US Patent 6846725 Wafer-level package for micro-electro-mechanical systems

A method for forming wafers having through-wafer vias for wafer-level packaging of devices, the method comprising the steps of depositing metal on one of two wafers; bonding the two wafers using the metal deposited on the one of the two wafers; forming a through-wafer via in one of the two wafers; filling the through-wafer via with a conductive material; and forming a cavity in the one of the two wafers having the through-wafer via wherein the cavity is superposable over a device.