Scanning Electron Microscope Point Spread Function Determination Through the Use of Particle Dispersions

AbstractPoint spread function (PSF) deconvolution is an attractive software-based technique for resolution improvement in the scanning electron microscope (SEM) because it can restore information which has been blurred by challenging operating conditions. In Part 1, we studied a modern PSF determination method for SEM and explored how various parameters affected the method's ability to accurately estimate the PSF. In Part 2, we extend this exploration to PSF deconvolution for image restoration. The parameters include reference particle size, PSF smoothing (K), background correction, and restoration denoising (λ). Image quality was assessed by visual inspection and Fourier analysis. Overall, PSF deconvolution improved image quality. Low λ enhanced image sharpness at the cost of noise, while high λ created smoother restorations with less detail. λ should be chosen to balance feature preservation and denoising based on the application. Reference particle size within ±0.9 nm and K within a reasonable range had little effect on restoration quality. Restorations using background-corrected PSFs had superior quality compared with using no background correction, but if the correction was too high, the PSF was cut off causing blurrier restorations. Future efforts to automatically determine parameters would remove user guesswork, improve this method's consistency, and maximize interpretability of outputs.

Download Full-text

Exploring the Parameter Space of Point Spread Function Determination for the Scanning Electron Microscope—Part I: Effect on the Point Spread Function

Microscopy and Microanalysis ◽

10.1017/s1431927619014806 ◽

2019 ◽

Vol 25 (05) ◽

pp. 1167-1182

Author(s):

Mandy C. Nevins ◽

Kathryn Quoi ◽

Richard K. Hailstone ◽

Eric Lifshin

Keyword(s):

Particle Size ◽

Electron Microscope ◽

Scanning Electron Microscope ◽

Point Spread Function ◽

Background Correction ◽

Support Material ◽

Material Thickness ◽

Point Spread ◽

Spread Function ◽

Scanning Electron

AbstractThe point spread function (PSF) of the scanning electron microscope (SEM) can be determined using a recently developed nanoparticle calibration method. Many parameters are involved in PSF determination and introduce a previously unstudied amount of uncertainty into the PSF size and shape. Signal type, support material thickness, reference particle size, PSF smoothing (K), and background correction were investigated regarding their effect on the PSF. Experimental data were complemented by CASINO simulations. Differences in detector position between the observed particles and the method's simulated reference particles caused shifting between secondary electron PSFs and backscattered electron PSFs. Support material thickness did not have a practical effect on the PSF at the tested voltages. Uncertainty in reference particle size varied the PSF full width at half maximum (FWHM) within ±0.7 nm at 2σ, with virtually no uncertainty in some cases. K and background correction within a reasonable range of values resulted in PSF FWHM differences within ±0.9 nm, except at 2 kV for K with an upper bound of ±1.9 nm due to increased noise. Tailoring K and background correction case-by-case would result in smaller differences. The interconnection of these parameters may help in future efforts to calculate their best selection.

Download Full-text

UHV ENFINA - A New High-Performance EELS Spectrometer for the VG STEM

Microscopy and Microanalysis ◽

10.1017/s1431927600031731 ◽

2001 ◽

Vol 7 (S2) ◽

pp. 1132-1133

Author(s):

John A. Hunt ◽

Frank E. Dickerson ◽

A. Abbott ◽

Gabriel Szantai ◽

Paul E. Mooney

Keyword(s):

Electron Microscope ◽

Point Spread Function ◽

High Performance ◽

Detection System ◽

Detector System ◽

Thermo Electric ◽

Point Spread ◽

Spread Function ◽

Readout Noise ◽

New Generation

The Gatan Enfina EELS spectrometer, featuring a new generation of detection system, was recently developed to upgrade or replace Gatan PEELS / DigiPEELS systems. Major advantages of the system include significant improvements to the detector point spread function, readout speed, sensitivity, readout noise, and increased number of detection channels. This design was until now not available for VG STEM systems because compatible detectors must not significantly degrade the UHV column vacuum and must survive column baking. in this abstract we report on a new detector system with comparable specifications to the standard Enfina system but designed for new or for upgrading existing Gatan UHV PEELS / DigiPEELS systems on the VG STEM.The standard Enfina design has the scintillator, fibers, CCD, CCD socket board, flex-cables, thermo electric cooler and coupling grease in the shared vacuum of the EELS spectrometer and the electron microscope.

