碳化温度对异质外延3C-SiC薄膜结晶质量及表面形貌的影响

Effects of Carbonization Temperature on the Crystal Quality and Surface Morphology of Heteroepitaxial 3C-SiC Films

本文以Si(100)为衬底,利用水平式常压冷壁化学气相沉积(APCVD)系统在不同温度(1100～1250℃)下制备的"缓冲层"上生长了3C-SiC薄膜。结果表明,薄膜为外延生长的单一3C-SiC多型,薄膜表面呈现"镶嵌"结构特征,Si/3C-SiC界面平整无孔洞。碳化温度对薄膜的结晶质量和表面粗糙度有显著的影响,当碳化温度低于或高于1200℃时,薄膜的结晶质量有所降低,且随着碳化温度的升高,薄膜表面粗糙度呈现增大的趋势。当在1200℃下制备的"缓冲层"上生长薄膜时,可以获得最优质量的3C-SiC外延膜,其(200)晶面摇摆曲线半峰宽约为0.34°,表面粗糙度约为5.2 nm。

3C-SiC thin films were heteroepitaxially grown on different buffer layers carbonized at temperatures ranging from 1100 ℃ to 1250 ℃ using a horizontal cold-wall atmospheric pressure chemical vapor deposition system.The high resolution X-ray diffraction(HRXRD) and Raman spectroscopy characterizations indicate that the as-grown films were 3C-SiC polytype with the same orientation to Si(100) substrates.The atomic force microscopy(AFM),scanning electron microscopy(SEM) and transmission electron microscopy(TEM) characterizations show that the surface of 3C-SiC films presents typical mosaic-like morphology and the Si/3C-SiC interface is very smooth and no voids have been detected.The crystal quality is deteriorated when the carbonization temperature is lower or higher than 1200 ℃,while the surface roughness is increased with improving the carbonization temperature.The 3C-SiC film grown on the buffer layer carbonized at 1200 ℃ shows the best quality with full-width-at-half-maximum of 0.34° and surface roughness of 5.2 nm.