LATERAL IMPLANTATION DOSE MEASUREMENTS OF PLASMA IMMERSION ION-IMPLANTED NONPLANAR SAMPLES

The homogeneity of plasma immersion ion implantation of non-planar sam ples was determined by Rutherford backscattering analysis. Half-cylind ers made of carbon treated by argon ions served as a model system. The distribution of the implanted argon dose on the top plane and on the side plane of the samples was analysed. The results show a maximum dos e at the centre of the top plane acid a decrease towards the edges. On the side plane the dose increases from top to bottom. These variation s were up to fifty percent. Additionally, a variation in implantation depth depending on the energy of the implanted ions and on the angle o f incidence was observed. These effects are due to the sample size and the process parameters determining the dimensions of the plasma sheat h which wraps the sample. A possible explanation for these phenomena i s based on the assumption that on their way from the plasma to the sam ple the ions do not follow bent electrical field lines which occur nea r the edges of a sample.