含硅量子点的碳化硅薄膜制备工艺和微结构表征研究

The deposition and microstructural properties of hydrogenated amorphous silicon carbide thin films imbedding silicon QDs

采用等离子体增强化学气相沉积法制备了氢化非晶富硅碳化硅薄膜。通过在高温750℃,900℃,1050℃,和1200℃进行热退火处理,薄膜样品晶化出硅量子点。利用傅立叶红外光谱仪(FTIR)对样品化学键进行了分析。利用X射线衍射(XRD)和拉曼散射光谱仪(LabRAM)对样品微结构随温度的演化进行了表征。利用高分辨透射电镜(HRTEM)和选区电子衍射(SAED)对1050℃退火样品微结构进行了表征。研究发现,在退火温度低于900℃时,薄膜以非晶织构存在。当退火温度从900℃增加到1050℃时,硅(Si)原子从非晶Si1-xCx织构析出,形成硅量子点。硅量子点的平均尺寸从3.1nm增加到4.0nm。

Hydrogenated amorphous silicon carbide(SiC:H) thin films have been deposited by plasma-enhanced chemical vapor deposition(PECVD). The samples were post-annealed at 750 ℃,900 ℃,1050 ℃,and 1200 ℃,respectively. Silicon quantum dots(QDs) were successfully synthesized at 900 ℃. The chemical composition was analyzed by Fourier transform infrared absorption measurements(FTIR). The evolution of microstructure with temperature was characterized by glancing incident X-ray diffraction(XRD) and Raman diffraction spectroscopy. The microstructure of the sample annealed at 1050 ℃ was characterized by high-resolution transmission electron microscope(HRTEM) and selected area electron diffraction(SAED). The results showed that when the temperature was below 900 ℃,the thin films were in amorphous nature. When the temperature was increased from 900-1050 ℃,the precipitation of Si atoms from the amorphous Si1-xCx hosts was strengthened. The average sizes of the silicon QDs were increased from 3.1 nm to 4.0 nm.