Development of DAF (Die Attach Film) with functional gettering agent for metal impurities

Gettering effect which is to trap metal ions on the dangling-bonds located far from the device area is widely known as an inhibition way of this problem. Extrinsic Gettering (EG) method that is formed during back side grinding in the wafer thinning process is one of the most significant technologies considering of reducing cost. However the chip strength has been decreased with increasing the roughness derived from crystal defect. Under these circumstances, we focused on the DAF (Die Attach Film) which is commonly used as an adhesive sheet to stack thin chips and attempted to add a functional gettering agent in this film. We selected Inorganic Ion-Exchange materials as a gettering agent and prepared some samples which have Oxidized Sb for gettering agent. From the result based on this study, the main factor determining gettering effect is an amount of substance of Ion-Exchange materials in the DAF. It's also estimated the quantity of Cu ion adsorption was about 33~50% in the whole of trapped Cu ions in the DAF. And we obtained 38 % Cu ions were adsorbed in the DAF with 10um thickness, which is about 68 % compared to the value from #2000.