基于空间频域算法的三维微观形貌的测量

白光干涉术测量表面形貌,解决了单色光干涉测量中的相位不确定困扰。基于扫描白光干涉术的空间频域算法,具有受噪声影响小、计算精度高的优点。运用这一算法通过Mirau扫描干涉显微镜对台阶状样品表面进行了两次白光扫描测试,得出了台阶表面形貌结果,且两次测量的台阶高度相差不超过1 nm。同时,利用Zygo Newview 7200白光形貌仪对同一样品表面进行了测试对比,结果表明:两者得到的样品表面形貌一致,台阶高度相差0.9 nm。此外,实验数据处理的结果还表明:运用空间频域算法进行分析时二阶以上的色散完全可以忽略。     

利用计量型原子力显微镜进行纳米台阶高度测量

计量型原子力显微镜纳米测量系统主要由扫描器、测针位置传感器和一体化微型激光干涉三维测量系统等部分构成．针对计量型原子力显微测量系统,采用三维激光干涉测量系统作为测量基准,以实现原子力测量系统的纳米尺度量值溯源和校准工作．建立了校准模型,分析了扫描器9项主要误差项,并将该模型应用到原子力显微镜扫描器的校准中．校准后的结果表明,除z轴位置误差不超过±2nm外,其他8项的残余误差均不超过±1nm．通过台阶高度国际比对,建立了台阶高度标准计算方法及不确定度分析模型．台阶高度国际比对的测量结果表明,计量型原子力显微镜的测量值与参考值相差均小于1．5nm．     

基于白光干涉测量技术的微器件三维形貌重构

垂直扫描法可以重构微系统中微纳结构的表面形貌, 更适合具有台阶结构的微纳结构, 其分辨率高、解算速度快、精度较高. 本文利用基于白光干涉技术的垂直扫描法, 对微器件的台阶形貌在微系统测试仪下所得的干涉图进行分析, 并重构台阶结构的表面形貌, 微系统测试仪所取的干涉图符合垂直扫描法的要求, 即光强峰值附近没有达到饱和, 得出了清晰的三维形貌图, 解算出的台阶高度和实际台阶高度一致, 其横向分辨率为 1.6 μm, 纵向分辨率为 0.05 μm.     

基于白光干涉仪台阶高度测量的不确定度分析

介绍了一种基于白光干涉仪测量台阶高度的方法。首先,介绍了白光干涉的原理;其次,对台阶高度的定义及其表征方法进行了论述,依据该方法,使用白光干涉仪对VLSI的型号为SHS-9400QC的样块进行测量;最后,对影响测量结果的分量进行分析,给出了不确定度评定方法。     

一种可溯源原子力探针显微镜

研制了一种基于白光干涉的可溯源原子力探针扫描显微镜,提出了一种稳健的白光干涉零级条纹定位算法,建立了一套高分辨激光干涉位移测量系统。在此基础上提出了一种探针标定方法,实现微纳表面可溯源测量。通过对台阶高度为(21.4±1.5)nm的标准光栅进行10次重复测量,其结果的平均值为21.56 nm,标准差为0.51 nm;同时对高度为150 nm的三维特征样件进行了三维测量,验证了所研制仪器测量的准确性和稳定性。     

基于干涉显微原理的表面形貌测量系统

根据光学干涉显微法原理,设计开发了一套微纳结构表面形貌测量系统.该系统采用林尼克干涉显微镜,通过参考镜扫描的方法将扫描器与相移器集为一体,分别采用五步相移算法和基于采样定理的包络均方函数(SEST)算法实现相移干涉法(PSI)和垂直扫描干涉法(VSI)两种模式对微纳结构的表面形貌测量.为验证该系统性能,采用标准多刻线样板和标准台阶作为样件对VSI 和PSI 两种模式分别进行了测量实验.结果证明,该系统能够完成微纳结构表面形貌的快速精确测量,可以满足微电子、微机电系统中微纳结构的表面形貌测量要求.     

白光相移干涉中频谱对测量精度的影响

在相移干涉中有时采用白光干涉来扩大深度测量范围,白光光源的使用,缩短了光束的相干长度,降低了测量精度。本文从干涉理论出发推导了白光相移干涉法测量三维表面形貌的计算公式,通过数值积分的方法分析了干涉光频谱对测量精度的影响。分析表明,在白光相移干涉测量中表面形貌的测量精度与中心波长和频谱宽度有关,白光频谱越宽,测量精度越低,中心波长越大,测量精度越高。     

利用白光扫描干涉测量表面微观形貌

由于激光显微干涉只能测量表面微观形貌的相对高度值,不能进行绝对测量,本文提出了白光显微干涉测量方法,研制了测量仪器,并对CCD像素格值和PZT进行了标定.该仪器以白光干涉理论为基础,利用空间频域算法计算白光干涉图零级条纹中心位置,根据零级条纹中心移动量来得到被测工件表面微观形貌.对被测工件表面进行了测试,试验结果表明:...     

