第二十一讲 真空卷绕镀膜

正(接2021年第4期104页)A镀铝层厚度的测量由于真空镀铝薄膜的镀铝层非常薄,因此不能用常规的测厚仪器检测其厚度,通常在线可以通过电阻测量辊测量表面电阻,测量透过镀层的光密度和测量镀层的高频涡流感应电流等三种方式现实。离线用四探针电阻仪或欧姆表测量表面电阻。a电阻法电阻法是利用欧姆定律来对镀铝层的厚度进行测量,根据欧姆定律R=ρ×L/S,单位面积镀铝薄膜的电阻值越小,其镀铝层的厚度越厚,反之则越薄。     

一种渗硼层厚度在线测试法

本文简要介绍了一种渗硼层厚度在线测量系统。渗硼层厚度的测量采用电涡流测量原理和涡流测量技术，即采用了频率扫描技术和有标样定量分析技术，它具有电阻率突变明显、易于判定的特点，可对渗硼层厚度进行在线、快速、无损检测。     

纳米薄膜厚度的X射线测量

研究了通过小角度X射线衍射(XRD)技术测量纳米薄膜沉积厚度与沉积速率的方法,并测定了在SiC表面沉积Fe纳米薄膜的厚度和沉积速率。结果表明,采用小角度XRD技术测量纳米薄膜厚度和沉积速率,能克服基片性质、表面平整度和金属膜氧化的影响,准确、方便地测量纳米薄膜的厚度和沉积速率。     

涡流测量球铰涂层及其不确定度分析

本文阐述了利用涡流测量球铰涂层厚度的方法 ,并且分析了影响测量准确度的主要因素 ,制定了测量工艺规范     

基于光谱干涉椭偏法的薄膜厚度测量

薄膜厚度的测量在芯片制造和集成电路等领域中发挥着重要作用。椭偏法具备高测量精度的优点,利用宽谱测量方式可得到全光谱的椭偏参数,实现纳米级薄膜的厚度测量。为解决半导体领域常见的透明硅基底上薄膜厚度测量的问题并消除硅层的叠加信号,本文通过偏振分离式光谱干涉椭偏系统,搭建马赫曾德实验光路,实现了近红外波段硅基底上膜厚的测量,以100 nm厚度的二氧化硅薄膜为样品,实现了纳米级的测量精度。本文所提出的测量方法适用于透明或非透明基底的薄膜厚度测量,避免了检测过程的矫正步骤或光源更换,可应用于化学气相沉积、分子束外延等薄膜制备工艺和技术的成品的高精度检测。     

电涡流传感器电路设计

在无损测量当中,电涡流传感器测量因为能够实现工件在线非接触测量,测量精度高、无污染、制作价格低廉等优点,一直被作为一种重要的检测设备,在涡流技术高速发展的今天,电涡流的优势越来越明显应用也越来越广泛。电涡流传感器是电涡流测量淬火层厚度的核心部分,传感器的测量精度直接影响整个测厚设备的精度,传统的电涡流传感器包括测量探头、整流滤波电路的设计、放大器的设计等,电涡流传感器的精确测量也离不开位移测厚标定器,这里主要研究电涡流测厚核心电路的设计。     

薄膜厚度测量研究

本文介绍一种简便的薄膜厚度测量方法。可在普通的光切显微镜上，利用光切原理测量薄膜厚度。能测量0．8－80微米的薄膜厚度。     

有包覆层铁磁试件的脉冲涡流检测

测量由钢板制作的压力容器和管道的壁厚,可以了解其腐蚀程度.用脉冲涡流检测钢板等铁磁材料的厚度时,由保护层和保温层构成的包覆层会对测厚结果产生影响.根据脉冲涡流检测的工作原理,使用有限元法,对有包覆层铁磁试件的厚度测量进行了仿真研究,重点分析了覆盖层对测量结果的影响.研究结果表明:包覆层对测量的影响与保护层材料、试件厚度和保温层厚度有关;对试件厚度测量范围的影响铝皮比铁皮保护层大,使用铝皮保护层时,不能测量厚度小于6mm的试件;试件与保温层越厚,测量误差越小,试件的厚度大于10 mm,保温层的厚度大于50mm时,测量结果不再受保覆层的影响.     

