No abstract

We describe progress in low-k 1 factor double patterning using 172 nm ultraviolet (UV) curing as a resist stabilization method. Factors that have contributed to enhanced patterning capability include a) resists design and optimization for both patterning and UV curing; b) use of unique R&D tooling capabilities to rapidly identify and optimize key process variables; c) development of simple process metrics for characterizing double patterning process quality, and d) use of 172 nm-resistant antireflective materials. A designed resist, XP-7600A, was selected for detailed evaluation based on superior patterning and curing behavior (less than 10 percent volumetric shrinkage during cure.) Process optimization on 172 nm damage-prone antireflective coatings produced 60 nm cross-grid contact holes at 0.93 NA (litho k 1 = 0.28) with good uniformity when an ancillary 150 o C post-UV bake was used. Additional optimization on improved antireflective coatings yielded superior process latitude (>20 percent 172 nm dose latitude) and also demonstrated that a UV-cure-only resist stabilization process flow may be attainable. Under optimized conditions, highly uniform 60 nm half-pitch cross-grid contacts with cross-sectional area uniformity (1σ) of approximately 200 nm 2 (5 percent) are produced at 135 nm resist film thickness.

No abstract

No abstract