Comparative Study of Scanning Electron Microscopy and Electron-Acoustic Microscopy Images

Many reports have been published which compare between scanning electron microscopy (SEM) images and electron acoustic microscopy (EAM) images (EAIs). Thus far, these images have been independently obtained for all areas under the microscopic field, and any corelational factors immanent in their formation have been neglected. We subject quasi-color-coded SEM and EAM images of a test element group of metal-oxide-semiconductor LSI chips to a detailed comparative analysis. It was found, for the same sampling of sites on a specimen, that each technique offers a different set of signal intensities. Results show (1) that back scattered electron image and electron beam induced current image of obtained in the SEM mode, and EAIs obtained in the EAM mode, corresponding to the same geometrical siteson a specimen, reveal information concerning their proper and interrelated differences, and (2) that collective observations of the three types of images yield more useful information concerning the internal properties of a specimen than that obtained heretofore by nondestructive observation.