电阻法测试超薄膜厚度的研究

常规方法测试超薄膜的厚度存在很大困难。介绍一种测试约4nm PtSi厚度的电阻率法。先制备厚度约40nm的薄膜,测试出薄膜电阻率,再考虑超薄膜的表面效应、尺寸效应,推导出超薄膜电阻率与薄膜电阻率的关系式,测试超薄膜方电阻,计算出超薄膜厚度。给出了TEM晶格像验证结果,误差小于6%。实验表明该方法简单易行,对其他超薄膜厚度的测试提供了参考。     

具有Pt扩散阻挡层的n-GaAs欧姆接触的可靠性

针对传统n-GaAs的Au/AuGe/Ni欧姆接触合金系统的缺点,提出了添加Pt扩散阻挡层的新型欧姆接触合金系统。扫描电子显微镜(SEM)和微束分析(EDS)测试显示,添加Pt扩散阻挡层的合金系统比没有Pt扩散阻挡层的合金系统的表面更加光滑,粗糙度降低。矩形传输模型(RTLM)测试显示,添加Pt阻挡层的比接触电阻率均匀性为85%,最低比接触电阻率为4.25×10-6Ω·cm2;而未添加Pt阻挡层的比接触电阻率均匀性为12%,最低比接触电阻率为3.86×10-6Ω·cm2,表明Pt扩散阻挡层的添加能够增加n-GaAs欧姆接触的重复性和均匀性,提高器件在使用过程中的热稳定性和可靠性。     

具有Pt扩散阻挡层的n-GaAs欧姆接触的可靠性北大核心CSCD

针对传统n-GaAs的Au/AuGe/Ni欧姆接触合金系统的缺点,提出了添加Pt扩散阻挡层的新型欧姆接触合金系统。扫描电子显微镜(SEM)和微束分析(EDS)测试显示,添加Pt扩散阻挡层的合金系统比没有Pt扩散阻挡层的合金系统的表面更加光滑,粗糙度降低。矩形传输模型(RTLM)测试显示,添加Pt阻挡层的比接触电阻率均匀性为85%,最低比接触电阻率为4.25×10-6Ω·cm2;而未添加Pt阻挡层的比接触电阻率均匀性为12%,最低比接触电阻率为3.86×10-6Ω·cm2,表明Pt扩散阻挡层的添加能够增加n-GaAs欧姆接触的重复性和均匀性,提高器件在使用过程中的热稳定性和可靠性。     

一种基于人工神经网络的反馈式神经元数优化方法

针对纳米级Cu薄膜电阻率,基于BP神经网络模型,本文提出了一种反馈式神经网络优化方法,利用蒙特卡洛分析方法对隐含层神经元数进行了优化,并基于随机样本集进行网络训练,建立了反馈式BP神经网络的电阻率预测模型。通过100组学习样本训练后的神经网络模型,与50组测试样本进行测试,结果表明,所提方法能够实现电学参数值与金属Cu电阻率较好的非线性映射,预测结果与Marom模型相比较,最大误差不超过4%,并且训练范围外的预测结果与测试样本吻合较好,验证了该方法的精度和泛化能力,为超薄金属互连电阻率模型估算提供了重要参考。     

半绝缘半导体切片电阻率无接触测定方法研究

与很多测试方法一样,电阻率是通过流过电接触样品的电流,测出其电压下降值来测定的.文中通过对无接触和接触两种主要测试方法的研究对比,探讨了用电容式探测器对半绝缘半导体切片电阻率的无接触测定,并论述了其测试原理、测试所用电容器、测试条件、测试过程及结果计算.     

平面型器件欧姆接触的衡量——圆形传输线模型外推法

本文提出一个衡量平面型器件欧姆接触的新方法——圆形传输线模型外推法.样品无需台面绝缘,只须一次合金化即能完成测试结构图形.用圆形传输线模型导出了测量接触电阻率ρ_c的表达式,以硅和砷化镓两种半导体材料进行验证,与线性传输线模型的结果一致.讨论了接触电极之下与接触电极之外薄层电阻差异的影响.     

