Study on the temperature effect on line-scan profile of nanorods under electron irradiation

Abstract

Scanning electron microscope (SEM) is widely used in imaging rather than for thermometry. In this work, the temperature-dependent line-scan profiles for two systems (one gold (Au) nanorod (Au-NR) and one silicon (Si) nanorod (Si-NR) on Si substrate, respectively) were investigated by a simulation approach. Various electron signals (secondary electron (SE) and backscattering electron (BSE)) were recorded with different values of temperature at various primary electron (PE) energies. It is found that the SE line-scan profile varies with the temperature and the size of the NR. However, the BSE line-scan profile is almost unchanged with temperature for the Au/Si system, but remarkably varied for the Si/Si system. The deposited energies contributed by full electrons, PEs and cascaded electrons as functions of depth and radial direction at different temperatures for these two systems were also investigated. It was concluded that the influences of the temperature of a solid on the scattering processes of PEs and cascaded electrons are different. Possible mechanisms were systematically analyzed based on the theory of electron-solid interaction. Finally, the temperature effect on the size measurement based on a line-scan profile was also investigated through the regression to baseline method. It was found that the broaden value slightly increases with temperature. This work poses a potential possibility of measuring the temperature of nanostructures by acquiring the temperature-dependent line-scan profile by a standard SEM.