氢化非晶硅薄膜的热导率研究

采用铂电极为加热电阻，研究了厚度为300—370nm等离子体化学气相沉积(PECVD)工艺制备的氢化非晶硅(a-Si：H)薄膜的热导率随衬底温度的变化规律.用光谱式椭偏仪拟合测量薄膜的厚度，得到了沉积速率随衬底温度变化规律，傅里叶红外(FTIR)表征了在KBr晶片衬底上制备的a-Si：H薄膜的红外光谱特性，SiH原子团键合模的震动对热量的吸收降低了薄膜热导率.从动力学角度分析了薄膜热导率随平均温度升高而增大的原因，并比较了声子传播和自由电子移动在a-Si：H薄膜热导率变化上的作用差异. 关键词： 非晶硅 热导率 薄膜 热能

Study on thermal conductivity of hydrogenated amorphous silicon films

The thermal conductivity of hydrogenated amorphous silicon (a-Si：H) film was measured using platinum metal as heating resistance. The films are prepared by plasma enhanced chemical vapor deposition (PECVD) and the thickness of them is in the range of 300—370nm. The dependence of thermal conductivity of the films on substrate temperature was studied. The influence of substrate temperature on the growth rate of a-Si：H films was obtained by spectra ellipsometer (SE). Fourier-transform infrared spectrometer (FTIR) was used to characterize the infrared spectra of films deposited on KBr substrate. The thermal absorption duc to vibrational mode of Si-H bond decrease the thermal conductivity of the films. Kinetic theory was used to analyze the result that the thermal conductivity of the films increases with the increasing of mean temperature. The effects of phonon propagation and free electrons displacement on thermal conductivity was also compared.