Synchrotron radiation analysis of microstructures

Abstract

the outstanding spectral and spatial characteristics of synchrotron radiation make it a powerful analytical tool in microstructure technology. We apply absorption spectroscopy to study foils of electroplated Permalloy (NiFe), and of nickel phosphorus, because they are of interest to microfabrication for their soft magnetic properties and their selective etching behaviour, respectively. In particular, we show that in the electroplated Permalloy foils Ni keeps the structure of pure Ni while Fe changes from b.c.c. to f.c.c. NiP foils become increasingly amorphous with growing P content. In this way, radial elemental distributions which determine magnetic or other properties can be monitored sensitively to improve electroplating process control, even in situ. We also measure the radial thickness profile of a gold layer sputtered on top of a chromium coated silicon wafer. This technique might be extended to measure a given layer in a multilayer structure selectively and non-destructively even when hidden or opaque.