TFT-LCD驱动电路浅析

本文针对栅源矩阵液晶显示器件,介绍了TFT-LCD驱动技术的发展历史,并讨论了实现动态画面的数字TFT-LCD驱动电路的原理以及实现方法.通过对一种简单数字屏TFT-LCD驱动电路的介绍,深入了解TFT-LCD驱动电路的工作原理.     

TFT-LCD的宽视角技术

随着TFT-LCD显示技术的不断发展,宽视角模式已经成为业界追求的目标。本文通过对TFT-LCD显示模式的叙述,分析了各种流行显示模式的特点,希望能为了解TFT-LCD有所帮助。     

第五代TFT-LCD生产线的工艺设备和材料

TFT-LCD是当前平板显示器(FPD)的主流显示器.从整个产业链上对第五代TFT-LCD生产线的工艺、设备、材料及发展趋势作一概要的介绍,为大家初步了解第五代TFT-LCD生产线提供参考.     

手机用TFT-LCD Source Driver电路模块研究与设计

SourceDriver电路模块是彩色TFT-LCD驱动控制芯片的关键电路之一,其功能是将数字图像显示数据转换成模拟驱动电压,从而驱动TFT-LCD显示各种彩色图像。本文从TFT-LCD的驱动原理出发,提出了一种适合于手机用TFT-LCD的低功耗、小面积的SourceDriver电路体系结构,用0.25μmCMOS工艺设计并实现了显示26万(26×26×26)色,支持132RGB×176分辨率的手机用TFT-LCD驱动控制芯片中的SourceDriver电路,电路面积约15mm×0.6mm。Hspice仿真结果表明,SourceDriver电路的响应时间为1.49μs,静态功耗小于1mW。     

液晶显示器新技术

常见的液晶显示器分为TN-LCD、STN-LCD、DSTN-LCD、TFT-LCD四种类型。其中,DSTN-LCD和TFT-LCD被广泛应用到计算机系统、PDA、移动通信等领域。尤其是TFT-LCD已在笔记本电脑领域得到推广。目前,由于TFT-LCD技术的不断完善,再加上DSTN-LCD自身存在的缺陷,使得TFT-LCD成为当前计算机市场中前景最好的液晶显示器。由于显示工作原理不同,LCD显示器的有些性能(技术)参数与CRT显示器大同小异,而有些则区别较大。主要参数包     

CFT-LCD制造过程中篚盒厚控制工艺研究

以国内最先进的第5代TFT-LCD生产线为基础,对生产过程中影响盒厚的因素进行探讨和研究,为TFT-LCD生产中的盒厚控制提供参考。主要探讨了TFT-LCD生产中,液晶滴下工艺、垫料散布工艺、封框胶涂敷工艺对液晶盒厚的影响。     

基于CPLD的TFT-LCD控制器的设计

文章介绍了一种基于CPLD的TFT-LCD控制器的设计和实现方法。增加片外SRAM,以提供显示缓存。并使用CPLD实现两大主要功能,一是产生TFT-LCD要求的时序信号,二是协调TFT-LCD和MCU对SRAM的读写访问。相对于常见的TFT-LCD控制器,该设计方法优势明显:结构简单,并且性价比高,驱动小尺寸TFT屏时具有较高应用价值。     

TFT-LCD面板缺陷检测方法综述

TFT-LCD面板缺陷边界模糊、与背景对比度低、检测速度慢等问题一直是该领域缺陷检测的难点。首先介绍TFT-LCD结构及缺陷的定义与分类,在分析缺陷的成因和特点基础上,对TFT-LCD面板缺陷检测方法进行综述。详细分析了TFT-LCD面板缺陷图像识别法中的图像降维技术、缺陷特征提取和缺陷分类器识别等关键技术和图像处理法中的边界模糊缺陷分割法、差影法和滤波法,归纳总结各类缺陷检测方法的特点及优势,并指出TFT-LCD面板缺陷检测未来的研究方向。     

美国国家半导体在小尺寸TFT-LCD市场发力

过去的几年中TFT-LCD技术在PC市场的成功给相关基础产品供应商以很大的激励,因而伴随着手机市场的兴起,他们正在积极考虑在小尺寸TFT-LCD领域攻城掠地.美国国家半导体在2003年推出FPD94128控制器/列驱动器芯片和FPD93140电源供应/门驱动器芯片之后,正式吹响了向小尺寸TFT-LCD半导体市场进军的号角."虽然我们刚刚进入这个领域,但我们不是生手,我们希望借助以前在大尺寸TFT-LCD市场上建立的经验在这个小尺寸领域获得好成绩."美国国家半导体亚太区TFT-LCD业务经理陈永信说.     

