Study Of 4H-SiC Power MOSFET And DC-DC Boost Converter Application

4H-SiC are attractive semiconductor materials for high-power and high temperature electron devices because they have excellent physical properties such as a wide bandgap, high breakdown voltage, and high thermal conductivity. In addition, SiC has the advantage of a thermally grown native oxide, which provides the opportunity for its application in metal-oxide-semiconductor (MOS) devices. 4H-SiC high voltage metal-oxide-semiconductor (MOS) devices is a potential candidate for the application in high frequency and high voltage switching power supplies system. To reduce the electron in the conductive channel scattering from surface roughness due to high temperature annealing process after ion implantation and the acceptor impurity of P-base area , this paper suggest a new type of SiC MOSFET structure: the P -base divided into the P + ionimplantation layer and the P-epitaxial layer. In this paper, 4H-SiC MOSFET's reverse breakdown characteristics and on-resistance are researched and analyed. The relationship between the breakdown voltage, the on-resistance and structural parameters also are researched and analyed,obtained 1400V breakdown voltage and 7.3 mΩ·cm2 on-resistance.Base on the DC simulation of the devices, the SiC MOSFET and SBD transient switching characteristics are analyzed. A DC-DC Boost Converter based on the two switching devices is designed, the port properties of the two devices are extracted and put into the above circuit to be simulated, and the result is as follows: operating frequency is 20kHz, the output voltage is 500V, output voltage ripple rate is 1%, the power transmission efficiency is 96.1%; SiC MOSFET turn-loss (turn-on loss), and turn-off losses (turn-off loss) are 1.3W and 4.5W respectively.