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.