Microscopic measurement of surface topography is acontinuing need in microfabrication technology and materialsresearch. The aim Of this research is to adapt the scanningelectron microscope (SEM) to the quantitative measurement of awide range of surface structures. The SEM is a widely usedmeasurement tool in materials science and semiconductorfabrication. The SEM's strength is that it provides highresolution images which often have a three dimensionalappearance. Its weakness is that highly precise three dimensionalmeasurements are difficult or impossible even with stereotechniques. In addition the accuracy of two dimensionalmeasurement is degraded by the reliance of intensity profiles todetermine the location of edges.The proposed research will examine the feasibility of usingstructured illumination to generate SEM images that providepurely topographical information while maintaining the conditionsuseful for normal viewing as well. In this technique the SEMprojects a known pattern on the specimen. The beam either etchesthe surface or promotes a deposition process. The patternedsurface is viewed in the SEM from a different angle of incidence.The detected pattern is a direct measure of the topography Of thespecimen surface. The accuracy of the measurement depends Only anthe quality of the generated pattern and the SEM image. As longas the pattern is detectable, accuracy is independent ofcomposition and the multitude of contrast mechanisms in the SEM.In addition, the proposed device would be cost effective andprovide easily interpretable data that would make it suitable forwidespread use.Potential commercial applications of the research:FailureAnalysis, IC Metrology, Research SEMs, Recording Disk Technology,Micro Machining, Submicron Fabrication
