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This paper discusses applications of thin dilute Cu-alloy films in Cu-interconnections to reduce Cu electromigration (EM) and improve physical-vapor-deposited (PVD) Cu seed integrity. PVD CuSn, CuIn and CuZr films are studied with in-film concentration of Sn, In and Zr from 0.3 to 1.2 at. %. With either of the alloy films, significant reduction of thin Cu film agglomeration on TaN barrier is observed, suggesting suppression of Cu mobility along the Cu/barrier interface, which thus reduces EM. After annealing, the dopant redistribution rate is found in the order of Sn> In> Zr. The bulk resistivity differences between as-deposited Cu-alloy and pure Cu films are 3.6, 1.1 and 18 pLR-cm for CuSn, CuIn and C U B , respectively (normalized to 1 at. %). The resistance decreases 30-50% after annealing due to the dopant rejection from the grains. CuSn (0.3 at. %) is discussed as a specific example to correlate film propertie"'with wafer-level electrical and EM results. When annealed at 35OoC, Cu-interconnect lines with 500A (nominal thickness) CuSn films have similar metal line resistance to that of pure Cu. EM mean-time-tofailure (MTTF) improves with increasing CuSn film thickness. A 1kA CuSn film improves EM by a factor of two.

Effective dielectric constants of advanced interconnects with low-k and ultra-low-k dielectrics were evaluated by two-dimensional capacitance analysis. The analysis was performed for interconnect design rules proposed for 65 nm node high-performance integration. Interconnects with various pitches and integration schemes were examined, and the effects of supporting dielectric layers including cap layer, chemical mechanical polishing stop layer, and etch stop layer were evaluated. The results indicated that the use of the supporting layers greatly affects the effective dielectric constant of interconnect structures. The impacts of the supporting dielectric layers on the effective dielectric constant were evaluated quantitatively, and the implications on back-end-of-line integration schemes were discussed.

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Newport Beach, C a l i f o r n i a I n t r o d u c t i o n Although t h e c o n c e p t o f t h e b u r i e d channel CCD (1) o f f e r s many d i s t i n c t advantages over surface channel devices, it is necessary t o develop a d e v i c e s t r u c t u r e which can b e r e l i a b l y f a b r icated. I n t h i s p a p e r s u c h a device i s presented and t e s t results are given which d e m o n s t r a t e t h a t h i g h t r