J. Phys. IV France 09 (1999) Pr8-431-Pr8-436
H-termination effects on initial growth characteristics of W on Si using WF6 and SiH4 gasesY. Yamamoto, T. Matsuura and J. Murota
Laboratory for Electronic Intelligent Systems, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
Selective growth of W on the Si(100) surface at ~l00°C in a WF6 and SiH4 mixture was investigated using a cold-wall low-pressure CVD system. It is found that W film grows by preheating on the wet-cleaned substrate after an incubation period, which becomes shorter on the Si surface which has a lower hydrogen concentration. W nucleus formation before the film growth is also enhanced and the nuclei on the Si surface which has a lower hydrogen concentration are of a higher density and a smaller size. Even before the nucleus formation, the W atom is adsorbed and the adsorption rate on the Si surface which has a lower hydrogen concentration is higher than that which has a higher one. Consequently, hydrogen desorption from the Si surface enhances the W atom adsorption, and after adsorption of a certain concentration of W atoms, the W nucleus formation and growth start.
© EDP Sciences 1999