Multiprobe Measurement Method for Voltage-Dependent Capacitances of Power Semiconductor Devices in High Voltage

The characterization of voltage-dependent capacitances of power semiconductor devices [diode, MOSFET, insulated gate bipolar transistor (IGBT), etc.] is very important for modeling their dynamic performances. A measurement method using two current probes has been developed to characterize interelectrode capacitances of power devices while isolating the measurement devices from the high-voltage dc bias power source. C_iss and C_oss are shown to be accurately measured while C_rss is not convincing enough. Then an additional current probe is added to improve the method. C_rss is shown to be well characterized by this three-current-probe method. This method has been validated using various technologies of semiconductor devices including silicon MOSFET and silicon carbide JFET. The interelectrode capacitances of power devices can be safely and accurately measured with this multiprobe method even in high voltage.