有包覆层铁磁试件的脉冲涡流检测

测量由钢板制作的压力容器和管道的壁厚,可以了解其腐蚀程度.用脉冲涡流检测钢板等铁磁材料的厚度时,由保护层和保温层构成的包覆层,会对测厚结果产生影响.根据脉冲涡流检测的工作原理,使用有限元法,对有包覆层铁磁试件的厚度测量进行了仿真研究,重点分析了覆盖层对测量结果的影响.结果表明,包覆层对测量的影响与保护层材料、试件厚度和保温层厚度有关;对试件厚度测量范围的影响铝皮比铁皮保护层大,使用铝皮保护层时,不能测量厚度小于6mm的试件;试件与保温层越厚,测量误差越小,试件的厚度大于10mm,保温层的厚度大于50mm时,测量结果不再受保覆层的影响.     

多层微纳薄膜的高精度检测技术进展

在半导体、机械加工等行业中广泛应用的多层微纳薄膜通常是由数个纳米厚度的单层膜叠加形成的,在其制造过程中,由于工艺条件所限,薄膜厚度的均匀性会出现误差,进而影响其性能。因此薄膜厚度的准确测量至关重要,亟需一种无损、高精度、快速的检测技术对薄膜的厚度及其均匀性进行测量、检测。回顾近年来多层膜在不同领域的应用现状,分析了目前应用于多层膜厚度测量的技术（如X射线衍射等）及其不足,以及椭圆偏振法技术的研究进展,最后介绍了机器学习在厚度测量中的应用,并对未来机器学习与测量结合的前景进行了展望。     

薄膜热导率测试方法研究进展

薄膜材料的热导率一般与其相应的块体材料有较大的差异.由于其厚度较小,对块体材料热导率的测试方法一般不适用于薄膜材料,因此近几十年来,研究工作者们发明了很多新的用于薄膜热导率的测试方法.综述了薄膜热导率的一些常用测试方法,着重介绍了薄膜热导率的最新测试方法的特点及其适用范围,并针对广泛使用的3ω法进行了详细介绍.     

Measurement of the refractive index and thickness of a transparent film from the shift of the interference pattern due to the sample rotation

A method is described for the simultaneous measurement of the refractive index and thickness of a transparent film. The method is based on the rotational shift of the interference pattern caused by the change of the light incidence angle. The refractive index is evaluated without any prior information about film thickness or about the substrate and its refractive index. In addition, the roughness of the interfaces and/or the presence of an unidentified thin layer are not important. In two experimental examples, the refractive index and thickness are measured for a GaN thin film and a cling-film.     

Determination of film thickness and refractive index in one measurement of phase-modulated ellipsometry

Ellipsometry is often used to determine the refractive index and/or the thickness of a polymer layer on a substrate. However, simultaneous determination of these parameters from a single-wavelength single-angle measurement is not always possible. The present study determines the sensitivity of the method to errors of measurement for the case of phase modulated ellipsometry and identifies conditions for decoupling film thickness and refractive index. For a specific range of film thickness, both the thickness and the refractive index can be determined from a single measurement with high precision. This optimal range of the film thickness is determined for organic thin films, and the analysis is tested on hydrogel-like polymer films in air and in water.     

Calculation of self- and mutual impedances in planar sandwichinductors

High-frequency planar magnetic components, employing thin film and thick film technology, have become important components in applications, such as filters and switching converters, due to their ease of manufacture and reliability. In a previous paper, the authors established a frequency dependent impedance formula for planar coils on a magnetic substrate that is infinitely thick. In this paper, two new impedance models are described: the first is for planar coils on a magnetic substrate of finite thickness, and the second represents a planar coil sandwiched between two substrates. The models include the electrical conductivity of the magnetic material so that the effects of eddy currents, particularly at high frequencies, are taken into account. The eddy currents reduce the inductance and increase the losses associated with the device. The new impedance formulas are derived from Maxwell's equations. Simulations were carried out on a typical device, using finite element analysis, and the results validate the new formulas. This paper establishes the frequency limitations of lossy magnetic substrates     

