Development of multiple As delta layer Si reference thin film for shallow junction secondary ion mass spectrometry profiling

Abstract

To meet the demand for shallow junction secondary ion mass spectrometry (SIMS) profiling, the surface transient Si sputtering effect should be corrected in addition to the improvement of depth resolution. With low-energy grazing incident ions, the SIMS depth resolution can be improved better than 1 nm. For the correction of the surface transient effect, we report that multiple As delta-layer Si thin films characterized with high-resolution transmission electron microscopy and medium-energy ion scattering spectroscopy can be used as a reference thin film. With the reference thin films, the depth scale shift in the surface transient region can be calibrated under each analysis condition. For low-energy Cs+ ion bombardment, the average Si sputtering yield in the surface 5 nm layer can be 70% higher than that in the steady state, which corresponds to a depth scale shift of 2.0 nm to the shallower direction.