Improved technique for voltage measurement in the scanning-electron microscope

Abstract

Some preliminary results from experiments designed to lead to quantitative voltage measurement in the scanning-electron microscope are presented. The experimental technique is based on the use of a control loop which stabilises the operating conditions of the secondary-electron collector of the scanning-electron microscope by appropriately defining the voltage at the output lead of the specimen. This technique has already been described, and a version of it has been used for quantitative voltage measurement with a low-energy electron beam. The results described here show improvement in linearity and extension of useful dynamic range of the standard secondary-electron collector system provided in the ‘Stereo-scan’ electron microscope.