Fully self-aligned power trench-MOSFET utilising 1 μm pitch and 0.2 μm trench width

Using advanced photolithography and etching techniques, plus an innovative self-aligned process, trench MOSFETs with cell pitches between 1 μm and 4 μm with a trench width of 0.2 μm have been fabricated. The 1 μm cell pitch stripe technology achieves a specific (silicon only) on-resistance 10 mΩ.mm² at a gate voltage of 10 V and with a blocking voltage of 26 V. The trade-off between device on-state resistance and ´Miller´ charge was investigated by varying the cell pitch. The 4 μm cell pitch stripe technology achieves a figure of merit (Rds[on]×Q_gd) of 13 mΩ.nC at a gate voltage of 10 V with a blocking voltage of 27 V.