Dr. Eran Amit Profile

Dr. Eran Amit

at KLA Israel

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Author

Publications (10)

Proceedings Article | 26 March 2019 Paper

Improved accuracy and robustness for advanced DRAM with tunable multi-wavelength imaging and scatterometry overlay metrology

Honggoo Lee, Sangjun Han, Minhyung Hong, Jieun Lee, Dongyoung Lee, Ahlin Choi, Chanha Park, Dohwa Lee, Seongjae Lee, Jungtae Lee, Jeongpyo Lee, DongSub Choi, Sanghuck Jeon, Zephyr Liu, Hao Mei, Tal Marciano, Eitan Hajaj, Lilach Saltoun, Dana Klein, Eran Amit, Anna Golotsvan, Wayne Zhou, Eitan Herzel, Roie Volkovich, John Robinson

Proceedings Volume 10959, 109591E (2019) https://doi.org/10.1117/12.2515015

KEYWORDS: Overlay metrology, Semiconducting wafers, Metrology, Scatterometry, Wafer-level optics, Manufacturing, Quality measurement, Imaging systems, Scanning electron microscopy, Diffractive optical elements

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Overlay process control is a critical aspect of integrated circuit manufacturing. Advanced DRAM manufacturing overlay error budget approaches the sub-2nm threshold, including all sources of overlay error: litho processing, non-litho processing, metrology error, etc. Overlay measurement quality, both for accuracy and robustness, depends on the metrology system and its recipe setup. The optimal configuration depends on the layer and materials involved. Increased flexibility of metrology setup is of paramount importance, paired with improved methods of recipe optimization.

Both optical image-based overlay (IBO) and scatterometry diffraction overlay (SCOL®) are necessary tools for overlay control. For some devices and layers IBO provides the best accuracy and robustness, while on others SCOL provides optimum metrology. Historically, wavelength selection was limited to discrete wavelengths and at only a single wavelength. At advanced nodes IBO and SCOL require wavelength tunability and multiple wavelengths to optimize accuracy and robustness, as well as options for polarization and numerical aperture (NA). In previous studies^1,2,3 we investigated wavelength tunability analysis with landscape analysis, using analytic techniques to determine the optimal setup. In this report we show advancements in the landscape analysis technique for IBO through both focus and wavelength, and comparisons to SCOL. A key advantage of imaging is the ability to optimize wavelength on a per-layer basis. This can be a benefit for EUV layers in combination with those of 193i, for example, as well as other applications such as thick 3D NAND layers. The goal is to make accurate and robust overlay metrology that is immune from process stack variations, and to provide metrics that indicate the quality of metrology performance. Through both simulation and on-wafer advanced DRAM measurements, we show quantitative benefits of accuracy and robustness to process stack variability for IBO and SCOL applications.

Methodologies described in this work can be achieved using Archer™ overlay metrology systems, ATL™ overlay metrology systems, and 5D Analyzer® advanced data analysis and patterning control solution.

Proceedings Article | 27 April 2018 Paper

Spectral tunability for accuracy, robustness, and resilience

Einat Peled, Eran Amit, Yuval Lamhot, Alexander Svizher, Dana Klein, Anat Marchelli, Roie Volkovich, Tal Yaziv, Aaron Cheng, Honggoo Lee, Sangjun Han, Minhyung Hong, Seungyoung Kim, Jieun Lee, Dongyoung Lee, Eungryong Oh, Ahlin Choi, DongSub Choi, DoHwa Lee, Sanghuck Jeon, Jungtae Lee, Seongjae Lee, Zephyr Liu, Jeongpyo Lee, John Robinson

Proceedings Volume 10585, 105850S (2018) https://doi.org/10.1117/12.2300507

KEYWORDS: Metrology, Semiconducting wafers, Laser scattering, Laser metrology, Overlay metrology, Quality measurement, Scatterometry, Apodization, Polarization, Image quality

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In overlay (OVL) metrology the quality of measurements and the resulting reported values depend heavily on the measurement setup used. For example, in scatterometry OVL (SCOL) metrology a specific target may be measured with multiple illumination setups, including several apodization options, two possible laser polarizations, and multiple possible laser wavelengths. Not all possible setups are suitable for the metrology method as different setups can yield significantly different performance in terms of the accuracy and robustness of the reported OVL values. Finding an optimal measurement setup requires great flexibility in measurement, to allow for high-resolution landscape mapping (mapping the dependence of OVL, other metrics, and details of pupil images on measurement setup). This can then be followed by a method for analyzing the landscape and selecting an accurate and robust measurement setup. The selection of an optimal measurement setup is complicated by the sensitivity of metrology to variations in the fabrication process (process variations) such as variations in layer thickness or in the properties of target symmetry. The metrology landscape changes with process variations and maintaining optimal performance might require continuous adjustments of the measurement setup. Here we present a method for the selection and adjustment of an optimal measurement setup. First, the landscape is measured and analyzed to calculate theory-based accurate OVL values as well as quality metrics which depend on details of the pupil image. These OVL values and metrics are then used as an internal ruler (“self-reference”), effectively eliminating the need for an external reference such as CD-SEM. Finally, an optimal measurement setup is selected by choosing a setup which yields the same OVL values as the self-reference and is also robust to small changes in the landscape. We present measurements which show how a SCOL landscape changes within wafer, wafer to wafer, and lot to lot with intentionally designed process variations between. In this case the process variations cause large shifts in the SCOL landscape and it is not possible to find a common optimal measurement setup for all wafers. To deal with such process variations we adjust the measurement setup as needed. Initially an optimal setup is chosen based on the first wafer. For subsequent wafers the process stability is continuously monitored. Once large process variations are detected the landscape information is used for selecting a new measurement setup, thereby maintaining optimal accuracy and robustness. Methods described in this work are enabled by the ATL (Accurate Tunable Laser) scatterometry-based overlay metrology system.

