Measurement of heat transfer in sub-micron area of thin films by transmission electron microscope

透射电子显微镜测量薄膜亚微米区域的传热

• 批准号: 05650052
• 负责人: TAKAOKA Akio
• 金额: $ 1.22万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05650052/
• 关键词: Transmission electron microscope; Thin film; Thermal conductivity measurement; Local temperature measurement; Laser heating; Electron thermal diffuse scattering; レーザ加熱

With the high-spatial resolution (-nm) of transmission electron microscopes(TEM), a measurement method of thermal conductivity of thin films is investigated and it is applied to polycrystalline films whose thickness is 30-300nm.Electrons through a film are scattered by the thermal vibration of lattice and the beam intensity at TEM image changes by the temperature of the specimen. When the laser beam is focused on a film, the film can be heated locally, quickly and repeatedly. combining these functions, we can investigate the mechanize of heat transfer in this films.A He-Ne gas laser with amplitude modulator and an optical system for focusing and aligning are attached to the TEM.The laser beam with about 10mW is focused on the specimen to the area of 10-20mum in diameter. The magnified image of the specimen is observed and the beam intensity in a small area (1mumphi on specimen) is detected by a scintillator and a photo-multiplier.The rise of film temperature is delayd to the laser power by the heat capacity and heat diffusivity. The phase difference is converted to the thermal conductivity. Then, this method has advantage that the deduction is independent to the absolute temperature and the film thickness.Some vacuum-deposited films (Al, Sn, Ni, Ge, Cu, Mg, Bi) with various thicknesses are prepared and measured. In most cases, film conductivity is in 30-80% of bulk conductivity and approaches to it as the grain size increases. The film conductivity reduces as the thickness decreases.In the term of project, we have not finished the investigation to the relation between heat transfer and crystal structure. This will be studied in succession.

利用透射电子显微镜的高空间分辨率(-nm)，研究了一种测量薄膜导热系数的方法，该方法适用于厚度为30-300 nm的多晶薄膜。通过薄膜的电子被晶格的热振动散射，透射电子显微镜图像上的光束强度随样品的温度而变化。当激光聚焦在薄膜上时，可以对薄膜进行局部、快速和重复的加热。结合这些功能，我们可以研究这种薄膜中的换热机理。在TEM上安装了带有幅度调制器的He-Ne气体激光器和用于聚焦和对准的光学系统。大约10 mW的激光聚焦在样品上，直径为10-20微米。用闪烁体和光电倍增器观察了样品的放大图像，并测量了小区域(样品上1mumphi)的光束强度，薄膜温升由热容和热扩散率滞后于激光功率。将相位差转换为导热系数。该方法具有与绝对温度和膜厚无关的优点。制备了不同厚度的真空沉积薄膜(Al、Sn、Ni、Ge、Cu、Mg、Bi)，并对其进行了测量。在大多数情况下，薄膜的电导率在体电导率的30-80%之间，并且随着颗粒尺寸的增大而接近。薄膜的导电性随着厚度的减小而减小。在工程方面，我们还没有完成对导热与晶体结构之间关系的研究。我们会陆续研究这方面的问题。

项目成果

A.Takaoka and R.Nishi: "Measurement of thermal concluctivity of thin films with TEM" Proc,13th Int.Congr.on Electron Microscopy 1994. 1. 261-262 (1994)

A.Takaoka 和 R.Nishi：“用 TEM 测量薄膜的热凝结率”Proc，第 13 届电子显微镜国际会议 1994. 1. 261-262 (1994)

Akio Takaoka and Katsumi Ura: ""Accuracy of temperature measurement in micro-area of polycrystalline film with transmission electron microscope"" Meas.Sci.Technol.Vol.5 No.1. 105-109 (1994)

Akio Takaoka 和 Katsumi Ura：“利用透射电子显微镜测量多晶薄膜微区温度的精度”Meas.Sci.Technol.Vol.5 No.1。

Akio Takaoka and Ryuji Nishi: ""Measurement of thermal conductivity of thin films with TEM"" Proc.13th Int.Congr.on Electron Microscopy. Vol.1. 261-262 (1994)

Akio Takaoka 和 Ryuji Nishi：“用 TEM 测量薄膜的热导率”Proc.13th Int.Congr.on Electron Microscopy。

A.Takaoka and R.Nishi: "Measurement of thermal conductirity of thin films with TEM" Proc.13th Int Congr on Electron Microscopy,1994. 1. 261-262 (1994)

A.Takaoka 和 R.Nishi：“用 TEM 测量薄膜的热导率”Proc.13th Int Congr on Electron Microscopy，1994。

Akio Takaoka,Katsumi Ura: "Accuracy of temperature measurement in micro-areas of polycrystalline film with transmission electron microscope" Meas.Sci.Technol.4. 105-109 (1993)

Akio Takaoka、Katsumi Ura：“用透射电子显微镜测量多晶薄膜微区域温度的精度” Meas.Sci.Technol.4。