Void reduction in wafer bonding by simultaneously formed ventilation channels

We introduced two techniques for reducing formation of voids in wafer-level hybrid bonding with copper and polymer. As for the first technique, the amount of voids was reduced without any additional processes by forming ventilation channels simultaneously with the bump layer. As a result, dicing yield of 100% was achieved. As for the second technique, post-CMP annealing prevents breakage of bonded wafers after thinning during annealing.