Disclosing the annihilation effect of ion-implantation induced defects in single-crystal diamond by resonant MEMS

Single-crystal diamond presents as an ideal semiconductor material for high-performance and high-reliability MEMS devices, on account of its outstanding mechanical and physical properties. A smart-cut technology based on ion-implantation was proposed to fabricate the SCD-on-SCD MEMS resonators. However, the ionimplantation damage induced defects would degrade the quality (Q) factors of the diamond MEMS resonators. Here, we systematically investigate the effect of ultra-high vacuum annealing on the resonance properties of SCD cantilevers. It is observed that the Q factors are markedly improved by nearly twice after annealing at 1100 degrees C due to the annihilation of the ion implantation induced damage in the resonators. Therefore, reducing the defects in the resonators by high-temperature annealing the as-fabricated SCD MEMS cantilevers is one of the strategies to improve the Q factors. This work also proves out that MEMS represents a more sensitive tool for characterizing the crystalline quality of diamond, compared with the conventional structural methods.

Automated summary

Single-crystal diamond is an ideal semiconductor material for high-performance and high-reliability MEMS devices due to its excellent mechanical and physical properties. In this study, it was found that the quality factors (Q values) of SCD cantilevers were significantly improved by almost twice after annealing at 1100 degrees C, as the annealing process can eliminate the damage induced by ion implantation. Therefore, high-temperature annealing is an effective method to improve the Q factors of SCD MEMS cantilevers. This work also demonstrates that MEMS can be a more sensitive tool for characterizing the crystalline quality of diamond compared with conventional structural methods.