多晶硅TFT模型的研究进展

全面介绍了多晶硅薄膜晶体管(TFT)紧凑模型的现状和应用前景,简单说明了多晶硅TFT特有的电学特性,这是多晶硅TFT建模的基础,重点介绍了基于阈值电压和基于表面势的多晶硅TFT紧凑模型的研究进展,并对这些模型进行了评述,其中RPI模型是基于阈值电压的TFT模型的典范.虽然TFT模型已经有所发展,但成熟度还远远不够.最后提出了改进多晶硅TFT模型的方向和策略,包括二维器件模拟的应用、基于表面势模型的发展、多晶硅材料特性的应用、统一模型的发展、短沟效应的建模和参数提取等.     

Polysilicon TFT technology for active matrix OLED displays

The integration of active matrix polysilicon TFT technology with organic light emitting diode (OLED) displays has been investigated with the goal of producing displays of uniform brightness. This work identifies and addresses several process integration issues unique to this type of display which are important in achieving bright and uniform displays. Rapid thermal processing has been incorporated to achieve uniform polysilicon microstructure, along with silicides to reduce parasitic source and drain series resistance. Using these processes, TFT drain current nonuniformity has been reduced below 5% for 90% of the devices. This work also introduces transition metals to produce low resistance contacts to ITO and to eliminate hillock formation in the aluminum metallization. These processes, along with spin on glasses for planarization, have been used to produce functional active matrix arrays for OLED displays. The final array pixel performance is also presented     

Polysilicon TFT circuit design and performance

Both n- and p-channel polysilicon TFTs can be fabricated, allowing CMOS circuit techniques to be used. However, TFT characteristics are poor in comparison to conventional single-crystal MOSFETs, and relatively coarse design rules must be used to be compatible with processing on large-area glass plates. The authors examine these issues and describe the performance of a range of digital and analog circuit elements built using polysilicon TFTs. Digital circuit speeds in excess of 20 MHz are reported, along with operational amplifiers with over 80 dB of gain and more than 1-MHz unity-gain frequency. Several polysilicon TFT switched-capacitor circuits are also reported and shown to have adequate linearity, output swing, and settling time to form integrated data line drivers on an active-matrix liquid crystal display     

多晶硅薄膜晶体管kink效应的建模

从kink效应产生的物理机理出发,介绍了目前国内外研究多晶硅薄膜晶体管kink电流所采用的两种主要方法.一种是基于面电荷的方法,另一种是基于求雪崩倍增因子的方法.kink效应具体表现为器件在饱和区跨导和漏电流的显著增加.在数字电路中,kink效应会引起功耗的增加和开关特性的退化;而在模拟电路中,kink效应将降低最大增益和共模抑制比.因此,多晶硅薄膜晶体管kink效应的研究对液晶显示的发展具有重大意义.     

多晶硅TFT有源层晶粒间界的研究

由于多晶硅薄膜晶粒间界存在大量的悬挂键与缺陷，形成带隙能态，从而导致在有源层中形成载流子陷阱和杂质分凝，本文从微观方面解释悬挂键形成带隙能态的原因极其影响，并给出降低带隙密度的方法-氢化。     

A high-voltage polysilicon TFT with multigate structures

An approach is proposed for obtaining a high-voltage thin-film transistor (TFT) with multigate structure where polysilicon TFTs are connected in series. A basic principle for high-voltage operation has been investigated in detail through calculations based on a model describing log I_DS-V_GS characteristics observed in a single-gate polysilicon TFT. It has been found that off-state (V_GS<0) operation of the polysilicon TFT causes a large increase of breakdown voltage of the multigate TFT with the result that a nearly equal fraction of drain voltage is applied across the region around each elemental TFT. The breakdown voltage of drain of the fabricated multigate TFT which has five elemental TFTs has been elevated up to 80 V     

Surface-wave suppression of resonance-type periodic structures

Periodic structures of the resonance type are investigated with a focus on the utilization of structure dispersion to achieve a wide-band operation for the surface-wave suppression. Both approximate and exact formulations are presented to illustrate wave processes involved in the resonant structure and to develop useful criteria for design purpose. In addition, experiments are performed to verify the phenomena with stopband and leakage associated with the resonance-type periodic structures.     

A Simple Model of DIGBL Effect for Polysilicon Films and Polysilicon Thin-Film Transistors

Based on charge conservation assumption, analytical models of the drain-induced grain barrier lowering effect are developed for polysilicon films by 1-D Poisson's equation and for polysilicon thin-film transistors (poly-Si TFTs) by quasi-2-D Poisson's equation. It is shown that the voltage drop at the lower barrier side is less than that at the higher barrier side for both poly-Si films and poly-Si TFTs when applying a lateral bias across the grain-boundary barrier.     

