TY - GEN A1 - Schmeißer, Dieter A1 - Pressel, Klaus A1 - Yamamoto, Yuji A1 - Tillack, Bernd A1 - Krüger, D. T1 - Ge instabilities near interfaces in Si-SiGe-Si heterostructures T2 - Materials Science & Engineering B N2 - Compositional characterization of interfaces in Si-cap/SixGe1-x/Si heterostructures is an important topic in SiGe based advanced microelectronics and in quantum wells. Extremely high depth resolution is required to detect and optimize near-interface compositional gradients which are crucial for high circuit performance. We report on non-destructive, high-resolution, near-interface depth profiling using SR photoelectron spectroscopy at an undulator beamline. We measured the Ge content at the SixGe1-x interface towards the native SiO2 layer and investigated the influence of additional (1nm and 2nm) Si capping layers (Si-cap). For the uncapped samples we found near the oxide/ SiGe interface region a strong mixing of Ge-oxides and SiOx. This indicates a high instability of the Ge atoms at those interfaces while silicon capped (1nm, 2nm) SixGe1-x films are more stable. We detect sharp Ge concentration gradients within the first 1nm at the Si/SixGe1-x interface. These results open new possibilities for Ge profile optimization in Si-cap/SixGe1-x/Si heterostructures. In the Ge3d spectra we differentiate the Ge atoms to occupy three different lattice sites and are able to follow their relative occupation within the Ge gradient. KW - SiGe KW - Depth profiling KW - Interfaces KW - XPS Y1 - 2005 UR - https://opus4.kobv.de/opus4-UBICO/frontdoor/index/index/docId/1972 SN - 0921-5107 SN - 1873-4944 VL - 101 IS - 1-3 SP - 208 EP - 211 ER -