采用射频等离子体增强化学气相沉积(PECVD)技术,以SiH4、CH4和 H2为反应气体,在单晶硅和石英衬底上制备a-Si∶H/a-SiC∶H 多层薄膜。利用透射电子显微镜(TEM)对样品的微结构进行了表征,同时对其电子输运性质和光吸收特性进行了实验研究。结果表明,本实验条件下制备的多层薄膜样品为非晶态多层薄膜结构,并且样品具有良好的周期性结构和陡峭的界面特性。室温条件下,样品在垂直方向上呈现出多势垒顺序共振隧穿特性。由于量子限制效应,当a-Si∶H 势阱层厚度<8 nm,随着势阱层厚度减小,样品的光学带隙增大,光吸收系数减小。
The a-Si∶H/a-SiC∶H multilayer film was prepared on the monocrystalline silicon and quartz sub-strates by radio frequency plasma enhanced chemical vapor deposition technique(RF-PECVD),using SiH4 ,CH4 and H2 as reaction gas sources.The microstructures of a-Si∶H/a-SiC∶H samples characterized represented u-sing transmission electron microscope(TEM).At the same time,the electrical transport and optical absorption properties of a-Si∶H/a-SiC∶H multilayer films were experimental studied.The results show that the multilay-er film samples were amorphous multilayer film with good periodic structure and steep interfaces.At room tem-perature,sequential resonant tunneling peculiarities on the vertical direction of multilayer film samples were ob-served.When well layer thickness of a-Si∶H is smaller than 8 nm,the optical band increase and optical absorp-tion coefficient decrease with the decreasing of well layer thickness,which results from quantum size confine-ment effect.