Abstract The use of a thin film of atomic number Z 1 , on an electron microscope grid of atomic number Z 2 in a SAM for the measurement of the Auger backscattering factor R ( R > 1) and the elucidation of background shapes in AES is described. Experimental results of R in the case of C, Cu and W are reported and show good agreement with previous Monte Carlo calculations. The use of Auger spectra from self- and substrate-supported regions of the film to test pragmatic solutions for the isolation of an Auger peak in AES is also demonstrated. This method can be used to study the causes of the background in AES. Further it could also be used in the study by AES of radiation or heat sensitive materials deposited on a thin C film.