Microelectromechanical Systems (MEMS) resonator is used in various fields such as filters, sensors, transducers and the like. Examples of sensors using the MEMS resonator include inertial sensors, such as a resonant MEMS gyroscope and an accelerometer. In regard to the resonant MEMS gyroscope (MEMS resonant gyroscope), if a frequency of a driving unit matches with a frequency of a measuring unit, a sensing capability greatly increases. Thus, a method for controlling a natural frequency of the MEMS resonator is required. Additionally, when a natural frequency error occurs in a device using the MEMS resonator, such natural frequency control method is used to correct the error and increase product uniformity.
A laser ablation, a Chemical Vapor Deposition (CVD), a Focused Ion Beam (FIB) and the like are usually used as the natural frequency control method for the MEMS resonator. The MEMS resonator frequency control method using the laser ablation is configured to control the frequency by removing a mass of the resonator using a laser. The CVD and the FIB control the frequency by depositing a material on the MEMS resonator to increase the mass of the resonator. However, those methods require expensive equipment and facilities, take a longer time to perform the control, and is unable to restore the controlled frequency.
Therefore, an MEMS resonator and a manufacturing method capable of overcoming those drawbacks may be considered.
USPTO Backgrounds
USPTO Backgrounds