Analysis of junction capacitance characteristics of trench gate IGBT
Trench gate field termination IGBT represents the latest structure of insulated gate bipolar transistor (IGBT). Because the internal current of IGBT includes the charging and discharging current of gate capacitance and internal junction capacitance during switching transient, the influence of junction capacitance should be considered. The conductive channel of trench gate structure is different from that of planar gate structure, and the analysis method of junction capacitance using planar gate structure will inevitably bring some deviation. Based on the characteristics of trench gate structure, this paper analyzes the different expressions of internal gate-drain junction capacitance in two cases according to whether the base depletion layer can be widened to cover the trench gate, and finally carries out simulation and experimental verification.