22 Original scientifc paper  MIDEM Society Journal of Microelectronics, Electronic Components and Materials Vol. 43, No. 1(2013), 22 – 26 Two-Port Piezoelectric Silicon Carbide MEMS Cantilever Resonator Boris Sviličić 1,2 , Enrico Mastropaolo 1 , Rebecca Cheung 1 1 University of Edinburgh, Institute for Integrated Micro and Nano Systems, United Kingdom 2 University of Rijeka, Department of Marine Electronics and Communications, Faculty of Maritime Studies, Croatia Abstract: A two-port silicon carbide single-clamped beam (cantilever) microelectromechanical system (MEMS) resonant device actuated piezoelectrically and sensed piezoelectrically has been designed, fabricated and tested. Lead zirconium titanate (PZT) has been used as active material to implement the piezoelectric actuator and sensor. Piezoelectric electrodes have been placed on the top of the single 3C-SiC beam forming a flexural-mode resonator. Operation has been demonstrated with two-port measurements of the transmission frequency response. The 250-µm long device resonates at 371 kHz with Q factor of 385 in atmospheric conditions. The tuning of the resonant frequency has been demonstrated by applying DC bias voltage in the range 0 V – 10 V and frequency tuning range of 1025 ppm has been achieved. Key words: Silicon carbide, MEMS, resonator, cantilever, piezoelectric actuation, piezoelectric sensing, frequency tuning Dvovhodni piezoelektrični MEMS resonator na ročico iz silicijevega karbida Povzetek: Načrtovan, izdelan in testiran je bil, piezoelektrično vzbujan in merjen, dvovhodni mikroelektromehanski (MEMS) resonatorski sistem z ročko. Za aktuator in senzor je bil uporabljen svinčev cirkonijev titanat (PZT). Piezoelektrične elektrode so nameščene na vrh enojne 3C-SiC gredi, ki tvori upogibni resonator. Delovanje je demonstrirano z dvovhodnimi meritvami prenosa odzivne frekvence. pod atmosferskimi pogoji 250-µm dolg element resonira s frekvenco 371 kHz in Q faktorjem 385. Uglaševanje resonančne frekvence je predstavljeno s spreminjanjem DC napetosti od 0 – 10 V, pri čemer je bilo območje uglaševanja frekvence doseglo 1025 ppm. Ključne besede: silicijev karbid, MEMS, resonator, ročica, piezoelektrično vzbujanje, piezoelektrični senzor, uglaševanje frekvence * Corresponding Author’s e-mail: svilicic@pfri.hr 1. Introduction Microelectromechanical system (MEMS) resonant de- vices are being increasingly considered for replacing filter [1] components and quartz crystal [2] currently used in communication systems. Relatively small di- mensions and low operating voltages enable MEMS resonators to solve power consumption and minia- turisation issues in portable wireless devices [2, 3]. Se- lection of the material plays a very important role for realization of high efficiency MEMS resonant devices. Silicon carbide (SiC), a wide band-gap semiconduc- tor, possesses outstanding mechanical properties that make SiC the most promising material for MEMS reso- nator applications [4]. SiC exhibits a large Young’s mod- ulus to mass density ratio and the resonant frequency of a SiC resonator can be three times higher than its silicon (Si) equivalent [5]. 3C-SiC has emerged as the dominant polytype for MEMS applications as it can be synthesised on Si wafers, potentially leading to large- scale production. Other polytypes such as 4H-SiC and 6H-SiC form at temperatures above the melting point of Si [4]. Electrical actuation and sensing of resonator mechani- cal vibration is essential requirement for the practical implementation of MEMS resonators. Electrostatic and piezoelectric transductions have emerged as the lead- ing techniques and both have been widely implement- ed in Si and SiO 2 resonators [3,6]. However, the complex fabrication process in electrostatic transduction asso- ciated with achieving an electrode-to-resonator gap