Title :
IGBT negative gate capacitance and related instability effects
Author :
Omura, I. ; Ohashi, H. ; Fichtner, W.
Author_Institution :
Integrated Syst. Lab., Swiss Fed. Inst. of Technol., Zurich, Switzerland
Abstract :
For high collector voltages, Insulated Gate Bipolar Transistors (IGBTs) exhibit a negative gate capacitance. In this condition, a p-channel inversion layer is formed on the N-base surface. The positive charges in the p-channel induce negative charges in the MOS gate electrode. This results in a negative gate capacitance. As a consequence of this negative capacitance, IGBT operation is inherently unstable, leading to current redistribution between cells or even chips.
Keywords :
capacitance; current distribution; current fluctuations; insulated gate bipolar transistors; inversion layers; semiconductor device models; semiconductor device reliability; 1200 V; IGBT; MOS gate electrode; N-base surface; current redistribution; high collector voltages; inherent instability; instability effects; negative gate capacitance; p-channel inversion layer; p-channel positive charges; Bipolar transistors; Capacitance; Charge measurement; Controllability; Current measurement; Electrodes; Insulated gate bipolar transistors; Laboratories; Low voltage; Safety;
Journal_Title :
Electron Device Letters, IEEE
