MEMS device and manufacturing method thereof

A micro electro mechanical system (MEMS) device, comprising:

• a cap sheet defining a recess;
• and
• a device sheet bonded with the cap sheet and defining a functional cavity directly facing the recess;
• wherein
• the device sheet includes a silicon substrate and a functional portion received in the functional cavity, wherein the functional portion includes two device structure layers stacked in a first direction perpendicular to a surface of the silicon substrate, one conductive structure layer arranged between the two device structure layers, and a dielectric layer sandwiched between the silicon substrate and the device structure layer closer to the silicon substrate, and wherein the two device structure layers are coupled via the conductive structure layer to form electrical paths between the two adjacent device structure layers and the conductive structure layer;
• and
• the functional portion has a first region, a second region, and a third region, wherein
• the two device structure layers and the conductive structure layer each are across the first region, the second region, and the third region, and the two device structure layers and the conductive structure layer cooperatively form a first movable structure in the first region, define an anchor point in the second region, and form a second movable structure in the third region;
• and
• the first movable structure is configured to sense an angular velocity around Z-axis and the second movable structure is configured to sense an angular velocity around X-axis and Y-axis;
• each layer of the two device structure layers and the conductive structure layer in the first region includes two comb-like structures, wherein one of the two comb-like structures includes fixed beams, another of the two comb-like structures includes movable beams, and beams of the two comb-like structures are alternately arranged, forming a forked finger arrangement;
• the two comb-like structures of a respective device structure layer in the first region are separated from the two comb-like structures of the conductive structure layer in the first region, and the two comb-like structures of a device structure layer closer to the silicon substrate are separated from the dielectric layer by a first space.