Patent ID: 8217474

Claim:
A hermetic microelectromechanical system (MEMS) package, comprising: a CMOS MEMS chip, having a silicon substrate and a structural dielectric layer, wherein the silicon substrate have a first surface and a second surface opposite to the first surface and has a MEMS region and a CMOS integrated-circuit (IC) region, wherein CMOS transistors are formed on the first surface of the silicon substrate in the CMOS IC region and the silicon substrate is used as a transistor substrate of the CMOS transistors, wherein the silicon substrate is structural to form a chamber at the MEMS region and a MEMS structure within the chamber, wherein the structural dielectric layer comprises an interconnection structure formed on the first surface of the silicon substrate over the CMOS IC region and the MEMS region, wherein the interconnection structure is used to connect the CMOS transistors to form a CMOS IC and electrically couple between the CMOS IC and the MEMS structure within the chamber, wherein the interconnection structure further comprises a protection structure layer formed in the structural dielectric layer and the chamber is covered by the protection structure layer, wherein the chamber is exposed to an environment at the second surface of the silicon substrate, the interconnection structure further comprises an output pad structure to couple an electrical signal of the CMOS MEMS chip out; and a first substrate, adhered to the second surface of the first substrate on the chamber via an adhesive layer to form a hermetic space, wherein the MEMS structure is within the hermetic space.