Characterization of GaAs films grown on vicinal Si(110) substrates by molecular-beam epitaxy

The optical and structural properties of GaAs films grown at temperatures of between 460 and 690° C on vicinal Si(110) substrates by molecular-beam epitaxy are discussed and compared with the optical properties of (110) GaAs with (100) GaAs. We have discussed the residual strain and stress after annealing. The residual stress in films shifted the PL spectra to lower photon energies as the off-angle increased toward the [001] direction. The orientation dependence of the stress is explainable by the mechanical properties of GaAs films. The thermal stress and strain of (110) GaAs were larger than those of (100) GaAs after annealing. The thermal stress of GaAs on vicinal Si(110) tilted at 6° toward the [001] direction increased from 3×109 to 4.1×109 dyn/cm2 after 1000° C annealing.