Enabling 3D-IC foundry technologies for 28 nm node and beyond: through-silicon-via integration with high throughput die-to-wafer stacking

Abstract

High density through-silicon-via (TSV) and cost-effective 3D die-to-wafer integration scheme are proposed as best-in-class foundry solutions for high-end CMOS chips at 28 nm node and beyond. Key processes include: TSV formation, extreme thinning of the TSV wafer and die-to-wafer assembly. The impact of extreme thinning on device threshold voltage, leakage currents, and I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</inf> -I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</inf> characteristics of bulk CMOS devices with and without e-SiGe/CESL stressors has been minimized. The presence of TSV caused no significant changes in Cu/ELK reliability. These excellent characteristics suggest the 300mm 3D-IC processes are promising and suitable for adoption in next generation integrated circuits and interconnects.