E-BEAM SNMS - A COMPLEMENTARY SURFACE-ANALYSIS TECHNIQUE

Sputtered neutral mass spectrometry (SNMS) with ionization by low-energy electron beam offers several analytical advantages that complement the capabilities of the major surface analysis techniques: XPS, AES and SIMS. These include easy operation on insulator specimens, reduced influence of topography or sample tilt, low spread of elemental relative sensitivity factors (RSFs) across the periodic table, near-constant RSFs in different matrices and hence quantification from 100% down to trace concentrations, ppm detection limits, microprobe operation for depth profiling and submicron imaging and depth resolutions as for SIMS (greater-than-or-equal-to 1 nm). In addition to these analytical performances, the equipment shares much in common with quadrupole SIMS facilities and, as with that technique, is easily integrated into multitechnique instruments. This paper compares performances of SNMS and SIMS on the same samples and presents some imaging and useful yield data from a close-coupled ionizer, which is a new development on the 410 SIMSLAB. Comparisons are also made between SIMS, SNMS and AES.