Scanning electron microscopy(SEM)is currently widely employed in metrology applications,where nanoscale imaging in a liquid environment is in high demand;however,information regarding the nano-objects size measurement...Scanning electron microscopy(SEM)is currently widely employed in metrology applications,where nanoscale imaging in a liquid environment is in high demand;however,information regarding the nano-objects size measurement limitation of the SEM applications is lacking.In this thesis,we study the size measurement limit of nano gold particle by theoretical equation,Monte-Carlo Simulation and SEM.The size effect of the nanoparticles in the aqueous environment of the membrane based liquid devices measured by SEM was studied.The results of theoretical calculation and simulation show that the analytical capability of SEM decreases with the liquid depth.When the membrane thickness is less than 30 nm,the electron beam penetrates the membrane and reaches the depth of 100 nm below the membrane.The size of the smallest detectable particle is between 10 nm to 20 nm.The experimental results show that the measuring limit of nano gold particle size with 30 nm Si3N4 membrane and 15 keV electron energy is 20 nm.The measuring of polystyrene particle size is not easy to image.We inferred that the reason should be related to the atomic weight and conductivity of the particles.The particle size measured by SEM has a certain error,so it is necessary to take an average after multiple measurements to increase the reliability of the particle size measurement result.展开更多
文摘Scanning electron microscopy(SEM)is currently widely employed in metrology applications,where nanoscale imaging in a liquid environment is in high demand;however,information regarding the nano-objects size measurement limitation of the SEM applications is lacking.In this thesis,we study the size measurement limit of nano gold particle by theoretical equation,Monte-Carlo Simulation and SEM.The size effect of the nanoparticles in the aqueous environment of the membrane based liquid devices measured by SEM was studied.The results of theoretical calculation and simulation show that the analytical capability of SEM decreases with the liquid depth.When the membrane thickness is less than 30 nm,the electron beam penetrates the membrane and reaches the depth of 100 nm below the membrane.The size of the smallest detectable particle is between 10 nm to 20 nm.The experimental results show that the measuring limit of nano gold particle size with 30 nm Si3N4 membrane and 15 keV electron energy is 20 nm.The measuring of polystyrene particle size is not easy to image.We inferred that the reason should be related to the atomic weight and conductivity of the particles.The particle size measured by SEM has a certain error,so it is necessary to take an average after multiple measurements to increase the reliability of the particle size measurement result.
