Direct Die-to-Wafer Hybrid Bonding Using Plasma Diced Dies and Bond Pad Pitch Scaling Down to 2 µm

In this paper, direct die-to-wafer (D2W) hybrid bonding flow is explored using plasma diced dies with bond pad pitch scaling down to 2 μm. All the die preparation steps (including backside thinning, plasma dicing, surface activation, and pick-and-place) are proposed and demonstrated on the carrier wafers to minimize the defects at the bonding surface of die wafers and enable thin die handling capability. With plasma dicing, flexible die shape design (chamfered corners) can be realized, and the inspection results show well-defined die edge and clean sidewall. Good Kelvin and daisy chain yields have been achieved for both 3 and 2 μm test structures.