氧化物半导体薄膜晶体管的研究进展

简要说明了非晶硅、多晶硅和有机半导体用作薄膜晶体管沟道层的不足,从电学性质、光学性质和制备温度等几方面介绍了氧化物薄膜晶体管在有源阵列驱动显示技术中的优势,并介绍了氧化物沟道层制备工艺的优化和掺杂方法.最后,展望了氧化物半导体薄膜晶体管应用前景.     

受激光辐照而局部晶化的新型多晶硅TFT

提出一种新型多晶硅ＴＦＴ结构，它在沟道中设置了高阻的非晶硅区，从而有效地减小了漏电流。这种新器件的有源层被局部晶化，而沟道区中与源极相邻的两个边界层未被晶化，保持非晶硅态。     

a-Si TFT OLED有源驱动阵列参数的优化与布图设计

主要介绍了用于有源驱动有机发光二极管显示屏的非晶硅薄膜晶体管阵列中各种电子器件参数的设计依据，通过理论计算，确定了单元像素中的各种器件参数；利用Aim-spice进行模拟仿真，对器件的参数进行了优化；利用L-Edit进行布图设计，完成了阵列像素的版图。该设计对小尺寸非晶硅有源驱动OLED的研究开发有一定的意义。     

不同沟道宽长比有机薄膜晶体管性能的研究

以酞菁铜为有源层,二氧化硅为绝缘层,钛/金作为电极,制作了三种不同沟道宽长比的有机薄膜晶体管器件。通过对这三种器件的电学特性进行对比,分析了不同沟道宽长比对器件电学性能的影响。结果表明,沟道宽长比对器件的迁移率影响很小,阈值电压随着宽长比的增大而减小,漏电流随沟道宽长比的增大而增大;当源漏极间电压在一定范围内时,开态电流也随沟道宽长比的增大而增大。     

双层有源层非晶铟镓锌氧化物薄膜晶体管的仿真

采用SILVACO软件的ATLAS对双有源层非晶铟镓锌氧化物薄膜晶体管进行二维器件模拟,研究了在底栅顶接触的结构下,不同沟道厚度比的情况下的器件的电学特性。在IZO材料的厚度为5nm、IGZO材料的厚度为35nm时,器件的最佳开关电流比约为3.5×1013,亚阈值摆幅为0.36V/dec。并在此厚度比的基础上,模拟了两层材料的隙态密度,并通过改变态密度模型中的相关参数,观察两层材料对器件的电学特性的影响情况。     

薄膜晶体管研究进展

薄膜晶体管是液晶显示器的关键器件，对显示器件的工作性能具有十分重要的作用。本文论述了薄膜晶体管的发展历史，描述了薄膜晶体管的工作原理，分析了非晶硅薄膜晶体管、多晶硅薄膜晶体管、有机薄膜晶体管、ZnO活性层薄膜晶体管的性能结构特点与最新进展，并展望了薄膜晶体管的应用。     

非晶硅薄膜晶体管基于表面势的栅电容模型

基于Lambert W函数,推导出非晶硅薄膜晶体管表面势的解析解,并将其与泊松方程的数值解进行对比.结果显示:该求解大大提高了计算效率,且精确度极高.基于有效温度近似,并利用所求解到的表面势,建立器件的栅电容模型.该模型可连续、准确地描述a-Si:H TFT在所有工作区的动态特性.最后,将模型结果与实验数据进行了对比,两者拟合良好.     

An Analytical Threshold Voltage Model for Fully Depleted SOI MOSFETs

提出了一种新的全耗尽SOI MOSFETs阈值电压二维解析模型.通过求解二维泊松方程得到器件有源层的二维电势分布函数,氧化层-硅界面处的电势最小值用于监测SOI MOSFETs的阈值电压.通过对不同栅长、栅氧厚度、硅膜厚度和沟道掺杂浓度的SOI MOSFETs的MEDICI模拟结果的比较,验证了该模型,并取得了很好的一致性.     

