Enhancement of current drivability in Field PMOS by optimized Field Plate

This paper presents a novel Field PMOS (FPMOS) with a LOCOS oxide film as a gate oxide for Plasma Display Panel scan drivers. In this novel FPMOS, an Aluminum Field Plate (Al-FP) is connected to a gate electrode and works as a secondary gate at high gate voltage (Vg). The drain current (Ids) of the novel FPMOS is about three times larger than that of conventional one at drain voltage (Vd)/Vg=-150/-200V, because the secondary gate accumulates holes in the drift region. Furthermore, the hot carrier reliability is superior; the absolute amount of Ids shift under DC stress conditions for the novel FPMOS is smaller than that of conventional one. This causes the drain current in the novel FPMOS to flow through the accumulated drift region induced by Al-FP at high Vg, and the trapped charge now has little influence on the Ids. Using a field plate as the second gate realizes higher drivability, and makes the Ids shift smaller at hot carrier stress.