Representation of GaP formation by a reduced order surface kinetics model using p-polarized reflectance measurements

This contribution presents results on the parameter estimation of rate cons tants and optical response factors in a reduced order surface kinetics (ROS K) model, which has been developed to describe the decomposition kinetics o f the organometallic precursors involved and their incorporation into the f ilm deposition. As a real-time characterization technique, we applied p-pol arized reflectance spectroscopy (PRS) during low temperature growth of epit axial GaP heterostructures on Si(001) substrates by pulsed chemical beam ep itaxy. The high surface sensitivity of PRS allows us to follow alterations in the composition and thickness of the surface reaction layer as they are encountered during periodic precursor supply. Linkage of the PRS response t o the ROSK model provides the base for the parameter estimation of the redu ced order surface kinetics model, giving insights into the organometallic p recursor decomposition and growth kinetics. (C) 1999 American Institute of Physics. [S0021-8979(99)07713-0].