ROOM-TEMPERATURE LUMINESCENCE FROM ER-IMPLANTED SEMIINSULATING POLYCRYSTALLINE SILICON

Semi-insulating polycrystalline silicon films with oxygen concentratio ns in the range 4-27 at. % were deposited by low-pressure chemical vap or deposition of SiH4 and N2O onto silicon substrates, annealed at 920 -degrees-C, and then implanted with 2 X 10(15) 500 keV Er ions/cm2. Af ter annealing at temperatures in the range 300-900-degrees-C, the samp les show intense room-temperature luminescence around 1.54 mum, charac teristic of intra-4f emission from Er3+, upon excitation using an Ar i on laser. The luminescence intensity increases with increasing oxygen concentration in the film. The luminescence is attributed to Er3+ ions in oxygen-rich shells around Si nanograins, excited by a photocarrier -mediated process.