CHARACTERIZATION OF STRAINED SI SI1-YCY STRUCTURES PREPARED BY MOLECULAR-BEAM EPITAXY/

Various structures containing Si1-yCy alloy layers have been prepared and characterized by x-ray diffraction , cross sectional transmission electron microscopy, photoluminescence (PL), Fourier transform infrare d spectroscopy, and spectroscopic ellipsometry. A band gap reduction e qual to 63 meV/% C has been estimated from PL when taking into account the quantum well (QW) confinement shift using an effective mass calcu lation. The QW-related emission observed from a multiple QW structure has a temperature quenching behavior with an activation energy equal t o 8 meV. Carbon outdiffusion from the QWs has been evidenced by a blue shift of the PL peak and changes in the x-ray diffraction data after f urnace annealing at 800 and 850 degrees C. (C) 1998 American Vacuum So ciety.