Micro-electro-mechanical-system (MEMS) resonator and manufacturing method thereof

1. A MEMS resonator, comprising:

a substrate;

a fixed electrode formed on the substrate; and

a movable electrode arranged facing the fixed electrode;

wherein the fixed electrode has a tapered surface on a side surface portion facing the movable electrode, and wherein an internal surface of a support beam of the movable electrode facing the tapered surface of the fixed electrode has an inclined surface.

2. The MEMS resonator as set forth in claim 1 , wherein the tapered surface of the fixed electrode has an inclination angle.

3. The MEMS resonator as set forth in claim 2 , wherein the inclined surface of the support beam has an inclination angle.

4. The MEMS resonator as set forth in claim 1 , wherein a gap between the tapered surface of the fixed electrode and the inclined surface of the support beam of the movable electrode is constant.

5. The MEMS resonator as set forth in claim 1 , wherein the moveable electrode comprises a movable portion, and wherein the moveable portion is a portion extending from the support beam of the movable electrode.

6. A method for manufacturing a MEMS resonator, comprising:

forming, on a substrate, a fixed electrode having a tapered surface on a side surface portion;

forming a sacrificial film on an upper surface portion of the fixed electrode and on the tapered surface of the fixed electrode;

forming, on the substrate and on the sacrificial film, a movable electrode and a support beam of the movable electrode, so that at least part of the upper surface portion of the fixed electrode and the tapered surface of the fixed electrode are arranged opposite to each other; and

removing the sacrificial film.