AVS 45th International Symposium
    Surface Science Division Thursday Sessions
       Session SS1+NS-ThM

Paper SS1+NS-ThM11
Effects of Ion Pretreatments on the Nucleation of Silicon on Silicon Dioxide

Thursday, November 5, 1998, 11:40 am, Room 308

Session: Growth and Thin Films
Presenter: C Basa, University of North Carolina, Chapel Hill
Authors: C Basa, University of North Carolina, Chapel Hill
Y.Z. Hu, AG Associates Inc.
M.T. Tinani, University of North Carolina, Chapel Hill
E.A. Irene, University of North Carolina, Chapel Hill
Correspondent: Click to Email
It is well known that the silicon (Si) surface condition is crucial for low temperature Si expitaxy.@footnote 1@ In particular, hydrogen has been implicated as an important factor inhibiting Si nucleation on Si,@footnote 2@ and SiO@sub 2@ surfaces.@footnote 3@ In addition, nuclei densities can change depending upon the preparation of the surface film.@footnote 3@ We previously studied the effects of pretreatments of various forms of hydrogen (molecular and ionic) on nucleation parameters (nuclei density, and incubation time (t@sub inc@)).@footnote 4@ We found that H@sub 2@ pretreatments passivated the surface causing longer t@sub inc@, lower nuclei density, larger nuclei, and rougher final films. H@super +@ pretreatments increased the number of nucleation sites resulting in shorter t@sub inc@, higher nuclei density, smaller nuclei, and smoother final films. However, the mechanism for H@super +@ effects on nucleation was not elucidated in that study. Therefore, the study was extended to include the effects of (1) ion dose and energy, (2) other ions (Ar@super +@, He@super +@, N@super +@) and (3) temperature of the pretreatment on the nucleation of poly-Si on SiO@sub 2@. There are three major results from the surface pretreatment experiments. First, in the range tested, ion dose has more influence on nucleation parameters than ion beam energy. Second, results with different ionic species indicate a physical, rather than chemical mechanism, for creating nucleation sites. Third, high temperature ionic pretreatments damage the surface less than room temperature treatments. @FootnoteText@ @footnote 1@T. Yamazaki, M. Miyata, T. Aoyama, and T. Ito, J. Electrochem. Soc., 139, p. 1175 (1992). @footnote 2@K. Tsubochi and K. Masu, Mat. Res. Soc. Symp. Proc., 315, p. 59 (1993). @footnote 3@J. T. Fitch, J. Electrochem. Soc., 141, p. 1046 (1994). @footnote 4@Y. Z. Hu, C. Y. Zhao, C. Basa, W. X. Gao, and E. A. Irene, Appl. Phys. Lett., 69, p. 485 (1996).