Abstract
We have investigated in situ monitoring of growth rate and refractive index by laser reflectometry during InGaAs on GaAs (00 1) substrate growth in atmospheric pressure metalorganic vapour-phase epitaxy (AP-MOVPE). The indium solid composition (x(In)(s)) was varied by changing the substrate temperature or the indium vapour composition (x(In)(s)). The refractive index of InGaAs alloys as a function or temperature and composition was quantified and compared which that of GaAs for 632.8 nm wavelength by simulation of experimental reflectivity responses. Composition analyses were carried out by high-resolution X-ray diffraction (HRXRD) and optical absorption (OA). The layers thicknesses were estimated by scanning electron microscopy (SEM) observations. The temperature dependence of InGaAs growth. rate has been investigated in the temperature range 420-680 degrees C using trimethylgallium (TMGa), trimethylindium (TMIn) and arsine(AsH3) Sources. It shows Arrhenius-type behaviour with an apparent activation energy E-a of 0.62eV (14.26 kcal/mol ). This value is close to that determinate in the AP-MOVPE of GaAs. (c) 2008 Elsevier Ltd. All rights reserved.