Download Full-text

Off-axis electron holography in an aberration-corrected transmission electron microscope

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2009.0126 ◽

2009 ◽

Vol 367 (1903) ◽

pp. 3773-3793 ◽

Cited By ~ 20

Author(s):

Hannes Lichte ◽

Dorin Geiger ◽

Martin Linck

Keyword(s):

Electron Microscope ◽

Transmission Electron Microscope ◽

Point Spread Function ◽

Signal To Noise Ratio ◽

Electron Holography ◽

Signal To Noise ◽

Point Spread ◽

Transmission Electron ◽

Spread Function ◽

Noise Ratio

Electron holography allows the reconstruction of the complete electron wave, and hence offers the possibility of correcting aberrations. In fact, this was shown by means of the uncorrected CM30 Special Tübingen transmission electron microscope (TEM), revealing, after numerical aberration correction, a resolution of approximately 0.1 nm, both in amplitude and phase. However, it turned out that the results suffer from a comparably poor signal-to-noise ratio. The reason is that the limited coherent electron current, given by gun brightness, has to illuminate a width of at least four times the point-spread function given by the aberrations. As, using the hardware corrector, the point-spread function shrinks considerably, the current density increases and the signal-to-noise ratio improves correspondingly. Furthermore, the phase shift at the atomic dimensions found in the image plane also increases because the collection efficiency of the optics increases with resolution. In total, the signals of atomically fine structures are better defined for quantitative evaluation. In fact, the results achieved by electron holography in a Tecnai F20 Cs-corr TEM confirm this.

Download Full-text

Point-spread functions for backscattered imaging in the scanning electron microscope

Journal of Applied Physics ◽

10.1063/1.2817591 ◽

2007 ◽

Vol 102 (12) ◽

pp. 123101 ◽

Cited By ~ 23

Author(s):

Philipp Hennig ◽

Winfried Denk

Keyword(s):

Electron Microscope ◽

Scanning Electron Microscope ◽

Point Spread Functions ◽

Point Spread ◽

Scanning Electron

Download Full-text

Bayesian deconvolution of scanning electron microscopy images using point-spread function estimation and non-local regularization

2016 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) ◽

10.1109/embc.2016.7590735 ◽

2016 ◽

Cited By ~ 6

Author(s):

Joris Roels ◽

Jan Aelterman ◽

Jonas De Vylder ◽

Hiep Luong ◽

Yvan Saeys ◽

...

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Point Spread Function ◽

Function Estimation ◽

Local Regularization ◽

Point Spread ◽

Spread Function ◽

Non Local ◽

Microscopy Images ◽

Scanning Electron

Download Full-text

The Alteration of the Pore Spaces in Sandstones

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071491 ◽

1973 ◽

Vol 31 ◽

pp. 210-211

Author(s):

R. E. Ferrell ◽

G. G. Paulson

Keyword(s):

Electron Microscope ◽

Scanning Electron Microscope ◽

The Other ◽

Coarse Grained ◽

Depositional Fabric ◽

Soluble Components ◽

Scanning Electron ◽

Shape And Size

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.

Download Full-text

The Broad Applications of the Scanning Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100062002 ◽

1969 ◽

Vol 27 ◽

pp. 20-21

Author(s):

C. T. Nightingale ◽

S. E. Summers ◽

T. P. Turnbull

Keyword(s):

Electron Microscope ◽

Scanning Electron Microscope ◽

Light Microscopy ◽

Surface Topography ◽

Great Depth ◽

Resolving Power ◽

Depth Of Field ◽

Pictorial Representations ◽

Scanning Electron

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.

Download Full-text

Observability of Very Thick Specimen by Using Transmission Scanning Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100064189 ◽

1971 ◽

Vol 29 ◽

pp. 26-27

Author(s):

K. Shibatomi ◽

T. Yamanoto ◽

H. Koike

Keyword(s):

Electron Microscope ◽

Image Quality ◽

Scanning Electron Microscope ◽

Chromatic Aberration ◽

Image Contrast ◽

Objective Lens ◽

Thick Specimen ◽

Transmission Electron ◽

Scanning Electron

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.

Download Full-text