In situ phase-modulated ellipsometry was employed to monitor the nucleation
and growth processes of diamond thin films fabricated by chemical vapor de
position. The effective extinction coefficient (k) at 1.96 eV was used as a
basis for dividing the deposition process into intervals. The film growth
was aborted at various k values yielding diamond film samples that represen
t snapshots of the growth process at different stages. Ex situ characteriza
tion of the films was performed using Raman spectroscopy, scanning electron
microscopy, and x-ray diffraction. The results indicate that the diamond f
ilm deposition process consists of various stages in which the crystalline
quality, the net compressive stress, and the relative amount of non-sp(3) c
arbon follow different trends. A correlation between the effective k value
measured in situ and the film microstructure characterized ex situ was esta
blished which enables the monitoring of the diamond film growth process in
real time. (C) 2000 American Institute of Physics. [S0021-8979(00)05721-2].