300 mm ultrathin Silicon-On-Insulator (SOI) wafers with SiGe/Si stacks on top were used as pre-structures for the fabrication of 5 nm thick SiGe-On-Insulator (SGOI) substrates obtained by the Ge enrichment technique. Those substrates will be used as the channel of advanced Fully Depleted (FD) p-type Metal Oxide Semiconductor Field Effect Transistors (pMOSFET). We present in the first part the successful fabrication of 5 nm SGOI wafers. Various characterization techniques are used to investigate the Ge profile and the final strain in the fabricated 5 nm Si0.7Ge0.3 film. Secondary Ions Mass Spectrometry (SIMS) and Scanning Transmission Electron Microscopy (STEM) clearly show that the Ge content is very homogeneous (x(Ge) = 30 +/- 1%) in the SiGe layer. Raman spectroscopy and High Angle Annular Dark Field (HAADF) STEM both confirm that the 5 nm thick SiGe film is compressively strained (-2 GPa). The second part is dedicated to the sensitivity of the Ge enrichment process (based on numerical modelling). We investigate the impact of single and combined fluctuations of the pre-structure parameters (T-si, T-SiGe,T-0, x(Ge,0)) on the final SiGe layer (T-SiGe, x(Ge)). (C) 2014 Elsevier Ltd. All rights reserved.