Electron microscopy investigations of stress-related degradation of AlGaAs/GaAs quantum well laser diodes

Abstract

The effects of process-induced stress on the formation of defects in AlGaAs/GaAs quantum well laser diodes with a ridge-type waveguide are examined using EBIC, CL and TEM, and the degradation patterns at, and adjacent to, mirror facets are correlated with stress induced by the laser's waveguide overlay. Lasers were separately degraded by operation and by electron irradiation in an SEM. These experiments showed that regions near the lower ridge edges exhibit enhanced susceptibility to degradation. The effect of the ridge on degradation is similar to that of a stripe window.