Title :
Solidly mounted resonator based on aluminum nitride thin film
Author :
Dubois, M.-A. ; Muralt, Paul ; Matsumoto, Hirokazu ; Plessky, V.
Author_Institution :
Lab. de Ceramique, Swiss Fed. Inst. of Technol., Lausanne, Switzerland
Abstract :
A piezoelectric thin film sandwiched between two conductors is the basic structure for high frequency bulk acoustic wave devices. For that purpose, AlN thin films deposited by DC reactive sputtering on various electrode materials were investigated. Highly c-axis oriented thin films as thick as 2 μm were grown and analyzed. Intrinsic stress values ranging from strong compression to high tension were observed and piezoelectric d33,f coefficients up to 3.9 pm/V were measured. Solidly mounted resonators with a 10-layer acoustic reflector have been fabricated. They exhibited a pronounced resonance peak centered at 2 GHz with a high Q factor and a k2 coupling coefficient of 1%. These characteristics are discussed as a function of the processing conditions and the thin film properties
Keywords :
Q-factor; aluminium compounds; bulk acoustic wave devices; crystal resonators; internal stresses; piezoelectric thin films; sputtered coatings; 2 GHz; AlN; DC reactive sputtering; Q-factor; aluminum nitride thin film; bulk acoustic wave device; electrode; electromechanical coupling coefficient; intrinsic stress; multilayer acoustic reflector; piezoelectric coefficient; solidly mounted resonator; Aluminum nitride; Bulk acoustic wave devices; Conducting materials; Conductive films; Electrodes; Frequency; Piezoelectric films; Sputtering; Stress; Transistors;
Conference_Titel :
Ultrasonics Symposium, 1998. Proceedings., 1998 IEEE
Conference_Location :
Sendai
Print_ISBN :
0-7803-4095-7
DOI :
10.1109/ULTSYM.1998.762291
