Raman measurements of stress in silicon-on-sapphire device structures

Spatially resolved (∼1 μm) Raman scattering measurements of the Si optical phonon spectrum have been used to map the stress in silicon-on-sapphire device structures. Devices defined by an isolated island etch technique exhibit a stress relaxation extending about 1.5 μm from the edges of a 6-μm-wide Si stripe. Devices defined by a local oxidation of the Si exhibit a more uniform stress profile.