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 ion-implantation 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 °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.