Monitoring of Si molecular-beam epitaxial growth by an ellipsometric method

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.