Carrier Lifetime Control and Characterization of High-Resistivity Silicon Used for High-Power Devices

High-power devices require a thick silicon layer with high resistivity to achieve high breakdown voltages. In order to optimize the turn-on and turn-off behavior of these devices, precise adjustment of the carrier lifetime is necessary, together with knowledge of its dependence on process parameters and operation parameters (e.g. temperature and injection level). Therefore, the carrier lifetime of starting material (FZ-grown silicon) as well as processed devices that have both been either doped with transition metals (Pt, Au, Fe) or irradiated with electrons or light ions is analyzed by two different measurement techniques based on photoconductivity and free carrier absorption measurements.