Low voltage superjunction power MOSFET: An application optimized technology

A detailed analysis of the power loss mechanisms in synchronous DC-DC converters has been undertaken to identify the critical MOSFET parameters that require improving to ensure that system efficiencies and power densities continue to increase. The analysis shows that the commonly used figures of merit (FOMs) based on Q_G and Q_GD (i.e. R_DS(on)×Q_G and R_DS(on)×Q_GD) are no longer sufficient when developing power MOSFET technologies, and if followed religiously, can lead to non-optimal technology choices. The insights gained from this work have been employed to define a set of FOMs that were then used to develop a new low voltage power MOSFET technology. The resulting 30V technology, based on the superjunction concept, is ideally suited for DC-DC conversion and in contrast to competing technologies such as lateral and split-gate trench MOSFETs, this approach simultaneously offers low specific R_DS(on), Q_G, Q_GD, Q_OSS, and high gate-bounce immunity.