AUGER IMAGING FROM ROUGH, CHEMICALLY INHOMOGENEOUS, MATERIALS

Surface analysis of practical materials often presents a challenging s ituation in Auger spectroscopy and imaging because the yield of Auger electrons depends not only on the composition of the surface but also upon the local surface inclination (the topography) and the compositio n of the material below the surface. The use of simultaneous imaging o f the same area of a sample with an electron spectrometer and four qua drants of a backscattered electron (BSE) detector has been demonstrate d previously to be very useful for the separate correction of either t opographical contrast or sub-surface composition effects. In this work the possibility is tested of using BSE detector images to correct sim ultaneously acquired Auger images for the presence of both topographic al and sub-surface composition effects in the same sample. Measurement s on model samples with known topography and sub-surface composition a re used. The samples are formed from anisotropically etched Si(100) co ated in some places with a thick Au film and then overcoated everywher e with either a thin film of CuSn alloy or partially coated with a thi n film of Au. The correction process is successful in reducing the art efacts everywhere and the extent of this correction is discussed.