Ellipsometric measurements were applied to investigate Si homoepitaxial gro
wth by molecular-beam epitaxy on a Si(lll)substrate, and the changes in fil
m thickness and optical parameters were monitored. The reflection high-ener
gy electron diffraction (RHEED) intensity oscillation monitoring method was
also employed for comparison. In the epitaxial growth mode, Psi and Delta
values showed only a small spiral variation and the analyzed optical consta
nts were nearly the same as those of single-crystal Si. The film thickness
obtained by the ellipsometric method exhibited good agreement with that obt
ained by RHEED oscillation as well as by a quartz crystal monitor. Thus, it
was shown that the film thickness monitoring by ellipsometry is useful eve
n for the Si/Si homoepitaxial growth with a step Row mechanism, where the R
HEED oscillation monitoring method is not available.