Reliability prediction of 3C-SiC cantilever beams using dynamic Raman spectroscopy

Abstract

We propose an extension and improvement to reliability predictions in epitaxially grown 3C-SiC cantilever beam MEMS by utilizing dynamic Raman spectroscopy to allow the gathering of Weibull fracture test data to be done directly on devices thereby taking account of actual geometrical tolerances, dynamic load conditions and effects from the microfabrication process due to high lattice and thermal mismatch between 3C-SiC and Si. In this work, 3C-SiC devices were fabricated, modeled and actuated to determine both theoretical and experimentally measured strain levels within the device during operation. Initial results indicate both characteristic Raman peaks of 3C-SiC are suitable for this characterization and measurement resolution of 0.02 cm-1 is demonstrated. As the technique is performed directly on devices, it simplifies the frequently found time consuming methodology of preparations of micron-sized specimen fracture test pieces and gives a mechanism for feedback to optimize the fabrication process.