Experimental and Theoretical Study on EMI Noise of Superjunction MOSFET with Different Pillar Doping

The EMI (Electro-Magnetic Interference) noise and capacitance characteristics of the Superjunction MOSFETs (SJ-MOS) with different P/N pillar doping concentration are tested in the switching circuit. It is found that the radiation noise is not just affected by the value of Gate-Drain capacitance (Cgd). According to the simulations and proposed theoretical model, the SJ-MOS with small slope of Cgd ~ Vds curve and larger Cgd at the same time has smaller overshoot voltage (ΔV
m
) and current (ΔI
m
), and thus has better EMI characteristic in the switching process.