Embedded micromechanical devices for the monolithic integration ofMEMS with CMOS

摘要

A flexible, modular manufacturing process for integratingmicromechanical and microelectronic devices has been developed. Thisprocess embeds the micromechanical devices in an anisotropically etchedtrench below the surface of the wafer. Prior to microelectronic devicefabrication, this trench is refilled with oxide, chemical-mechanicallypolished, and sealed with a nitride cap in order to embed themicromechanical devices below the surface of the planarized wafer. Thefeasibility of this technique in a manufacturing environment has beendemonstrated by combining a variety of embedded micromechanicalstructures with a 2 μm CMOS process on 6 inch wafers. A yield of 78%has been achieved on the first devices manufactured using this technique