A new SEM CD operator verified against Monte Carlo simulations

Frase, C. G.; Gnieser, D.; Dirscherl, K.; Buhr, E.; Bosse, Harald

doi:10.1117/12.712503

Cited by 3 publications

(1 citation statement)

References 9 publications

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“…[31][32][33][34][35][36][37][38][39] In this study, we used the MONSEL program, 5,31,[40][41][42][43][44][45][46] which was developed at the National Institute of Standards and Technology (NIST) for applications to line-width metrology using CD-SEM. Overview of electron-scattering simulator Many electron-scattering simulators based on various physical models have been developed to simulate SEM images.…”

Section: Simulationmentioning

confidence: 99%

Simulation of electron scattering in a scanning electron microscope for subsurface metrology

Okai

Sohda

2012

Journal of Vacuum Science &Amp; Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phen

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Articles you may be interested inImaging and analysis of subsurface Cu interconnects by detecting backscattered electrons in the scanning electron microscope Electron scattering on a flat sample with a subsurface structure was simulated to investigate the signal profile and critical dimension (CD) measured by scanning electron microscope (SEM). The authors modified an electron-scattering simulator, MONSEL, which was developed by the National Institute of Standards and Technology for applications to line-width metrology using CD-SEM, to simulate a flat tungsten (W) and silicon (Si) pattern under a nanometer-order-thick amorphous carbon (a-C) film and to classify the emitted electrons from the sample according to their generation processes. The simulation result shows that the material contrast between W and Si regions for measuring backscattered electrons (BSEs) is larger than that for measuring secondary electrons (SEs), though the yield of BSEs is lower than that of SEs. The low contrast given by the SE profile is attributed to the contribution of SEs generated from the a-C film by the incident electrons, which becomes an offset component. In contrast, the offset component in the BSE profile (which is also attributed to the a-C film) is much smaller than that in the SE profile. It is therefore concluded that BSE detection is suitable for CD measurement of a subsurface pattern even under a several-nanometer-thick layer. The simulation result also shows that both CD bias (between the top width of the pattern and measured CD) and material contrast increase with increasing irradiation energy for a tapered pattern. This tradeoff relationship (i.e., where both factors increase) indicates that control of the irradiation energy is necessary to obtain an accurate CD measurement of a flat sample with a tapered subsurface pattern. Moreover, in a similar manner to the simulation result, the experimentally measured SE contrast shows a similar dependence on a-C film thickness and irradiation energy.

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Section: Simulationmentioning

confidence: 99%

Simulation of electron scattering in a scanning electron microscope for subsurface metrology

Okai

Sohda

2012

Journal of Vacuum Science &Amp; Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phen

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Modeling and algorithm of three-dimensional metrology with critical dimension scanning electron microscope

Chen,

Zhou,

Zhang

et al. 2023

Journal of Vacuum Science &Amp; Technology B

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To address the challenges of accurate metrology of height and sidewall angle (SWA) of three-dimensional structures with critical dimension scanning electron microscopy, general modeling and algorithms based on tilted electron beam technology and the corresponding application skills are proposed, and the validity and error accuracy are evaluated as well. Three typical structures, the trapezoid, inverted trapezoid, and step, are investigated with Monte Carlo simulation. The maximum derivative method is used to extract key parameters from the secondary electron linescan. The efficiency of the proposed modeling, algorithms, and the accuracy of the calculated height and SWA are improved further with the application of wavelet transform.

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Scatterometry reference standards to improve tool matching and traceability in lithographical nanomanufacturing

et al. 2015

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High quality scatterometry standard samples have been developed to improve the tool matching between different scatterometry methods and tools as well as with high resolution microscopic methods such as scanning electron microscopy or atomic force microscopy and to support traceable and absolute scatterometric critical dimension metrology in lithographic nanomanufacturing. First samples based on one dimensional Si or on Si 3 N 4 grating targets have been manufactured and characterized for this purpose. The etched gratings have periods down to 50 nm and contain areas of reduced density to enable AFM measurements for comparison. Each sample contains additionally at least one large area scatterometry target suitable for grazing incidence small angle X-ray scattering. We present the current design and the characterization of structure details and the grating quality based on AFM, optical, EUV and X-Ray scatterometry as well as spectroscopic ellipsometry measurements. The final traceable calibration of these standards is currently performed by applying and combining different scatterometric as well as imaging calibration methods. We present first calibration results and discuss the final design and the aimed specifications of the standard samples to face the tough requirements for future technology nodes in lithography.

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A new SEM CD operator verified against Monte Carlo simulations

Cited by 3 publications

References 9 publications

Simulation of electron scattering in a scanning electron microscope for subsurface metrology

Simulation of electron scattering in a scanning electron microscope for subsurface metrology

Modeling and algorithm of three-dimensional metrology with critical dimension scanning electron microscope

Scatterometry reference standards to improve tool matching and traceability in lithographical nanomanufacturing

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