A microelectromechanical system (MEMS) device is provided that includes a substrate having a dielectric cavity formed therein and a movable electromechanical device suspended in the dielectric cavity. The dielectric cavity includes a substantially planar bottom surface and at least one sidewall surface extending substantially perpendicularly from the bottom surface. The movable electromechanical device is suspended in the dielectric cavity such that the movable electromechanical device is spaced apart from the bottom surface and the at least one sidewall surface of the dielectric cavity. The bottom surface of the cavity and each of the at least one sidewall surface of the cavity meet at a rectilinear corner.

A microelectromechanical system (MEMS) device is provided that includes a substrate having a dielectric cavity formed therein and a movable electromechanical device suspended in the dielectric cavity. The dielectric cavity includes a substantially planar bottom surface and at least one sidewall surface extending substantially perpendicularly from the bottom surface. The movable electromechanical device is suspended in the dielectric cavity such that the movable electromechanical device is spaced apart from the bottom surface and the at least one sidewall surface of the dielectric cavity. The bottom surface of the cavity and each of the at least one sidewall surface of the cavity meet at a rectilinear corner.

A vibration transducer includes a silicon substrate, a first oxide film formed on the silicon substrate, an activation layer formed on the first oxide film, a second oxide film formed on the activation layer, a polysilicon layer formed on the second oxide film, and a substrate contact part. A vibrator, a vibrator electrode electrically conducted with the vibrator, a fixed electrode close to the vibrator and a vacuum chamber configured to surround the vibrator are formed in the activation layer. The polysilicon layer forms a shell. The substrate contact part is configured to electrically conduct the polysilicon layer and the silicon substrate, and is formed to continuously surround the vacuum chamber in a region, in which the vibrator, the vibrator electrode and the fixed electrode of the activation layer are not formed, of the activation layer.

A vibration transducer includes a silicon substrate, a first oxide film formed on the silicon substrate, an activation layer formed on the first oxide film, a second oxide film formed on the activation layer, a polysilicon layer formed on the second oxide film, and a substrate contact part. A vibrator, a vibrator electrode electrically conducted with the vibrator, a fixed electrode close to the vibrator and a vacuum chamber configured to surround the vibrator are formed in the activation layer. The polysilicon layer forms a shell. The substrate contact part is configured to electrically conduct the polysilicon layer and the silicon substrate, and is formed to continuously surround the vacuum chamber in a region, in which the vibrator, the vibrator electrode and the fixed electrode of the activation layer are not formed, of the activation layer.