Threading dislocations in the Si layer of 3 different types of Si-on-insulator sample, which had been produced by using implanted O (SIMOX) processes (standard or improved separation), were investigated by means of synchrotron X-ray topography,

scanning electron microscopy, and optical microscopy. The densities and Burgers vectors of the dislocations were determined non-destructively by using synchrotron X-ray topographic methods. The line directions of the same dislocations were then determined by means of scanning electron microscopy, after Secco etching. The results were compared with those which had been obtained via the optical microscopy of Secco-etched samples. The threading dislocations in the Si layer were found to occur mainly in pairs, with densities that were of the order of 105/cm2 in standard SIMOX samples and of the order of 104/cm2 in improved SIMOX samples.E.Prieur, C.Guilhalmenc, J.Härtwig, M.Ohler, A.Garcia, B.Aspar: Journal of Applied Physics, 1996, 80[4], 2113-20