1.54 μm wavelength emission of erbium-doped silicon films grown by ion beam epitaxy using sputtering-type metal ion source

Abstract

Erbium-doped silicon films are grown by ion beam epitaxy using a newly developed electric-mirror sputtering-type metal ion source in an ultrahigh vacuum. A precise and steep profile of the erbium concentration, ranging from 1×1016 to 6×1020 cm−3, is achieved in situ by sputtering the erbium metal pellet with ions extracted from the silicon ion source. The oxygen concentration in the films, which is important to effective luminescence of erbium in silicon, is controlled in situ in the range from below 1×1018 to 2×1020 cm−3 by using argon gases containing oxygen impurities ranging from 1 ppb to 100 ppm. The oxygen concentration trapped in the silicon films strongly depends on the erbium concentration doped in the films. The erbium atoms are selectively oxidized in the host silicon film. As a result, the photoluminescence of 1.54 μm wavelength light is clearly observed in as-deposited films.