Study on Chemical Reactions on the Growing Surface to Control the Structures of µc-Silicon from Fluorinated Precursors

Abstract

We investigated the roles of atomic hydrogen in the crystal growth process from fluorinated precursors of SiH _n F _m under the two conditions that are dominated by the surface reaction on the substrate and by the gas phase reaction. Differences in structural morphology of microcrystal were observed by TEM (Transmission Electron Microscopy) measurement, and the dependence of crystal structure and orientation on growth thickness were compared. Furthermore, a slight amount of guest molecules modified the crystal structure effectively and improved the elliptic-shaped crystals in the case of PH₃ doping gas without any post treatment. The shape of the elliptical crystal, especially the length of the longer axis of the crystal, was clearly changed according to the experimental conditions. This behavior appears as the key factor in elucidating the role of doping constituents of P.