面向薄膜材料光热特性参数的FPTR检测技术研究

该文提出采用频域光热辐射测量技术(FPTR)对金刚石薄膜的光热特性进行检测。首先,建立调制激光作用于一维有限厚度试件的热波频域响应模型,并搭建光热辐射测量检测系统;其次,采用该试验系统对厚度为200μm、直径为1.5 mm的金刚石薄膜进行频域光热辐射测量技术检测试验研究,得到了调制激光作用于金刚石薄膜的光热动态响应特性;最后,采用反问题求解方法获取金刚石薄膜的光热特性参数。试验结果表明,频域光热辐射测量技术可以对金刚石薄膜进行高精度检测。     

倾斜溅射制备TbFe薄膜的磁力显微镜研究

磁力显微镜(MFM)作为研究表面磁结构的有力工具广泛地应用于磁性薄膜的研究中.TbFe磁致伸缩薄膜在实际应用中要求易磁化轴平行于膜面,以具有较低的面内饱和场Hs,传统的成膜技术难以实现这一目标,采用倾斜溅射方法制备TbFe薄膜可有效降低面内饱和场Hs.通过测量样品的磁滞回线可以发现,易磁化轴随着溅射角度的增加逐渐偏离样品的法线方向,而取向于平行膜面.本研究工作利用MFM研究了不同溅射角度得到的TbFe薄膜的磁畴结构.发现薄膜的磁畴结构随着溅射角度的增加逐渐由垂直畴转化为水平畴,与磁滞回线测量得到的易轴方向发生偏转的结果相吻合.     

用透射式光热偏转技术测量光学薄膜的微弱吸收率

建立了一套透射式光热偏转光谱术实验装置,将它应用于光学薄膜微弱吸收率的测量,灵敏度可达10~(-6),实验结果与用激光量热法及横向光热偏转法所得者皆符合良好。     

利用光热反射法研究多层薄膜结构的散热性能

搭建了纳秒激光加热、连续激光探测的光热反射实验系统,通过测量芯片中多层微米厚度薄膜不同位置的反射信号,评估了不同薄膜结构对器件散热的影响.在多层薄膜热传导模型的基础上,结合Laplace逆变换的Stehfest数值解拟合得到了微米级厚度薄膜的热物性参数以及界面传热特性.拟合得到绝缘层热导率为0.75 W/(m·K),与磁控溅射Al薄膜间的界面热阻约为10~(-8) m~2K/W.进而建立了电子器件封装镀膜的热分析有限元模型,比较了沉积类金刚石薄膜前后芯片热点温度的变化,结果表明:类金刚石薄膜可以进一步改善芯片的散热性能.     

溶胶-凝胶法制备太阳能薄膜的研究及展望

介绍了溶胶-凝胶法的反应机理、工艺过程,着重介绍了太阳能光电/光热转换的原理、薄膜的分类以及最新研究现状,指出采用溶胶-凝胶法可获得高效率太阳能薄膜,并展望了溶胶-凝胶法在太阳能薄膜制备方面的发展趋势及应用前景.     

介质薄膜的透射光谱测量及其光学参数的分析

介绍介质薄膜透射光谱的测量以及基于分析薄膜透射光谱的计算薄膜光学参数的方法。对制备在玻璃基板上的二氧化钛，二氧化硅和氧化锌薄膜进行了可见光谱区的透射比测量，并用包络线方法和最优化方法对这些透明薄膜的光学参数进行了计算和分析。     

AZO靶材的制备与镀膜应用研究

以ZnO和Al2O3粉体为原料，在不同的热压温度下制备AZO靶材。通过阿基米德法测量靶材的密度，压汞法测量靶材的孔径分布，扫描电镜观察靶材的断面形貌。将所制备的靶材作为溅射源，进行射频磁控镀膜测试。采用台阶仪测量膜厚，紫外分光光度计测量薄膜透光率，四探针电阻图谱仪测量薄膜电阻率，XRD分析薄膜结构，研究靶材密度及孔径分...     

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。     

金属基体上硬质薄膜内应力的释放测量法

提出了一种基于Stoney公式测量金属基体上硬质薄膜内应力的应力释放法，并研究了不同基底温度对磁控溅射TiN薄膜内应力的影响。     

太阳能选择性吸收薄膜研究进展及展望

太阳能选择性吸收薄膜是太阳能集热器的主要功能组件,是太阳能光热转换中最为关键的部分,也是获得高光热转换效率的重要方式.本文从太阳能选择性吸收薄膜的原理出发,对材料选择、吸收机理以及制备方法等方面进行了介绍,对太阳能选择性吸收薄膜的国内外发展现状进行了论述,同时对限制太阳能选择性吸收薄膜性能的主要因素进行了分析,并对今后的发展进行了展望.     

Theoretical Modeling of Obliquely Crossed Photothermal Deflection for Thermal Conductivity Measurements of Thin Films

A three-dimensional theoretical model has been developed to calculate the normal probe beam deflection of the obliquely crossed photothermal deflection configuration in samples which consist of thin films deposited on substrates. Utilizing the dependence of the normal component of probe beam deflection on the cross-point position of the excitation and probe beams, the thermal conductivity of the thin film can be extracted from the ratio of the two maxima of the normal deflection amplitude, which occurs when the cross-point is located near both surfaces of the sample. The effects of other parameters, including the intersect angle between the excitation and the probe beams in the sample, the modulation frequency of the excitation beam, the optical absorption and thickness of the thin films, and the thermal properties of substrates on the thermal conductivity measurement of the thin film, are discussed. The obliquely crossed photothermal deflection technique seems to be well suited for thermal conductivity measurements of thin films with a high thermal conductivity but a low optical absorption, such as diamond and diamond-like carbon, deposited on substrates with a relatively low thermal conductivity.     