顶栅共面结构非晶氧化物薄膜晶体管的低成本制备及性能研究

将溶液法制备的不含镓的非晶InAlZnO薄膜和有机聚甲基丙烯酸甲酯薄膜分别作为沟道层和介质层,制备了顶栅共面结构的非晶氧化物薄膜晶体管(TFT)器件,探讨了沟道层中Al含量对器件性能的影响。结果表明：Al对InZnO薄膜中氧空位的形成能起到一定抑制作用,增加Al含量即可降低沟道层中的电子载流子浓度,使得InAlZnO TFT器件阈值电压正向移动、关态电流减小,以有利于器件开关比的提升。此外,基于沟道层中Al含量的调整可通过优化沟道层/介质层界面状态来促进器件阈值电压滞回稳定性的提升。当沟道层中Al含量为30%时,制备的器件具有最佳综合性能。     

用于室温红外探测的新型非晶硅薄膜晶体管

研究了用于室温红外探测的非晶硅薄膜晶体管。分别从理论和实验角度对非晶硅薄膜晶体管的沟道电流随着宽长比的线性变化进行了分析验证。理论分析和实验结果表明,增大晶体管的宽长比不会影响沟道电流温度系数,但可以显著改善探测器的探测率,从而为a2SiTFT红外探测器的优化设计指明了方向。     

Quantitative measurement of channel temperature of GaAs devices for reliable life-time prediction

The channel temperature of Gallium Arsenide (GaAs) devices was quantitatively measured using scanning thermal microscopy (SThM), which is a variation of atomic force microscopy (AFM). The temperature of the devices was also characterized by infrared (IR) imaging and thermal modeling. The measured SThM temperature values were close to the calculated values from the model, and were higher than those found by IR, as predicted. In contrast to most published AFM results which have reported only qualitative and indirect semi-quantitative thermal information about the sample, the results presented here can be used directly to determine accurately the device-temperature. These results are useful to the reliability community in that they help to predict a more accurate semiconductor device lifetime. By careful calibration of an AFM thermistor probe tip, a quantitative temperature measurement of the channel temperature of the GaAs PHEMTs and MESFETs can be made. The result of the measurement can be substantiated by applying a suitable thermal calculation, such as the Cooke model. A secondary measurement technique, such as IR microscopy, can also be useful in providing further information about the thermal response of the device. Published results using AFM techniques have been unable to determine the channel temperature quantitatively. The method in this paper applies to other types of electronic devices for which the channel (or junction) temperature can be probed from the top surface of the device.     

强激光与靶材相互作用的力学效应研究

根据模拟激光源加热金属材料的实验情况,考虑材料的物性参数随温度的变化,通过求解热传导方程得到各种情况下材料的温度时空分布,并利用热弹性本构方程,应变－位移关系以及应力平衡关系,建立了激光辐照金属材料时的轴对称热应力的计算模型,通过数值是到在不同激光强度辐照时靶材内不同时刻的温升分布和热应力分布,并对造成金属材料热应力损伤的激光阈值强度进行了讨论。     

Physical origin of negative differential resistance in SOI transistors

From a two-dimensional solution of Laplace's equation it is shown that a significant increase in temperature occurs in the channel of SOI transistors due to the relatively poor thermal conductivity of the buried insulator. Based on this simulation an equation is derived which predicts that at small channel lengths the pinchoff point is shifted, an effect which is consistent with experimental observations. In addition, the positive 'kink' is reduced with the negative differential resistance, can be explained by a temperature increase in the channel.<>     

一个解析的适用于短沟SOIMOSFET's的高频噪声模型

提出了一个新的解析的适用于SOI MOSFET's的高频噪声模型.该模型通过耦合能量平衡方程克服了以往噪声模型所具有的缺点,并对短沟SOI器件的噪声给出精确地描述.同时,利用该模型可以容易地计算出相对于最小噪声值处的优化的栅源电压,为低噪声的电路设计提供优化的设计方向.由于该噪声模型的简单性,可以很方便地将模型植入电路模拟器如SPICE中完成电路设计.     

