Abstract: A microelectromechanical system (MEMS) structure and method of forming the MEMS device, including forming a first metallization structure over a complementary metal-oxide-semiconductor (CMOS) wafer, where the first metallization structure includes a first sacrificial oxide layer and a first metal contact pad. A second metallization structure is formed over a MEMS wafer, where the second metallization structure includes a second sacrificial oxide layer and a second metal contact pad. The first metallization structure and second metallization structure are then bonded together. After the first metallization structure and second metallization structure are bonded together, patterning and etching the MEMS wafer to form a MEMS element over the second sacrificial oxide layer. After the MEMS element is formed, removing the first sacrificial oxide layer and second sacrificial oxide layer to allow the MEMS element to move freely about an axis.

Abstract: An etching method with less waste gases. Firstly, provide a substrate covered by a dielectric layer, and put both the substrate and the dielectric layer into a chamber that is coupled with a power source and a C3F8 reactive gases source. Next, provide a plasma inside the chamber under an environment with a low RF power, and a low pressure. Finally, terminate the existence of the plasma and move both the substrate and the etched dielectric later out the chamber.