Ag. Taylor et al., DYNAMIC REFLECTANCE ANISOTROPY AND REFLECTANCE MEASUREMENTS OF THE DEPOSITION OF SI ON GAAS(001)-C(4X4), Journal of crystal growth, 172(3-4), 1997, pp. 275-283
Dynamic reflectance anisotropy and reflectance data recorded using a p
hoton energy of 1.96 eV is presented for the deposition of atomic Si o
n singular GaAs(001)-c(4 x 4) surfaces under molecular beam epitaxy co
nditions at 400, 450 and 500 degrees C. Changes in reflectance anisotr
opy were detected at the 0.1% of a monolayer level underlining the sen
sitivity of the method. Dynamic changes were found in the reflectance
anisotropy response upon the interruption of dosing providing a caveat
that static reflectance difference spectroscopy does not provide true
dynamical information on the surface processes and that temporal info
rmation on surface migration is available. Evidence for dramatic chang
es in reflectance was found during deposition, these changes being par
ticularly pronounced at higher temperatures and are an indicator of su
rface roughening processes. Subsequent growth of GaAs returns the surf
ace to GaAs like behaviour after similar to 15 monolayers and provides
real time evidence for Si segregation at the surface.