Surface migration of the group-III precursors and strain relaxation at the ridge sidewalls are compared for 2.5 μm wide waveguides based on InGaAsP and InGaAlAs multiple-quantum-well (MQW) structures. The cross-sectional thickness and strain variations have been measured using synchrotron radiation-based x-ray diffraction with an angular resolution of 2 arc s and a beam size of (0.24×0.35) μ m2. Indium-rich overgrowth has been observed for the InGaAsP-based waveguides, while InGaAlAs-based waveguides demonstrate thickness uniformity of the MQW active region with a strain relief of 0.4%μm at the sidewalls.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)