Comparison of surface sputtering characteristics by a low energy secondary ion mass analysis using a quadrupole type analyser with those by Auger electron spectrum analysis

Abstract

A secondary ion mass spectrometer (SIMS) with a quadrupole mass analyser and a low energy ionization.gun has been developed and applied to the investigation of the sputtering behavior on alloys with various compositions were used as samples, which were with abrasing paper and ultrasonically cleaned by acetone prior to the measurements. The copper-nickel alloy samples were sputtered by argon ions with energy of 1.5 keV, ionic current of 0.4μA and 23×16 mm oval spot at 5×10^-5 Torr. Nickel peak was initially detected higher than those expected from the bulk composition.and then decreased gradually to a constant value of Ni/Cu. The behavior of SIMS signals (time variation of the peak height) were almost the same as those obtained by Auger electron spectrometry (AES), although the signals of copper and nickel show the inverse behavior in SIMS and AES. This fact suggests that SIMS signals give information on the composition of the sputtered ions from the surface, while AES signals give those of the inner matrix.