Piezo-actuated MEMS

A microelectromechanical system (MEMS) resonator comprising:

• a single-crystal silicon layer degenerately doped with an impurity concentration, the single-crystal silicon layer serving as a first electrode;
• a polysilicon layer degenerately doped with an impurity concentration, the polysilicon layer serving as a second electrode;
• and
• a piezoelectric layer in between the single-crystal silicon layer and the polysilicon layer.

An oscillator system comprising:

• a microelectromechanical system (MEMS) resonator comprising
• a single-crystal silicon layer degenerately doped with an impurity concentration, the single-crystal silicon layer serving as a first electrode,
• a polysilicon layer degenerately doped with an impurity concentration, the polysilicon layer serving as a second electrode, and
• a piezoelectric layer in between the single-crystal silicon layer and the polysilicon layer;
• a storage circuit for programmed data associated with a temperature-dependent behavior of a frequency of vibration of the MEMS resonator;
• and
• circuitry to output a timing signal dependent on the vibration of the MEMS resonator.

A method of fabricating an oscillator integrated circuit comprising:

• providing a microelectromechanical system (MEMS) resonator having
• a single-crystal silicon layer degenerately doped with an impurity concentration, the single-crystal silicon layer serving as a first electrode, and
• a polysilicon layer degenerately doped with an impurity concentration, the polysilicon layer serving as a second electrode;
• programming a storage circuit of the integrated circuit with data associated with a temperature-dependent behavior of a frequency of vibration of the MEMS resonator;
• such that, during operation of the oscillator integrated circuit, circuitry of the oscillator circuit is operable to output a timing signal dependent on the vibration of the MEMS resonator and dependent on the programmed data.