Room Temperature Debonding - An Enabling Technology for TSV and 3D Integration

Abstract

Thin wafer processing is a critical technology for TSV manufacturing and 3D integration. Thin wafer processing allows to reduce the aspect ratio of the vias, thereby reducing the total processing cost and enables ultra-thin packages for handheld applications. Temporary bonding to a rigid support carrier and debonding after backside processing have been used for thin wafer handling/processing for many years. However, so far all the debonding methods imposed severe limitations on the manufacturability. For light induced debonding the carrier had to be transparent and for solvent based debonding the carrier had to be perforated. For thermally induced debonding, “slide-off debonding” the debonding temperature had to be below the reflow temperature of the solder bumps, which limited the maximal process temperature of the adhesive. In this paper we describe a new debonding method at room temperature. This new technology decouples the debonding process from the adhesive properties, which creates a de facto material independent debonding standard. As the debonding process does not rely on the adhesive properties a major boundary for adhesive engineering has been removed. The debonding method is compatible with bumps or pillars in the bond interface as well as on the backside of the wafer stack. No force is applied on the bumps during debonding which results in very high yields.