In situ growth of an epitaxial CoSi2 layer on a Si(100) substrate by reactive chemical-vapor deposition using a cobalt metallorganic source

Uniform epitaxial CoSi2 layers have been grown in situ on a (100) Si substr ate at temperatures above 600 degrees C by reactive chemical-vapor depositi on of cyclopentadienyl dicarbonyl cobalt, Co(eta(5)-C5H5)(CO)(2). Co-rich p hases such as Co2Si and CoSi were suppressed during cobalt metallorganic ch emical-vapor deposition at substrate temperatures above 500 degrees C. A th in carbon layer was found on the top of the epitaxial CoSi2 layer grown on the Si substrate due to incomplete decomposition of the cobalt metallorgani c source and diffusion of Co into the Si substrate. In spite of the existen ce of a surface carbon layer, an ion channeling minimum yield, chi(min), of 8% in Rutherford backscattering/channeling spectrometry has been achieved in the epitaxial layer, indicating a nearly perfect epitaxial order. The ca rbon pileup on the surface of the CoSi2 layer at the initial stage of Co de position seems to play the role of a cobalt diffusion barrier, avoiding the formation of Co-rich phases. (C) 1999 American Institute of Physics. [S000 3-6951(99)02021-5].