Application of SIMS to measure the spatial distribution of N+ implantation dose in the internal surface of small hollow cylinders for wear reduction applications

Abstract

Ion implantation technology is used for industrial tools and component treating. Because of its line-of-sight geometry, it is always difficult to determine a priori the spatial dose and angle distribution of the implanted ions onto tools of complex geometry, especially when both the beam and the sample are in motion during the treatment, and the tool details are of dimensions smaller or comparable to the beam cross-section. Secondary ion mass spectrometry (SIMS) is attractive for a posteriori dose measurements because of its spatial resolution (analysis crater <100 μm), its wide measurement range and rapidity, but its application is normally difficult for accurate dose and depth profiling in the case of high doses or complex matrices such as steels or samples that are not flat. In this work it is shown how SIMS can be used to determine the nitrogen implantation dose and its distribution on the surface of small silicon samples placed on the surface of the industrial component to be studied. This was possible owing to the good linearity and repeatability found in dose determination by SIMS for N + implantation into silicon over a wide range up to 10 17 ions cm -2 . An application of the method proposed in this work is reported in the case of implantation onto the internal surface of a hollow cylinder of diameter 25 mm. The dose measurements were performed by SIMS on silicon flat samples placed in a properly cut steel cylinder. These samples were implanted with N + at 100 keV, and the cylinder was rotating around its longitudinal axis, which was inclined at 65° with respect to the beam line. The dose was controlled by a Faraday cup, fixed to the implantation chamber. The accurately calculated dose distribution along the height of the cylinder was compared with experimental data, showing very good agreement with the dose distribution measured on the silicon samples.