Implementing flare compensation for EUV masks through localized mask CD resizing

Krautschik, Christof G.; Chandhok, Manish; Zhang, Guojing; Goldstein, Michael; Panning, Eric M.; Rice, Bryan J.; Bristol, Robert; Singh, Vivek K.

doi:10.1117/12.482344

Cited by 31 publications

(18 citation statements)

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“…It results from surface roughness, especially MSFR, and is inversely proportional to the square of the wavelength [64]. EUV flare can be predicted based on the surface roughness of the individual mirrors and can be corrected in the mask design [64,65]. The EUVL exposure tool flare target is in a range of within 8%, which corresponds to a projected optic MSFR level of 0.14 nm rms [14].…”

Section: Opticsmentioning

confidence: 99%

Next-generation lithography for 22 and 16 nm technology nodes and beyond

2011

Sci. China Inf. Sci.

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In this paper, next-generation lithography (NGL) for the 22 and 16 nm technology nodes and beyond is reviewed. A broad range of topics, including history, technologies, critical challenges, and the most plausible candidates are discussed. The 22 and 16 nm technology nodes rely on NGL. NGLs have been extensively studied. Because of technological issues, the semiconductor industry has stopped pursuing several NGLs, such as X-ray proximity lithography, ion projection lithography, and scattering with angular limitation projection electron lithography. Currently, the primary candidate technologies are extreme ultraviolet lithography (EUVL), maskless lithography (ML2), and nanoimprint lithography (NIL), with EUVL being the leading candidate. Since EUVL was first proposed in 1988, many studies have been conducted. Currently, there is no "show stopper" for EUVL. Moreover, challenges are present in almost all aspects of EUVL technology. Almost all primary semiconductor manufacturing companies plan to implement commercial pre-production step-and-scan exposure tools in 2011. However, EUVL power at an intermediate focusing level has not yet met the volume manufacturing requirements. EUVL resists have been significantly improved recently, but there is still a critical need to meet requirements on resolution, line width roughness, and sensitivity. Creating a defect-free EUVL mask is another obstacle to the application of EUVL. ML2 and NIL, like EUVL, have also undergone significant progress recently, but throughput, defect control, and cost remain the critical impediments for practical application.

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Section: Opticsmentioning

confidence: 99%

Next-generation lithography for 22 and 16 nm technology nodes and beyond

2011

Sci. China Inf. Sci.

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“…For EUV where flare varies over small distances, flare variation was modeled by varying the local pattern density. 13 Flare variation effects on CD control are included in the calculated value of σ image . The simulations for EUV were carried out over a finite 2% FWHM temporal bandwidth with a Gaussian-shaped spectral distribution.…”

Section: Calculation Of σ Imagementioning

confidence: 99%

Evaluation of the critical dimension control requirements in the ITRS using statistical simulation and error budgets

2004

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To evaluate the ability to achieve the CD control requirements listed in the International Technology Roadmap for Semiconductors (ITRS) and to set error budget targets for focus, dose, PEB temperature uniformity, and mask CD control, statistical lithography simulation was used. A statistical model of total CD control, including the effects of intrafield and interfield error sources, was developed. The exposure tool settings such as wavelength, NA and partial coherence, focus and dose error budgets, lens aberration levels, mask type and pattern pitch values were determined for each node. Monte Carlo simulation was used to predict the CD error due to intrafield dose and focus errors. The contribution to CD error due to the mask was determined using mask CD control values in the ITRS and a calculated MEEF value at various defocus settings. The contribution to CD error due to PEB temperature variations, across wafer dose variations, and variation of aberrations and flare within the exposure field was also simulated. To meet ITRS CD control targets for 130-nm and 90-nm nodes, an alternating PSM mask is required along with a larger CD printed in resist than indicated in the ITRS. Meeting ITRS CD control requirements for 65-nm node and beyond not possible using assumptions detailed here, even with a near ideal APSM. The simulations predicted that if a relaxed pitch and a larger CD in resist were used at the 32nm node, 193nm immersion lithography in combination with a nearly ideal alternating PSM might provide CD control that is comparable to that obtainable using extreme ultraviolet lithography (EUVL).

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“…[1][2][3][4][5][6][7][8][9] The range of influence of flare in EUV is extremely broad ͑millimeters or more͒, thus implying that an effective full-chip compensation strategy is needed to be able to satisfy the requirements for the 32-nm node and beyond. 4,5 At the core of any strategy for flare correction is the ability to accurately and effectively calculate the local flare levels across the chip design, producing what is commonly known as a flare map.…”

Section: Introductionmentioning

confidence: 99%

Flare in extreme ultraviolet lithography: metrology, out-of-band radiation, fractal point-spread function, and flare map calibration

Lorusso

Roey

Hendrickx

et al. 2009

J. Micro/Nanolith. MEMS MOEMS

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The critical role of flare in extreme ultraviolet ͑EUV͒ lithography is well known. In this work, the implementation of a robust flare metrology is discussed, and the proposed approach is qualified both in terms of precision and accuracy. The flare measurements are compared to full-chip simulations using a simplified single fractal point-spread function ͑PSF͒, and the parameters of the analytical PSF are optimized by comparing the simulation output to the experimental results. After flare map calibration, the matching of simulation and experiment in the flare range from 4 to 12% is quite good, clearly indicating an offset of about 3%. The origin of this offset is attributed to the presence of DUV light. An experimental estimate of the DUV component is found in good agreement with the predicted value.

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Implementing flare compensation for EUV masks through localized mask CD resizing

Cited by 31 publications

References 0 publications

Next-generation lithography for 22 and 16 nm technology nodes and beyond

Next-generation lithography for 22 and 16 nm technology nodes and beyond

Evaluation of the critical dimension control requirements in the ITRS using statistical simulation and error budgets

Flare in extreme ultraviolet lithography: metrology, out-of-band radiation, fractal point-spread function, and flare map calibration

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