Comparison of measured and calculated dose for plasma source ion implantation into 3-D objects

Plasma source ion implantation is a method for implanting 3-D objects, The homogeneity of the implantation is measured for two cylinders, representing drills, and a hale, each with a diameter of 8 mm, and compared with theoretical calculations. Nitrogen was implanted in aluminum foil covering the samples using plasma source ion implantation with 30 kV pulses. Rutherford backscattering spectroscopy (RBS) was used to measure the implanted dose at different positions. Using a discrete approximation for the sheath dynamics, the ion distribution was calculated with a simple model. The measured and calculated doses are usually in good agreement for all three samples. The ion dose for the cylinders has an absolute maximum on the top with a position dependent lower dose on the sidewall, In the bottom of the hole the dose was 25% of the dose at the surface, while the dose in the wall was below the RBS detection limit.