Tunable Oxide-Bypassed Trench Gate MOSFET: Breaking the Ideal Superjunction MOSFET Performance Line at Equal Column Width

Abstract

The superjunction (SJ) MOSFET power device is highly recognized for its higher blocking capability and lower on-state resistance that breaks the conventional unipolar silicon limit However, SJ devices below 100 V rating incur constraint of unrealistic narrower column widths [1], [2] and their performance is greatly handicapped due to difficulties in formation of perfect charge-balanced SJ p-n columns by current process technology. Based on the alternative approach of tunable oxide-bypassed (TOB) SJ MOSFET concept proposed in [15], a TOB-UMOS device of 79 V rating has been successfully fabricated for the first time. Laboratory measurements indicate that the device has broken the ideal SJ MOSFET performance line at equal column width of 3.5 μm, and potentially the ideal silicon limit as well.