Published online by Cambridge University Press: 16 February 2011
A variety of optical methods are now available for studying surface processes and for monitoring layer thicknesses and compositions during semiconductor crystal growth by molecular beam epitaxy (MBE), organometallic chemical vapor deposition (OMCVD), and related techniques. New capabilities for surface analysis are being provided by developing techniques such as reflectance-difference spectroscopy (RDS), which use intrinsic symmetries to suppress ordinarily dominant bulk contributions. Bulk and microstructural properties such as compositions and layer thicknesses can be determined by techniques such as spectroellipsometry (SE), which return information integrated over the penetration depth of light. Recent advances include the application of reflectance to monitor dynamic surface processes, RDS to characterize (001) GaAs surfaces in OMCVD environments, and SE to control growth of AlxGa1-x, As materials and structures.