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

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.

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Measurement of the Electron Beam Point Spread Function (PSF) in a Scanning Electron Microscope (SEM)

Microscopy and Microanalysis ◽

10.1017/s1431927615004298 ◽

2015 ◽

Vol 21 (S3) ◽

pp. 699-700 ◽

Cited By ~ 2

Author(s):

Yudhishthir P. Kandel ◽

Matthew D. Zotta ◽

Andrew N. Caferra ◽

Richard Moore ◽

Eric Lifshin

Keyword(s):

Electron Beam ◽

Electron Microscope ◽

Scanning Electron Microscope ◽

Point Spread Function ◽

Point Spread ◽

Spread Function ◽

Scanning Electron

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Exploring the Parameter Space of Point Spread Function Determination for the Scanning Electron Microscope—Part II: Effect on Image Restoration Quality

Microscopy and Microanalysis ◽

10.1017/s1431927619014831 ◽

2019 ◽

Vol 25 (05) ◽

pp. 1183-1194

Author(s):

Mandy C. Nevins ◽

Richard K. Hailstone ◽

Eric Lifshin

Keyword(s):

Particle Size ◽

Electron Microscope ◽

Image Quality ◽

Scanning Electron Microscope ◽

Image Restoration ◽

Point Spread Function ◽

Background Correction ◽

Point Spread ◽

Spread Function ◽

Scanning Electron

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.

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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.

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

Microscopy and Microanalysis ◽

10.1017/s1431927617001301 ◽

2017 ◽

Vol 23 (S1) ◽

pp. 124-125 ◽

Cited By ~ 2

Author(s):

Matthew D. Zotta ◽

Eric Lifshin

Keyword(s):

Electron Microscope ◽

Scanning Electron Microscope ◽

Point Spread Function ◽

Point Spread ◽

Spread Function ◽

Scanning Electron

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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.

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