Monitoring and modeling silicon homoepitaxy breakdown with real-time spectroscopic ellipsometry

Real-time spectroscopic ellipsometry (RTSE) is used to monitor the breakdown of low-temperature homoepitaxial growth of silicon on silicon wafers in a hot-wire chemical-vapor deposition reactor. We develop and evaluate two optical models to interpret the RTSE data, revealing the progression of epitaxy and its eventual breakdown into amorphous silicon growth. Comparison of the RTSE analysis with cross-sectional transmission electron microscopy, ex situ variable-angle spectroscopic ellipsometry, and Raman spectroscopy measurements shows that RTSE provides accurate and fast quantitative feedback about the progression of epitaxy.