Abstract
Real-time spectroscopic ellipsometry (SE) has been applied to investigate the nucleation and grain growth processes in microcrystalline silicon thin films deposited by a conventional plasma-enhanced chemical vapor deposition using hydrogen dilution of silane source gas. Real-time SE results revealed the nucleation from hydrogenated amorphous silicon phase, followed by the coalescence of isolated grains exposed on growing surfaces. In the grain growth process, the shows an enhanced surface roughening. The onset of the grain growth and the coalescence of grains were readily characterized by monitoring surface roughness evolution. We found that a nuclei density increases significantly as the hydrogen dilution ratio increases. In contrast, a film thickness at which most of the surface is covered with the gradually reduces with increasing R. The real-time SE results described above showed remarkable agreement with those estimated by transmission electron microscopy and atomic force microscopy. For the mixed-phase surface formed during the phase transition, however, the SE results showed relatively large errors in the analyses. Such difficulties in the real-time SE analysis for the thin film are discussed.
- Received 5 September 2000
DOI:https://doi.org/10.1103/PhysRevB.63.115306
©2001 American Physical Society