Comparison of ultralow specific on-resistance UMOSFET structures: the ACCUFET, EXTFET, INVFET, and conventional UMOSFET's

Three new ultralow specific on-resistance, vertical channel, power UMOSFET structures, with a trench (UMOS) gate extending all the way between N/sup +/ source and the N/sup +/ substrate (drain), are compared with the conventional UMOSFET structure. Specific on-resistances in the range of 100-250 /spl mu//spl Omega/cm/sup 2/ have been experimentally demonstrated for devices capable of supporting 25 V. This is due to current conduction via an accumulation and/or inversion layer formed under gate bias along the trench gate surface, resulting in the lowest specific on-resistance ever reported.<
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