Potential analyzer

摘要

A potential analyzer for analyzing a potential at a specimen such as an LSI device or the like. This analyzer comprises: a detector to detect secondary electrons to be emitted from a specimen by radiating a primary electron beam thereto; a retarding grid, provided between the specimen and the detector, for controlling a detection amount of the secondary electrons; a circuit for applying a voltage to the retarding grid to keep the output of the secondary electron detector at a constant value; and a setting circuit for automatically setting the gain of the detector so as to allow an operating range of the voltage to the retarding grid to be within a specified value.