Investigation into a prototype extreme ultraviolet low-n attenuated phase-shift mask

Lare, Claire van; Timmermans, Frank; Finders, Jo; Romanets, Olena; Man, Cheuk-Wah; Adrichem, Paul van; Ikebe, Yohei; Aizawa, T.; Onoue, T.

doi:10.1117/1.jmm.20.2.021006

Cited by 11 publications

(10 citation statements)

References 12 publications

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“…The same SMO strategy in the paper of Xu et al 17 . was carried out together with the actual low-n attPSM stack provided by the maskshop (low-n and low-k absorber with 35∼50 nm) thickness 20 to obtain the optimized source for the low-n attPSM.…”

Section: Contextmentioning

confidence: 99%

“…13 shows the schematic of the incident light direction of the two-bar at left and right edge of the slit for both DF and BF masks. The Ta-based absorber binary mask has reflectivity ∼2%, and the low-n attPSM absorber has reflectivity in the range of 8% and 15%, 20 which has four to seven times more reflectivity than Ta-based absorber. Considering the DF masks [cf.…”

Section: Lithographic Performance Comparison Between Low-n Attpsm And...mentioning

confidence: 99%

“… – 17 The low-n attenuated phase-shift mask (attPSM) has shown substantial imaging improvements in simulations and experiments: a higher depth of focus (DoF) at similar NILS and a smaller telecentricity errors than the best binary mask configuration 13 , 18 – 22 In this paper, the patterning of metal pitch 28-nm design using low-n attPSM mask technology is investigated in simulation and experimentally. The impact of the mask tone will also be considered.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Extend 0.33 NA extreme ultraviolet single patterning to pitch 28-nm metal design by low-n mask

Gillijns

Tan

et al. 2022

J. Micro/Nanopattern. Mats. Metro.

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Extending 0.33 NA extreme ultraviolet single patterning to 28-nm pitch becomes challenging in stochastic defectivity, which demands high-contrast lithographic images. The low-n attenuated phase-shift mask (attPSM) can provide superior solutions for individual pitches by mitigating mask three-dimensional effects. The simulation and experiment results have shown substantial imaging improvements: higher depth of focus at similar normalized image log slope and smaller telecentricity error values than the best binary mask configuration. In this work, the exploration of low-n attPSM patterning opportunity for pitch 28-nm metal design is investigated. Using generic building block features, the lithographic performance of the low-n attPSM is compared with the standard binary Ta-based absorber mask. In addition, the impact of mask tone (bright field (BF) versus dark field) on the pattern fidelity and process window is evaluated both by simulations and experiments. The results indicate that BF low-n attPSM provides the best patterning performance. Consequently, the BF low-n attPSM patterning performance is assessed with an actual imec N3 pitch 28-nm random logic metal design. The wafer data indicate BF low-n attPSM enables good patterning fidelity, as well as good overall process window with high exposure latitude (∼20%).

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Section: Contextmentioning

confidence: 99%

Section: Lithographic Performance Comparison Between Low-n Attpsm And...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Extend 0.33 NA extreme ultraviolet single patterning to pitch 28-nm metal design by low-n mask

Gillijns

Tan

et al. 2022

J. Micro/Nanopattern. Mats. Metro.

View full text Add to dashboard Cite

show abstract

“…The quest for an ever increasing aerial image contrast in EUV lithography continues to be an important development topic, with the industry and whole infrastructure defining new and parallel paths towards the ultimate resolution. Innovations are seen in scanner roadmap development, along with new mask absorber materials (low n, high k) [5,6,7,8], attenuated EUV phase shift masks [9], optical proximity correction and subresolution assist features as well as source mask optimization (SMO) techniques. The list is not complete and could be further extended.…”

Section: Introductionmentioning

confidence: 99%

The power of algorithmic employed in a metrology system: AIMS EUV Digital Flex Illu

Capelli

Gwosch²,

Kersteen³

et al. 2022

International Conference on Extreme Ultraviolet Lithography 2022

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Digital Flex Illu is a fully digital solution which provides SMO functionality to the AIMS ® EUV system by combining an adaptation of the already built-in system metrology with a powerful algorithm and most importantly, without changing the machine hardware. In this paper, we will present the concept of Digital Flex Illu functionality, its significant advantages in combination with a binary aperture-based illumination concept, together with showing imaging results obtained on the AIMS ® EUV prototype system. This digital solution is a paradigm change for the AIMS ® EUV usability and final user, it allows ZEISS to guarantee an agile roadmap for the AIMS ® EUV with limited development effort and great benefits in sustainability and roadmap scaling.

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“…The third strategy of maximizing image contrast, i.e. NILS, is a major EUV research theme, encompassing work on high NA EUV optics 5 , improved mask absorbers 6 , better focus control 7 , Bright Field imaging modes 8 , etc. Besides LCDU, other stochastic errors like LER and stochastic defect levels directly benefit from improved image contrast, along with better exposure latitude.…”

Section: Introductionmentioning

confidence: 99%

Image contrast metrology for EUV lithography

Brunner¹,

Truffert²,

Ausschnitt³

et al. 2022

International Conference on Extreme Ultraviolet Lithography 2022

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Image contrast is an important measure of image quality, especially for EUV lithography where high contrast can mitigate stochastic process fluctuations1 such as Line-Edge Roughness (LER), Line Width Roughness (LWR), Local CD Uniformity (LCDU) and stochastic defects. In this paper, several aspects of image contrast for EUV lithography are discussed. We will look at some of the fundamental mechanisms which degrade image contrast, including resist blur from acid diffusion. We assume the imaging of dense line/space images with k1<0.5. This assumption guarantees that the image is a simple sinusoid, and implies that the exposure latitude is proportional to the image contrast. We then consider various methods to experimentally measure image contrast. The classic measure would be to measure the exposure latitude from a Focus/Exposure Matrix (FEM) wafer. The exposure latitude is generally giving a contrast measure which is averaged over some portion of the wafer. In this paper, we propose the use of MEEF (Mask Error Enhancement Factor) targets to track contrast at specific locations on the wafer. In principle, one could measure many points across the image field (or even across the whole wafer) to map out the spatial variation of contrast, i.e. a contrast map. The paper includes experimental contrast measurements that relate to stage fading, source shape and resist blur from different processes. We will also briefly look at fading from the Pole-to-Pole image shift, and how to mitigate this with a novel exposure method called Dual Monopole.

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Investigation into a prototype extreme ultraviolet low-n attenuated phase-shift mask

Cited by 11 publications

References 12 publications

Extend 0.33 NA extreme ultraviolet single patterning to pitch 28-nm metal design by low-n mask

Extend 0.33 NA extreme ultraviolet single patterning to pitch 28-nm metal design by low-n mask

The power of algorithmic employed in a metrology system: AIMS EUV Digital Flex Illu

Image contrast metrology for EUV lithography

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