A method including fusion bonding a handle wafer to a first side of a device wafer. The method further includes depositing a hardmask on a second side of the device wafer, wherein the second side is planar. An etch stop layer is deposited over the hardmask and an exposed portion of the second side of the device wafer. A dielectric layer is formed over the etch stop layer. A via is formed within the dielectric layer. The via is filled with conductive material. A eutectic bond layer is formed over the conductive material. Portions of the dielectric layer uncovered by the eutectic bond layer is etched to expose the etch stop layer. The exposed portions of the etch stop layer is etched. A micro-electro-mechanical system (MEMS) device pattern is etched into the device wafer.