Single crystalline 4H-polytype silicon carbide microresonator sensor for mass detection

• Published in: Materials letters 2014-08, Vol.128, p.64-67
• Main Authors: Chen, Zhibang, Zhao, Feng
• Format: Article
• Language: English
• Subjects: Mass detection; Resonant frequency; Sensor; Silicon carbide; Single crystalline
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2014.04.093

In this paper, the mass detection capability of microresonator sensors formed on a wide bandgap semiconductor material platform – single crystalline 4H-polytype silicon carbide (4H-SiC) was investigated. Microresonators in the cantilever configuration were fabricated on a 4H-SiC substrate and a dynamic vibration method was applied to characterize the resonant frequency and its shift with the point mass added at the cantilever tip by focused ion beam induced platinum (Pt) deposition. As experimental results show, a mass sensitivity of 799.3Hz/pg (1.25fg/Hz) was demonstrated by cantilevers of 80μm×2.9μm×1μm in size. The linear dependence of frequency shift with added Pt mass and sensitivity data agree very well with an analytical model. This mass sensing capability together with the superior chemical, biological and mechanical properties of single crystal 4H-SiC material makes 4H-SiC microresonator sensor very promising for chemical sensing and bio-sensing. •The mass detection capability of a microresonator sensor on a wide bandgap semiconductor – single crystal 4H-SiC was investigated.•The sensor is capable of sensing picogram and femtogram mass with a sensitivity of 799.3 Hz/pg (1.25fg/Hz).•The experimental results agree well with an analytical model which gives approaches to further improve the sensitivity.•The sensitivity and material properties make 4H-SiC microresonator sensor promising for chemical and biomedical sensing.