摘要
用椭偏光谱法测量了 ( 35ke V,1 .0× 1 0 18cm- 2 )和 ( 65ke V,1 .0× 1 0 18cm- 2 ) C+ 注入 Si形成的 Si C/Si异质结构 .应用多层介质膜模型和有效介质近似 ,分析了这些样品的 Si C/Si异质结构的各层厚度及主要成份 .研究结果表明 :注 35ke V C+ 的样品在经 1 2 0 0℃、2 h退火后形成的 Si C/Si异质结构 ,其β- Si C埋层上存在一粗糙表面层 ,粗糙表面层主要由β- Si C、非晶 Si和 Si O2 组成 ,而且 β- Si C埋层与体硅界面不同于粗糙表面层与 β- Si C埋层界面 ;注 65ke V C+的样品在经1 2 50℃、1 0 h退火后形成的 Si C/Si异质结构 ,其表层 Si是较完整的单晶 Si,埋层β- Si C分成三层微结构 ,表层 Si与β- Si C埋层界面和β- Si C埋层与体硅界面亦不相同 .这些结果与 X射线光电子谱 ( XPS)和横截面透射电子显微镜 ( TEM)
Spectroscopic Ellipsometry (SE) has been used to investigate the SiC/Si heterostructures formed by (35keV, 1 0×10 18 /cm\+2) and (65keV, 1 0×10 18 /cm\+2) C\++ implantation into silicon. The measured SE spectra (2 3—5 0eV) wese analyzed with appropriate multilayer fitting models and the Bruggeman effective medium approximation. Remarkably good agreement between the measured spectra and the model calculation has been obtained. The layer thicknesses, compositions and the optical constants of buried β\|SiC are determined by SE. For SiC/Si heterostructure produced by 35keV C\++ implantation and annealing at 1200℃ for 2h, it is indicated that a thin surface stoichiometric β\|SiC layer, with a thickness of 117nm also has been formed. Above the buried β\|SiC layer, these is a thin rough surface layer mainly containing β\|SiC, armorphous Si and SiO\-2. While for SiC/Si heterostructure produced by 65keV C\++ implantation and annealing at 1250℃ for 10h, the top Si layer is an almost perfect single crystal of silicon and the stoichiometric buried β\|SiC layer is 158nm. For both SiC/Si heterostructures, the strong asymmetry of the two main interfaces has been obtained. These results are in good agreement with those tiom X\|ray Photoelectron Spectroscopy (XPS) analysis and cross\|section Transmission Electron Microscopy (TEM) analysis.
