New Planar 4.5 kV Split-gate (SG) Si-IGBT Device for Improved Switching Characteristics and High Frequency Operation

Abstract:
This paper presents the new split-gate (SG)-IGBT design concept implemented in Hitachi Energy’s 4.5 kV enhanced-planar Si-IGBT technology platform. The proposed SG-IGBT design, shows lower gate capacitances that lead to improved switching characteristics as observed from both TCAD simulations and experimental investigations. Our new design shows about a 33% reduction in the duration of Miller plateau in turn-off switching, a 38% reduction in the measured gate-charge and about 60% reduction in the gate-leakage current. The lower gate capacitances in SG-IGBT design also lead to an improved trade-off between switching speed (dI/dt) and IGBT turn-on losses (Eon), leading to about a 15% reduction in the combined IGBT and diode losses at the same dI/dt. Furthermore, our new SG-IGBT design is accompanied by additional cell protection features which prevents any reduction in blocking capability and other static characteristics typically observed in conventional SG devices.