Patent ID: 7598125

Claim:
A method for wafer level packaging comprising steps of: providing a cap wafer; forming a plurality of cavities on a surface of the cap wafer; forming a patterned photoresist on the cap wafer and etching the cap wafer through the patterned photoresist to form a plurality of openings, then removing the patterned photoresist; bonding the cap wafer to a transparent wafer at the surface having the cavities, wherein the cavities are not bonded to the transparent wafer; segmenting the cap wafer around the cavities and removing a portion of the cap wafer not bonded to the transparent wafer to form a plurality of cap structures; providing a device wafer with a plurality of devices and a plurality of contact pads electrically connected to the devices; and hermetically bonding the cap structures to the device wafer at positions corresponding to the devices to form a plurality of hermetic windows.