EUV source-mask optimization for 7nm node and beyond

Liu, Xiaofeng; Howell, Rafael C.; Hsu, Stephen; Yang, Kaiyu; Gronlund, Keith; Driessen, Frank; Liu, Huayu; Hansen, Steven G.; Schenau, Koen van Ingen; Hollink, Thijs; Adrichem, Paul van; Troost, Kars; Zimmermann, Jörg; Schumann, O.; Hennerkes, Christoph; Gräupner, Paul

doi:10.1117/12.2047584

Cited by 17 publications

(14 citation statements)

References 5 publications

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“…In both scanner systems a large degree in flexibility of illumination pupil can be created. SMO maximizes the process window and minimizes the placement errors in the mask design for the optimum illumination source [3]. Pattern placement optimization is done in the design phase as well during the manufacturing phase.…”

Section: Architecture For Across Platform Performance Controlmentioning

confidence: 99%

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Across scanner platform optimization to enable EUV lithography at the 10-nm logic node

et al. 2014

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EUV lithography is expected to be introduced in volume manufacturing at the 10-nm and 7-nm node. Especially in these first EUV nodes, critical layer patterning will be balanced with the use of ArF immersion. As a consequence a good overlay and placement matching between both lithography methods becomes an enabling factor for EUV. In this paper we present an integral method to optimize critical layer patterning across the EUV and ArF scanner platform, such that good overlay and device pattern placement is achieved. It is discussed that besides classical overlay control methods, also the optimization of the ArF and EUV imaging steps is needed. Best matching is achieved by applying high-order field-to-field overlay corrections for both imaging and overlay. The lithography architecture we build for these higher order corrections connects the dynamic scanner actuators with the angle resolved scatterometer via a separate computational application server. Improvements of CD uniformity are based on source mask optimization for EUV combined with CD optimization using freeform intra-field dose actuator in the immersion scanner.

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Section: Architecture For Across Platform Performance Controlmentioning

confidence: 99%

“…The SMO optimization flow for EUV is explained in reference [3]. The SMO flow includes illumination source optimization based on real physical pupil designs of NXE:3300B system and the CD uniformity calculation is based on scanner design performance budgets.…”

Section: Printing Of Cut Hole Pattern With Euvmentioning

confidence: 99%

Across scanner platform optimization to enable EUV lithography at the 10-nm logic node

et al. 2014

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“…4 Reliance on the technique is expected to continue even as next-generation lithography approaches like Extreme Ultra-Violet (EUV) lithography are introduced. 5 Due to the many degrees of freedom involved in the joint optimization, practical SMO implementations require that patterning input targets be sampled using either clips created from design requirements or clips trimmed from a larger design. Spatial extents of these input clips are usually required to be reasonably small, in order to guarantee a reasonable number of variables and a fast solution.…”

Section: Introductionmentioning

confidence: 99%

Full-flow RET creation, comparison, and selection

Lafferty

Silakov

et al. 2014

SPIE Proceedings

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Patterning scaling trends are expected to continue until at least the 5 nm node. With the introduction of EUV now delayed until at least the 7 nm node, 193i patterning will continue mainstream use for the foreseeable future. This scaling increases reliance on optimized OPC and illumination and imposes strict requirements on RET solutions, which we define here as source, optics, and mask synthesis (including SRAF). Along with the patterning requirements, any solution must be calculated efficiently. To meet these requirements, a new RET Selection flow has been built using the Calibre platform. This flow includes SMO, Mask synthesis to further tune the output mask, Verification, and Analysis. The entire flow is session based, allowing runs to be cloned, queued, and compared. The flow is built on a robust GUI framework featuring persistent database integration. The central component of the flow is a new SMO algorithm that offers improved scalability using parallel implementation, and improved accuracy using thick mask modeling and resist models. Lithography-aware mask manufacturability limit enforcement is possible using an integrated inverse lithography tool. This also allows large area patterns to be included for RET benchmarking purposes. Finally, the analysis and visualization stages of the flow allow a particular solution to be compared against other candidates using any image metric desired. Comparison metrics can be customized for layer and customer requirements. In this paper, we will summarize the key points of our flow, and demonstrate it using several experiments.

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“…Illumination system with freeform fly's eye to generate pixelated pupil prescribed by source-mask optimization in extreme ultraviolet lithography 1 Introduction Source-mask optimization (SMO) has been a key enabler for 7-nm node and beyond in the extreme ultraviolet (EUV) lithography. 1,2 The pupil predicted by SMO is usually pixelated, with a free choice of intensity per pixel.…”

mentioning

confidence: 99%

“…2. 1 In recent years, the diffractive optical element and mirror array have been used to realize the freeform pixelated pupil in deep ultraviolet lithography. 8,9 For EUV lithography, however, adding additional elements to the illumination system is not advisable since it would greatly reduce the light energy efficiency of the system.…”

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confidence: 99%

Illumination system with freeform fly’s eye to generate pixelated pupil prescribed by source-mask optimization in extreme ultraviolet lithography

Jiang

Mei

et al. 2017

Opt. Eng

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Abstract. Source-mask optimization (SMO) has emerged as a key technique for 7-nm node and beyond in extreme ultraviolet (EUV) lithography. The pupil required by SMO is usually pixelated, with a free choice of intensity per pixel. However, due to the discrete nature of the EUV illumination system, pupil intensity in current EUV SMO must also be discretized. An illumination system with a freeform fly's eye that is able to generate the pixelated pupil is proposed. Clear apertures of the field facets in the fly's eye are different from each other so that the intensity of each pixel on the pupil can meet the requirements of SMO. Each of the field facets is constructed with a freeform surface to get the required arc-shaped illuminated area on the reticle. A method integrated with a numerical method and an optimization process is used to design the freeform surface of the field facets. The simulation result of the design for a prescribed freeform pixelated pupil shows that the uniformity on the reticle is 96.4%, and the pupil intensity error is approximated to be 0.035. The results indicate that the system is effective in generating the required freeform pixelated pupil and reducing the restrictions imposed on the SMO process in EUV lithography.

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EUV source-mask optimization for 7nm node and beyond

Cited by 17 publications

References 5 publications

Across scanner platform optimization to enable EUV lithography at the 10-nm logic node

Across scanner platform optimization to enable EUV lithography at the 10-nm logic node

Full-flow RET creation, comparison, and selection

Illumination system with freeform fly’s eye to generate pixelated pupil prescribed by source-mask optimization in extreme ultraviolet lithography

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