Simulation Of Novel SiC Trench IGBT

In recent years, Silicon carbide(Si C) has received more and more attention for its excellent characteristics of wide bandgap, high critical breakdown voltage, higher thermal conductivity, high electron saturation drift velocity and high resistance to radiation. Since the Si C power devices reduce the power consumption of electronic devices that are called green energy and promote a new energy revolution. In the fileds of high-performance radar, modern military electronic communication systems, aerospace systems, electromagnetic weapons, propulsion systems and power electronic equipment, solar power, high-speed rail traction equipment, hybrid and other defense and civilian, Si C power devices have great prospects.Si C insulated gate bipolar transistor(IGBT)is a complex device that combines the features of voltage-control in MOS devices and conductivity modulation in bipolar transistor. There are high input impedance, low power control, easy to drive in the MOSFET and a large current density, low saturation voltage characteristics in the bipolar transistor.So the Si C IGBT devices are mainly used in the fields of rail traffic, photovoltaic and wind green energy, smart grid and mobile communications.The basic characteristics of Si C TIGBT is mainly analyzed in this dissertation,such as the electronic concentration distribution in drift region,the forward voltage drop, turn-off loss and the trade-off between forward voltage drop and turn-off loss, the results obtained are as follows:1.The basic characteristics of the 4H-Si C n-TIGBT have been studied.The simulation results shows that compared to PIGBT, the forward voltage drop of TIGBT reduced by half, which is due to the elimination of the JFET resistance and the strong conductivity modulation effect cause by high electron drift region accumulation zone in TIGBT. But at the same time the turn-off time of TIGBT compared to PIGBT increased by 10%.2.Research on the basic characteristics of the 4H-Si C n-TIGBT with different emitter electrode width and trench depth.(1)The study found that whatever the circumstances, with the emitter electrode width increasing, the electron concentration in drift region is decreased, which makes the forward voltage drop increase and the turn-off loss reduce.(2)The ratio of the emitter electrode width and trench depth is changed and both of them are increased. With the depth of the trench increasing, the electron concentration in the drift region increase, resulting in a strong conductivity modulation effect which causes the forward voltage drop decrease and the turn-off loss increase.(3)The ratio of the emitter electrode width and trench depth is unchanged and both of them are increased. With the depth of the trench increasing, the electron concentration in the drift region is reduced, resulting in the forward voltage drop increase but the turn-off loss reduce. In summary, the different structure parameters of IGBT will lead to the different carrier concentration distribution in drift region, thereby affecting the forward voltage drop and turn-off loss. The carrier concentration distribution in the drift region have a significant impact on the forward voltage drop,which may be the future research forward for the trade-off between forward voltage drop and turn-off loss.3.A new structure combines the trench and plane called the 4H-Si C TPIGBT. In this dissertation, the electron concentration in the drift region, forward voltage drop, turn-off loss and the trade-off relationship have been studied in the same basic structural parameters of TIGBT, TPIGBT and PIGBT.The results shows that the forward voltage drop and turn-off loss of TPIGBT are between TIGBT and PIGBT.In comparision to PIGBT, the TPIGBT indicates 26.2% improvement in the forward voltage drop, while achieving 2.05% improvement in the he turn-off energy loss in comparision to TIGBT.