Impact of Nitrogen Doping on the Q-Factor of Polycrystalline 3C-SiC MEMS Resonators

Abstract

This paper reports on the impact of nitrogen doping on the quality factor (Q) of polycrystalline 3C-SiC MEMS resonators. The resonance characteristics of mechanical beam resonators fabricated from an unintentionally and an intentionally doped 3C-SiC thin film were measured with laser Doppler vibrometry. We find a reduction of Q of 28% and 39% for the first and second out-of-plane modes when comparing the unintentionally with the intentionally doped thin film. The difference in Q is attributed to a modification of Young’s modulus (E), due to a change in microstructure and/or the average bond strength.