Advanced RFC diode utilizing a novel vertical structure for soilness and high dynamic ruggedness

This paper reports for the first time that the freewheeling diode (FWD) with Relaxed Field of Cathode (RFC) technology can achieves excellent total performance by adopting a novel vertical structure. The proposed vertical structure consists of a “Light Punch-Through (LPT) II” and a “Controlling Carrier-Plasma Layer (CPL)”. The measured results of 1200 V diode show that the total loss and dynamic behavior such as the recovery softness and the dynamic ruggedness are greatly improved thanks to the proposed vertical concept. These improvements are the result of controlling the charge-carrier plasma layer and moderating the electric field gradient in CPL zone during the recovery operation. The advanced RFC diode clearly breaks through the trade-off triangle of the total loss, the recovery softness and the recovery SOA of the FWD.