A hemispherical retarding-field energy analyser with a microchannel plate detector and a high extraction field for voltage measurement in the scanning electron microscope

Abstract

The previous hemispherical retarding-field energy analyser with a hemispherical mesh collector followed by an operational amplifier as a detector is improved in respect to the response time by using a microchannel plate (MCP) detector. The electron beam exposure (beam current*irradiation time) has been reduced to about 1/5000 of that in the previous experiment. In addition to this modification, the high extraction field is applied to the specimen without degrading the performance in the improved analyser by installing an auxiliary secondary electron extraction grid. The high extraction field can suppress the potential barrier formation in front of the fine electrode. The voltage on the 2 mu m electrode with dimensions similar to those of a current IC has been measured with the same accuracy as the previous results for the 10 mu m electrode.