Two complimentary techniques, micro-Raman spectroscopy and white beam synchrotron X-ray topography were employed to study both the micro-cracks and the associated strain fields produced by nano-indentations in Si wafers, which were used as a means of introducing controlled strain in the wafers. It was shown that both the spatial lateral and depth distribution of these long range strain fields were relatively isotropic in nature. The Raman spectra suggested the presence of a region under tensile strain beneath the indents, which could indicate a crack beneath the indent and the data strongly suggested that there exists a minimum critical applied load below which cracking will not initiate.

Observation of Nano-Indent Induced Strain Fields and Dislocation Generation in Silicon Wafers using Micro-Raman Spectroscopy and White Beam X-Ray Topography. D.Allen, J.Wittge, A.Zlotos, E.Gorostegui-Colinas, J.Garagorri, P.J.McNally, A.N.Danilewsky, M.R.Elizalde: Nuclear Instruments and Methods in Physics Research B, 2010, 268[3-4], 383-7