大尺寸TFT-LCD的LED背光技术

传统的薄膜晶体管液晶显示器(thin film transister crystal display,TFT-LCD)通常采用冷阴极荧光灯(cold cathode fluorescent lamps,CCFL)作为背光光源。相比较而言,由于发光二极管(LED)TFT-LCD背光源系统具有色彩还原性好、对比度高、亮度高等优点,近年来应用于大尺寸TFT-LCD的LED背光技术取得了长足的进步。当前应用于大尺寸TFT-LCD的LED背光源主要有两种:RGBLED背光源和白光LED背光源。大尺寸的LED背光系统结构主要采用直下式和侧式结构。本文将对这几方面进行系统阐述,并对大尺寸TFT-LCD的LED背光系统的应用前景进行预测。     

400 dpi integrated contact type linear image sensors with poly-SiTFT's analog readout circuits and dynamic shift registers

Four-hundred-dots-per-inch (dpi) sensors, including poly-Si thin-film-transistor (TFT) scanning circuits, and a-Si photodiodes fabricated on borosilicate glass have been developed. This contact-type image sensor contains TFT analog buffer amplifiers in the readout circuits. The scanning circuits can operate in a frequency range between 200 kHz and 1 MHz. The readout circuits incorporating TFT analog impedance converters decrease photodiode impedance by more than three orders of magnitude and improve the linearity between illumination intensity and the sensor output. High-resolution reading is achieved by the new contact-type linear image sensors with a storage time of 2 ms/line     

Application of focused ion beam techniques and transmission electron microscopy to thin-film transistor failure analysis

The locations of process-induced defects in hydrogenated amorphous silicon thin-film transistors (a-Si:H TFTs), which are used as elements of active-matrix liquid crystal displays, were investigated by combining focused ion beam techniques with cross-sectional transmission electron microscopy (X-TEM). The FIB technique is applied to TFT failure analysis problems, which require considerable localised etching without inducing mechanical stress or damage at fragile failure locations. We demonstrate the manner in which these techniques are used to characterise TFT defects such as pinholes and portions of the multilayer damaged by mechanical stress. A dramatic improvement brought about by the FIB technique is the increase in temporal efficiency of sample preparations. X-TEM observations also lead to identification of the fault and analysis of its cause, which in turn lead to a marked yield improvement.     

Carbon-Incorporated Amorphous Indium Zinc Oxide Thin-Film Transistors

We propose the use of amorphous-carbon indium zinc oxide (a-CIZO) as a channel material for thin-film transistor (TFT) fabrication. This study chose a carbon dopant as a carrier suppressor and strong oxygen binder in amorphous-indium zinc oxide (a-IZO) channel material. a-CIZO thin films were deposited using radiofrequency (RF) sputtering and postannealed at 150°C. X-ray diffraction and transmission electron microscopy analysis revealed that the film remained amorphous even after postannealing. The a-CIZO TFT postannealed at 150°C exhibited saturation field-effect mobility of 16.5 cm² V^?1 s^?1 and on–off current ratio of ～4.3 × 10⁷.     

On the conduction mechanism in polycrystalline silicon thin-film transistors

Physical and electrical analyses were carried out on n-channel polycrystalline silicon thin-film transistors (nTFTs) with active regions as thin as approximately 6 nm. Such thin active regions extinguish the dominating effects of anomalous leakage and allow the conduction energy barrier height to be analyzed as a function of gate voltage in the femtoampere source/drain current regime. Grain size statistics were determined using plan view transmission electron microscopy. It is shown for the first time that in the absence of anomalous leakage, the barrier height does not decrease with decreasing gate voltage. In addition, the maximum measured barrier height is almost independent of active region thickness and grain size statistics. The source/drain current at low lateral field and high vertical field is also independent of channel length for all devices with length varied over an order of magnitude. These important discrepancies with existing TFT conduction theory are discussed within a physics-based model that addresses the effects of disorder-induced localized electron states in the bandgap. Besides describing existing data and well-known TFT behavioral trends, the model predicts a previously unknown relationship between threshold voltage variation, average threshold voltage and the number of grains in the channel. Analysis of data gathered from hundreds of devices of different dimensions across three different grain size distributions not only leads to agreement with the model but also to a remarkable universal behavior linking electrical and physical properties. This study shows the physics of polycrystalline silicon TFT conduction to be of the same form as amorphous and single crystal devices with the degree of disorder as the sliding scale between the two extremes.     

