US 7,331,092 B2
Method and manufacturing surface acoustic wave device
Michio Miura, Kawasaki (Japan); Takashi Matsuda, Kawasaki (Japan); Yoshio Satoh, Kawasaki (Japan); Masanori Ueda, Yokohama (Japan); and Hideki Takagi, Tsukuba (Japan)
Assigned to Fujitsu Media Devices Limited, Yokohama (Japan); Fujitsu Limited, Kawasaki (Japan); and National Institute of Advanced Industrial Science and Technology, Tokyo (Japan)
Filed on Mar. 23, 2004, as Appl. No. 10/806,148.
Claims priority of application No. 2003-136511 (JP), filed on May 14, 2003.
Prior Publication US 2004/0226162 A1, Nov. 18, 2004
Int. Cl. H04R 17/10 (2006.01)
U.S. Cl. 29—25.35  [29/594; 29/830; 204/192.18; 310/313 R; 310/313 B; 310/322] 3 Claims
OG exemplary drawing
 
1. A method of manufacturing a surface acoustic wave device that has a surface acoustic wave filter including comb-shaped electrodes, electrode pads, and wiring patterns formed on a joined substrate produced by joining a piezoelectric substrate and a supporting substrate to each other,
the method comprising the steps of:
activating at least one of the joining surfaces of the piezoelectric substrate and the supporting substrate; and
joining the piezoelectric substrate and the supporting substrate in such a manner that the activated joining surfaces face each other, wherein:
the activating step includes the step of carrying out an activation process using one of ion beams, neutralized high-energy atom beams, or plasma of inert gas, or oxygen, on at least one of the joining surfaces of the piezoelectric substrate and the supporting substrate;
the joining step includes the step of directly joining the piezoelectric substrate and the supporting substrate at room temperature;
the piezoelectric substrate is a lithium tantalite, or a lithium niobate piezoelectric single-crystal substrate, that is a rotated Y-cut plate having a surface acoustic wave propagation direction X; and
the supporting substrate is a single-crystal substrate containing sapphire as a main component, or a ceramic substrate containing aluminum oxide, aluminum nitride or silicon nitride as a main component.