Preparation of High-Quality Microcrystalline Silicon from Fluorinated Precursors by a Layer-by-Layer Technique

Microcrystalline silicon thin films exhibiting high crystallinity and high quality were successfully fabricated from the fluorinated precursors SiHnFm (n+m≤3) by repeating the deposition of very thin layers, 10 nm thick, and by treatment with atomic hydrogen. Hydrogen concomitant with dangling bonds is efficiently removed from the Si network at the levels of 0.45 at.% and 3.7×1016 spins/cm3, respectively. A specific texture showing a strong orientation toward (220) is observed in the X-ray diffraction (XRD) spectra. High photoconductivity and a considerable diffusion length of 400 nm for holes under the ambipolar condition verify the films' high quality and high crystallinity.