Improved energy analyzer for voltage measurement in electron beam probing for LSI diagnosis

To reduce the error caused by the local field effect in electron beam voltage measurement, a hemispherical retarding field energy analyzer extraction system for secondary electrons has been investigated. Based on the results of experiments, an improved energy analyzer was devised, which has a planar extraction grid combined with spherical extraction and retarding grids. It can generate a uniform extraction field of about 800 V/mm, keeping the retarding field spherical. Linearization error was reduced to ±0.15 V. Measurement error was also reduced to about one‐tenth of our previously developed hemispherical analyzer. Typically error is less than ±0.3 V for electrodes more than 5 μm wide over electrode voltages from 0 to 5 V.