| US 7,432,631 B2 | ||
| Piezoelectric thin-film resonator and filter and fabricating method | ||
| Shinji Taniguchi, Kawasaki (Japan); Tokihiro Nishihara, Kawasaki (Japan); Takeshi Sakashita, Kawasaki (Japan); Tsuyoshi Yokoyama, Kawasaki (Japan); Masafumi Iwaki, Kawasaki (Japan); Masanori Ueda, Yokohama (Japan); and Tsutomu Miyashita, Yokohama (Japan) | ||
| Assigned to Fujitsu Media Devices Limited, Yokohama (Japan); and Fujitsu Limited, Kawasaki (Japan) | ||
| Filed on May 27, 2005, as Appl. No. 11/138,893. | ||
| Claims priority of application No. 2004-162646 (JP), filed on May 31, 2004. | ||
| Prior Publication US 2005/0264137 A1, Dec. 01, 2005 | ||
| Int. Cl. H01L 41/04 (2006.01); H03H 9/00 (2006.01) | ||
| U.S. Cl. 310—320 [310/324; 310/369; 333/187; 333/189] | 6 Claims |
| 1. A piezoelectric thin-film resonator comprising:
a device substrate; and
a laminated body provided on the device substrate and composed of a lower electrode, an upper electrode and a piezoelectric
film sandwiched between the lower and upper electrodes,
the laminated body having a membrane portion in which the upper electrode overlaps the lower electrode through the piezoelectric
film,
a gap having a dome shape being formed between the device substrate and the lower electrode and located below the membrane
portion, the gap being a closed space in the laminated body, and having an outline of a closed curve in a projection shape
projected on the device substrate.
|