Raman spectroscopic investigation of the stress state in silicon substrates near edges of Pt/PZT microstructures

Hydrostatic stresses in Si substrates near edges of Pt/PZT microstructures used in pyrosensor fabrication have been predicted theoretically by finite element (FE) calculations. Within the absorption limited depth zone from which Raman radiation can be detected the substrate stress varies considerably. The characteristic lateral length scale of the average stress profile perpendicular to the film edges is less than 50 mu m resulting from contributions of different depth. These stresses could be measured by spatially resolved Raman spectroscopy with an accuracy of 1-2 mu m. The values of the film stress of Pt and PZT have been estimated by fitting the FE models to the measured curves of the stress distribution in the Si substrate.