain the electron emission from diamond ceramic thin film.

As we approach the new millennium, the ongoing aim of human society is not only for promoting scientific technology but also creating new industries. To achieve this goal, each person in industry must recognize anew that the real meaning of science is to explore the absolute truth. It is also important that people recognize that there are unlimited matters which we humans do not yet know.