In situ investigation of the low-pressure metalorganic chemical vapor deposition of lattice-mismatched semiconductors using reflectance anisotropy measurements

The growth of InAs on InP and InP on GaAs is investigated using reflectance anisotropy (RA) measurements. Very large optical anisotropies are observed, related to the three-dimensional growth mode of these materials. A model is proposed to account for the optical properties of the samples, using effective medium theories to describe the roughness. Good quantitative agreement is obtained for small roughness thickness, and a qualitative description is found for larger roughness features. The RA technique is found to be very useful to monitor the growth of lattice-mismatched materials, particularly at the nucleation stage.