Microbeam High Resolution X-ray Diffraction and Reciprocal Space Mapping Characterization of Selective Area Grown InGaN/GaN Waveguides

We present microbeam high-resolution x-ray diffraction (HRXRD) and Reciprocal Space Mapping (RSM) analysis of InGaN/GaN-based MQW ridge-waveguide arrays for monolithically integrated optoelectronic devices. InGaN/GaN waveguides were produced by the MOVPE technique in the Selective Area Growth (SAG) regime with the width of 6 microns and the oxide mask widths varied between 2 and 14 microns. Synchrotron Radiation-based triple- axis HRXRD measurements with the angular resolution of 13 arcsec were carried out at CHESS with the x-ray beamsize of 10 microns. Strain, thickness, and Indium composition variation in the active region of the ridge waveguides have been measured for different configurations of the SAG mask. Gas-phase diffusion coefficients have been determined for In and Ga precursors. Strain-induced relaxation effects in the active regions have been studied using RSM analysis.