晶圆级导通电阻测试精度的改进方法

针对晶圆级导通电阻测试误差过高,满足不了低压金属氧化物半导体场效应晶体管(MOSFET)毫欧级导通电阻的测试精度要求,给产品晶圆测试规范的制定及品质监控带来困扰的问题,提出了晶圆级导通电阻测试精度的改进方法。基于开尔文法电阻测试理论,具体分析了晶圆级导通电阻测试原理,且得出其测试精度不高的根本原因是减薄背金后粗糙不平的硅片背面与测试机的承片台的非充分接触而引入了毫欧级接触电阻。提出3种相应改进测试精度的方法,单相邻芯片辅助的测试方法、双相邻芯片辅助的测试方法和正面漏极测试窗的测试方法。经过验证,3种方法均能将毫欧级导通电阻测试误差控制到小于10%,实现低压MOSFET晶圆级导通电阻参数的有效监测。     

电阻率对电容法测Si片厚度的影响

在对电容法测量Si片厚度的原理分析基础上,根据电阻率与介质介电常数ε的对应关系,分析了用电容法测试Si片厚度时,电阻率及电阻率均匀性对测试结果的影响,并采用千分尺(有接触测试)、ADE6034及Wafer Check 7000(电容法测试)分别对不同电阻率及电阻率均匀性的样品进行测试比对。实验结果证明,电容法可以测量高电阻率Si片的厚度等几何参数,但不能测量电阻率均匀率较差的Si片。同时,校正电容法测量设备时,以校正样片电阻率与被测Si片电阻率范围接近为原则。     

哑铃型DGS的快速分析和综合方法

基于对偶电路定理和等效电路模型,提出了哑铃型缺陷地面结构（DGS）的快速综合和分析方法,给出了详细的综合和分析步骤。综合设计和分析了谐振于5GHz的哑铃型DGS,综合的结构参数误差小于5%,频偏误差只有2.8%。理论和测试结果显示了该方法的有效性,可被广泛应用于DGS的设计当中。     

微型薄膜电阻的制备及研究

将具有优异特性的碳纳米管（CNTS）与负性感光胶（SU-8 2002）混合得到复合材料,将不同比例的碳纳米管通过超声工艺分散到SU-8 2002感光胶中,通过UV-LIGA加工工艺,热压处理后实现了微型电阻的快速制备。对复合薄膜电阻的性能进行测试,测试结果表明复合薄膜电阻率随着碳纳米管比例的增加而减小,当碳纳米管的比例为12%时,电阻率减小到0.06 ,复合材料达到逾渗阈值,频率小于1.2GHz时,电阻值的变化范围小于5%,为快速制备微型电阻提供了新的方法。     

New method of resistance measurement

A new method of resistance measurement is reported. A transistor-resistor negative-resistance device has been used for resistance measurements in the range 103?107 ?, with an accuracy within ± 1%. The performance of this new method is compared the with conventional 4-point voltmeter-ammeter method.     

TiSi2的形成及其在浅结多晶硅发射极工艺中的应用

采用蒸发淀积、快速热退火等技术，通过Ｔｉ／Ｓｉ，Ｔｉ多晶硅固相反应，形成高电导均匀的ＴｉＳｉ２薄膜，并将这种钛硅化物形成技术应用于浅结多晶硅发射极工艺中，自对准形成钛硅化物薄膜，以形成良好的欧姆接触减小器件互连线电阻。本文介绍了钛与单晶硅、多晶硅形成的硅化物及其在浅结多晶硅发射极工艺中的应用研究。     

Evaluation of Transmission Line Model Structures for Silicide-to-Silicon Specific Contact Resistance Extraction

In order to measure silicide-to-silicon specific contact resistance rho_c, transmission line model (TLM) structures were proposed as attractive candidates for embedding in CMOS processes. We optimized TLM structures for nickel silicide and platinum silicide and evaluated them for various doping levels of n- and p-type Si. The measurement limitations and accuracy of the specific contact resistance extraction from the optimized TLM structures are discussed in this paper.     

