Laser based edge zone release process for ZoneBOND temporary bonding and debonding

Thin wafer handling is extremely important for 3D multichip packaging because ultra-thin wafers of below 50 μ m thickness are difficult to produce and easy to break. Temporary bonding and debonding (TBDB) is necessary process for thin wafer handling. Device wafers that are attached to rigid carrier wafers using temporary adhesives in temporary bonding process don't break during thinning and patterning process. After that processes, the thin wafers can be detached to carrier wafers by debonding process, and ultra thin device wafers are finally produced without breakage. The TBDB process using ZoneBOND carriers are recently introduced as powerful solution for thin wafer handling. The ZoneBond carriers have two zones; the edge zone possesses a full adhesion in several millimeter widths, while the center zone has a lower adhesion. In order to separate ZoneBONB carriers to the thin device wafers after bonding process, the edge zone only need to release. In this study, the laser based edge zone release(EZR) is presented as a faster debonding method without damages for ZoneBOND TBDB process. In addition, the results of feasibility tests to find optimal debonding valuables of laser are shown in this paper. (author)