Li Zhibin, Wang Hairong, Zhao Huiying, Gu Hanqing, Wang Jiuhong, Wei Xueyong
School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, Shanxi 710049, China.
Rev Sci Instrum. 2020 Aug 1;91(8):084901. doi: 10.1063/5.0014083.
We propose a test method to study the effects of strain on the thermal conductivity of thin films. First, a strain setup was designed to apply stress to a thin film, and a test system was built to measure its thermal conductivity by combining the strain setup with the 3-ω method. The strain setup can apply stress to the specimen by adjusting load weights, while the strain of a thin film was obtained by measuring the applied stress with a force sensor. Second, the effects of strain on the resistance and temperature coefficients of a metal thin film were studied using the strain setup and the four-wire resistance measurement method; the results show that the resistance and temperature coefficients of metal thin films decrease with strain. Finally, the effects of strain on the thermal conductivity of a silicon dioxide thin film and silicon substrate were studied using the proposed method and test system. As the strain increased from 0% to 0.072%, the thermal conductivity of the 300-nm thick silicon dioxide thin film decreased from 0.907 W/(m K) to 0.817 W/(m K). The thermal conductivity of the 0.5-mm thick silicon substrate fluctuated in the range of 130.6 W/(m K) to 118.8 W/(m K) and then tended to stabilize around 126.4 W/(m K).
我们提出一种测试方法来研究应变对薄膜热导率的影响。首先，设计了一种应变装置以对薄膜施加应力，并构建了一个测试系统，通过将应变装置与3-ω方法相结合来测量其热导率。应变装置可通过调整负载重量对样品施加应力，而薄膜的应变则通过用测力传感器测量施加的应力来获得。其次，使用应变装置和四线电阻测量方法研究了应变对金属薄膜电阻和温度系数的影响；结果表明，金属薄膜的电阻和温度系数随应变而降低。最后，使用所提出的方法和测试系统研究了应变对二氧化硅薄膜和硅衬底热导率的影响。当应变从0%增加到0.072%时，300纳米厚的二氧化硅薄膜的热导率从0.907瓦/（米·开尔文）降至0.817瓦/（米·开尔文）。0.5毫米厚的硅衬底的热导率在130.6瓦/（米·开尔文）至118.8瓦/（米·开尔文）范围内波动，然后趋于稳定在126.4瓦/（米·开尔文）左右。
