Quantitative surface analysis of coated hard metals with SIMS

Abstract

In the case of the development of highly wear resistant coatings on hard metals the application of powerful topochemical methods was mandatory to receive quantitative information on the distribution of boron in Al-B-mixed oxide layers and of oxygen in Ti(C,N,O)-layers. These elements are contained in layers of a few μm thickness in concentrations of 0.0X–X%. After evaluation of different surface techniques the capabilities of SIMS using the ion microprobe CAMECA IMS 3f for this problem were investigated systematically. The result was that quantitative distribution analysis of B in Al-B-mixed oxides using depth profiling and O in Ti(C,N,O) using microanalysis with step scanning over angle lapped specimens can be performed with an accuracy of about ± 25 rel.%. Spatial resolution is a few nm for depth profiles and several μm for step-scanning profiles (corresponding to about 20–50 nm on the depth scale). The high detection power of SIMS for depth profiling and microanalysis makes this method superior to other surface techniques. Additional compound specific information about the structure of such CVD-coatings can be obtained from the molecular ions. The measurements indicate that SIMS is a very powerful technique for compound-specific microanalysis at high lateral resolutions.