Simultaneous doping of silicon layers with erbium and oxygen in the courseof molecular-beam epitaxy

Epitaxial silicon layers codoped with erbium and oxygen were grown by molec ular-beam epitaxy using a silicon sublimation source. For growing the erbiu m-doped silicon layers, two types of impurity sources were used: (i) erbium -doped silicon plates were used as a source of fluxes of Er and Si atoms; a nd (ii) metallic erbium plates were used as an impurity-vapor source in com bination with the silicon sublimation source. If gaseous oxygen was used fo r in situ codoping with erbium and oxygen, then concentrations ranging from 10(18) to 10(20) cm(-3) were attained. When oxygen is in the growth chambe r, the erbium-entrapment efficiency of a layer increases substantially, wit h the surface segregation of erbium also being suppressed by oxidation. (C) 2001 MAIK "Nauka/Interperiodica".