Metrology and deep learning integrated solution to drive OPC model accuracy improvement

Yuan, Wei; Lü, Yifei; Zhao, Yuhang; Chen, Shoumian; Li, Ming; Hu, Hongmei; Yao, Shuxin; Liu, Zhunhua; Li, Qiaoqiao; Tian, Yu; Zhou, Zhiquan; Gu, Lingjia; Wang, Jinze; Sheng, Xichen; Yan, Guanyong; Zheng, Yazhong; Yao, Yueliang; Xiao, Yanjun; Liu, Liang; Zhao, Qian; Mu, Feng; Lang, Jun

doi:10.1117/12.2516236

Cited by 6 publications

(3 citation statements)

References 1 publication

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“…CD and EP metrology is done after D2DB alignment. By processing all SEM images through MXP, we can output high-quality measurement for complex 2D patterns [4] .…”

Section: Wafer Metrologymentioning

confidence: 99%

EUV OPC modeling of dry photoresist system for pitch 32nm BEOL

Chen,

Rio,

Delorme

et al. 2024

Optical and EUV Nanolithography XXXVII

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As technology nodes further shrink, high yield becomes more and more challenging to achieve. Photoresist resolution (see Figure 2) and CD uniformity are two core yield limiters. This can be improved with the use of Lam's EUV dry photoresist system [1] , where the dry develop technique is used to replace wet develop. This process is also less prone to pattern collapse [1] . Another advantage of this new photoresist system consists in its higher dose sensitivity compared to conventional photoresists which leads to higher throughput [1][2] . High resolution process needs to be combined with optical proximity correction (OPC) to enable cutting edge EUV patterning. OPC relies on the capability of a model to predict accurately the behavior of such an innovative process. The purpose of this study is to provide a comprehensive quantification and characterization of the accuracy of an OPC model fitted for this process ADI and AEI (after carbon open).We generated wafers exposed with an OPC calibration reticle, processed with Lam's dry deposited and dry developed photoresist. The anchor is a horizontal line-space grating at pitch 32nm (Figure 2). We acquired CDSEM images of more than 1800 features ADI (after dry develop) and AEI (after carbon open). A subset of the features were collected through FEM ADI. To better understand the characteristics of the dry photoresist system, we used metrics such as proximity, MEEF, DoF and EL. ADI OPC models were calibrated using ASML Tachyon software. Finally, we evaluated the OPC model accuracy of both Tachyon FEM+ (physically motivated) and Newron (machine-learning) engines, ADI for pitch 32nm BEOL metal layer use case.

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“…CD and EP metrology is done after D2DB alignment. By processing all SEM images through MXP, we can output high-quality measurement for complex 2D patterns [4] .…”

Section: Wafer Metrologymentioning

confidence: 99%

EUV OPC modeling of dry photoresist system for pitch 32nm BEOL

Chen,

Rio,

Delorme

et al. 2024

Optical and EUV Nanolithography XXXVII

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“…It seems that the LWR becomes larger as the absolute defocus becomes larger (left and right images of the bottom row), and the isolated LS is not printing (right image of the bottom row). To quantify the patterning quality, ASML MXP tool 25,26 is used to extract the CD gauges, as well as the CD variation across the focus exposure matrix on the wafer. Figure 19 shows the OPW of the measured two clips where the main features shown in Fig.…”

Section: Opw Evaluation Of Random Logic Metal Design At Pitch 28 Nm F...mentioning

confidence: 99%

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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“…This conflict is shown in Figure 5a and Figure 5b. One strategy to circumvent the elevated CDSEM noise from less invasive conditions is to use denoising algorithms and average multiple instances after initial alignment [4]. This approach also comes with minimizing lithography process noise (Figure 5c and Figure 5d).…”

Section: Optics and Resist Modellingmentioning

confidence: 99%

Direct print EUV patterning of tight pitch metal layers for Intel 18A process technology node

Venkatesan

Guven²,

Bhawe³

et al. 2022

International Conference on Extreme Ultraviolet Lithography 2022

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This paper describes the direct print Extreme Ultra Violet (EUV) technology used for lithographic patterning of ~30-36 nm pitch metal layers of Intel 18A technology node. Direct print EUV delivers cost effective pitch scaling to enable flexible design rules and ease of use for layout designers. Careful co-optimization of the illumination source, photoresist and lithography stack is essential to resolve the tightest pitches. Optimum CDSEM metrology conditions and EUV specific requirements such as full field correction with thru slit, flare and black border compensation are critical to improve the quality of the optical proximity correction (OPC) flows. OPC algorithms were used to maximize the process window by using width sizing and pitch shifting to meet lithographic printability criteria while pushing mask manufacturability constraints to their healthy limits. The sizing of metal lines is modelled and fed to the RC extraction flows to close the fabdesign house feedback loop to improve accuracy of timing closure. Multiple test masks were specifically designed to increase sensitivity of defect metrology and accelerate yield learning. Our results from multiple product vehicles demonstrate achievement of technology readiness milestones.

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Metrology and deep learning integrated solution to drive OPC model accuracy improvement

Cited by 6 publications

References 1 publication

EUV OPC modeling of dry photoresist system for pitch 32nm BEOL

EUV OPC modeling of dry photoresist system for pitch 32nm BEOL

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

Direct print EUV patterning of tight pitch metal layers for Intel 18A process technology node

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