Quantitative Voltage Measurement By A Software Closed Loop Technique In Electron Beam Testing

Abstract

A software closed loop technique was devised for quantitative voltage measurement in electron beam testing for LSIs. A retarding voltage of an energy analyzer is controlled iteratively by a computer to reduce difference between a slice level and a secondary electron signal to zero. The voltage is determined by the retarding voltage at the cross point of the slice level and the energy distribution curve. Using this technique, the waveform of 256 sampling phases with more than 5 V amplitude can be measured in about 30 s with 200 mV voltage resolution and 100 ps time resolution.