Vibration transducer

A vibration transducer comprising:

• a silicon single crystal substrate;
• vibration beams provided on the silicon single crystal substrate;
• a shell made of a silicon material, surrounding the vibration beams to keep a gap around the vibration beams, and forming vacuum chambers together with the substrate;
• an exciting module configured to excite the vibration beams;
• and
• a vibration detection module configured to detect vibrations of the vibration beams;
• wherein the vibration beams include first and second silicon single crystal vibration beams provided in the vacuum chambers, each of which has a sectional shape with a longer sectional thickness in a direction perpendicular to a surface of the substrate than a sectional thickness in a direction parallel to the surface of the substrate, and which are provided in parallel with the substrate and in parallel with each other, and
• wherein the vibration transducer further comprises:
• a plate-like first electrode plate provided in parallel with the surface of the substrate and connected to one end of each of the first and second vibration beams;
• a second electrode plate provided in parallel with the surface of the substrate and between the first and second vibration beams;
• plate-like third and fourth electrode plates provided on opposite sides of the first and second vibration beams so that the first and second vibration beams are put between the third and fourth electrode plates, forming one plane in parallel with the surface of the substrate together with the first and second vibration beams and the first and second electrode plates;
• and
• asperities provided in opposed side wall portion surfaces of the vibration beams and the second, third and fourth electrode plates so as to prevent the vibrating beams from adhering to the second, third and fourth electrode plates.