Mapping of non-planar surfaces and film conformality by alpha-particle energy loss spectroscopy

A method of mapping 3D periodic structures in the micron- and submicron ran ge is presented. The method consists of implanting alpha-emitting nuclei cl ose to the surface and measuring the emerging alpha-particles at various di rections. Information about surface topography is then obtained from the nu mber of alphas that are observed directly by the detector. Measuring the sh ift in energy due to deposition of overlayers permits the analysis of the c onformality of films deposited on complex periodic structures. Typical appl ications include the characterization of gratings in semiconductor layers f abricated during the production of laser structures and of quantum wires. A n experimental example for periodic V-grooves etched in GaAs is shown. (C) 2000 Elsevier Science B.V. All rights reserved.