Method and device for measuring transverse thermal conductivity of thin film

Abstract

The invention provides a method for measuring transverse thermal conductivity of a thin film. The method comprises measuring longitudinal thermal conductivity of a thin film to be measured through a second metal strip as a heating source deposited on the surface of the thin film to be measured through a 3 omega method, wherein the bottom of the thin film to be measured is provided with a substrateand the longitudinal direction is perpendicular to the thin film to be measured, measuring temperature rising of the thin film to be measured along a longitudinal direction through a first metal strip as a heating source through the 3 omega method, deducing thermal power of the thin film to be measured along the longitudinal direction through the measured longitudinal thermal conductivity, simultaneously, detecting the temperature rising of the first metal strip and the temperature rising of the second metal strip caused by the heat field produced by the temperature rising of the first metalstrip along the horizontal direction of the thin film to be measured, and calculating the horizontal thermal conductivity of the thin film with thickness d to be measured. The substrate / measured thinfilm / metal strip sample structure is adopted so that the process difficulty of preparing a suspension structure sample is effectively avoided. The bimetal strip can accurately measure the transverse temperature difference of the thin film, and the measurement result has high accuracy.

Description

technical field [0001] The invention belongs to the technical field of thermal physical property testing of thin film materials, and in particular relates to a method and a device for measuring the transverse thermal conductivity of thin films. Background technique [0002] Thermal conductivity is one of the important parameters to characterize the thermophysical properties of thin film materials. The thermal conductivity of the film material determines the ability of the film to conduct or insulate heat. For example, with the development of microelectronic devices towards higher integration, if the heat dissipation performance of microelectronic devices is not good, it will lead to local high temperature of the device unit, which will shorten the life of the device or even cause the device to break down. The higher the thermal conductivity, the higher the thermal conductivity The stronger it is, the better the heat dissipation capability; in addition, heat insulation mater...

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Problems solved by technology

Laser flash method (Measurement of thinfilm thermal conductivity using the laser flash method) requires laser heating and testing and involves the extraction of laser signals, so it requires precise optical circuits, and it is limited for multilayer films and thin films with large thickness. In addition, the flash method cannot directly test transparent materials; in the 3ω method, because the sample size is small, the radiation error can be effectively reduced by reducing the heat transfer area, and the test time is compared with the stable measurement method. It is shorter and increases the test speed, so the 3ω method is an important method for measuring the thermal conductivity of thin films. At present, there are also some methods for measuring the transverse thermal conductivity of thin films with the 3ω method, for example, Su Guoping’s paper (Thermal conductivity based on harmonic method The object of the anisotropic thermal conductivity measurement method in the experimental research on the thermal conductivity of functional materials is an anisotropic semi-infinite solid, so it cannot be applied to thin films with nanometer thickness; use the 3ω method to measure the suspended film structure sample (Phys.StatusSolidi A 210,No.1,106–118(2013)), it is impossible to accurately determine the transverse heat transfer distance of the film

In addition, the sample structure in the quasi-steady-state double-bridge method (Thermal conductivity measurement and interface thermal resistanceestimation using SiO2thin film) is somewhat similar to the structure mentioned in the present invention, but the quasi-steady-state double-bridge method is used for longitudinal thermal conductivity Rate measurement, and the error caused by multimeter measurement is large

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