EXTENDED X-RAY-ABSORPTION FINE-STRUCTURE INVESTIGATION ON BURIED INASP INP INTERFACES/

As K-edge extended x-ray absorption fine structure has been carried ou t on the 2-3 monolayers thick interface of ad hoc grown InAsP/InP expi taxial multistructures deposited by low pressure metalorganic vapor ph ase epitaxy. The goal was to characterize the local structure of the u nwanted, strained interface layers of InAsP produced by the exposure o f the InP surface to AsH3 as occurs during the growth of InP/InGaAs he terostructures. We observed that the first shell environment of As at these interfaces is identical to that found in bulk InAs. In particula r, we measure a constant As-In bond length, independently of As concen tration at the interface; this implies that epitaxy with InP is accomp anied by local structural distortions which accommodate the constant A s-In bond length.