Investigating SEM-contour to CD-SEM matching

Weisbuch, François; Schatz, Jirka; Mattick, Sylvio; Schuch, Nivea G.; Figueiro, Thiago; Schiavone, Patrick

doi:10.1117/12.2583715

Cited by 7 publications

(13 citation statements)

References 14 publications

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“…In this section, the methodology used to match CD-SEM tools, in the meaning stated above, is described. It is derived from [22] and a short overview of it would be : a large set of patterns of various dimensions and shapes is imaged with two different CDSEM (SEM A & SEM B); the images produced by the two CD-SEM are post-processed with the following steps : 1/ Extract the contours using a calibrated model based contour extraction algorithm 2/ Apply a matching model that will modify contours extraction process such that CD metrology performed on the extracted contours are matched for images produced by two CD-SEM (Figure 1).…”

Section: Methodsmentioning

confidence: 99%

“…Through the anchoring capability, it is then possible to match a large set of CD measurements to a large set of reference CD measurements enabling to match SEM contour metrology to CD-SEM, as in [22] (and as illustrated on figure 6-top).…”

Section: Sem Contour Metrology Anchoring and Matching Flowmentioning

confidence: 99%

“…However, to perform a precise accuracy assessment it should be assumed that both variables (xi, yi) in a regression process, have an amount of uncertainty. This leads to consider a Mandel regression instead of an ordinary least square regression and synthetize the results of the Mandel regression through a total measurement uncertainty (TMU) analysis [26][27]22].…”

Section: Metricsmentioning

confidence: 99%

“…A large effort is being made to establish SEM contour metrology as a mature enough technology for manufacturing environment [16,22]. While the challenges associated with implementing SEM contour have been identified early [23], recently, a method to evaluate and optimize the matching of a reference CD-SEM measurement with SEM contour metrology approach have been proposed and successfully implemented over a large set of patterns [22].…”

Section: Introductionmentioning

confidence: 99%

“…In this work, it is proposed to extend the work of [22] by using similar methodology to match CD measurements performed on images produced by two different CD-SEM from different tool suppliers and different generations. The first part relates with the dataset, the protocol and the metrics used while the second part presents the matching results obtained with this methodology/dataset.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Can remote SEM contours be used to match various SEM tools in fabs?

Pradelles

Perraud

Sezestre

et al. 2023

Metrology, Inspection, and Process Control XXXVII

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CD-SEM is one of the workhorse metrology tools for evaluating the patterning performances in the semiconductor industry. With the continuous shrink of device feature sizes, measurement uncertainty, of such devices should improve accordingly, including tool-to-tool matching. Great efforts are made in fabs to ensure matching between CD-SEMs. Basically, there are two approaches : tool matching based on statistical CD measurements and tool matching based on physical tool parameters. The first methods require long recipe run on each tool for data collection while the second methods require dedicated maintenance tool time. In parallel, the emergence of SEM contour metrology brought new opportunities, for example in OPC modeling, process assessment or overlay metrology. Recently, a step has been made to demonstrate that offline SEM contour metrology can be matched with standard CD-SEM. In this paper we evaluate the possibility to use SEM contour metrology to perform a remote CD matching on images coming from two different CD-SEM. A large set of patterns of various dimensions and shapes (both 1D and 2D) is imaged with two different CD-SEM after etch process step. For each image the contours are extracted using a remote software. A matching model is calibrated to match contour measurements of the same pattern imaged with the two CD-SEMs. The matching model can be calibrated using either one or both inline SEM measurement or using additional metrology data (typically AFM measurement or any reference metrology measurement). The matching model parameters include both parameters for the contour extraction calibration and measurement matching parameters. Two modeling approaches are compared : one matching model averaging multiple measurement matching sites and a multiple (per pattern type) contour calibrations/ measurement matching sites model. These different matching models are assessed using as main metrics the remaining CD difference between SEM contour measurements on images coming from the two CD-SEM (ΔCDmatching) and TMU analysis. We show that an overall ΔCDmatching variability of 0.6 nm and a TMU below 2 nm can be obtained with the dataset. We evaluated a strategy to achieve matching of two CD-SEM using a remote contour extraction solution and a matching model.

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Section: Methodsmentioning

confidence: 99%

Section: Sem Contour Metrology Anchoring and Matching Flowmentioning

confidence: 99%

Section: Metricsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Can remote SEM contours be used to match various SEM tools in fabs?

Pradelles

Perraud

Sezestre

et al. 2023

Metrology, Inspection, and Process Control XXXVII

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CD-SEM Contour Extraction for Complex Features Measurement

Zhang

Wang

2022

2022 China Semiconductor Technology International Conference (CSTIC)

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Applications of large field of view e-beam metrology to contour-based optical proximity correction modeling

Wei,

Kang,

Das

et al. 2023

J. Micro/Nanopattern. Mats. Metro.

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.BackgroundFor complex two-dimensional (2D) patterns, optical proximity correction (OPC) model calibration flows cannot always satisfy accuracy requirements with the standard cutline-based input data. Utilizing after-development inspection e-beam metrology image contours, better model predictions of 2D shapes and wafer hotspots can be realized.AimWe compare model accuracy performance of conventional cutline-based and contour-based OPC models on the regular and hotspots patterns.ApproachBy utilizing image contours that are directly extracted from large field of view (LFoV) e-beam metrology, OPC models were calibrated and verified with both cutline-based and contour-based modeling flows. We also used a wafer sampling plan that contained bridging hotspots. Using that sampling plan, a hotspot-aware three-dimentional resist (R3D) compact model was created.ResultsFirst, a contour-based OPC model was generated with <1 nm root mean square error of contour sites. Compared with cutline-based models, it shows better predictions on 2D feature corners. Second, when combined with a hotspot sampling plan, a hotspot-aware compact model could be generated. The accuracy of hotspot predictions on false positives and false negatives was reduced to around 1% with this approach.ConclusionsOPC model calibration and verification with LFoV image contours provide improved predictions on corner rounding shapes and great potential to increase design space coverage. We also observed improved accuracy of hotspot predictions when using an update hotspot aware model when comparing with that of the OPC model. Furthermore, the combination of R3D and stochastic compact models also demonstrated great potential on predictions of rare wafer failure events.

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Investigating SEM-contour to CD-SEM matching

Cited by 7 publications

References 14 publications

Can remote SEM contours be used to match various SEM tools in fabs?

Can remote SEM contours be used to match various SEM tools in fabs?

CD-SEM Contour Extraction for Complex Features Measurement

Applications of large field of view e-beam metrology to contour-based optical proximity correction modeling

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