Capability of tip-enhanced Raman spectroscopy about nanoscale analysis of strained silicon for semiconductor devices production

Abstract

Localized strained silicon was observed with a suitable resolution in a real semiconductor device by tip-enhanced Raman spectroscopy (TERS). The device was made via a standard industrial process and its silicon trench isolation structures were used for the silicon strain analysis obtaining results according to finite element method-based simulation data. We have achieved a reliable and repeatable enhancement factor obtaining a trace of strained silicon along the structure with suitable nanometer spatial resolution compatible with IC industry requirements. We demonstrate that the complexity to analyze a real 3D structure, directly from the production lines and not ad hoc realized, entails the challenges to individuate the optimal tip shape, tip contact angle, tip composition, tip positioning system, laser power, and wavelength to achieve an appropriate plasmon resonance inducing a relevant signal to noise ratio. This work gives the base to address the development in TERS optimization for real industrial applications.