STM vs. NFESEM: On Epitaxial Metal Overlayers

摘要

We have fabricated an instrument designed to couple both the imaging process in scanning electron microscopy and the precise positioning of scanning probe microscopy. This microscope is comprised of a metallic field emitter that generates an electron beam with a minimal impingement diameter of approximately one nanometer. In particular, the sensitivity of the field emission current to local topographic variations on the specimen surface enables the microscope to achieve atomic vertical resolution. Our technique, which we call Near Field Emission Scanning Electron Microscopy (NFESEM) [1, 2], produces two simultaneously-generated images by raster-scanning the field emitter, placed at a distance of some ten nanometers above a sample surface via a piezoelectric device.