PHOTOLUMINESCENCE AND X-RAY CHARACTERIZATION OF RELAXED SI1-XGEX ALLOYS GROWN ON SILICON-ON-INSULATOR (SOI) AND IMPLANTED SOI SUBSTRATES

Boron and oxygen were implanted into the SiO2 region of a thin silicon on insulator (SOI) substrate to form borosilicate glass and reduce th e reflow temperature needed for compliant substrates. The effect of lo wering the reflow temperature was examined by characterizing a straine d Si0.7Ge0.3 layer which was grown on the implanted compliant substrat e by molecular beam epitaxy. Photoluminescence (PL) and triple-axis X- ray diffraction were used to characterize film quality, Ge concentrati on and percent relaxation, A marked decrease in the annealing temperat ure required (roughly a difference of 300 degrees C) to relax the Si0. 7Ge0.3 layer was fully observed. The PL spectra show a broad band arou nd 800 meV that is believed to be related to the relaxation of the SiG e layer. The intensity of this peak first increases and then decreases dramatically when the annealing temperature reaches the point when th e SiGe layer begins to relax or the underlying glass begins to flow, F or the sample grown on the boron and oxygen implanted BESOI, this low- energy peak is shown to disappear completely at an annealing temperatu re of 900 degrees C. Above 900 degrees C, we begin to see the evolutio n of near band-gap luminescence for the Si0.7Ge0.3 layer grown on impl anted BESOI. An energy peak which shifts to higher energies, from 970 to 1025 meV, with greater relaxation is only observed for the sample g rown on the implanted substrate, It is believed that the observation o f near band-gap luminescence is primarily due to the reduced reflow te mperature and a low-defect dislocation concentration in the Si0.7Ge0.3 film.