Lattice deformations in strained-silicon rib structures for photonic devices

This work reports a theoretical and experimental study on lattice deformation in silicon-rib structure induced by deposition of a stoichiometric silicon-nitride (Si₃N₄) layer. Simulations of stress and strain distributions in silicon rib were performed along with estimation of optical properties for structures on a silicon-on-insulator (SOI) platform; moreover, locally-accurate strain measurements were performed on the microfabricated rib structures in proximity of the nitride-to-silicon interface employing the Convergent Beam Electron Diffraction (CBED) technique. Experimental results, as well as comparison with simulations, pointed out significant induced stress values permitting to achieve electro-optical devices such as modulators and switches.