MEMS device and fabrication method

摘要

MEMS devices and methods for forming the same are provided. A first metal interconnect structure is formed on a first semiconductor substrate to connect to a CMOS control circuit in the first semiconductor substrate. A bonding layer having a cavity is formed on the first metal interconnect structure, and then bonded with a second semiconductor substrate. A conductive plug passes through a first region of the second semiconductor substrate, through the bonding layer, and on the first metal interconnect structure. A second metal interconnect structure includes a first end formed on the first region of the second semiconductor substrate, and a second end connected to the conductive plug. Through-holes are disposed through a second region of the second semiconductor substrate and through a top portion of the bonded layer that is on the cavity to leave a movable electrode to form the MEMS device.

主权项

1. A method of forming a MEMS device, comprising:
providing a first semiconductor substrate and a second semiconductor substrate, wherein the first semiconductor substrate includes a CMOS control circuit and the second semiconductor substrate includes a first region and a second region, the second region being between adjacent first regions; forming a first dielectric layer on the first semiconductor substrate; forming a first metal interconnect structure through the first dielectric layer and on the first semiconductor substrate, the first metal interconnect structure connected to the CMOS control circuit; forming a sacrificial layer on a surface portion of the first dielectric layer; forming a bonding layer on the first dielectric layer such that the sacrificial layer is within the bonding layer; bonding the second semiconductor substrate and the bonding layer together, wherein the second region of the second semiconductor substrate correspondingly covers the sacrificial layer; forming a plurality of first through-holes passing through the first region of the second semiconductor substrate and through the bond layer to expose at least a surface portion of the first metal interconnect structure; forming an isolation layer on a sidewall surface of each first through-hole and on a top surface of the second semiconductor substrate; filling a conductive material in the each first through-hole to form a conductive plug on the first metal interconnect structure; forming a second metal interconnect structure including a first end formed through the isolation layer and on the first region of the second semiconductor substrate, and including a second end connected to an upper end of the conductive plug; forming a plurality of second through-holes through the second region of the second semiconductor substrate and through a top portion of the bonded layer that is on the sacrificial layer; and removing the sacrificial layer along the plurality of second through-holes to form a cavity under the top portion of the bonded layer to leave a movable electrode formed by the top portion of the bonded layer and a remaining portion of the second semiconductor substrate to form the MEMS device.