氮化硅薄膜热性能测试研究

Measurement of Thermal Performance of Silicon Nitride Thin Films

提出了一种可以测试氮化硅薄膜热导、热容的方法。该方法采用微机械加工技术制作成悬空结构,利用Pt薄膜来做加热与测温电阻。设计了合理的测试方案来减小测试过程中Pt薄膜附加热导、热容带来的影响。用Matlab模拟了结构的热响应特性。在Pt薄膜中通入直流电流后,桥面温度逐渐升高,最终达到稳定,在相同的电流输入下,微桥的热容、热导越大,桥面的温升越小。讨论了无效加热电阻和微结构加工工艺对测试精度的影响,并给出了提高测试精确度的方法。

This paper presents a new approach for measuring the thermal conductance and thermal mass of silicon nitride fill with suspended structure fabricated by micromachining technique. In the structure, the Pt thin film is used as both heater and temperature detector based on its temperature resistance characterization. A reasonable scheme has been designed to reduce the additional thermal conductance and thermal mass introduced by Pt thin film. During the test, when DC current is input in the Pt thin film, the microbridge temperature rises gradually until the system reaches steady. The simulation for the thermal response characterization by Matlab indicates that bigger thermal conductance and thermal mass result in higher microbridge temperature at the steady state. Finally, the impact of invalid heating Pt resistance and microfabrication process on the measurement precision is discussed and the methods to improve the precision are given.