The development of III-V semiconductor growth techniques on crystalline oxide substrates, such as SrTiO3, has become a field of increased interest, since it allows for the elaboration of integrated devices combining the specific properties of functional oxides and the electronic or optical properties of semiconductors (1,2) . Moreover, the epitaxial growth of crystalline oxides on Si has attained a good state of art (3), which could thus allow for the subsequent integration of optoelectronic functionalities on Si.
In this work, we present in a first step results of the epitaxial growth of III-V semiconductor (InP, InAs) on single crystalline SrTiO3 (STO) substrates. The samples were grown by molecular beam epitaxy, and a detailed study of the growth modes was done by Reflection High Energy Electron Diffraction (RHEED) and Atomic Force Microscopy (AFM).The formation of 3D semiconductor quantum dots is observed on the STO(001) surface. We have done a detailed study of island densities as a function of temperature and deposition rate at different nominal thicknesses. From the maximum density of stable clusters as a function of temperature, and using an approximation of Venables rate theory, we could estimate the activation energies for diffusion and absorption.
We have also studied the epitaxial growth of III-V semiconductor on SrTiO3 layers epitaxially grown on Si (001) substrates, and the 3D islands growth is compared with the model system III-V SC / SrTiO3 (001). All these results are also compared with other SC / oxide systems and some general trends of the nucleation behaviour of III – V quantum dots on oxide surfaces are discussed.
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