A Scanning Electron Microscope With Two Secondary Electron Detectors and Its Application to the Surface Topography Measurements of Magnetic Media

Abstract

A scanning electron microscope (SEM) with two secondary electron detectors is applied for the surface topography measurement of magnetic media. The principle of gradient determination of the SEM is based on a relation that the difference in the square signals between the two detectors is linearly proportional to surface gradient. The great advantage of the instrument is the capability of relocation for profiling. It is extremely useful for the examination of wear process at a fixed position in a sequential manner during wear testing. This is demonstrated by two sample data of measurement on thin film rigid disks.