用于纳米级表面形貌测量的光学显微测头

为了满足纳米级表面形貌样板的高精度非接触测量需求,研制了一种高分辨力光学显微测头。以激光全息单元为光源和信号拾取器件,利用差动光斑尺寸变化探测原理,建立了微位移测量系统,结合光学显微成像系统,形成了高分辨力光学显微测头。将该测头应用于纳米三维测量机,对台阶高度样板和一维线间隔样板进行了测量实验。结果表明：该光学显微测头结合纳米三维测量机可实现纳米级表面形貌样板的可溯源测量,具有扫描速度快、测量分辨力高、结构紧凑和非接触测量等优点,对解决纳米级表面形貌测量难题具有重要实用价值。     

智能测量系统中测量结果的自动计量支持

系统地探讨了智能测量系统中计量保证的一些紧迫问题，即表述（选择、评估、检定和报告）计量特性；最终测量结果不确定度的自动在线评定（称为测量结果的自动计量支持MAS）；自动计量支持手段的校准测试以及集成测量软件环境的具体实现方法。也提出了智能测量系统的实际定义，并给出其通用功能模块结构。     

2 m激光干涉测长基准装置

阐述了2 m激光干涉测长基准装置工作原理及系统组成,以线间距测量功能为基础,研究了接触式和非接触式的几何测长对准方法,实现了其测长功能拓展应用。介绍了实现纳米精度测长的技术措施。对称布局的双光电显微镜同步扫描测量接长的方式实现2 m刻线间距测量,信号处理系统具有标准间距位置脉冲发生功能,可以实现位移传感器动态触发校准和其它应用。对于高质量的线纹尺,2 m激光干涉测长基准装置单次测量刻线间距的最佳瞄准精度优于10 nm(1σ),1 m测量范围内的线纹测量不确定度U=（20+40 L） nm （k=2）。     

MEMS Young’s Modulus and Step Height Measurements With Round Robin Results

This paper presents the results of a microelectromechanical systems (MEMS) Young’s modulus and step height round robin experiment, completed in April 2009, which compares Young’s modulus and step height measurement results at a number of laboratories. The purpose of the round robin was to provide data for the precision and bias statements of two \ related Semiconductor Equipment and Materials International (SEMI) standard test methods for MEMS. The technical basis for the test methods on Young’s modulus and step height measurements are also provided in this paper.Using the same test method, the goal of the round robin was to assess the repeatability of measurements at one laboratory, by the same operator, with the same equipment, in the shortest practical period of time as well as the reproducibility of measurements with independent data sets from unique combinations of measurement setups and researchers. Both the repeatability and reproducibility measurements were done on random test structures made of the same homogeneous material.The average repeatability Young’s modulus value (as obtained from resonating oxide cantilevers) was 64.2 GPa with 95 % limits of ± 10.3 % and an average combined standard uncertainty value of 3.1 GPa. The average reproducibility Young’s modulus value was 62.8 GPa with 95 % limits of ± 11.0 % and an average combined standard uncertainty value of 3.0 GPa.The average repeatability step height value (for a metal2-over-poly1 step from active area to field oxide) was 0.477 μm with 95 % limits of 7.9 % and an average combined standard uncertainty value of 0.014 μm. The average reproducibility step height value was 0.481 μm with 95 % limits of ± 6.2 % and an average combined standard uncertainty value of 0.014 μm.In summary, this paper demonstrates that a reliable methodology can be used to measure Young’s modulus and step height. Furthermore, a micro and nano technology (MNT) 5-in-1 standard reference material (SRM) can be used by industry to compare their in-house measurements using this methodology with NIST measurements thereby validating their use of the documentary standards.     

Accuracy of Nanoscale Pitch Standards Fabricated by Laser-Focused Atomic Deposition

The pitch accuracy of a grating formed by laser-focused atomic deposition is evaluated from the point of view of fabricating nanoscale pitch standard artifacts. The average pitch obtained by the process, nominally half the laser wavelength, is simply traceable with small uncertainty to an atomic frequency and hence can be known with very high accuracy. An error budget is presented for a Cr on sapphire sample, showing that a combined standard uncertainty of 0.0049 nm, or a relative uncertainty of 2.3 × 10⁻⁵, is readily obtained, provided the substrate temperature does not change. Precision measurements of the diffraction of the 351.1 nm argon ion laser line from such an artifact are also presented. These yield an average pitch of (212.7777 ± 0.0069) nm, which agrees well with the expected value, as corrected for thermal contraction, of (212.7705 ± 0.0049) nm.     

