Inelastic electron analysis in reflection high-energy electron diffraction condition

Abstract Electron energy loss spectra (EELS) has been measured under reflection high-energy electron diffraction (RHEED) condition using a newly developed energy filtered RHEED measurement system to investigate incident and exit angle dependence of plasmon excitation process. As a specimen, clean Si(1 1 1)7×7 surface is used. From Poisson distribution analysis of EELS spectra, mean number of surface ( n s ) and volume ( n v ) plasmon excitation has been obtained. Dependency of n s on incident and exit angle of electron is different from that expected from Lucas theory. It is considered that refraction of electrons near surface region caused the difference. While n v value stays constant for glancing angle, which shows little dependence of effective penetration depth for volume plasmon excitation on glancing angle.