Abstract

Modulation of Cu interconnect microstructure in a low- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">$k$ </tex-math></inline-formula> dielectric was achieved at an elevated anneal temperature of 250 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">$^{\circ}{\rm C}$ </tex-math></inline-formula> . In contrast to the unpassivated conventional structure, a TaN metal passivation layer was deposited on the plated Cu overburden surface before annealing at the elevated temperature to prevent stress migration reliability degradation. As compared with the conventional structure annealed at 100 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">$^{\circ}{\rm C}$ </tex-math></inline-formula> , the elevated annealing process enabled further Cu grain growth, which then resulted in an increased Cu grain size and improved electromigration resistance in the interconnects.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call