An energy analyzer for high-speed secondary electrons accelerated in inspection SEM imaging

Takafuji, A.; Murakoshi, H.; Shinada, Hiroyuki; Matsui, Miyako; Nishiyama, Hidetoshi; Nozoe, Mari

doi:10.1016/s0167-9317(02)00542-7

Cited by 5 publications

(3 citation statements)

References 3 publications

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“…The reason is that the electric field produced by a negative bias increases the escape probability and repels the electrons from the surface, which acquire an extra kinetic energy equal to eV S. This can be exploited in the so called 'voltage contrast' images acquired from ET detector to give a qualitative evaluation of the surface charging [25,26]. Moreover, using the grid in front of the detector as a low pass filter allows also to measure the SE energy distribution like in more specialized instruments [27,28].…”

Section: Resultsmentioning

confidence: 99%

High charge density silica micro-electrets fabricated by electron beam

Bonacci

Michele

Caponi

et al. 2018

Smart Mater. Struct.

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Electret based smart materials have been attracting increasing attention for their versatility combined with easy fabrication. In particular, electret microparticles can be embedded in micro- and nano-electronic devices, enabling applications such as sensing, actuating, biological transducers and energy harvesting. In this work, silica micro-electrets are charged by electron injection in a SEM environment. The particle charge distribution is precisely controlled adjusting the energy of the primary beam. The surface potential, measured in the SEM chamber by the shift of the Duane–Hunt limit and by secondary electron spectroscopy reaches up to 200 V for 1 micron particles. The increase of the particle surface potential with the electron penetration depth is explained by a theoretical model, which also provides the value of about 0.1 C cm−3 for the charge concentration. The charge decay is studied in time monitoring the secondary electron emission by an in–lens SEM detector, showing that most of the charge injected deeper than 200 nm is retained in the particles for several months after the charging process. The capability to reach high values of surface potential stable over time on micrometric scale makes these materials as ideal candidates for applicative purposes and strategic elements in nanotechnology.

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Section: Resultsmentioning

confidence: 99%

High charge density silica micro-electrets fabricated by electron beam

Bonacci

Michele

Caponi

et al. 2018

Smart Mater. Struct.

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“…The charging voltages of the surfaces of the inspected wafers were measured using an energy filter. 7 Secondary electrons that pass through the energy filter were detected by varying the voltage of a high-pass filter. The detected signal decreased as the voltage of a high-pass filter decreased.…”

Section: Calibration Curve For Estimating Defect Resistance 31 Expermentioning

confidence: 99%

Quantitative measurement of voltage contrast in scanning electron microscope images for in-line resistance inspection of wafers

Matsui

Odaka

Nagaishi

et al. 2010

J. Micro/Nanolith. MEMS MOEMS

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We develope an in-line inspection method for partial-electrical measurement of defect resistance, which is quantitatively estimated from the voltage contrast formed in a scanning electron microscopy (SEM) image of an incomplete-contact defect. We first manufacture standard calibration wafers for the voltage-contrast calibration. The contact resistance of systematically formed defects varied from 10 8 to 10 17 . Then, we quantitatively analyze the gray scales of these defect images captured using a review SEM. As a result, calibration curves for estimating the contact resistance of the incomplete-contact defect are obtained at a probe current of 60 pA and a charging voltage of 4 V. The estimated contact resistance is between 10 7 and 10 12 . Finally, this inspection method is applied to wafers manufactured for a static random access memory device. Accordingly, the gray scales of defective plugs formed for shared contact patterns are classified into two levels. The resistances of these defects are estimated from the calibration curve. The estimated resistances of the lower contrast defects (with an accuracy of about one order of magnitude) agree well with the resistances measured using a nanoprober. The resistances of the higher contrast defects are estimated as well, although they are too high to be measured using a nanoprober. C 2010 Society of Photo-Optical Instrumentation Engineers.

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“…The energy filtering is very useful for the characterization of semiconductors, such as studying the image contrast of doped areas and semiconductor dopant mapping [9,10,11,12,13,14,15]. An energy selective scanning electron microscopy (ESSEM) can be used for the reduction of the effect of contamination layers on contrast [16].…”

Section: Introductionmentioning

confidence: 99%

In-Lens Band-Pass Filter for Secondary Electrons in Ultrahigh Resolution SEM

et al. 2019

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Scanning electron microscopes come equipped with different types of detectors for the collection of signal electrons emitted from samples. In-lens detection systems mostly consist of several auxiliary electrodes that help electrons to travel in a direction towards the detector. This paper aims to show that a through-the-lens detector in a commercial electron microscope Magellan 400 FEG can, under specific conditions, work as an energy band-pass filter of secondary electrons that are excited by the primary beam electrons. The band-pass filter properties verify extensive simulations of secondary and backscattered electrons in a precision 3D model of a microscope. A unique test sample demonstrates the effects of the band-pass filter on final image and contrast with chromium and silver stripes on a silicon substrate, manufactured by a combination of e-beam lithography, wet etching, and lift-off technique. The ray tracing of signal electrons in a detector model predicate that the through-the-lens detector works as a band-pass filter of the secondary electrons with an energy window of about 3 eV. By moving the energy window along the secondary electron energy spectrum curve of the analyzed material, we select the energy of the secondary electrons to be detected. Energy filtration brings a change in contrast in the image as well as displaying details that are not otherwise visible.

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An energy analyzer for high-speed secondary electrons accelerated in inspection SEM imaging

Cited by 5 publications

References 3 publications

High charge density silica micro-electrets fabricated by electron beam

High charge density silica micro-electrets fabricated by electron beam

Quantitative measurement of voltage contrast in scanning electron microscope images for in-line resistance inspection of wafers

In-Lens Band-Pass Filter for Secondary Electrons in Ultrahigh Resolution SEM

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