Abstract: The present disclosure includes micro-electro mechanical system (MEMS) structures and methods of forming the same. Substrates of the MEMS structures are bonded together by fusion bonding at high processing temperatures, which enables more complete removal of chemical species from the dielectric materials in the substrates prior to sealing cavities of the MEMS structures. Fusion bonding of MEMS structures reduces outgassing of chemical species and is compatible with the cavity formation process. The MEMS structures bonded by fusion bonding are mechanically stronger compared to eutectic bonding due to a higher bonding ratio. In addition, fusion bonding enables the formation of through substrate vias (TSVs) in the MEMS structures.

Abstract: A microelectromechanical system (MEMS) device may include a MEMS structure over a first substrate. The MEMS structure comprises a movable element. Depositing a first conductive material over the first substrate and etching trenches in a second substrate. Filling the trenches with a second conductive material and depositing a third conductive material over the second conductive material and the second substrate. Bonding the first substrate and the second substrate and thinning a backside of the second substrate which exposes the second conductive material in the trenches.

Abstract: A method includes forming a Micro-Electro-Mechanical System (MEMS) device on a front surface of a substrate. After the step of forming the MEMS device, a through-opening is formed in the substrate, wherein the through-opening is formed from a backside of the substrate. The through-opening is filled with a dielectric material, which insulates a first portion of the substrate from a second portion of the substrate. An electrical connection is formed on the backside of the substrate. The electrical connection is electrically coupled to the MEMS device through the first portion of the substrate.