CARBON-DOPED IMPURITY-INDUCED LAYER DISORDER 0.98 MU-M LASERS

We have fabricated high power carbon-doped InGaAs/AlGaAs lasers using an impurity-induced layer disordering process to define the active reg ion. The advantage of carbon doping is that it exhibits significantly lower diffusivity compared to other p-type dopants, thereby avoiding d isplacement of the p-n junction, even at the high temperatures and lon g diffusion times required by the disordering process. Secondary ion m ass spectrometry (SIMS) measurements before and after Si diffusion sho w the p-n junction position to be unchanged during processing. The car bon was introduced using CCl4 as an extrinsic precursor, giving improv ed control over doping levels and ternary growth conditions that is no t available with intrinsic carbon doping. Thresholds of 20 mA and slop e efficiencies of 0.44 mW/mA at 25-degrees-C were obtained for lasers with cavity lengths of 500 mum and coated facets.