IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Surface Science Tuesday Sessions
       Session SS+SC-TuP

Paper SS+SC-TuP2
Growth Characteristics of Si@sub 1-x-y@Ge@subx@C@sub y@ on Si(100) and SiO@sub 2@ in Ultraclean Low-Temperature LPCVD

Tuesday, October 30, 2001, 5:30 pm, Room 134/135

Session: Semiconductor Deposition Poster Session
Presenter: Y. Hashiba, Tohoku University, Japan
Authors: Y. Hashiba, Tohoku University, Japan
M. Sakuraba, Tohoku University, Japan
T. Matsuura, Tohoku University, Japan
J. Murota, Tohoku University, Japan
Correspondent: Click to Email
The growth characteristics of Si@sub 1-x-y@Ge@subx@C@sub y@ films on Si(100) and SiO@sub 2@ were investigated. The films were deposited at 550°C in a SiH@sub 4@-GeH@sub 4@-CH@sub 3@SiH@sub 3@-H@sub 2@ gas mixture using ultraclean hot-wall low pressure chemical vapor deposition (LPCVD) system. The total deposition pressure was 30Pa, and the partial pressures of SiH@sub 4@, GeH@sub 4@ and CH@sub 3@SiH@sub 3@ were in the range of 6.0Pa, 0-2.0Pa (Ge fraction x=0-0.57) and 0-0.2Pa (C fraction y=0-0.05), respectively. Si films are epitaxial on Si(100) and amorphous on SiO@sub 2@. The deposition rate of Si on SiO@sub 2@ (1.2-1.4nm/min) is 10-20% larger than that on Si(100), however, with the addition of CH@sub 3@SiH@sub 3@, the deposition rate on SiO@sub 2@ decreases to that on Si(100). It is considered that CH@sub 3@SiH@sub 3@ molecules are scarcely adsorbed at Si-Si pair site on Si(100) but not at the other sites on amorphous Si surface. With the addition of GeH@sub 4@, the deposition rate increases and that on Si(100) becomes larger than that on SiO@sub 2@. Si@sub 1-x@Ge@sub x@ films are epitaxial on Si(100) and <110> or random oriented polycrystalline on SiO@sub 2@. This is explained by the modified Langmuir-type adsorption and reaction with the assumption that SiH@sub 4@ and GeH@sub 4@ are adsorbed more preferentially on the Si-Ge pair site than Si-Si, Ge-Ge pair site, single Si and Ge bond sites. With the addition of CH@sub 3@SiH@sub 3@, the deposition rates decreases and that on Si(100) tends to become the same as that on SiO@sub 2@. It is suggested that the adsorption and reaction of SiH@sub 4@ and GeH@sub 4@ are suppressed by the adsorption of CH@sub 3@SiH@sub 3@ molecule at the Si-Ge pair site. From XPS measurement, Ge fraction on Si(100) is almost equal to that on SiO@sub 2@ within 10% error. The relationship among lattice constant, Ge and C fraction is under investigation.