Effect of silicon nitride and silicon dioxide bonding on the residual stress in layer-transferred SOI

A detailed investigation of the stress minimisation effect, produced in non-standard SOI wafers by introducing a thin silicon nitride layer in the buried insulator film, has been made. Because the thermal expansion coefficient of Si 3 N 4 is much larger than the one of silicon, this new layer changes the average mechanical behaviour. Then, provided the relative thickness of the buried layers can be properly adjusted, one should be able to get almost perfectly strain-free wafers.