Recent developments in superjunction power devices

Abstract

Superjunction (SJ) is one of the most innovative concepts in the field of power semiconductor devices and is often referred to as a "milestone" in power MOS. Its balanced charge field modulation mechanism breaks through the strong dependency between the doping concentration in the drift region and the breakdown voltage V B in conventional devices. This results in a reduction of the trade-off relationship between specific on-resistance R on,sp and V B from the conventional R on,sp∝V B 2.5 to R on,sp∝W∙V B 1.32, and even to R on,sp∝W·V B 1.03. As the exponential term coefficient decreases, R on,sp decreases with the cell width W, exhibiting a development pattern reminiscent of "Moore’s Law". This paper provides an overview of the latest research developments in SJ power semiconductor devices. Firstly, it introduces the minimum specific on-resistance R on,min theory of SJ devices, along with its combination with special effects like 3-D depletion and tunneling, discussing the development of R on,min theory in the wide bandgap SJ field. Subsequently, it discusses the latest advancements in silicon-based and wide bandgap SJ power devices. Finally, it introduces the homogenization field (HOF) and high-K voltage-sustaining layers derived from the concept of SJ charge balance. SJ has made significant progress in device performance, reliability, and integration, and in the future, it will continue to evolve through deeper integration with different materials, processes, and packaging technologies, enhancing the overall performance of semiconductor power devices.