Direct optical stress sensing in semiconductor manufacturing using Raman micro-spectrometry

Local mechanical stresses in semiconductor devices, introduced e.g. by dicing, are an important manufacturing concern. Raman spectroscopy can measure stress in silicon directly, non-destructively and quantitatively. Here, we used Raman spectroscopy to analyse the stress along die sidewalls formed by mechanical and laser dicing, demonstrating that micro-Raman spectroscopy is a feasible sensing method for measuring stress in silicon die sidewalls during manufacture. We found that laser dicing introduces stresses that are significantly lower than those induced by mechanical dicing (typically 170MPa c.f. 70MPa). In addition, for mechanical diced chips different metaphases of silicon were found.