Temperature reduced direct bonding by plasma assisted wafer surface pre-treatment

As standard wafer bonding processes require typically a high temperature annealing step, this limits the use of wafer bonding. Due to the need to expand the applications field, low temperature (< 400 degrees C) wafer bonding processes were developed. One promising technology is plasma activated wafer bonding. This process consists of a plasma treatment of the substrates surfaces prior to bonding, which results in considerably decreased process temperature. Experimental results illustrating this process' benefits are presented.