Epitaxial Growth and Thermal Stability of CoSi2 on (001)Si Substrate with an Interposing Mo Layer

• Main Authors: You, Jiun-Pyng, 尤君平
• Other Authors: Chen, Lih-Juann
• Format: Others
• Language: en_US
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/91065514195584366644

碩士 === 國立清華大學 === 材料科學工程學系 === 85 === Effects of a thin interposing Mo layer on the formation and growth of epitaxial CoSi2 on (001)Si have been investigated by x-ray diffraction, transmission electron microscopy and sheet resistance measurement. A thin interposing Mo interlayer was found to be very effective in promoting the formation and growth of epitaxial CoSi2 on (001) Si in non-UHV conditions. Results are presented which demonstrate the efficacy of an interposing Mo layer. The epitaxial CoSi2 was formed on the (001)Si substrate in the Co/Mo/Si system. Mo layer acts as a diffusion barrier to control the Co flux reacting with Si atoms. After annealing, a bilayer structure was formed, whereas the lower epitaxial CoSi2 layer is adjacent to the Si substrate and the upper layer is a mixing layer consisting of CoSi2 and MoSi2. Phase separation of CoSi2 and MoSi2 were observed and no ternary compound were found to form in the Co/Mo/Si system. The thermal stability an dinterface morphology of the bilayer thin films were improved with the presence of a thin interposing Mo layer. In miniature size oxide opening samples, no voids were found near the oxide edge in the formation of CoSi2 by using a Co/Mo bilayer structure. Epitaxial CoSi2 with good coverage was grown in the miniature size oxide opening samples. The supprression of the formation of voids near the oxide edge is attributed to the relatively high reaction temperature of the Mo-Si system.