Piezoelectric-driven mems element
AssigneeKabushiki Kaisha Toshiba
InventorsMichihiko Nishigaki, Toshihiko Nagano, Hiroshi Ono, Takashi Kawakubo
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Abstract
A piezoelectric-driven MEMS element includes a substrate, a beam, a fixed portion, a fixed electrode portion and a power source. The beam is provided with a lower electrode film, a lower piezoelectric film, a middle electrode film, an upper piezoelectric film and an upper electrode film. The fixed portion fixes one end of the beam onto the substrate so as to hold the beam with a gap above the substrate. The fixed electrode portion has a capacitive gap between the fixed electrode portion and the other end of the beam. In addition, at least one or two of the lower electrode film, the middle electrode film and the upper electrode film is thicker than the rest thereof.
Claims12
A piezoelectric-driven MEMS element, comprising:
- a substrate;
- a beam including a lower electrode film, a lower piezoelectric film formed on the lower electrode film, a middle electrode film formed on the lower piezoelectric film, an upper piezoelectric film formed on the middle electrode film and an upper electrode film formed on the upper piezoelectric film;
- a fixed portion fixing an end of the beam onto the substrate so as to hold at least a portion of the beam with a gap above the substrate;
- a fixed electrode portion arranged on the substrate so as to have a capacitive gap between the fixed electrode portion and the other end of the beam;
- a power source to apply a voltage between the lower electrode film and the middle electrode film of the beam, and between the upper electrode film and the middle electrode film of the beam,
- wherein
- at least one or two of the lower electrode film, the middle electrode film and the upper electrode film is thicker than the rest thereof.
A piezoelectric-driven MEMS element, comprising:
- a substrate;
- a beam having a lower electrode film, a lower piezoelectric film formed on the lower electrode film, a middle electrode film formed on the lower piezoelectric film, an upper piezoelectric film formed on the middle electrode film and an upper electrode film formed on the upper piezoelectric film;
- a fixed portion fixing one end of the beam so as to hold at least a portion of the beam with a gap above the substrate to be arranged on the substrate;
- a fixed electrode portion arranged on the substrate so as to have a capacitive gap between the fixed electrode portion and the other end of the beam;
- and
- a power source to apply a voltage between the lower electrode film and the middle electrode film of the beam, and between the upper electrode film and the middle electrode film of the beam,
- wherein
- the lower electrode film and the upper electrode film are prevented from being in contact with the middle electrode film.
A piezoelectric-driven MEMS element, comprising:
- a substrate;
- a forward beam and a backward beam to be arranged in a line symmetry, the forward beam and the backward beam being provided with a lower electrode film, a lower piezoelectric film formed on the lower electrode film, a middle electrode film formed on the lower piezoelectric film, an upper piezoelectric film formed on the middle electrode film and an upper electrode film formed on the upper piezoelectric film;
- a connection portion connecting the middle electrode film of the forward beam to the upper electrode film and the lower electrode film of the backward beam, and the upper electrode film and the lower electrode film of the forward beam to the middle electrode film of the backward beam;
- a fixed portion to be arranged on the substrate and on a side opposite to the connection portion of the forward beam, the fixed portion fixing an end of the forward beam to hold a portion thereof with a gap above the substrate;
- a fixed electrode portion arranged on the substrate so as to have a capacitive gap between the fixed electrode portion and the other end of the beam;
- and
- a power source to apply a voltage between the lower electrode film and upper electrode film of the beam, and the middle electrode film of the beam,
- wherein
- the middle electrode film is thicker than the lower electrode film and the upper electrode film.
Dependencies are inferred from the claim text.