In-process ellipsometric monitoring of diamond film growth by microwave plasma enhanced chemical vapor deposition

Abstract

In-process monitoring of diamond film growth was performed with near-infrared ellipsometry (1550 nm). The trajectories in the ellipsometric parameters (ψ,Δ) differ according to the method of substrate pretreatment and the CO/H2 gas ratio used in the microwave plasma-enhanced chemical vapor deposition process. The nucleation density determined from ellipsometry shows qualitative agreement with that from scanning electron microscopy performed after deposition. The rate at which nuclei develop is also monitored, and the observed induction time is shorter for conditions leading to a higher nucleation density.