Determination of the distribution of process induced strain in silicon by confocal Raman microscopy

Raman spectroscopy was used to determine the degree and spatial distribution of strain induced in silicon by laser drilling. Imaging of the strain as indicated by displacement of the silicon Raman peak position showed indicated distortion of the silicon lattice up to a few tens of micrometers from the laser drilled hole. Less aggressive drilling minimized the strain. A two minute KOH etch was sufficient to remove the strained material.