Ion Beam Epitaxy of in-situ Er-O Co-Doped Silicon Films

Abstract

AbstractErbium-doped silicon films are grown by ion beam epitaxy (IBE) using an electric-mirror sputtering-type metal ion source in ultrahigh vacuum. In-situ erbium doping with concentrations ranging from 1×1016 to 6×1020 cm−3 is achieved by sputtering the erbium metal pellet with ions extracted from the silicon metal ion source. The oxygen concentration in the films is also controlled in-situ over the range from below 1×1018 to 2×1020 cm−3 by using argon gases containing 1 ppb to 100 ppm of oxygen impurities. The erbium incorporation probability drastically increases (by two or more orders of magnitude) when oxygen is contained in the argon gas during film growth. Erbium is selectively oxidized in the Si host. Erbium segregation and precipitation formation are well suppressed by the oxidation. Sharp and well-split photoluminescence is clearly observed in as-deposited films grown typically at 480°C with oxygen co-doping.