Stress Characterization of Si by Near-Field Raman Microscope Using Resonant Scattering

We have developed a tapping-mode scanning near-field optical Raman microscope (SNORM) with a caved and pyramidical probe, using resonant Raman scattering, and have measured the stress distribution of Si. The peak frequency shifts to a lower frequency by 0-0.5 cm(-1) in the area covered by silicon dioxide, whereas it shifts to a higher frequency by 0-0.3 cm(-1) in the area uncovered by silicon dioxide, showing that the areas covered and uncovered by silicon dioxide are under tensile and compressive stresses, respectively. It has been found that compressive stresses of about 0.69 GPa/cm2 are concentrated on the corner of the area uncovered by silicon dioxide. The comparison of stress distributions measured with and without the cantilever shows that the SNORM we developed has a spatial resolution of at least less than 250 nm.