High-resolution low-voltage electron optical system for very large specimens

Abstract

This article introduces an unconventional electron optical probe forming system which is particularly suitable for low beam voltages and very large specimens, such as semiconductor wafers which also require a large angle tilting. The system can produce an electron probe of less than 20 Å for a nontilting specimen at 1-kV beam voltage with a working distance of 2.5 mm. The particular design allows a large volume of free space below the specimen which may be used to accommodate a complicated transporting mechanism.