The Evolution of Bonding from Packaging to the Front End

Wafer processing and assembly and packaging have been distinct, separate areas of semiconductor processing since the very beginning of the semiconductor era. However, with device scaling reaching fundamental limits, advanced packaging incorporating stacking with traditional FEOL technologies (such as CMP) and scaled packaging technologies (such as bonding, thinning, TxV) is now in the forefront for achieving higher bandwidth and density. This presentation focuses on bonding, beginning with a short overview of different bonding technologies. It will then transition to a discussion of fusion and hybrid bonding and their applications in the semiconductor industry. Hybrid bonding, with its multiple benefits of scalability, reliability, SI/PI and across stack thermal conductivity, is rapidly emerging as a key enabler of heterogenous integration, so the focus will then shift to an in-depth discussion of fusion and hybrid bonding technology, with applications ranging from CMOS image sensors to high performance computing to stacked FET [1].