Real-Time Scanning Charged-Particle Microscope Image Composition with Correction of Drift

摘要

In this article, a new scanning electron microscopy (SEM) image compositiontechnique is described, which can significantly reduce drift related imagecorruptions. Drift-distortion commonly causes blur and distortions in the SEMimages. Such corruption ordinarily appears when conventional image-acquisitionmethods, i.e. "slow scan" and "fast scan", are applied. The damage is oftenvery significant; it may render images unusable for metrology applications,especially, where sub-nanometer accuracy is required. The described correctiontechnique works with a large number of quickly taken frames, which are properlyaligned and then composed into a single image. Such image contains much lessnoise than the individual frames, whilst the blur and deformation is minimized.This technique also provides useful information about changes of the sampleposition in time, which may be applied to investigate the drift properties ofthe instrument without a need of additional equipment.