STRESS DISTRIBUTIONS AND DEFECT NUCLEATION IN BURIED HETEROSTRUCTURE LASER-DIODES

Shear stress distributions, arising at the corners of the active region of buried heterostructure laser diodes, are calculated for a given mismatch and various dimensions of the buried stripe and also for a single and a multiple quantum well structure. The locations of high stresses are compared to the nucleation sites of shear stress induced defects, as observed by transmission electron microscopy in real lasers. The implications of the defects are illustrated and discussed for the case of an overstress tested diode as well as possibilities to prevent the defect formation.