The use of silicon wafer substrates with a diameter of 300 mm for the manufacturing of electronic devices strongly increases the overall productivity of a device manufacturing line. However, ...float‐zone (FZ) silicon, which is traditionally used for insulated gate bipolar transistors (IGBTs), is not available for wafer diameters exceeding 200 mm. Therefore, a silicon material fabricated by the magnetic Czochralski (m:Cz) method has to be used for IGBT production on 300 mm wafers. Critical issues of this material are the so‐called crystal originated particles (COPs) and the strong axial variation of the doping level along the crystal. Furthermore, the m:Cz material contains a relatively high concentration of oxygen so that the influence of carbon/oxygen complexes has to be considered. CIOI complexes can be decorated with hydrogen atoms, resulting in donor‐like complexes. In particular, the application of proton irradiation for the doping of the field‐stop zone results in a relatively high concentration of interstitial carbon, which is continuatively associated with the generation of undesired donors. It is shown that the electrical behavior of IGBTs fabricated on FZ substrates can be well reproduced using the m:Cz material if the parameters of the hydrogen implantation are adjusted appropriately.
This brief describes the influence of switching conditions and a dynamic avalanche on the extraction of the charge-carrier plasma during the reverse-recovery period of p + -n - -n + diodes. The ...influence of the drift components and the diffusion components of the electron- and hole-current densities on the evolution of the plasma layer was investigated. The analysis shows that diffusion currents influence the plasma extraction process and can induce a change in the direction of the particle flux. Such a change in the particle flux may result in a longitudinal displacement of the plasma layer and significantly modify the reverse-recovery behavior. The results explain how a low on -state current density, a high circuit inductance, and the appearance of a dynamic avalanche will modify the reverse-recovery behavior.