Error analysis leading to design criteria for transmission linemodel characterization of ohmic contacts

The transmission line model (TLM) is a standard method for planar specific contact resistance measurement. Although widely used, the accuracy of a measurement is typically not stated. In addition to contributions from random errors, there can be substantial contributions from systematic errors in typical TLM measurements. In this paper, we develop an analytical model for the experimental uncertainty from the fundamental TLM expressions in order to understand and calculate the uncertainty associated with the specific contact resistance and sheet resistance derived by the TLM method. The experimental uncertainties in measured resistances, together with the pad width and pad spacing, are the dominant contributions to the total uncertainty. Analytical expressions for relative random and systematic uncertainties in contact resistance and sheet resistance are developed in terms of the error contributions and the parameters of the TLM geometry. Expressions for minimum uncertainty, with associated optimum widths and sheet resistances, serve as a basis for the design of TLM structures with minimum uncertainty. The model quantifies the increase in relative uncertainty associated with decreasing contact resistance. Simulations of uncertainty under various sheet resistance, contact resistance, and pad width are implemented and uncertainties are calculated for realistic data sets     

手眼相机位姿测量精度理论分析及验证

从理论和实验上对手眼相机位姿测量精度进行了研究。首先,根据靶标设计形式和P3P 算法介绍位姿测量原理。接着,从理论上分析了位置测量精度和姿态测量精度,即靶标沿X 轴平移位置测量精度和靶标绕X 轴、Y 轴、Z 轴旋转测量精度。然后,对通常的检测方法进行分析,提出了以产生相对位姿实现六维自由度变化的检测方法,提出用中误差对测量精度进行评价,并具体介绍了检测方法。最后,对手眼相机测量精度进行了实际检测,将实验数据与理论数据进行了对比分析。实验结果表明:距离测量精度最大为25.60 mm,旋转测量精度最大为1.4毅,均满足测量精度的要求。     

A Nondestructive Method of Extracting the Width and Thickness of Interconnects for a 40-nm Technology

In this paper, a simple and nondestructive method of modeling 40-nm interconnects is proposed. Traditional methods based on charge-based capacitance measurement model the interconnects by fitting the capacitance or resistance curves, first by assuming one constant process parameter, such as metal thickness, and then by extracting the metal width, metal spacing, and interlevel dielectric (ILD) thickness from certain test patterns that may therefore result in model inaccuracy while the transmission and scanning electron microscopy methods are both destructive and time consuming. The proposed new methodology directly extracts the metal width based on the metal resistance test structures, and then the metal thickness, metal spacing, and ILD thickness without any presumption. It is also nondestructive and fast, with a model accuracy higher than 95%. Furthermore, with the ensured accuracy of layout parameter extraction, the necessity of an accurate interconnect model in the 40 nm technology and beyond is emphasized.      

A new method to determine MOSFET channel length

A new method is proposed to electrically determine MOS transistor channel length with both accuracy and convenience. Based on the linear region relationship between effective channel length Leffand channel resistance Rchanof an MOS transistor, this method determines Leffby applying relatively large but constant gate voltage to eliminate threshold voltage determination and takes into account external resistance. Comparison of this method with SEM measurement shows very good agreement (within ±0.1 µm resolution limit of our SEM technique).     

Precise extraction of emitter resistance from an improved floatingcollector measurement

A distributed transistor model is developed which comprehensively explains the non-linear characteristics of floating collector measurements. The non-linearity is attributed to the fact that the intrinsic collector current is not zero when the collector terminal is opened. Based on this understanding, a new procedure to extract emitter resistance is proposed. Combining the measurements of forward and reverse current gains and intrinsic base sheet resistance, the ambiguity in the conventional floating collector measurement is diminished and hence the accuracy is significantly improved     

Accurate noise measurements on transistors

This paper is concerned with a method of noise measurement which permits improved accuracy by circumventing some of the problems of the usual comparison techniques. Results are presented of measurements of Ieqand Rnshowing good agreement between theory and experiment. It is suggested that noise measurements may be a very satisfactory method of determining the effective base resistance for inhomogeneous structures. The theoretical representation of the noise sources, including the effect of generation-recombination in the emitter-base region, is summarized in the appendix.