Protection of InP epi-ready wafers by controlled oxide growth

The quality of thermally cleaned InP (100) surfaces and that of GaInAs and InP layers subsequently grown by molecular beam epitaxy (MBE) are analyzed to assess the potential of two epi-ready oxidation procedures. GaInAs/InP structures were fabricated using a multichamber integrated UHV system combining a MBE reactor and a VWS surface analysis chamber with high resolution X-ray photoelectron spectroscopy (XPS) facilities. It is shown that by protecting thin oxide layers grown by thermal or UV oxidation on epi-ready InP wafers. the preparation of clean substrate surfaces prior to MBE growth can be achieved without any additional chemical cleaning by the grower. Results concerning substrate morphologies, oval defect density in epitaxial layers and interface contaminations compare favorably with results obtained using conventional wet chemical cleaning procedures