This letter concentrates on a quantitative description of surface roughness effects on Auger peak-line profiles for pure and alloyed specimens. The nanometer lateral electron probe size of the order of 10 nm yielded peak-line profiles that capture surface topology variations down to nanometer-length scales. Surface roughness leads to peak-intensity fluctuations, which are described within the weak roughness limit by a simple form, I(r) ≈ Iav[1+βh(r)]. Iav is the average peak intensity, h(r) represents the roughness fluctuation along a lateral in-planar distance r, and β is a constant (<1). In addition, analyses of the peak-difference correlation function Iz(r) = 〈∣I(r)−I(0)∣2〉1/2 showed a power-law behavior Iz(r)∝rα with α ranging between 0.7 and 1 at small-length scales, i.e., for r≪ξ, with ξ a peak correlation length that was comparable to average specimen cluster sizes. © 1999 American Institute of Physics.