Realization of Si_1-x-yGe_xC_y Si heterostructures by pulsed laser induced epitaxy of C⁺ implanted pseudomorphic SiGe films and of a-SiGeC: H films deposited on Si(100)

Si_1-x-yGe_xC_y Si heterostructures are realized by pulsed laser induced epitaxy (PLIE) from C⁺ implanted pseudomorphic Si_0.84Ge_0.16 films and from hydrogenated amorphous SiGeC films deposited on Si(100). The laser treated samples are examined by electron channelling, energy dispersive X-ray analysis, Rutherford backscattering spectroscopy and ion channelling, X-ray diffraction, secondary ion mass spectrometry, and infrared and Raman spectroscopy. We show that PLIE occurs when the laser fluence exceeds a threshold for which the liquid-solid interface reaches the crystalline substrate at each laser pulse. Above this threshold, germanium and carbon atoms diffuse inside the melted layer, and carbon incorporation in substitutional sites increases with the laser fluence and the number of pulses. The resulting SiGeC layers are pseudomorphic.