To confirm the uniformity on the whole bonded pair by means of a variety of surface energy testings inside bonded pair, a dynamic procedure based on low-temperature (120 degrees C) O-2-plasma assisted wafer bonding was studied. The necessary annealing time was requested to efficiently resist the following post-processes although the optimal plasma exposure time was achieved to avoid annealing voids generated. Experimental results indicated that the procedure of bonding strength enhancement includes two parts; bonding reaction triggers rapidly and subsequent the byproducts diffuse slowly through the interface diffusion. However, the void can exist and lower the local bonding strength thanks to the byproduct's staying in the interface even if no voids are observed by infrared inspection. The uniformity of bonding strength can be improved as annealing time extension. (c) 2005 The Electrochemical Society.