Novel IR Laser Cleaving for ultra-thin Layer Transfer and 3D Stacked Devices

IR laser debonding has been developed enabling the combination of silicon as a carrier substrate as well as laser debonding through silicon. One solutions is in advanced packaging, where silicon can be seen as a replacement for glass wafers but still in combination with developed adhesive systems. The more impacting application, however, is the combination of IR laser release with fusion bonding, enabling fusion bonding to carriers and area selective detachment after processing. As we base IR laser release on readily available front end compatible materials, processes do not change for backside processes and more importantly the final product wafer thicknesses are not linked to the carrier system but can be thinner than a single
$\mu \mathrm{m}$
prior to laser detachment. Especially in the SRAM, where face to back stacking in combination with high interconnect bandwidth is driving hybrid bonding, a fully anorganic carrier system is essential to enable know hybrid bonding process flows. IR laser release technology in combination with fusion and hybrid bonding for 3D integration or full area wafer stacking. A first use case is in 3D system on chip with multiple stacked memory layers such as SRAM. A second use case will be in 3D integration transferring thin silicon layers for integration processes such as 3D sequential integration. The design of experiments covers the evaluation of different IR laser release layers and stacks of these layers. In this initial step an optimized debonding behavior is determined