A Genetic Algorithm for Simultaneous Determination of Thin Films Thermal Transport Properties and Contact Resistance

A genetic algorithm （GA） was studied to simultaneously determine the thermal transport properties and the contact resistance of thin films deposited on a thick substrate. A pulsed photothermal reflectance （PPR） system was employed for the measurements. The GA was used to extract the thermal properties. Measurements were performed on SiO2 thin films of different thicknesses on silicon substrate. The results show that the GA accompanied with the PPR system is useful for the simultaneous determination of thermal properties of thin films on a substrate.     

无损检测固体表面、次表面不均匀性和缺陷的激光光热偏转技术

本文介绍非接触无损检测固体物质表面、次表面不均匀性和缺陷的激光光热偏转技术,设计并建立了测量装置。文中列出了对光学薄膜弱吸收率的测量,对碳素纤维材料、光学薄膜表面激光损伤和对金属材料次表面模拟缺陷的成像检测等一些应用的结果。     

Photodiodes based on fullerene semiconductor

Fullerene thin films have been deposited by thermal evaporation on glass substrates at room temperature. A comprehensive optical characterization was performed, including low-level optical absorption measured by photothermal deflection spectroscopy. The optical absorption spectrum reveals a direct bandgap of 2.3 eV and absorption bands at 2.8 and 3.6 eV, which are related to the creation of charge-transfer excitons. Various photodiodes on indium-tin-oxide coated glass substrates were also fabricated, using different metallic contacts in order to compare their respective electrical characteristics. The influence of a poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) buffer layer between the indium-tin-oxide electrode and the fullerene semiconductor is also demonstrated. These results are discussed in terms of the workfunction for each electrode. Finally, the behaviour of the external quantum efficiency is analyzed for the whole wavelength spectrum.     

CuNiSi溅射薄膜热性能与溅射靶材中稀土元素加入量之间关系的研究

应用光热辐射和光学速反射的方法了靶材中Ｌａ系混合稀土元素加入量对ＣｕＮｉＳｉ溅射薄膜热性能的影响。靶材中Ｌａ系混合稀土元素的加入引起被溅射薄膜热行为的差异,随着靶材料中Ｌａ系稀土元素加入量的提高,被溅射的ＣｕＮｉＳｉ薄膜的热扩散系数α也增加。     

Thermal Conductivity Measurement of Submicron-Thick Films Deposited on Substrates by Modified ac Calorimetry (Laser-Heating Ångstrom Method)

Technological development, especially in microelectronics, necessitates the development of new and improved methods for measuring the thermal properties of materials, especially in the form of ultrathin films. Previously, modified ac calorimetry (laser-heating Ångstrom method) using a scanning laser as the energy source was developed and shown to provide accurate values of thermal diffusivity and derived thermal conductivity for a broad range of materials in the form of free-standing thin sheets or films, wires including fiber bundles, and some films on substrates. This paper describes further applications of the modified ac-calorimetry technique for measurements of the thermal conductivity of thin films deposited on substrates. It was used to measure successfully the thermal conductivities of 1000- to 3000-Å-thick aluminum nitride films, aluminum oxide films, etc., which were deposited on a glass substrate. It was also shown to be suitable for developmental measurements on submicron-thick chromatic films deposited on a PET substrate, which are photothermal recording layers, used in the media of CD-R drives of computer systems.     

Photoconductivity spectroscopy in hydrogenated microcrystalline silicon thin films

Steady-state photoconductivity and sub-bandgap absorption measurements by the dual-beam photoconductivity (DBP) method were carried out on undoped hydrogenated microcrystalline silicon thin films prepared by VHF-PECVD and hot-wire chemical vapor deposition. The results are compared with those of the constant-photocurrent method (CPM) and photothermal deflection spectroscopy (PDS). It is found that DBP, CPM, and PDS provide complementary data on the optoelectronic processes in microcrystalline silicon.     

Absolute Measurement of Thermophysical and Optical Thin-Film Properties by Photothermal Methods for the Investigation of Laser Damage

Perspectives and limits of the application of the photothermal technique are given for the measurement of absorption, thermal, and thermoelastic properties in thin films. The peculiarities of this technique in the frequency and time domains are discussed in some detail, and selected important results with respect to laser damage studies in optical coatings are pointed out. Emphasis is placed on the absolute measurement of both optical and thermophysical properties in dielectric materials in thin-film form and, also, on the influence of both absorption and changed thermal properties in thin films on their thermally induced laser damage resistance.     

氮化硅介质薄膜内应力的实验研究

研究了等离子体增强化学气相沉积氮化硅介质薄膜的内应力。采用钠光平面干涉测量了氮化硅薄膜内应力,通过改变薄膜沉积时的工艺参数,考察了反应气体流量比、沉积温度、射频功率密度等因素对氮化硅薄膜内应力的影响。在此基础上,对氮化硅介质薄膜本征应力的形成机制进行了分析讨论。     

Separation of Optical Thin Film and Substrate Absorption by Obliquely-crossed Photothermal Deflection: Theory

Abstract

An explicit three-dimensional calculation of c.w. modulated photothermal deflection (PTD) with obliquely crossed geometry, including optical thin film and substrate absorption, has been presented. Theoretical results show that the obliquely crossed PTD technique is feasible to separate the thin film and substrate absorption, and to measure low thin film absorption under high substrate absorption by appropriately adjusting the cross-point position of the excitation and probe beams. Measurement of the thin film absorption is not affected by the thermal properties of the substrate. The obliquely crossed PTD also provides a method for real-time monitoring of thin film generation.