Adhesive Selection and Bonding Parameter Optimization for Hybrid Bonding in 3D Integration

Abstract

Hybrid bonding, an emerging bonding approach with high yield and reliability, can achieve vertical interconnection with adhesive serving reinforcement of the mechanical stability between stacked ICs. To develop metal/adhesive hybrid bonding technology, four kinds of polymer materials, BOB, SU-8, AL-Polymer, and PI, were evaluated as the bonding adhesive. The compatibility between each polymer and metal was investigated, and the application range of each material was established thereof. Furthermore, the scheme of Cu-Sn-Cu interconnection hybridized with patterned BCB was designed and evaluated. Two key factors were discussed and optimized to perform the bonding integrity. The evaluation results and successful metal/adhesive hybrid bonding demonstration are disclosed in the paper.