Exploring Bond Strength for Advanced Chiplet with Hybrid Bonding

Due to the high demand for further density of vertical interconnection for advanced chiplet, hybrid bonding is now comprehensively investigated as an alternative to microbumps. However, there are a lot of obstacles and challenges that remain in the R&D phase to overcome for die-level hybrid bonding. For example, a method of bonding strength measurement of die-level hybrid bonding has not been well established yet. Therefore, the bonding strength measurement method at the die level was studied using the indentation method with a cube corner. The validity of the nanoindentation test was demonstrated by comparing the bonding strength calculated by the double-cantilever beam and nanoindentation tests. Then, by performing nanoindentation tests on the Die-to-Wafer sample, we compared it to the Wafer-to-Wafer, which has a similar bonding film. Moreover, it showed the difference in bonding strength due to the different bonding films.