Sidorov MV, Kardynal B, Smith DJ
Center for Solid State Science, Arizona State University, Tempe, AZ 85287-1704
Microsc Microanal. 1998 May;4(3):317-324. doi: 10.1017/s1431927698980321.
: Morphological evolution associated with silicidation of Co thin films deposited on (100) and (111) Si substrates has been followed using transmission electron microscopy with in situ thermal annealing from ambient temperature up to 850 degreesC. Noticeable structural changes associated with the formation of CoSi2 occur at temperatures as low as 400 degreesC and the reaction is essentially complete at about 500 degreesC. Prolonged heating above 500 degreesC leads to CoSi2 grain growth and coalescence and, finally, to pinholes formation. Silicidation of Co films on (100) and (111) Si substrates follows the same pattern. The morphology of films annealed in situ is similar to those annealed ex situ except that the Si/CoSi2 interface appears to be much rougher. This behavior is associated with the specific geometry of cross-sectional TEM specimens, where surface diffusion dominates bulk diffusion. Very thin Co films, which have less contribution from surface diffusion than thicker films, are ideal for studying dynamic phenomena at Co/Si reactive interfaces.
利用透射电子显微镜对沉积在（100）和（111）硅衬底上的钴薄膜进行硅化处理，并从室温到850摄氏度进行原位热退火，追踪了其形态演变。与CoSi2形成相关的明显结构变化在低至400摄氏度的温度下就会出现，反应在约500摄氏度时基本完成。在500摄氏度以上长时间加热会导致CoSi2晶粒生长和合并，最终形成针孔。（100）和（111）硅衬底上的钴薄膜硅化遵循相同模式。原位退火薄膜的形态与非原位退火薄膜相似，只是Si/CoSi2界面似乎更粗糙。这种行为与横截面透射电镜样品的特定几何形状有关，其中表面扩散主导体扩散。表面扩散贡献比厚膜小的非常薄的钴薄膜，是研究Co/Si反应界面动态现象的理想选择。
