There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

The American Society for Testing and Materials (ASTM) is an independent organization devoted to the development of standards.

American Society for Testing and Materials

http://experimentationlab.berkeley.edu/sites/default/files/AFMImages/butt_AFM.pdf

Force measurements with the atomic force microscope: Technique, interpretation and applications

In this article, we review special features of Gwyddion—a modular, multiplatform, open-source software for scanning probe microscopy data processing, which is available at http://gwyddion.net/. We describe its architecture with emphasis on modularity and easy integration of the provided algorithms into other software. Special functionalities, such as data processing from non-rectangular areas, grain and particle analysis, and metrology support are discussed as well. It is shown that on the basis of open-source software development, a fully functional software package can be created that covers the needs of a large part of the scanning probe microscopy user community.

https://www.degruyter.com/document/doi/10.2478/s11534-011-0096-2/pdf

Gwyddion: an open-source software for SPM data analysis

IEEE Transactions on Pattern Analysis and Machine Intelligence

In scanned probe microscopy the image is a combination of information from the sample and the tip. In order to reconstruct the true surface geometry, it is necessary to know the actual tip shape. It has been proposed that this shape may be reconstructed from images of ‘‘tip characterizer’’ artifacts of independently known shape. The requirements for this strategy—dimensional uncertainty and instability of the characterizer small compared to the tip size—are not trivial. An alternative is ‘‘blind reconstruction,’’ which requires no information about the characterizer geometry apart from that contained within its image, yet produces an outer bound on the tip shape which for appropriately chosen characterizers is a good approximation. With blind reconstruction dimensional instability of characterizers is less problematical, and characterizer measurability is no longer a constraint, so more complex distributed characterizer geometries may be advantageously employed. In situations where part of a characterizer has a known shape, blind reconstruction and the known‐characterizer method may be combined.

Scanned probe microscope tip characterization without calibrated tip characterizers

Scanning electron microscope measurement of width and shape of 10 nm patterned lines using a JMONSEL-modeled library

Scanning-tunneling-microscopy study of the Si(111)-7×7 rest-atom layer following adatom removal by reaction with Cl

Linewidth roughness (LWR) is usually estimated simply as three standard deviations of the linewidth. The effect of image noise upon this metric includes a positive nonrandom component. The metric is therefore subject to a bias or "systematic error" that we have estimated can be comparable in size to the roughness itself for samples as smooth as required by the industry roadmap. We illustrate the problem using scanning electron microscope images of rough lines. We propose simple changes to the measurement algorithm that, if adopted by metrology instrument suppliers, would permit estimation of LWR without bias caused by image noise.

Unbiased estimation of linewidth roughness

/pdf/determination-of-optimal-parameters-for-cd-sem-measurement-1478vmh8j0.pdf

John S. Villarrubia

Papers

Scanned probe microscope tip characterization without calibrated tip characterizers

Scanning electron microscope measurement of width and shape of 10 nm patterned lines using a JMONSEL-modeled library

Scanning-tunneling-microscopy study of the Si(111)-7×7 rest-atom layer following adatom removal by reaction with Cl

Unbiased estimation of linewidth roughness

Determination of Optimal Parameters for CD-SEM Measurement of Line Edge Roughness | NIST