Life Sciences Commons^™

Secondary Electron Imaging In The Scanning Transmission Electron Microscope, R. M. Allen

Scanning Electron Microscopy

The detailed correlation of surface morphology and subsurface microstructure has been made possible by the scanning transmission electron microscope. This instrument provides the capability for simultaneous and independent secondary electron and transmitted electron imaging from the same sample area. This includes the ability to generate mixed secondary/transmitted electron images, which form a concise visual presentation of the information in the two component images.

Correlative surface and through-volume specimen examination of this type has most frequently been applied to backthinned samples, which are specifically prepared in a way which produces electron-transparent material in the immediate vicinity of a surface of interest …

Recent Developments In Electrical Microcharacterization Using The Charge Collection Mode Of The Scanning Electron Microscope, D. B. Holt, M. Lesniak

Scanning Electron Microscopy

There are six distinguishable types of charge collection (CC) signal. Consequently specially designed CC detection systems are needed to obtain e.g. true EBIC and EBIV measurements and make quantitative electrical microcharacterization possible. EBIC and EBIV can arise from fields due to barriers such as p-n junctions or due to changes in doping e.g. p to p+. Materials, defect and device parameters are calculable from these signals. Hot-cold stages are important for temperature dependence studies of contrast, for improving signal to noise ratios and reducing leakage currents. Image processing and pattern recognition methods are vital for rapidly locating and evaluating the …

Interactive Image Processing For Electron Microscopy: Matching Hardware With Software, W. O. Saxton

Scanning Electron Microscopy

The image processing techniques used 'a posteriori' to extract information from electron micrographs are surveyed, including particularly image averaging, selective averaging, 3-D reconstruction, and high resolution focal series restoration; recent developments in online image pick up and control have led to fully automatic focussing, stigmating and alignment by a frame store system equipped with a real time correlator board. The diversity of the techniques encountered calls for large integrated program systems with flexible command languages; however, a dilemma exists between providing the user with convenient control of special hardware facilities such as frame stores and array processors, and preventing the …

Electron Signal And Detector Strategy, L. Reimer

Scanning Electron Microscopy

The scintillator-photomultiplier combination (Everhart-Thornley detector) for detecting secondary and backscattered electrons (SE and BSE) has the best properties concerning signal-to-noise ratio and bandwidth as compared to other detectors (semiconductor detectors or channel plates).

Two opposite Everhart-Thornley detectors A and B are proposed for a better and reproducible angular selection of the SE. The field strength at the specimen is reduced either by a grid or ring electrode to separate the SE with regard to their exit momenta. This offers the possibility to record the signals A, B, A+B, and A-B. The signal A+B shows material and channelling contrast and the …