New approach for improvement of secondary ion mass spectrometry profile analysis

In this paper, we describe the improvement of secondary ion mass spectrometry (SIMS) profile analysis by a new approach based on partial deconvolution combined with scale-frequency shrinkage. The SIMS profiles are obtained by analysis of the delta layers of boron doped silicon in a silicon matrix, analyzed using Cameca-Ims6f at oblique incidence. These profiles can be approximated closely by exponential-like tail distributions with decay length, which characterizes the collisional mixing effect. The partial deconvolution removes the residual ion mixing effect. The contributions of high-frequency noise are removed by shrinkage to a great extent of the profiles. It is shown that this approach leads to a marked improvement in depth resolution without producing artifacts and aberrations caused principally by noise. Furthermore, it is shown that the asymmetry of the delta layers, caused by the collisional mixing effect, is completely removed, the decay length is decreased by a factor of 4 compared with that before deconvolution.