Design Of IGBT For Intrgrated Temperature Sampling

The development of IGBT(Insulated-Gated Bipolar Transistor)has been focused on higher voltage,higher current density,and higher reliability in high temperature environments.The devices of 600V/100 A,600V/200 A,600V/300 A and the maximum junction temperature 175? have been widely used in high-frequency,high voltage and high current switching power supply,so prone to over-temperature failure.Another important development trend for IGBT is integration.IGBT with over-temperature protection is also a trend to solve the problem of over-temperature failure.So,this paper presents a 600V/300 A IGBT with integrated temperature sampling function.The main power device uses a Trench-FS structure with a CS layer,which has good thermal stability and high performance.Temperature sampling devices use poly-silicon diode and has high sensitivity to temperature change.Their process compatibility is better.Furthermore,the paper provides the driving and sampling circuit,which has a simple structure and high reliability,and eliminates the phenomenon of thermal oscillation.The main research contents are as follows:(1)Summarize the current development trend of IGBT and the way of over-temperature protection,and puts forward the 600 V Trench-FS-IGBT structure which integrates the poly-silicon diode of temperature sampling device.(2)Develop compatible process of 600V/300 A Trench-FS IGBT and poly-silicon diode.Achieve effective isolation between devices.The IGBT cell and terminal structure is designed using the simulation software.The performance parameters of IGBT are as follows:Breakdown voltage BV=767V,Threshold voltage VTH=5.5V,Forward conduction voltage drop with positive temperature coefficient VCE=1.67 V,Collector-Emitter leakage current is less than 1uA,Current fall time tf=70ns,Turn-off losses EOff=13.82 mJ.The operation performance of poly-silicon diode were analyzed by simulation software.The performance parameters of poly-silicon diode are as follows:Breakdown voltage BV=10.3V,Forward conduction voltage drop VF=0.627 V,The temperature gradient of VF is-2mV/?.(3)The over-temperature protection circuit module is designed and the Spice model of IGBT and poly-silicon diode is established.The model has high accuracy.IGBT is turned off at 170? and is turned on at 145? when the IGBT over-temperature occurs.The hysteresis temperature is 25?.The designed cicuit has strong anti-interference ability.Finally,the layout is designed according to the current density and current capacity.IGBT active area is 1.25cm~2 and the width of poly-silicon diode is2000?m;The poly-silicon diode are located on the field oxygen and closer to the active area.It does not affect the breakdown voltage and leakage current of the high voltage device.At the same time,it can realize the real-time and accurate temperature detection.