Raman spectroscopy measurement of local stress induced by LOCOS and trench structures in the silicon substrate

Micro-Raman spectroscopy is used to study local mechanical stress at trench-LOCOS structures. At the trench edges the stress is compressive. The local stress surrounding trench and LOCOS is highly affected when both structures are located close to each other. The stress picture obtained from both planar and cross-sectional experiments agrees very well with stress predicted by finite element calculations.