Study On A 3D Integrated TG DC SOI LIGBT

Insulated Gate Bipolar Transistor(IGBT)is a composite of Voltage-controlled MOS device structure and BJT device structure.It combines the advantages of both power MOS device and BJT devices,such as small input driving power,high input impedance,large current capacity,high switching speed and small on-resistance.Based on its superiority of better isolated capability,smaller parasitic capacitance,lower leakage current and higher integration due to silicon material,the Lateral Insulator Gate Bipolar Transistor(LIGBT)based on Silicon on Insulator(SOI)has been widely applied to smart power integrated circuit(SPIC).It has become the first choice for the application of power electronic devices with low-noise,high-performance,miniaturization and intelligence.Manufacturing methods,research progress,development trend of SOI LIGBT are firstly introduced in this paper.At the same time,basic structure,operational principle and the main electrical characteristics of SOI LIGBT are also analyzed.Secondly,the mathematical model of threshold voltage,on-state resistance and breakdown voltage of SOI LIGBT are established on the basis of the theory of semiconductor.And then,the analysis of the latch mechanism of the device contributes to the valuable relationship between some electrical characteristics and structure parameters,which directly guide the design and optimization of the device's structure parameters.Thirdly,to meet the increasing demand of high breakdown voltage and large on-state current of smart power Integrated Circuits,a novel three dimensionally integrated Double Cells SOI LIGBT with Trench Gate on silicon-based SOI substrate is proposed.In this structure,a second Buried Oxide Layer is further introduced in the drift region to isolate the device into two parallel LIGBT cells,which improves the electrical performance of the device.And the effects of some device parameters,such as the concentration of drift region,the thickness of the second buried-oxide,the length of field plate,the thickness of the field oxide and the concentration of P-Well on the main electrical characteristics of TG DC SOI LIGBT are obtained through a large amount of virtual simulation experiments with the Atlas simulator of SILVACO company.Finally,the Silvaco TCAD simulation results show that the proposed structure—Double Cells SOI LIGBT with Trench Gate increases the on-state current by 1.2 times,the breakdown voltage by1 time,the turn off speed by 18.3%,the latch-up voltage by 49% and reduces the on-state resistance by 65%,leakage current by one order of magnitude compared with the conventional TG SOI LIGBT.These are of great practical significance for energy saving and consumption reduction,lowcarbon environmental protection and sustainable development of SPIC and other power electronic applications.