Transient Analysis Of Super-Junction IGBT Power Semiconductor Device

Insulated Gate Bipolar Transistors(IGBTs)have been widely used in power converter systems including AC motors,traction drives,switching power supplies,lighting systems,and inveters,etc,owing to the combination of the advantages of MOSFET and BJT in terms of the low drive power consumptiuon and the low saturation voltage drop.Recently,super-junction(SJ)IGBT has been developed for optimizing the advantages on low power loss and small turn-on voltage drop.For a SJ IGBT,the transient process is particularly important,which is worth thorough investigation.In this thesis,the SJ IGBT and the subsidiary product-Semi-SJ IGBT are analyzed on their static characteristics and dynamic performance.Specifically,the anode current during their turn-off transient of the SJ IGBT in the test circuit with an inductive load has been studied: the anode voltage and the turn-off loss have been investigated using a two-dimensional(2D)simulation TCAD software tool-MEDICI.In addition,the analytical transient model of the SJ IGBT is developed as verified by the 2D device simulation to ensure its accuracy.In the first chapter of this thesis,the evolution of the semiconductor device is summarized with the device models itemized.Then,the significance of the IGBT is depicted in terms of the equirements on today's power electronics and the needs of scientific research.In the second chapter,the static characteristics and the dynamic characteristics of the SJ IGBT are analyzed in detail.The static characteristics include the analysis of the conduction characteristics and the blocking characteristics.The SJ IGBT in the test circuit with an inductive load has been used to analyze its turn-off transients.In the third chapter,based on the physical characteristics of the SJ IGBT during the turnon and turn-off processes,an anode current model,an anode voltage model,and a turn-off loss model for the SJ IGBT with an FS layer and p-and n-pillars are established.From the study,the doping density of the n-and p-pillars may cause a dramatic impact on the depletion region in the SJ IGBT,which leads to an important design hint: to maintain a low conduction voltage drop of the SJ IGBT when it's on,a high doping concentration of the n-and p-pillars is important without degrading its turn-off loss.In the fourth chapter,based on the understanding from SJ IGBT,the analysis of the SemiSJ IGBT is also provided,showing excellent operating characteristics.The analysis of the SJ IGBT and semi-SJ IGBT developed in this thesis indicates its modeling versatility applicable to various IGBTs.