Stress Evaluation of Si Single Crystal with Laser Raman Spectroscopy.

Abstract

The Raman spectrum of silicon that is applied undaxial stress in several directions are observed by micro Raman spectroscopy in order to relate the measured Raman shift to the local stress present In the silicon single crystal. From polarization selection rules, we can selectively observe scattering by optical phonons in Si and determine the stress using the theory of stress effects on optical phonons. If the Raman experiments are performed in backscattering mode on {100} silicon wafers, only σXX+σYY are derived theoretically. In our measurements, the uniaxial stress was applied to the samples which were oriented three different directions. The results of calculation from measured Raman shift are good agreement with applied stress. The ability of this technique is confirmed.