High-cyclic fatigue experiments of single crystal silicon in an oxygen-free environment

We report on the first study of fatigue in single crystal silicon MEMS resonators within an extremely clean and controlled environment using the `epi-seal´ encapsulation technology. This packaging technology provides a unique opportunity to investigate controversial issues in silicon fatigue since the devices are not exposed to air, oxygen, organics, or other residues that might complicate the initiation and observation of fatigue. We have conducted fatigue experiments on 10 devices over 10¹⁰ actuation cycles with various dynamic loadings ranging from 1.0 to 1.9 GPa at 29??C and from 0.2 to 1.1 GPa at 280??C. No fatigue related phenomena have been observed under these experimental conditions.