接触扫描法测量圆柱螺纹量规中径的测量不确定度评定

依据JJF 1345-2012《圆柱螺纹量规校准规范》和GB/T 28703-2012《圆柱螺纹检测方法》,圆柱螺纹量规可用二维螺纹量规扫描仪进行多参数自动测量,其测量方法为接触扫描法。即通过测针沿被测螺纹轴向剖面轮廓进行二维接触扫描,获取被测螺纹轴向剖面轮廓的二维坐标信息,由计算软件算出被测螺纹各参数的测得值。针对用接触扫描法测量的圆柱螺纹量规中径,建立测量模型,分析主要测量不确定度来源,对中径测量的不确定度进行合理的评估。     

High Accuracy Measurement of Aperture Area Relative to a Standard Known Aperture

Precise knowledge of the area of apertures used in high precision radiometry is extremely important. A method is presented here for the determination of the area of round and irregularly shaped apertures by comparison to a standard aperture which has been measured by other means to high accuracy. The method presented here is quick and has no physical contact with the fragile edge of the aperture opening. Total flux transfer methods are used in the area determination with total relative standard uncertainty of 0.033 % for 2 mm to 25 mm mean diameter apertures not including the area uncertainty of the standard aperture used. Currently the relative standard uncertainty in the area measurement for the stadard aperture is 0.022 %. The worst case relative standard uncertainty of the transfer measurement is 0.04 % including the uncertainty of the standard aperture area.     

Assessing Differences Between Results Determined According to the Guide to the Expression of Uncertainty in Measurement

In some metrology applications multiple results of measurement for a common measurand are obtained and it is necessary to determine whether the results agree with each other. A result of measurement based on the Guide to the Expression of Uncertainty in Measurement (GUM) consists of a measured value together with its associated standard uncertainty. In the GUM, the measured value is regarded as the expected value and the standard uncertainty is regarded as the standard deviation, both known values, of a state-of-knowledge probability distribution. A state-of-knowledge distribution represented by a result need not be completely known. Then how can one assess the differences between the results based on the GUM? Metrologists have for many years used the Birge chisquare test as ‘a rule of thumb’ to assess the differences between two or more measured values for the same measurand by pretending that the standard uncertainties were the standard deviations of the presumed sampling probability distributions from random variation of the measured values. We point out that this is misuse of the standard uncertainties; the Birge test and the concept of statistical consistency motivated by it do not apply to the results of measurement based on the GUM. In 2008, the International Vocabulary of Metrology, third edition (VIM3) introduced the concept of metrological compatibility. We propose that the concept of metrological compatibility be used to assess the differences between results based on the GUM for the same measurand. A test of the metrological compatibility of two results of measurement does not conflict with a pairwise Birge test of the statistical consistency of the corresponding measured values.     

荧光量子效率绝对法测量系统校准及不确定度评定

荧光量子效率是发射与吸收的光子数之比,是表征荧光材料发光性能的关键参数。然而,用于绝对法测量荧光量子效率的光路和探测器未经校准溯源或是校准方法不当,会造成测量光谱的不准确,进一步影响荧光量子效率计算结果的不准确。采用汞氩灯对单色仪进行校准,保证了激发波长和发射波长的准确性,利用标准辐射源对光路、发射单元单色仪和探测器进行光谱相对强度校准,保证了激发波段和发射波段光谱相对强度的准确性;最后从测量模型出发,对测量不确定度进行了分析,得到在300~360nm的激发光波段和370~900nm的发射光波段内相对合成标准不确定度为3.58%,相对扩展不确定度为7.16%,k=2。通过对单色仪波长校准以及对光谱相对强度进行校准,为荧光量子效率的准确测量提供了参考。     

大距离运动的直线度测量

机床轴沿轴向运动的直线度是最重要的性能指标.描述了不同的直线度测量方法(直尺法、钢丝绳法、激光干涉仪法、局部垂直度测量及球板和球杆法等),并讨论了这些方法对测量移动长度超过2000 mm的机床的适用性.详细叙述了无重叠的球板拼接,估计了测量的不确定度,测量结果不确定度U为3.4μm(因子κ=2).给出了减小主要影响测量不确定度,也就是影响机床轴重复性的主要因素的一些可能性.示出了500mm×500mm球板拼接测量,并且和轴向移动量900mm的比较仪进行了比对,两种测量结果的偏差小于0.6μm.因此不会超出原有的测量不确定度范围.球板拼接法也可应用于大距离移动中的垂直度测量.无论是利用垂直平面进行测量或者用近来引进的精密三维机床检测,无重叠的球板拼接均可用于水平和垂直的直线度测量,还可用于定位、倾斜、俯视及偏转等方面的测量.