Numerical analysis of the self-heating effect in SGOI with a double step buried oxide

To reduce the self-heating effect of strained Si grown on relaxed SiGe-on-insulator(SGOI) n-type metal-oxide-semiconductor field-effect transistors(nMOSFETs),this paper proposes a novel device called double step buried oxide(BOX) SGOI,investigates its electrical and thermal characteristics,and analyzes the effect of self-heating on its electrical parameters.During the simulation of the device,a low field mobility model for strained Si MOSFETs is established and reduced thermal conductivity resulting from phonon boundary scattering is considered.A comparative study of SGOI nMOSFETs with different BOX thicknesses under channel and different channel strains has been performed.By reducing moderately the BOX thickness under the channel,the channel temperature caused by the self-heating effect can be effectively reduced.Moreover,mobility degradation,off state current and a short-channel effect such as drain induced barrier lowering can be well suppressed.Therefore,SGOI MOSFETs with a thinner BOX under the channel can improve the overall performance and long-term reliability efficiently.     

脉冲工作状态下微波功率管瞬态特性研究

鉴于越来越多的领域要求微波功率管工作于脉冲应用状态,研究管子的瞬态温度特性就显得日益重要。假设热源为一无限大平面,且在芯片表面热源产生的热量只沿垂直于芯片表面一维地传递。从这一简化的理想热传导模型出发,对热传导方程离散化;在热沉端,定义了能够与实际情况相吻合的温度上升与下降时间常数来确定边界条件,从而得到了在脉冲应用情况下,芯片表面瞬态温度随时间变化的计算机模拟结果。通过在连续波工作下与红外显微镜实测温度的比较,验证了模拟程序的准确性,并且给出了最高结温随时间、脉宽、占空比的拟合公式。为微波脉冲功率晶体管的设计提供了育价值的参考。     

High-frequency small signal AC and noise modeling of MOSFETs for RFIC design

High-frequency (HF) AC and noise modeling of MOSFETs for radio frequency (RF) integrated circuit (IC) design is discussed. A subcircuit RF model incorporating the HF effects of parasitics is presented. This model is compared with the measured data for both y parameter and f_T characteristics. Good model accuracy is achieved against measurements for a 0.25 μm RF CMOS technology. The HF noise predictivity of the model is also examined with measured data. Furthermore, a methodology to extract the channel thermal noise of MOSFETs from HF noise measurements is presented. By using the extracted channel thermal noise, any thermal noise models can be verified directly. Several noise models including the RF model discussed in this paper have been examined, and the results show that the RF model can predict the channel thermal noise better than the other models     

空间热辐射对激光输能光电池特性影响研究

从激光辐照功率密度、光电池温度和光电转换效率的相互关系出发,基于热辐射平衡原理,建立了空间热辐射环境下光电池热辐射稳态平衡模型,根据该模型可以分析激光辐照功率密度、光电转换效率和光电池温度的相互影响。对已有的光电转换效率模型做温度上的修正,得到温度修正后的转换效率模型,将上述两个模型结合,即得到空间热辐射环境下激光辐照功率密度、光电池温度和转换效率的关系。通过MATLAB软件对模型进行仿真,仿真结果表明,随着激光辐照功率密度增加,光电池温度不断上升,光电转换效率和输出功率密度先上升后下降,但最大光电转换效率对应的激光辐照功率密度远小于最大输出功率密度对应的激光辐照功率密度,且日照区光电池温度高于地影区,日照区转换效率低于地影区。     

Compact LDD nMOSFET degradation model

In this paper, we present a compact degraded I-V model for submicron lightly-doped drain (LDD) MOSFET's. The analytical and physics-based model was developed using the drift equation and considering the nonuniform spatial hot-carrier-induced interface states and the detailed LDD structure. It can be used to calculate fresh channel electric field and drain current by turning off the effect of hot-carrier-induced interface states. Using the fresh electric field in conjunction with a simplified energy balance equation, the nonuniform spatial distribution of induced interface states ran be calculated. By incorporating this distribution into the degraded current model, we can describe the damaged I-V characteristics and channel electric fields as a function of stress time. The model includes the effects of series resistances and carrier velocity saturation. It can be used to calculate time-dependent degraded drain current, and is a time-saving CAD model     

激光侧泵晶体温度分布的非均匀发热模型计算

使用类高斯的非均匀发热模型，对LD侧面泵浦棒状固体激光介质的温度分布问题进行了计算，推导并最终得到了侧面泵浦情况下棒状激光晶体内温度分布的近似解析表达式。与以往的报道相比，所使用的类高斯发热模型比均匀发热模型更符合激光器的实际工作情况，使用该模型计算温度分布将得到更为精确的结果。