Study On The Mechanism And Characteristics Of Trench Gate MOS-GCT

The integrated gate commutated thyristor(IGCT)is a high-voltage,high-current power semiconductor device that has been widely used in the field of high power.However,IGCT's turn-off needs to be controlled with a strong gate current pulse,its gate drive circuit is very complicated.In order to reduce the complexity of the driving circuit,this paper proposes a trench gate MOS-GCT structure,which integrates the trench p-MO,SFET into the GCT to control the turn-off with voltage signal,thereby simplifying the driven circuit and reducing its volume.Taking 4.5kV trench gate MOS-GCT as an example,the operation mechanism,electrical characteristics and influence factors are studied,and its manufacture process is simulated and analyzed.The main research contents are as follows:Firstly,the trench gate MOS-GCT structure is proposed and its structural features and operation principle are analyzed.The structural model is set up,and the blocking,conducting,switching mechanisms and its parasitic pnp transistor,intergrated p-MOSFET are studied by T-CAD simulator.The results show that the negative gate voltage is applied to th e integrated pMOSFET to achieve rapid turn-off of the device.However,,the negative gate voltage must be applied to provide a channel for leakage current during blocking.Secondly,the blocking,conducting and switching characteristics of the trench gate MOS-GCT are studied.The influences of the structural parameters,such as n-base region,p-base region,n auxiliary layer on the device characteristics are analyzed;on this basis,the influences,of carrier life,temperature changes and overstress conditions on the static and dynamic characteristics of the device are studied,and the optimized structural parameters are extracted.The results show that the concentration and thickness of the p-base region and n auxitiary layer are sensitive parameters that influence the device characteristics.Finally,process design of trench gate MOS-GCT,the process flow and the realization method of each area of the device are analyzed,and the process is simulated by simulator to extract the process conditions.The research results have certain reference value for the development of GCT and gate control devices.