FORMATION OF GAASP INTERFACE LAYERS MONITORED BY REFLECTANCE ANISOTROPY SPECTROSCOPY

Reflectance anisotropy spectroscopy (RAS) has been used to study As-by -P exchange during metalorganic vapor phase epitaxy. The study focuses on the processes occurring during switching from GaAs to GaInP, espec ially the effect of purging PH3 over a GaAs surface. GaAsP/GaAs superl attices of different periodicity were grown and the P-content was dete rmined by high-resolution xray diffraction and correlated to the RAS s pectra. From the temperature dependence of the P-content, an activatio n energy of 0.56 eV was estimated for the incorporation mechanism. In addition to the insights into the processes at mixed group-V heteroint erfaces, our study demonstrates the reproducibility of RAS transients that thus can be used for process monitoring.