CHARACTERIZATION OF SHARP INTERFACES AND DELTA-DOPED LAYERS IN SEMICONDUCTORS USING SECONDARY-ION MASS-SPECTROMETRY

Methods for the quantitative analysis of very thin (delta) layers and sharp interfaces in semiconductors, differentiating between features c lose to or consisting of changes in matrix composition, and dilute fea tures are reviewed. Although it is shown that no method currently exis ts for accurate quantification in the former case, a number of experim ental techniques for obtaining the best estimate of the true concentra tion profile are described, in particular the use of XCs(+) secondary ions. For dilute features, it is shown that deconvolution of the chemi cal profile using a correctly defined response function gives complete quantification, and the formal framework of the method is given. Dept h resolution, and the difficulties inherent in defining and measuring consistent parameters, related to particular mechanisms are discussed within this context.