Timischl F.,JEOL Technics Ltd.
A novel dynamic scanning method for noise reduction in scanning electron microscopy and related applications is presented. The scanning method dynamically adjusts the scanning speed of the electron beam depending on the statistical behavior of the detector signal and gives SEM images with uniform and predefined standard deviation, independent of the signal value itself. In the case of partially saturated images, the proposed method decreases image acquisition time without sacrificing image quality. The effectiveness of the proposed method is shown and compared to the conventional scanning method and median filtering using numerical simulations. © 2013 Wiley Periodicals, Inc. Source
Timischl F.,JEOL Technics Ltd.
The contrast-to-noise ratio (CNR) is presented and characterized as a tool for quantitative noise measurement of scanning electron microscope (SEM) images. Analogies as well as differences between the CNR and the widely used signal-to-noise ratio (SNR) are analytically and experimentally investigated. With respect to practical SEM image evaluation using the contrast-to-noise ratio, a standard specimen and an evaluation program are presented. © 2014 Wiley Periodicals, Inc. Source
Nishiyama H.,JEOL Ltd. |
Koizumi M.,JEOL Technics Ltd. |
Ogawa K.,JEOL Technics Ltd. |
Kitamura S.,JEOL Ltd. |
And 6 more authors.
An atmospheric scanning electron microscope (ASEM) with an open sample chamber and optical microscope (OM) is described and recent developments are reported. In this ClairScope system, the base of the open sample dish is sealed to the top of the inverted SEM column, allowing the liquid-immersed sample to be observed by OM from above and by SEM from below. The optical axes of the two microscopes are aligned, ensuring that the same sample areas are imaged to realize quasi-simultaneous correlative microscopy in solution. For example, the cathodoluminescence of ZnO particles was directly demonstrated. The improved system has (i) a fully motorized sample stage, (ii) a column protection system in the case of accidental window breakage, and (iii) an OM/SEM operation system controlled by a graphical user interface. The open sample chamber allows the external administration of reagents during sample observation. We monitored the influence of added NaCl on the random motion of silica particles in liquid. Further, using fluorescence as a transfection marker, the effect of small interfering RNA-mediated knockdown of endogenous Varp on Tyrp1 trafficking in melanocytes was examined. A temperature-regulated titanium ASEM dish allowed the dynamic observation of colloidal silver nanoparticles as they were heated to 240. °C and sintered. © 2014 Elsevier B.V. Source
Otsuka T.,JEOL Ltd. |
Nakamura M.,JEOL Ltd. |
Yamashita K.-I.,JEOL Ltd. |
Honda K.,JEOL Ltd. |
And 3 more authors.
e-Journal of Surface Science and Nanotechnology
SEMs are usually equipped with a backscattered electron detector and a secondary electron detector. In addition to these, alternative detectors have recently been employed to obtain images with additional information content. These detectors are designed to detect electrons emitted within a certain predefined range of energy and takeoff angle. However, no attempt has ever been made to design a detector that allows direct detection of electrons in a user-defined energy and takeoff angle range. In this study, an electron detector was designed and experimentally manufactured to detect electrons emitted in a defined, variable range of energy and takeoff angle. With this 'E detector" a set of images was taken to obtain electrons in two distinct ranges of energy and two distinct ranges of takeoff angle. These images were compared with those obtained by ordinary secondary and backscattered electron detectors. As an application example, clear contrast originating from crystal orientation of a spherical tungsten single crystal was observed in an image composed of high takeoff angle secondary electrons. © 2014 The Surface Science Society of Japan. Source
Timischl F.,JEOL Technics Ltd. |
Date M.,JEOL Technics Ltd. |
Nemoto S.,JEOL Technics Ltd.
A statistical model describing signal-noise generation and development along the signal formation process in a standard scanning electron microscope (SEM) using an Everhart-Thornley secondary electron detector is derived. Noise in the detector signal is modeled to originate from a cascade of five signal conversion stages. Based on the derived model, general conclusions are drawn concerning the total signal-to-noise ratio (SNR) at each stage, and the influence of each stage on the total SNR of the detector signal. The model is furthermore applied to a real-world SEM, and verified by experimental data. © 2012 Wiley Periodicals, Inc. Source