发明名称 |
Piezoelectric thin-film resonator, method for fabricating same, filter and duplexer having an interposed film |
摘要 |
A piezoelectric thin-film resonator includes: a substrate; a piezoelectric film having a lower piezoelectric film provided on the substrate and an upper piezoelectric film provided on the lower piezoelectric film; lower and upper electrodes that face each other through at least a part of the piezoelectric film; an interposed film that is interposed between the lower piezoelectric film and the upper piezoelectric film and is located in an outer circumferential part of a resonance region in which the lower and upper electrodes face each other through the piezoelectric film, the interposed film not being provided in a central part of the resonance region; an upper surface of the lower piezoelectric film having a first roughness in a region in which the interposed film is not provided and a second roughness in another region in which the interposed film is provided, the first roughness being smaller than the second roughness. |
申请公布号 |
US9444429(B2) |
申请公布日期 |
2016.09.13 |
申请号 |
US201414553484 |
申请日期 |
2014.11.25 |
申请人 |
TAIYO YUDEN CO., LTD. |
发明人 |
Sakashita Takeshi;Nishihara Tokihiro;Yokoyama Tsuyoshi |
分类号 |
H03H9/70;H03H9/02;H03H3/02;C23C14/34;C23C16/44;H03H9/17 |
主分类号 |
H03H9/70 |
代理机构 |
Chen Yoshimura LLP |
代理人 |
Chen Yoshimura LLP |
主权项 |
1. A piezoelectric thin-film resonator comprising:
a substrate; a piezoelectric film having a lower piezoelectric film provided on the substrate and an upper piezoelectric film provided on the lower piezoelectric film; a lower electrode and an upper electrode that face each other through at least a part of the piezoelectric film; an interposed film that is interposed between the lower piezoelectric film and the upper piezoelectric film and is located in an outer circumferential part of a resonance region in which the lower electrode and the upper electrode face each other through the piezoelectric film, while the interposed film is not provided in a central part of the resonance region; an upper surface of the lower piezoelectric film having a first roughness in a region in which the interposed film is not provided and a second roughness in another region in which the interposed film is provided, the first roughness being smaller than the second roughness. |
地址 |
Tokyo JP |