In situ monitoring of GaSb, GaInAsSb, and AlGaAsSb

The suitability of the wavelength range provided by silicon photodiode dete ctor arrays for monitoring the spectral reflectance during epitaxial growth of GaSb, AlGaAsSb, and GaInAsSb, which have cutoff wavelengths at 25 degre es C of 1.7, 1.2, and 2.3 mu m, respectively, is demonstrated. These alloys were grown lattice matched to GaSb in a vertical rotating-disk reactor, wh ich was modified to accommodate near normal reflectance without affecting e pilayer uniformity. By using a virtual interface model, the growth rate and complex refractive index at the growth temperature are extracted for these alloys over the 600-1000 nm spectral range. Excellent agreement is obtaine d between the extracted growth rate and that determined by ex situ measurem ent. (C) 1998 Published by Elsevier Science B.V. All rights reserved.