In-Situ Characterization of AlGaAs Layers Grown by Chemical Beam Epitaxy Using Dynamic Optical Reflectivity

Characterization of A1GaAs layers grown in a VG-V80H chemical beam epitaxy chamber was achieved using dynamic optical reflectivity (DOR). The reflectivity for both stationary and rotating substrates was measured using a normal incidence visible laser. The DOR technique was used to measure the complex refractive index and the growth rate of the layer.The composition of the AlGaAs layer was then obtained from the published variation of refractive index with aluminum fraction. Using the refractive indices determined by DOR, good agreement with theory was achieved for the reflectivity trace from a AlGaAs/GaAs superlattice structure.