Practical Electron Microscopy and Database

An Online Book, Second Edition by Dr. Yougui Liao (2006)

Practical Electron Microscopy and Database - An Online Book

Chapter/Index: Introduction | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Appendix

Contrast Affected by Spot Size (Probe Current)

A change in spot size (probe current) changes the secondary electron to backscattered electron ratio, resulting Contrast changes. The emission of secondary electrons from a given spot size or probe current will remain relatively constant as the accelerating voltage changes. However as the accelerating voltage is increased the backscattered electron (BSE) influence increases, diminishing the contribution to the image from secondary electrons.