Low Energy Electron Microscopy for Semiconductor Applications

A novel low energy electron microscope (LEEM) aimed at improving the throughput and extending the applications for semiconductor devices has been developed. A dual beam approach, where two beams with different landing energies illuminate the field of view, is used to mitigate the charging effects when the LEEM is used to image semiconductor substrates with insulating or composite (insulator, semiconductor, metal) surfaces. We have experimentally demonstrated this phenomenon by imaging a variety of semiconductor device wafers without deleterious charging effects. Results from several important semiconductor device layers will be illustrated in detail.