Gas enhanced PFIB surface preparation enabled metrology and statistical analysis of 3D NAND devices

Ledoux, Micah; Clarke, James; Avedisian, Brett; Rue, Chad; Adiga, Umesh; Biedrzycki, Mark

doi:10.1117/12.2515069

Cited by 2 publications

(2 citation statements)

References 3 publications

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“…However, small field of view of TEM and XSEM images often do not provide the data necessary for reliable statistical analysis even with advanced and automated sample preparation 32 – 34 To obtain statistically relevant metrology information, other techniques have been proposed such as full 3D tomography 35 . In such approaches, full 3D volume of holes can be reconstructed but tilt information may be lost.…”

Section: System and Methodsmentioning

confidence: 99%

Inline metrology of high aspect ratio hole tilt and center line shift using small-angle x-ray scattering

Gin

Wormington

Amasay

et al. 2023

J. Micro/Nanopattern. Mats. Metro.

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High aspect ratio (HAR) structures found in three-dimensional NAND memory structures have unique process control challenges. The etch used to fabricate channel holes several microns deep with aspect ratios beyond 50:1 is a particularly challenging process that requires exquisitely accurate and precise control. It is critical to carefully analyze multiple aspects of the etch process, such as hole profile, tilt, uniformity, and quality during development and production. X-ray critical dimension (XCD) metrology, which is also known as critical dimension small-angle x-ray scattering, is a powerful technique that can provide valuable insights on the arrangement, shape, and size of periodic arrays of HAR features. XCD is capable of fast, nondestructive measurements in the cell-area of production wafers, making XCD ideal for in-line metrology. Through several case studies, we will show that XCD can be used to accurately and precisely determine key properties of holes etched into hard mask, multilayer oxide/nitride film stacks and slit trenches. We show that the measurement of hole and slit tilt can be achieved without the aid of a structural model using a Fast Tilt methodology that provides sub-nanometer precision. Measurements were performed across several production wafers to determine the etch uniformity and quality. Particular attention was given at the edge of the wafers to account for large variations observed. In addition, we used a detailed physical model to characterize the HAR structures beyond linear tilt. This approach provides a more complete picture of the etch quality.

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Section: System and Methodsmentioning

confidence: 99%

Inline metrology of high aspect ratio hole tilt and center line shift using small-angle x-ray scattering

Gin

Wormington

Amasay

et al. 2023

J. Micro/Nanopattern. Mats. Metro.

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“…When paired together, successful automation of delayering is achieved by allowing the intelligent workflow to defines the roadmap of target layers to stop at, while the endpoint detection algorithm provides live feedback from sample milling to determine whether milling should stop or resume to expose the correct target layer. [5] Experimental Setup…”

Section: Automated Endpointingmentioning

confidence: 99%

Enabling Automated Sample Delayering, Imaging, and Probing Prep with an Adaptive Endpointing Workflow

Morgan-Jones

Carleson

Najarian

et al. 2021

International Symposium for Testing and Failure Analysis

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The development of advanced logic processing technologies has hit a critical slowing period over the past 10 years. Long gone are the booming days of exponential growth seen in chip transistor density as described by Moore's Law back in 1965.[1] With modern logic manufacturers now capable of creating transistors in the 5-7 nm node range, having the ability to isolate, inspect, and probe individual metal and via layers is of utmost importance for defect inspection and design validation. In this realm of failure analysis, it is critical that design manufacturers possess the ability to isolate any given single layer of their logic samples. These isolated layers can be inspected for defects via SEM, provide validation of CAD designs, or tested with electrical probing for failure analysis. The work here-in describes a functional workflow that enables manufacturers to perform this kind of sample preparation in an automated fashion using the Thermo Scientific™ Helios™ G5 PFIB platform. This workflow can be utilized by both the Thermo Scientific Full Wafer and Small Dual Beam PFIB platforms to streamline sample analysis and failure testing in both the lab and fabrication environments.

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Gas enhanced PFIB surface preparation enabled metrology and statistical analysis of 3D NAND devices

Cited by 2 publications

References 3 publications

Inline metrology of high aspect ratio hole tilt and center line shift using small-angle x-ray scattering

Inline metrology of high aspect ratio hole tilt and center line shift using small-angle x-ray scattering

Enabling Automated Sample Delayering, Imaging, and Probing Prep with an Adaptive Endpointing Workflow

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