Patent ID: 8288211

Claim:
A method for encapsulating a device with a hermetic seal comprising: forming a device on a first substrate or a second substrate; forming a first layer of a first metal over a bonding surface of at least one of the first substrate and a second substrate; forming a keeper layer of the first metal over the first layer of the first metal, wherein the keeper layer is substantially thinner than the first layer of the first metal; forming a layer of a second metal over the keeper layer, wherein the layer of the second metal is substantially thicker than the keeper layer; forming a raised feature raised feature comprising a material which maintains its rigidity at the process temperature, and is disposed in at least a portion of a perimeter around the device and protruding from the bonding surface and into at least one of the first layer and a second layer of the first metal on the at least one of the first and the second substrate; and forming a second layer of the first metal on the other substrate not having the first layer of the first metal; coupling the first substrate to the second substrate; and heating the first and second substrates to form an alloy of the first metal and the second metal, by heating to the bonding temperature, wherein the bonding temperature is higher than the melting point of at least one of the first metal and the second metal, wherein the alloy is disposed over and around the raised feature; to encapsulate the device in a substantially hermetic seal formed by the alloy.