High-resolution signal detection of specimen-specific secondary electrons in an analytical SEM

Abstract

Field emission scanning electron microscopy (SEM) has produced high resolution images of secondary electron-I (SE-I) edge brightness contrast on small particles by the elimination of SE-III produced from backscattered electrons (BSE) within the microscope (SE-I image mode). The resolution of surface fine structure at high magnification is dependent upon signal type and collection efficiency, beam diameter and current, acceleration voltage, and the topography of the specimen. In an analytical SEM, an efficient detector placed above the objective lens specimen stage and a high brightness LaB6 emitter create a collection condition of specimen specific SE useful for imaging SE-I contrast. In the present study a test specimen of uncoated colloidal gold, ferritin and Tobacco Mosiac Virus (TMV) deposited onto silicon was used to determine conditions required for imaging edge brightness contrasts on the gold particles.