Abstract
Raman spectroscopy was used to study the spatial resolution of pulsed-photoabsorption-induced quantum-well intermixing in a GaInAs/GaInAsP laser structure. A differential band gap shift of up to 60 meV has been obtained from a sample masked with SixNy/Au and exposed to the laser irradiation. Intermixing was detected in the irradiated regions through the shift of GaAs-like modes to lower frequencies. In addition, the intermixing induced GaInP longitudinal optical modes in the irradiated regions, which is evidence of the intermixing between the upper GaInAs cap and the GaInAsP layer. The spatial resolution of this process, which was obtained from micro-Raman spectra when scanned across the interface of the intermixing mask, was found to be better than 2.5 mu m. (C) 2000 American Institute of Physics. [S0021-8979(00)04106-2].