Proceedings Article | 19 March 2015 Paper

Qmerit-calibrated overlay to improve overlay accuracy and device performance

Md Zakir Ullah, Mohamed Fazly Mohamed Jazim, Stella Sim, Alan Lim, Biow Hiem, Lieu Chia Chuen, Jesline Ang, Ek Chow Lim, Dana Klein, Eran Amit, Roie Volkovitch, David Tien, DongSub Choi

Proceedings Volume 9424, 942425 (2015) https://doi.org/10.1117/12.2085005

KEYWORDS: Overlay metrology, Calibration, Metrology, Optical filters, Scanning electron microscopy, Detection and tracking algorithms, Semiconductors, Target detection, Precision measurement, Inspection

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SPIE Journal Paper | 2 December 2014 Open Access

Techniques for improving overlay accuracy by using device correlated metrology targets as reference

Wei Jhe Tzai, Simon C. Hsu, Howard Chen, Charlie Chen, Yuan Chi Pai, Chun-Chi Yu, Chia-Ching Lin, Tal Itzkovich, Lipkong Yap, Eran Amit, David Tien, Eros Huang, Kelly T. Kuo, Nuriel Amir

JM3, Vol. 13, Issue 04, 041412, (December 2014) https://doi.org/10.1117/12.10.1117/1.JMM.13.4.041412

KEYWORDS: Metrology, Overlay metrology, Calibration, Optical filters, Etching, Semiconducting wafers, Detection and tracking algorithms, Polishing, Chemical vapor deposition, Chemical mechanical planarization

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Proceedings Article | 21 April 2014 Paper

Innovative techniques for improving overlay accuracy by using DCM (device correlated metrology) targets as reference

Wei-Jhe Tzai, Simon C. Hsu, Howard Chen, Charlie Chen, Yuan Chi Pai, Chun-Chi Yu, Chia Ching Lin, Tal Itzkovich, Lipkong Yap, Eran Amit, David Tien, Eros Huang, Kelly T. Kuo, Nuriel Amir

Proceedings Volume 9050, 90501R (2014) https://doi.org/10.1117/12.2046671

KEYWORDS: Metrology, Overlay metrology, Calibration, Optical filters, Etching, Semiconducting wafers, Chemical mechanical planarization, Detection and tracking algorithms, Polishing, Computer simulations

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Proceedings Article | 21 April 2014 Paper

Innovative fast technique for overlay accuracy estimation using archer self calibration (ASC)

Simon C. Hsu, Charlie Chen, Chun Chi Yu, Yuan Chi Pai, Eran Amit, Lipkong Yap, Tal Itzkovich, David Tien, Eros Huang, Kelly T. Kuo, Nuriel Amir

Proceedings Volume 9050, 90501N (2014) https://doi.org/10.1117/12.2046670

KEYWORDS: Overlay metrology, Calibration, Metrology, Optical filters, Lithography, Semiconducting wafers, Quality measurement, Analytical research, Microelectronics, Inspection

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Proceedings Article | 18 April 2013 Paper

Quality metric for accurate overlay control in <20nm nodes

Dana Klein, Eran Amit, Guy Cohen, Nuriel Amir, Michael Har-Zvi, Chin-Chou Kevin Huang, Ramkumar Karur-Shanmugam, Bill Pierson, Cindy Kato, Hiroyuki Kurita

Proceedings Volume 8681, 86811J (2013) https://doi.org/10.1117/12.2011454

KEYWORDS: Target detection, Semiconducting wafers, Overlay metrology, Yield improvement, Metrology, Calibration, Error analysis, Semiconductors, Manufacturing, Lithography

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Proceedings Article | 18 April 2013 Paper

Overlay accuracy calibration

Eran Amit, Dana Klein, Guy Cohen, Nuriel Amir, Michael Har-Zvi, Cindy Kato, Hiroyuki Kurita

Proceedings Volume 8681, 86811G (2013) https://doi.org/10.1117/12.2011416

KEYWORDS: Calibration, Overlay metrology, Metrology, Semiconducting wafers, Optical filters, Neodymium, Time metrology, Process control, Ions, Data modeling

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Proceedings Article | 5 April 2012 Paper

Overlay quality metric

Guy Cohen, Eran Amit, Dana Klein, Daniel Kandel, Vladimir Levinski

Proceedings Volume 8324, 832424 (2012) https://doi.org/10.1117/12.916379

KEYWORDS: Process control, Error analysis, Metrology, Quality measurement, Overlay metrology, Precision measurement, Control systems, Scanners, Inspection, Optical lithography

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Proceedings Article | 5 April 2012 Paper

Overlay accuracy fundamentals

Daniel Kandel, Vladimir Levinski, Noam Sapiens, Guy Cohen, Eran Amit, Dana Klein, Irina Vakshtein

Proceedings Volume 8324, 832417 (2012) https://doi.org/10.1117/12.916369

KEYWORDS: Overlay metrology, Semiconducting wafers, Metrology, Optical filters, Quality measurement, Clouds, Wafer-level optics, Diffraction, Optical simulations, Computer simulations

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Showing 5 of 10 publications

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