MBE growth of Nitride-Arsenides for long wavelength opto-electronics

To enable devices operating at 1.3 um on GaAs, MBE growth of a new III-V material formed by adding small amounts of nitrogen to InGaAs was developed. The growth of GaInNAs is complicated by the divergent properties of the alloy constituents and the difficulty of generating a reactive nitrogen species. To avoid phase segregation, nitride-arsenides must be grown at relatively low temperatures and high arsenic overpressures. Device quality material is obtained only after a rapid thermal anneal at 760 °C for 1 min. Nuclear reaction channeling measurements show that as-grown nitride-arsenides contain a considerable amount of interstitial nitrogen and that a substantial fraction of the non-substitutional nitrogen disappears during anneal. Secondary ion mass spectroscopy depth profiling on GaInNAs quantum wells shows that during anneal, the nitrogen diffusion is more pronounced than indium diffusion. To limit nitrogen diffusion, the GaInNAs QWs were inserted between GaAsN barriers. This also resulted in longer wavelength emission due to decreased carrier confinement energy. This new active region resulted in devices emitting at 1.3 um.