Full planar technology for tunable AlGaInAs/GaInAs-lasers by masked implantation enhanced intermixing

The authors report on the advances in ion implantation technology taking advantage of a masked implantation enhanced intermixing (MIEI)-technique for molecular beam epitaxy (MBE)-AlGaInAs/GaInAs multiple quantum well (MQW)-laser structures to realize a tunable laser by a full planar technology with less process steps for integration. Full planar technology requires a precise adjustment of epitaxy and implantation process steps to optimize the laser resonator structure with respect to defect interdiffusion and ion straggling. To overcome the ion straggling effect and to reduce crystal damage the MIEI-process has to be started from halfwaveguide structures. Masked implantation enhanced intermixing is based on the thermal stability of semiconductor heterostructures being modified by damage induced by ion implantation. Nearly unlimited flexibility in laser resonator design can be realized using local implantation of appropriately masked samples in combination with a rapid thermal annealing step. Vertical halfwaveguide Al/sub 0.24/Ga/sub 0.24/In/sub 0.52/As/ Ga/sub 0.47/In/sub 0.53/As MQW-structures were designed to analyze the MIEI-process. Sufficient lateral band structure variations necessary to integrate fully planar active/passive regions of a multisegment laser with the waveguide regions by the MIEI-technique were achieved. Results on room temperature laser operation of an IEI Al/sub 0.24/Ga/sub 0.24/In/sub 0.52/As/ Ga/sub 0.47/In/sub 0. /MQW-structure with a distributed feedback are demonstrated.