A Novel Method to Maintain Alignment Accuracy in Bonding Process Utilizing Resin as an Adhesive Material

In this paper, we have firstly reported that a novel method to maintain alignment accuracy in wafer bonding process utilizing resin as an adhesive material. In order to maintain alignment accuracy after aligning of two wafers, we have proposed tentatively localized bonding method with 1100 nm near infrared (NIR) radiation that is transparent to Si wafers. With the aid of NIR radiation spots onto the wafer after aligning, wafers are bonded locally and tentatively. The tentatively localized bonding areas act as anchors, which hold wafers during bonding process. In the experiment of wafer bonding process utilizing resin, we have achieved about 4 to 5 times more accurate alignment in micrometer order between wafers for typical case than without tantatively localized bonding.