MEMS based IEDF/IADF sensing: Kinetic analysis of the ion dynamics inside the sensor

Ion energy distribution functions (IEDFs) and ion angular distribution function (IADFs) are key parameters in the context of plasma based processing of materials. This holds particularly true when knowledge-based plasma processing is demanded or preferred, rather than processing which relies on trial and error. For this purpose robust, non-perturbing, and reliable IEFD and IADF sensors are asked for. Ideal would be of course a sensor which combines both, IEDF and IADF measurements. In this contribution we present an IEDF/IADF sensor based on a MEMS (microelectromechanical systems) structure. We describe the working principle and show first experimental results. Finally, a detailed analysis of the ion dynamics based on kinetic simulation is provided. The question which is intended to be answered is whether the IEDF/IADF at the orifice of the sensor is really the same as the IEDF/IADF at the current collector.