Electrical Characteristics Of SiC Devices And Their Application In High Temperature Electronics

The requirement for the performance of electronic Products is getting higher and higher as the development of science and technology.Due to the limitation of material properties,traditional SiC material gradually cannot fulfill the requirements.SiC material possesses the advantages of broad band gap,high heat-conducting rate,and so on,the electronic device developed with it not only has more excellent property,but also can be applied in severe environment like high temperature.This paper studies the following aspects on the application of SiC device in high temperature area:In the field of sensor application,this paper analyzes the working principles and performance features of different types of Sic base temperature sensors,carrying out the theoretical and experimental study of SiC MOSFET base temperature sensors.Compared with the most commonly used SiC SBD temperature sensor at present,SiC MOSFET base temperature sensor is easier to realize high sensitivity from the design angle of device structure.This paper researches the sensitivity improvement scheme from two respects: device structure and drive circuit.From device structure angle,this paper finds by simulation,it can effectively promote the sensitivity of temperature sensor to enhance MOSFET substrate doping concentration and gate oxide thickness.From drive circuit angle,this paper compares the influence of series connection,parallel connection,bridge type and other circuit configurations on SiC MOSFET sensitivity.The experimental measurement indicates that SiC MOSFET temperature sensor based on bridge circuit has realized the t he sensitivity of up to 19.3 mV / ?.In the respect of power electronics field,thought the device structure and electrical properties are both similar with Si MOSFET,SiC MOSFET is incapable to follow its driving method directly.It is one of the significant advantages of SiC device compared with Si base device that besides high operating voltage and low open impedance,it can work in higher temperature,however,the research of corresponding driving method is lesser.This paper analyzes the on resistance,switching time and switching loss of SiC MOSFET in differenttemperatures,raising the device driving method.Different from what Si base MOSFET often adopts 0V~+12V driving voltage,SiC MOSFET needs-5V~+22V grid voltage.The simulation and the experiment show that SiC MOSFET on resistance and switching loss can be less after using this driving voltage.In the end,this paper proposes that SiC device driving method can be applied to power supply for high power LED street lamps,and test system is developed.