| US 7,339,304 B2 | ||
| Surface acoustic wave device | ||
| Michio Kadota, Kyoto (Japan); Takeshi Nakao, Omihachiman (Japan); and Takuo Hada, Nagaokakyo (Japan) | ||
| Assigned to Murata Manufacturing Co., Ltd., Kyoto (Japan) | ||
| Appl. No. 10/595,237 PCT Filed Aug. 06, 2004, PCT No. PCT/JP2004/011364 § 371(c)(1), (2), (4) Date Mar. 29, 2006, PCT Pub. No. WO2005/034347, PCT Pub. Date Apr. 14, 2005. |
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| Claims priority of application No. 2003-346280 (JP), filed on Oct. 03, 2003. | ||
| Prior Publication US 2007/0096592 A1, May 03, 2007 | ||
| Int. Cl. H01L 41/08 (2006.01) | ||
| U.S. Cl. 310—313A [310/313 R; 310/364] | 35 Claims |
| 1. A surface acoustic wave device comprising:
a piezoelectric substrate made of LiNbO3 having an electromechanical coupling coefficient whose square (k2) is at least about 0.025;
at least one electrode made of one of a metal whose density is greater than that of Al, an alloy primarily including the metal
or that is composed of laminated films made of a metal whose density is greater than that of Al or an alloy primarily including
the metal and another metal, the at least one electrode being disposed on the piezoelectric substrate;
a first insulating layer disposed in a region other than a region where said at least one electrode is disposed, a thickness
of the first insulating layer being substantially equal to that of the at least one electrode; and
a second insulating layer covering the at least one electrode and the first insulating layer; wherein
a density of the at least one electrode is at least about 1.5 times greater than that of the first insulating layer.
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