US Patent 7713786 Etching/bonding chamber for encapsulated devices and method of use

A method for activating a getter at low temperature for encapsulation in a device cavity containing a microdevice comprises etching a passivation layer off the getter material while the device wafer and lid wafer are enclosed in a bonding chamber. A plasma etching process may be used, wherein by applying a large negative voltage to the lid wafer, a plasma is formed in the low pressure environment within the bonding chamber. The plasma then etches the passivation layer from the getter material, which is directly thereafter sealed within the device cavity of the microdevice, all within the etching/bonding chamber.