Gas-phase silicon atoms in silane chemical vapor deposition: Laser-excited fluorescence measurements and comparisons with model predictions

Abstract

Laser‐excited fluorescence was used to detect gas‐phase silicon atoms during chemical vapor deposition from silane. Relative Si densities were measured as a function of height above the susceptor, susceptor temperature, amount of H₂ added to the He carrier gas, and total pressure. The Si atom density decreased both upon addition of H₂ and as the total pressure was lowered below ∼100 Torr. Comparisons of these measurements with the model developed by Coltrin, Kee, and Miller [J. Electrochem. Soc. 1 3 1, 425 (1984)] show that the model predicts the qualitative behavior of the experimental Si atom profiles over a wide range of experimental conditions. Addition of a mechanism for particulate nucleation to the model may resolve some of the discrepancies between model and experiment.