| Title |
A Study of the Fabrication and Enhancement of Film Bulk Acoustic Wave Resonator using Two-Step Deposition Method of Piezoelectric Layer |
| Authors |
박성현(Park Sung-Hyun) ; 추순남(Chu Soon-Nam) ; 이능헌(Lee Neung-Heon) |
| Keywords |
FBAR ; ZnO ; Two-Step Deposition ; Filter ; RF Magnetron Sputtering |
| Abstract |
The 2 GHz film bulk acoustic wave resonator(FBAR), one of the most necessary device of the next generation mobile communication system, consisted of solidly mounted resonator(SMR) structure using Brags reflector, was researched in this paper The FBAR applied SiO_{2} and W had large difference of the acoustic impedance to reflector Al to electrode and ZnO to piezoelectric layer. Specially, the FBAR applied the two-step deposition method to improve the c-axis orientation and increase reproducibility of the fabrication device had good performance. The electrical properties of plasma such as impedance, resistance, reactance, V_{pp}, I{pp}, VSWR and phase difference of voltage and current, was analyzed and measured by RF sensor with the variable experiment process factors such as gas ratio, RF power and base vacuum level about concerning the thickness, c-axis orientation, adhesion and roughness. The FBAR device about the optimum condition resulted reflection loss(S_{11}) of -17 dB, resonance frequency of 1.93 GHz, electric-mechanical coefficient(k_{eff}) of 2.38 % and Qualify factor of 580. It was seen better qualify than the common dielectric filter at present and expected on business to the filter device of 2 GHz bandwidth with the MMIC technology. |