IGZO TFT与ZnO TFT的性能比较

分析比较了ZnO TFT与IGZO TFT的主要光电学特性以及阈值电压稳定性。结果表明:ZnO薄膜与IGZO薄膜在可见光波长范围内都有着较高的光学透过率;在同等制备条件下,IGZO TFT器件的场效应迁移率、开关电流比、阈值电压及亚阈值系数等方面的特性均明显好于ZnO TFT;二者都有着较低的泄漏电流,并且差别很小。另外,ZnO TFT在正负偏压下阈值电压都有漂移,而IGZO TFT在正偏压下阈值电压漂移比ZnO TFT的小且在负偏压下阈值电压没有漂移,由此可见IGZO TFT比ZnO TFT有着更好的稳定性。总之,IGZO薄膜比ZnO薄膜更适合作为下一代TFT的有源层材料。     

TFT LCD的过压驱动技术探讨

过压驱动技术是提高液晶显示器响应速度的关键技术之一。文章分析了TN型TFT液晶显示的原理及影响响应时间的因素,探讨了过压驱动的原理和系统结构,对灰阶亮度上升和下降两种状态下的应用进行了说明。对液晶显示系统进行了实验分析以及响应时间的测量,结果表明通过过压驱动可以在很大程度上提高液晶显示器的响应时间,有效改善显示画面的动态模糊问题。在0℃的环境温度下,最大灰阶响应时间不超过80ms。     

Amorphous-silicon TFT array for LCD addressing

A 64×64 element matrix array of amorphous-silicon thin-film transistors has been fabricated on a glass substrate. Using a drive scheme to simulate a 500-line display, an output voltage of 8.5 V RMS is obtained. This large output voltage is sufficient for an alphanumeric liquid-crystal display using the dyed cholesteric-nematic phase-change effect. The driving voltages for the array are compatible with LOCMOS (18 V) peripheral circuitry.     

New model for submicron-scale dual-gate TFT

A new model is proposed to represent the submicron-scale dual-gate thin-film transistor (DGTFT) as the association of three single-gate TFTs. The finite-difference method is applied to verify the conditions for which the model is valid, and using a new variant of this technique the quasistatic solution is obtained in an inhomogeneous medium.     

多晶硅热执行器阵列的宏模型

建立了多晶硅热执行器阵列的宏模型 .利用热传导原理分析了执行器的电热特性 ,根据结构力学原理给出了执行器阵列的偏转及驱动力 .用多晶硅表面微机械加工技术制备了阵列并进行了测试 .执行器偏转的测量与实验吻合较好 .该宏模型可以用于分析、优化和设计热执行器阵列 .     

多晶硅热执行器阵列的宏模型

建立了多晶硅热执行器阵列的宏模型.利用热传导原理分析了执行器的电热特性,根据结构力学原理给出了执行器阵列的偏转及驱动力.用多晶硅表面微机械加工技术制备了阵列并进行了测试.执行器偏转的测量与实验吻合较好.该宏模型可以用于分析、优化和设计热执行器阵列.     

Miniaturised electromagnetic bandgap structures for broadband switching noise suppression in PCBs

A novel concept for ultra-wideband suppression of switching noise in high-speed printed circuit boards (PCBs) is proposed, implemented and tested. This concept consists of using non-symmetrical, embedded electromagnetic bandgap (EEBG) structures in conjunction with material with high dielectric constants. The proposed design modifies the classical EEBG structures to achieve a high degree of miniaturisation and an unprecedented broadband suppression of switching noise.     

非晶硅TFT AMOLEDs

如果说非晶硅不是制作有机发光二极管显示器有源矩阵背板的理想材料，为什么会有这么多人正试图使用它呢?     

移动产品的TFT驱动器设计

根据DisplaySearch公司调查数据,2004年全球手机和PDA模组的需求量预计将达到6．69亿。其中TFT模组在手机和PDA市场的比重将从2003年的18％增加到2004年的28%。     

TFT LCD—未来主流显示技术

有资料表明,未来10年不可能有在性能上优于TFT-LCD的显示器问世,TFT-LCD产品将会越来越成熟。所谓平板显示器时代,实际上就是液晶平板显示时代。我国也将在最近10年内成为世界上重要的液晶平板显示基地之一。     

多晶硅微悬臂梁断裂的可靠性预测模型

分析了多晶硅微悬臂梁断裂失效机理,利用威布尔分布理论建立了多晶硅微悬臂梁在轴向拉抻和垂直两种受力方式下的断裂可靠性预测模型,模型考虑了由于实际加工工艺所带来的残余应力因素,模型所得的预测曲线与实验数据比较吻合。