Stress Relaxation in Sandwiched Si3N4/Al/Si3N4 Thin Films

Abstract

An in-situ investigation was performed on the stress relaxation of sandwiched Si3N4/Al/Si3N4 thin films by using multi-beam optical stress sensor (MOSS), a developed technique for substrate curvature measurement. Furthermore, the microstructures of the thin films were characterized by several analyzing techniques, such as X-ray Photoelectron Spectroscopy (XPS), Field Emission Scanning Electron Microscope (FE-SEM) and X-ray energy dispersive spectroscopy (EDS). The results indicated sharp rise and drop of the residual stress due to the cracks of Si3N4 surface layer or the separation of Al particles during annealing process. An appropriate model was suggested to interpret this phenomenon.