INFLUENCE OF GROWTH-CONDITIONS ON THE FORMATION OF DEEP PHOTOLUMINESCENCE BANDS IN MBE-GROWN SI LAYERS AND SIGE SI QUANTUM STRUCTURES/

Influence of the growth parameters, i.e. growth temperature and ion bo mbardment, on the quality of SiGe/Si quantum structures and Si thin fi lms, grown by molecular beam epitaxy (MBE), is studied using photolumi nescence (PL) spectroscopy, optically detected cyclotron resonance and high-resolution X-ray diffraction measurements. The bombardment of ev en a low flux of Si+ ions, as present in the MBE growth with biased su bstrates, is shown to degrade essentially the quality of epitaxial str uctures due to creation of both point-like and extended defects. The l ow temperature MBE growth primarily results in a quenching of SiGe-rel ated emissions relative to the substrate-related PL due to formation o f competing non-radiative channels associated, presumably, with vacanc y-type complex defects.