X射线反射法测量铋系超导薄膜的结构参数

以铋系超导薄膜材料为例,应用X射线反射法测量薄膜材料的厚度以及粗糙度等结构参数,对测量方法的原理、衍射仪的调试和步骤等进行了详细的说明。这一方法为薄膜材料结构参数的测量提供了新途径。     

Use of artificial neural networks to predict thickness and optical constants of thin films from reflectance data

Artificial neural networks and the Levenberg–Marquardt algorithm are combined to calculate the thickness and refractive index of thin films from spectroscopic reflectometry data. Two examples will be discussed, the first is a measurement of thickness and index of transparent films on silicon, and the second is a measurement of three thicknesses and index of poly-silicon in a rough poly-silicon on oxide stack. A neural network is a set of simple, highly interconnected processing elements imitating the activity of the brain, which are capable of learning information presented to them. Reflectometry has been used by the semiconductor industry to measure thin film thickness for decades. Modeling the optical constants of a film in the visible region with a Cauchy dispersion model allows the determination of both thickness and refractive index of most transparent thin films from reflectance data. The use of an alloy interpolation model for the optical constants of poly-silicon allows the determination of thicknesses and poly optical constants. In this work artificial neural networks are used to obtain good initial estimates for thickness and dispersion model parameters, these estimates are then used as the starting point for the Levenberg–Marquardt algorithm which converges to the final solution in a few iterations. These measurement programs were implemented on a Nanometrics NanoSpec 8000XSE.     

Correlation between optical path modulations and transmittance spectra of a-Si:H thin films

The optical constants of plasma-enhanced chemical-vapor-deposited amorphous silicon (a-Si:H) thin film upon a transparent substrate are determined within the UV-visible region by measurement of the transmittance spectrum. Apart from thickness irregularities, the effects of vertical film inhomogeneities (refractive-index distribution) on the spectrum are discussed. In this respect, although consideration of any possible variation in thickness of the film within the area illuminated by the probe beam is sufficient for correcting the modulation of the extrema of interference fringes, including in the model the thin transitional regions at substrate-film and film-air interfaces might be an alternative method for understanding the overall optical behavior of the spectrum.     

Effects of step slope on thickness measurement by optical interferometry for opaque thin films

Optical interferometry is a simple, quick and cheap method to measure the thickness of opaque thin films. The film edge, being formed as a step on the sample surface, is lighted with monochromatic light in an interference microscope, producing the interferogram that is recorded with a CCD camera. The film thickness (step height) is calculated by measuring offsets of the fringes across the step. However, the morphology of the film edge (step) significantly affects the thickness measurement, in some cases even yields false results. In this work, three kinds of methods were adopted to mask a part of the substrate surface during the deposition for fabrication of the step. The mask used was a thin silicon slice, a straight line of ink imprinted by a pen, or an Aluminum film. The step morphology recorded by a profilometer revealed large variation from one method to another. Accordingly, the accuracy of film thickness (step height) measurement by interferometry varies significantly. Results showed that large error occurs when the slope of the step is small and the step out spans the view field of the microscope. Therefore, the step should be fully visible in the view field of the microscope for reasonable measurement of thickness. A simple equation, in terms of geometrical configuration, is developed for this requirement.     

基于COMSOL的声表面波器件仿真

声表面波器件在通信、传感、射频识别等领域有着广泛的应用.以有限元方法为基础,利用有限元软件COMSOL对声表面波器件进行了仿真.从器件的模型建立入手,按由浅入深的顺序对无电极压电基片、压电基片表面沉积叉指换能器、叉指换能器表面溅射薄膜、薄膜上负载液体的4种结构进行了仿真分析.仿真研究表明:叉指换能器的电极效应会产生正、反特征频率,并且两种频率都随着叉指电极的敷金比与高度增加而向低频偏移;薄膜厚度的增加同样会导致器件频率向低频变化;当器件负载液体用于液体密度检测时,可通过器件频率变化对液体密度的灵敏程度来对薄膜厚度进行优化.其研究结果可以为声表面波器件的设计制作提供依据.