Patent ID: 8742860

Claim:
A Microelectromechanical system (MEMS) resonator comprising: a beam oscillator that oscillates mechanically when an electrostatic force is applied; a supporter that moveably supports the oscillator; and at least one electrode that includes an opposing face to the oscillator across a gap, wherein one of the oscillator and electrode is an input electrode and the other is an output electrode, the oscillator is excited by the electrostatic force caused by an AC signal that is applied through an input terminal connected with the input electrode, and an electric current generated by the oscillation of the oscillator is output through an output terminal connected with the output electrode, the oscillator oscillates in a torsional resonance mode with a center being a longitudinal axis of the beam oscillator, an opposing face of the oscillator and the opposing face of electrode are opposed to each other and are made of first and second impurity-doped semiconductors, respectively, and conductive types of the first impurity-doped semiconductor and the second impurity-doped semiconductor are different from each other, and a surface part of the oscillator including the opposing face to the electrode is doped with an impurity at a higher density than other part of the oscillator.