Growth of high quality micrometer scale GaAs/Si crystals from (001) Si nano-areas in SiO2
Résumé
High quality micrometer scale GaAs crystals were grown by chemical beam epitaxy from nanoscale Si seeds on a 0.6 nm thick SiO2 layer formed on Si(0 0 1). The use of small diameter openings is expected to lead to a dislocation-free relaxation and to the reduction of the antiphase defects. Thus, the so-formed GaAs crystals are found to be completely relaxed and antiphase boundaries free. The lateral epitaxy without misfit dislocation can evolve on the SiO2 layer that prevents the Si substrate from imposing its lattice parameter on the GaAs crystal. The effect of the growth temperature on the GaAs crystal materials quality was particularly studied by transmission electron microscopy and µ-Raman.