Free-carrier absorption experiments for the investigation of the physical device properties in IGBTs with hydrogen-related donors

Hydrogen-related donors can be advantageously used in IGBTs and power diodes with a view to creating field-stop layers and to optimising the electrical performance. In this work, the influence of hydrogen-related donors on the on-state plasma profile in field-stop IGBTs is analysed by means of free-carrier absorption measurements. For these investigations, dedicated IGBT test structures were used, which had been adapted to the specific properties of the employed measurement set-up. Two different hydrogen-related donor profiles were implanted into these IGBT samples and, subsequently, measurements with different current densities were compared to 2D TCAD numerical simulations. In the next step, the simulation models were adjusted, with respect to carrier lifetime and mobility to reflect the impact of a possible variation of these properties.