Copyright © (2008) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics
The integration of low and ultralow-k SiCOH dielectrics in the interconnect structures of VLSI chips involves complex stacks with multiple interfaces. Successful fabrication of reliable chips requires strong adhesion between the different layers of the stacks. A critical interface in the dielectric stack is the interface between the SiCNH diffusion cap and the SiCOH intra- and interlevel dielectric (ILD). It was observed that, due to the original deposition conditions, the interface layer was weakened both by a low adhesion strength between SiCNH and SiCOH and by the formation of an initial layer of SiCOH with reduced cohesive strength. The manufacturing process has been modified to engineer this interface and obtain interfacial strengths close to the cohesive strengths of the bulk ILDs. The paper discusses the causes for the original low interfacial strength and presents an approach for enhancing it by engineering the interface to the cap for both the dense SiCOH and porous pSiCOH ILDs.
By: A. Grill; D. Edelstein; M. Lane; V. Patel; S. Gates; D. Restaino; S. Molis
Published in: Journal of Applied Physics, volume 103, (no 5), pages Art. No. 054104 in 2008
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