Analytical modeling and simulation studies of high voltage super-junction drift layer for power MOSFET

In the conventional VDMOS high voltage super-junction (SJ) power transistor, to achieve high breakdown voltage (BV), you have to use lower doping and higher thickness of the drift layer which prohibitively increases it on resistance making it unsuitable for use. Super-junction power MOSFET (CoolMOS™) claim to resolve this limitation and high voltage device up 1000V are using super junction drift layer with relatively low on resistance. In this paper an effort is made to explain in detail with the help of analytical treatment and simulation results to understand the physical mechanisms involved in improving the on resistance with high BV. An analytical modeling method is also proposed to get the design guide line for device dimensions and optimum doping levels for minimum on resistance based on Super-junction Theory.