Getters films at wafer level for wafer to wafer bonded MEMS

Low cost and reliability are the main important factors for the successful commercialization of MEMs devices. It is possible to decrease the cost of the MEMs device by shifting from ceramic packages down to wafer to wafer bonded MEMs. On the other hand, the ability to maintain the suitable environmental conditions either vacuum or inert gas inside the package of some MEMs devices is the key for assuring high reliability to these MEMs devices. Getter materials are the viable and experienced way to assure long term stability of vacuum in sealed devices. In this paper, we describe the getter solution for wafer to wafer bonded MEMs: it consists of a Si or glass wafer where a getter film is patterned and placed into grooves. This Si or glass wafer with patterned getter film will be the cap wafer of the wafer to wafer bonded MEMs. The getter film is highly porous in order to maximize the sorption performances even at room temperature during the life of the MEMs devices.