A high-endurance low-temperature polysilicon thin-film transistorEEPROM cell

A planar type polysilicon thin-film transistor (poly-Si TFT) EEPROM cell with electron cyclotron resonance (ECR) N₂O-plasma oxide has been developed with a low temperature (⩽400°C) process. The poly-Si TFT EEPROM cell has an initial threshold voltage shift of 4 V for programming and erasing voltages of 11 V and -11 V, respectively. Furthermore, the poly-Si TFT EEPROM cell maintains the threshold voltage shift of 4 V after 100 000 program/erase cycles. The excellent high endurance of the fabricated poly-Si TFT EEPROM cell is attributed to the ECR N₂O-plasma oxide with good charge-to-breakdown (Qbd) characteristics     

TFT-LCD过孔接触电阻研究

研究了过孔接触电阻变化规律,并进行机理分析,为优化薄膜晶体管的过孔设计提供依据。首先,运用开尔文四线检测法对不同大小、形状、数量的钼/铝/钼结构的栅极和源/漏层金属与氧化铟锡连接过孔的接触电阻进行测试。然后,通过扫描电子显微镜、能量色散X射线光谱仪和聚焦离子束显微镜对过孔内部形貌进行表征。最后,对过孔接触电阻变化规律进行机理分析。实验结果表明:过孔面积越大,接触电阻越小;过孔面积相同时,长方形过孔的接触电阻小于正方形过孔的接触电阻,多小孔的接触电阻小于单大孔的接触电阻,栅极金属与氧化铟锡的过孔接触电阻小于源/漏层金属与氧化铟锡的过孔接触电阻。为了降低钼/铝/钼与氧化铟锡连接过孔的接触电阻,过孔面积尽可能最大化,采用长方形过孔优于正方形过孔,多小过孔优于单大孔设计,同时优化过孔刻蚀工艺,减少过孔内顶层钼的损失。     

Detection of glycoconjugates by lectin gold labelling, silver enhancement, and scanning electron microscopy

A method for detecting glycoconjugates on cell surfaces in scanning electron microscopy is described. Terminal saccharides were specifically recognized by a lectin conjugated to biotin, and, after incubation with an anti-biotin antibody conjugated to colloidal gold, silver enhancement was used to produce deposits large enough to be detected in standard scanning electron microscopes. Secondary electron images revealed the ultrastructure of the tissue investigated, while backscattered electron images showed the distribution of lectin binding sites. Using digital recording and processing, the two channels were combined in colour-encoded images. The new method brings together lectin histochemistry and scanning electron microscopy and thus allows the three-dimensional distribution of glycoconjugates to be analysed at an ultrastructural level.     

Investigation of Structural Defects in CdZnTe Detector-Grade Crystals

We investigated structural defects in CdZnTe detector-grade crystals grown under different conditions. Here, we report our findings from high-resolution electron microscopy [transmission electron microscopy (TEM) and scanning TEM (STEM)] and scanning electron microscopy integrated with energy-dispersive x-ray spectroscopy to characterize the material’s structural and chemical composition. Combining these techniques gave us important information about the defects, their concentration, and the elemental composition of the CdZnTe crystals. Our experimental observations demonstrated some distinct nanostructural defects in the crystals that may play a major role in device performance.     

Single-crystal silicon transistors in laser-crystallized thin films on bulk glass

High-performance thin-film transistors (TFT) have been fabricated in single-crystal silicon thin films on bulk fused silica. Deposited films of polycrystalline silicon were patterned to control nucleation and growth of single-crystal material in pre-selected areas and encapsulated with a dielectric layer (e.g., SiO2) in preparation for laser crystallization. Patterning also minimized microcracking during crystallization. The patterned silicon layer was crystallized with a scanning CO2laser, which produced islands with preferred crystal orientation. The single crystallinity of the islands was established with transmission electron microscopy after transistor evaluation. The silicon islands were processed with conventional microelectronic techniques to form metal-oxide-semiconductor-field-effect transistors operating in the n-channel enhancement mode. The devices display exceptional electrical characteristics with "low-field" channel mobilities > 1000 cm²/V sec and leakage currents < 10 pA, for a Channel length of 12 µm and width of 20 µm. Achievement of high-performance TFT's with the combined features of microcrack suppression, preferred orientation, and selected-area crystallization render CO2- laser processing of silicon films a viable and versatile basis for a silicon-on-insulator technology.     

Structural and optical characterisation of holey fibres usingscanning probe microscopy

An investigation of a holey fibre using scanning probe microscopy techniques, which the authors believe is the first such investigation, is presented. Atomic force microscopy images provide knowledge of the fibre structure without the artefacts associated with scanning electron microscopy imaging. A tapered fibre scanning near-field optical microscopy probe has been used to investigate holey fibre modes at 785 nm