【摘要】 通过Raman光谱、紫外-可见透射光谱技术及原子力显微镜对非晶碳化硅薄膜结构和光学特性的热退火效应进行了研究。结果表明,碳化硅拉曼谱带随退火温度的增加而逐渐红移和尖锐化,显示了薄膜中晶化有序度的提高。退火后薄膜包含大量紧凑的纳米团簇,膜面相对于未退火样品较为粗糙。根据紫外-可见透射光谱导出的光学带隙从原始样品的1.86 eV连续增加到经1 050℃退火样品的2.23 eV。碳化硅薄膜中纳米团簇的形成及其晶化程度的增加导致了薄膜光学带隙的蓝移效应。更多还原

【Abstract】 Thermal annealing effects on the structural and optical properties of amorphous SiC films at different temperatures,obtained by pulsed laser ablation deposition,have been investigated by scattering 、UV-VIS transmission analysis and AFM.The gradual red-shift and sharpening of the SiC Raman band with the annealing temperature increasing has been observed,indicating an enhancement of the degree of crystalline order of the films.The film after annealing contains many compact nanoclusters and presents rougher surface with respect to the as-deposited film.Optical band-gap deduced from UV-VIS transmission spectrum is continuously increased from 1.86 eV for as-deposited film to 2.23 eV for the 1050℃-annealed film.The improvement of crystallinity and the formation of SiC nanoclusters could account for this blue-shift effect of the optical band-gap.更多还原