Interface broadening in as-grown MOVPE InPGaInAs MQW structures: dominant intermixing of group V elements directly revealed by Auger analysis of a chemically bevelled section

Abstract The quality of a 100 period InP GaInAs multiquantum well stack grown by metalorganic vapour phase epitaxy has been assessed by transmission electron microscopy on cleaved corners and Auger analysis of chemically bevelled sections. A trend from sharp to diffuse interfaces was found from the top to the base of the stack. Direct measurement of the variation of each matrix element by Auger electron imaging clearly showed that this interface broadening is dominated by intermixing of the group V elements. The effect is consistent with thermally induced diffusion and was found to be partially suppressed within a sulphur diffused region.