Method and apparatus for measuring quantitative voltage contrast

Abstract

In a method and apparatus for measuring quantitative voltage contrast, an electron beam of the scanning electron microscope is located on a specimen electrode, and a grid voltage of an energy analyzer of the scanning electron microscope is varied. A detector detects secondary electron emission from the specimen electrode. A measured peak voltage of the specimen electrode is determined based on output from the detector. A specimen electrode voltage corrected for type I local field effect error is then obtained using the measured peak voltage and a type I calibration curve. The type I calibration curve represents peak voltage versus specimen electrode voltage. Type II local field effect error in the specimen electrode voltage is then corrected based on a type II calibration curve. The type II calibration curve represents a shift in specimen electrode peak voltage versus adjacent electrode voltage.