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Langasite for microelectromechanical systems
Author(s) -
Ansorge Erik,
Schmidt Bertram,
Sauerwald Jan,
Fritze Holger
Publication year - 2011
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201026508
Subject(s) - materials science , fabrication , resonator , surface micromachining , etching (microfabrication) , microelectromechanical systems , optoelectronics , q factor , planar , wafer , photoresist , composite material , computer science , medicine , alternative medicine , computer graphics (images) , pathology , layer (electronics)
Piezoelectrically actuated plano‐convex thickness shear mode (TSM) resonators in lanthanum gallium silicate (langasite, LGS, La 3 Ga 5 SiO 14 ) were fabricated. For the fabrication of the devices different micromachining technologies were investigated. Finally, a wet etching process and a dry etching process were developed and furthermore graytone‐lithography in combination with photoresist melting has been applied for the final device fabrication. The plano‐convex shape of the resonators is necessary to improve the Q ‐factor of the devices. Simulations have been run to show the influence of the spherically contoured surface. The resulting Q ‐factor was higher than for simple planar resonators, reaching values of about 25 000. Furthermore, the conductance spectra were significantly improved. The special characteristics of langasite allow working temperatures of up to 1450 °C. At 800 °C Q ‐factors of 1700 could be achieved.