A Study on the Optimization of Deep-Trench Super Junction Metal Oxide Semiconductor Field-Effect Transistor

Abstract

Power metal oxide semiconductor field-effect transistor is a switching device designed to handle large power consumption; it enables fast switching, resulting in low power consumption. Power devices are used as important components that determine the operation and performance of electrically powered products such as home appliances, smartphones, and automobiles. Power devices must be able to block high voltage so that current does not flow in the off state, have no power consumption in the on state, and have a small resistance so that high current can flow. For high efficiency, power loss must be minimized and resistance must be reduced during the turn-on state. To increase the breakdown voltage, the thickness and resistivity of the N-drift region must be increased. However, owing to the trade-off relationship, as the breakdown voltage increases, the on-resistance also increases. The super junction structure was proposed to improve this trade-off relationship. In this study, a process simulation using TCAD tool was carried out. Similar to the multi-epitaxial process, the P-pillar was divided into several layers, and the value of each concentration was specified. Thus, the charge balance of the pillar regions was achieved. For the maximum breakdown voltage characteristics and minimum on-resistance characteristics of the deep-trench super junction MOSFET, an experiment was conducted to optimize the cell pitch and pillar of the super junction MOSFET using a five-deep trench.