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Toward a better reliability in the deconvolution of SIMS depth profiles
Author(s) -
Gautier B.,
Prudon G.,
Dupuy J. C.
Publication year - 1998
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/(sici)1096-9918(199812)26:13<974::aid-sia445>3.0.co;2-o
Subject(s) - deconvolution , regularization (linguistics) , blind deconvolution , algorithm , chemistry , mathematics , computer science , artificial intelligence
In this paper, the problem of the deconvolution of SIMS depth profiles is addressed. In particular, the hypotheses that are necessary for the deconvolution to be possible (in the actual state of the art) in the case of the SIMS signal are reviewed. Then, the principle of regularization, which is a mandatory step in the resolution of an ill‐posed problem, is clarified. Two regularization methods used in the field of SIMS analysis are compared: Miller regularization and maximum entropy regularization. In a second part the study of a possible deconvolution, using a depth resolution function (DRF) that is not the DRF that has experimentally convolved the profile, is justified and theoretically addressed. Two cases arise: the DRF used in the deconvolution process is either thinner than the experimental DRF or it is thicker. It is shown that deconvolution using a DRF that is wider than the DRF that actually convolved the profile is possible, and must be taken into consideration. Some examples of simulated deconvolutions with a false DRF are given, and some tools are proposed that are theoretically able to detect a problem when the DRF used in the deconvolution process is wider than the real DRF. In the last section, an example of experimental deconvolution shows that the deconvolution process is able to provide reliable information. In particular, deconvolution of a SIMS analysis conducted at 5.5 keV O 2 + and 42.4° incidence (in a Cameca IMS 3/4f) reveals some features of the sample that require at least 1 keV O 2 + and 60° primary beam incidence to be detected experimentally. © 1998 John Wiley & Sons, Ltd.