A Comparison of Photoresist Resolution Metrics using 193 nm and EUV Lithography

Image blur due to chemical amplification represents a fundamental limit to photoresist performance and manifests itself in many aspects of lithographic performance. Substantial progress has been made in linking image blur with simple resolution metrics using EUV lithography. In this presentation, they examine performance of 193 nm resist and EUV resist systems using modulation transfer function, corner rounding, and other resolution metrics. In particular, they focus on cross-comparisons in which selected EUV and 193 nm resist are evaluated using both EUV and 193 nm lithography. Simulation methods linking 193 nm and EUV performance will be described as well. Results from simulation indicate that image blur in current generation 193 nm photoresists is comparable to that of many EUV resists, but that ultra-low diffusion materials designs used in very high resolution EUV resists can result in substantially lower blur. In addition to detailing correlations between EUV and 193 nm experimental methods, they discuss their utility in assessing performance needs of future generation photoresists

Corner Rounding in Photoresists for Extreme Ultraviolet Lithography

Deprotection blur in EUV resists fundamentally limits the smallest sized dense features that can be patterned in a single exposure and development step. Several metrics have recently been developed to explore the ways that different resist and process parameters affect the deprotection blur in EUV resists. One of these metrics is based on the imaging fidelity of a sharp corner on a large feature. As this metric has involved the close inspection of printing fidelity of corner features, it has brought attention to an interesting phenomena: corners print differently whether or not the remaining resist edge contains 270 degrees of resist or 90 degrees of resist. Here we present experimental data across a wide sampling of leading resists to show this effect is real and reproducible. They provide aerial image modeling results assuming thin and realistic mask models that show no corner bias between the aerial images in the 90-degree and 270-degree configurations. They also compare modeled patterning results assuming several resist models including the single blur, dual blur, and Prolith models, none of which reproduce the corner biasing that is observed experimentally

Measurement of through-focus EUV pattern shifts using the SHARP actinic microscope

This paper provides experimental measurements of through-focus pattern shifts between contact holes in a dense array and a surrounding pattern of lines and spaces using the SHARP actinic microscope in Berkeley. Experimental values for pattern shift in EUV lithography due to 3D mask effects are extracted from SHARP microscope images and benchmarked with pattern shift values determined by rigorous simulations

Characterization of LER propagation in resists: Underlayer interfaces in ultra-thin resist films

No abstract prepared

Performance impact of dynamic surface coatings on polymeric insulator-based dielectrophoretic particle separators

Efficient and robust particle separation and enrichment techniques are critical for a diverse range of lab-on-a-chip analytical devices including pathogen detection, sample preparation, high-throughput particle sorting, and biomedical diagnostics. Previously, using insulator-based dielectrophoresis (iDEP) in microfluidic glass devices, we demonstrated simultaneous particle separation and concentration of various biological organisms, polymer microbeads, and viruses. As an alternative to glass, we evaluate the performance of similar iDEP structures produced in polymer-based microfluidic devices. There are numerous processing and operational advantages that motivate our transition to polymers such as the availability of numerous innate chemical compositions for tailoring performance, mechanical robustness, economy of scale, and ease of thermoforming and mass manufacturing. The polymer chips we have evaluated are fabricated through an injection molding process of the commercially available cyclic olefin copolymer Zeonor 1060R. This publication is the first to demonstrate insulator-based dielectrophoretic biological particle differentiation in a polymeric device injection molded from a silicon master. The results demonstrate that the polymer devices achieve the same performance metrics as glass devices. We also demonstrate an effective means of enhancing performance of these microsystems in terms of system power demand through the use of a dynamic surface coating. We demonstrate that the commercially available nonionic block copolymer surfactant, Pluronic F127, has a strong interaction with the cyclic olefin copolymer at very low concentrations, positively impacting performance by decreasing the electric field necessary to achieve particle trapping by an order of magnitude. The presence of this dynamic surface coating, therefore, lowers the power required to operate such devices and minimizes Joule heating. The results of this study demonstrate that iDEP polymeric microfluidic devices with surfactant coatings provide an affordable engineering strategy for selective particle enrichment and sorting. [Figure not available: see fulltext.