Design Of 600V Quasi-vertical GaN Junction Barrier Controlled Schottky Diode

Gallium Nitride(Ga N),the third generation wide band gap semiconductor material,has many excellent characteristics,such as high breakdown voltage,high electron mobility,high thermal stability and so on.Ga N based junction barrier controlled Schottky diode(JBS)benefits from the advantages of Ga N materials,and combines the advantages of PN junction diode and Schottky barrier diode(SBD).It has the characteristics of high current,high resistance power-off voltage,fast switching and so on.So it has broad application prospects in the fields of radio frequency communication,industrial control,green energy and so on.In this paper,a quasi-vertical Ga N JBS diode with composite terminal structure is designed.Firstly,the effects of key parameters(including N~-drift region,P~+ring and anode contact barrier height)on the forward conduction and reverse blocking characteristics of the device are simulated and analyzed.On this basis,the cell structure with better Baliga figure of merit(BFOM)is obtained.In terms of terminal design,considering the problem of transverse size limitation of quasi-vertical structure,a composite terminal structure with junction terminal expansion,floating field limiting ring with slowly varying spacing and floating field plate is adopted,which can effectively alleviate the problem of electric field concentration at the edge of the main junction while reducing the terminal area,and shield the influence of oxide charges on the internal electric field distribution of the device,The voltage withstand capability of the device is significantly improved.Secondly,the high temperature and anti surge reliability of quasi-vertical Ga N JBS diode are simulated and analyzed.The results show that the quasi-vertical Ga N JBS diode with composite terminal structure has excellent thermal stability and strong anti surge ability.The final simulation results show that the turn-on voltage of quasi-vertical Ga N JBS diode is0.7V,the breakdown voltage is 860V,and the characteristic on-resistance is 4.2m?·cm~2.The breakdown voltage drift is less than 30%at high temperature(300?),and the surge withstand peak value is more than 30A,which meets the design requirements.