Optical anisotropy and surface morphology of InGaAs lattice-mismatched with GaAs(0 0 1)

We investigated surface morphology and optical anisotropy of strained InGaAs films grown on GaAs(0 0 1) substrate using atomic force microscopy (AFM) and reflectance difference/reflectance anisotropy spectroscopy (RDS/RAS). High temperature (HT)-grown samples were found to have a rippled surface structure, however for films grown using a low temperature (LT) growth technique, the surface morphology was significantly improved, without the ripple structure seen on the HT samples. Furthermore, ex situ RD spectra of LT-grown samples showed notable peaks near the critical energies of band structure originated from bulk electronic transitions.