表面加工多晶硅薄膜热扩散系数在线测试结构

基于目前已有的真空桥式薄膜热扩散系数测试结构和测试方法，综合考虑辐射、对流以及向衬底的传热等因素的影响，从而使得本文设计的测试结构和提取方法更具有实际价值。文中通过分析两个长度不同，但宽度与厚度相同的梁在相同加热电流下的瞬态电阻变化特性，来提取多晶硅薄膜的热扩散系数。同时利用有限元分析软件ANSYS进行了模拟分析，分析表明模拟提取值与理论值较好地吻合，从而验证了模型建立的正确性，说明该方法能够实现对多晶硅薄膜热扩散系数的在线提取，且具有较高的测试精确度。

Test structure to measure the thermal diffusivity of polysilicon films

Based on the present test structure and test method for measuring thermal diffusivity of polysilicon thin films under vacuum circumstance,the effects of all heat exchange factors such as convection,radiation and the heat transfer through the air gap to the substrate were considered in the electrothermal model.The same heating currents were applied in two beams that have same width and thickness but different length.When the thermal stable state was reached the resistance changes were measured,then the thermal diffusivity was obtained.A finite element analysis software-ANSYS was used to do simulation.The simulation result verifies the electrothermal model and shows that the proposed test method can be used to measure the thermal diffusivity of polysilicon thin films and a better test accuracy can be reached.