On Determination Method for Resolution of Secondary Electron Images in Scanning Electron Microscopy

A rational scheme for the determination of the resolving power of a scanning electron microscope (SEM) has been a long-standing unresolved scientific issue. The objective measurement of the image resolution according to the ISO terminology definition is always difficult, and different measurement methods used in practice now are all inconsistent with the ISO terminology definition and do not follow the Rayleigh criterion. Here, we establish a sharpness-resolution conversion curve method based on physical modeling of SEM imaging with the help of Monte Carlo simulation. The simulated secondary electron images of the resolution sample enable the build-up of the conversion curve via the simultaneous evaluation of image sharpness and image resolution under both the Rayleigh criterion and the Rose criterion. The obtained conversion curves for realistic 3D structures of resolution samples show nonlinearity and provide a convenient means by programmed measurement routine, establishing a scientifically sound way and robust framework for automatic evaluation of SEM instruments based on their resolving performance.