A micro-electro-mechanical system sensor and a preparation method thereof

A micro-electromechanical system sensor, wherein the micro-electromechanical system sensor comprises a device wafer (210) and a cap wafer (220), wherein the device wafer (210) comprises:

• a first substrate (211);
• a first dielectric layer (212) disposed on the first substrate (211);
• a first lead (2131), embedded within the first dielectric layer (212) and passing through the thickness direction of the first dielectric layer (212);
• a ground electrode (2141), disposed on a surface of the first dielectric layer (212) away from the first substrate (211), and is electrically connected to the first substrate (211) through the first lead (2131);
• and
• a functional layer (216), the functional layer (216) is electrically connected to the ground electrode (2141);
• the cap wafer (220) comprises:
• a second substrate (221);
• a second dielectric layer (222), disposed on a first surface of the second substrate (221);
• and
• a third conductive layer (223), disposed on a surface of the second dielectric layer (222) away from the second substrate (221), at least a portion of the third conductive layer (223) passes through the second dielectric layer (222) to be electrically connected to the second substrate (221);
• a surface of the third conductive layer (223) away from the second dielectric layer (222) is bonded to the functional layer (216), the second substrate (221) is electrically connected to the ground electrode (2141) through the third conductive layer (223) and the functional layer (216).