Elastomer-supported cold welding for room temperature wafer-level bonding

This paper presents a method for room-temperature wafer-level bonding that is applicable for the MEMS and NEMS packaging and fabrication processes, but does not require an applied voltage, high pressure or vacuum. By applying a layer of elastomer between the wafer and gold overlayer, we successfully bonded two silicon wafers under limited load (∼3 KPa) at room temperature (25°C). One of the important potential applications of this technique is to create a temporary cap wafer that would protect already released, bulk or surface-micromachined structures during the dicing process. The initial results of experiments on the detachment of the temporary cap wafers bonded using this method are presented.