Photoluminescence studies of selective-area molecular beam epitaxy of GaAs film on Si substrate

Abstract
GaAs films have been grown on Si substrates patterned with SiN by molecular beam epitaxy. The pattern consists of bare Si stripe of width ranging from 10 to 100 μm surrounded by SiN on both sides and a reference area of bare Si. 77 K photoluminescence (PL) spectrum and intensity are measured on the single crystalline GaAs films grown on these stripes and the reference area. For 1.5- and 3-μm-thick films, PL intensity from the 10 μm stripe shows 140% and 75% increase over the reference area, respectively. This remarkable increase in the PL intensity is believed due to the reduction of dislocations inside the window area. The improvement in the optical quality makes selective-area molecular beam epitaxy a very attractive technique for the fabrication of optical devices on Si substrate.