Abstract—In this brief, we propose a new dual-material-gatetrench power MOSFET that exhibits a signiﬁcant improvement in its transconductance and breakdown voltage without any degradation in on-resistance. In the proposed structure, we have split the gate of a conventional trench MOSFET structure into two parts for work-function engineering. The two gates share the control of the inversion charge in the channel. By using 2-D numerical simulation, we have shown that by adjusting the lengths of the two gates to allow equal share of the inversion charge by them, we get the optimum device performance. By using N+ poly-Si as a lower gate material and P+ poly-Si as an upper gate material, approximately 44% improvement in peak transconductance and 20% improvement in breakdown voltage may be achieved in the new device compared to the conventional trench MOSFET.
Index Terms—Breakdown voltage, dual material gate, on-resistance, power MOSFET, trench gate.
The above paper can be downloaded from http://web.iitd.ac.in/~mamidala/id11.htm