Narrow-pitch n-channel superjunction UMOSFET for 40–60 V automotive application

We report on ultra-low on-resistance 40–60 V-class n-channel superjunction UMOSFET (SJ-UMOS) with sufficient robustness for automotive applications. In the newly developed SJ-UMOS, we design a leading minimal pitch SJ structures with sub-micron wide p-type regions fabricated by high-energy multiple ion implantations of boron. This structure drastically improves the tradeoff between on-resistance and breakdown voltage (V B ), which has limited the performance of conventional SJ-UMOS. Record low specific on-resistance (R SP ) of 9.1 mΩmm2 and 16.1 mΩmm2 (V GS = 10 V) are obtained for V B of 44.8 V and 61.0 V, respectively. We also confirm high avalanche immunity for the chips showing the best performance.