Effect of anode material on high-field-induced hole current in SiO2 layer of metal-oxide-semiconductor field-effect transistor

The effects of three anode materials: polysilicon (semiconductor), aluminium and gold (metals) on hole currents in oxide layers of MOSFET's are presented for both thin (19 nm) and the thick (78 nm) oxide layers. Similar anode material effects were observed in both the thin and the thick oxide layers. The results suggest that anode hole generation plays the same role for both the thin and the thick oxide layers in our experiment. The larger the anode electron barrier height, the larger the hole current generation efficiency. The observable anode material effect decreases with increase of oxide electric field. When the oxide electric field is larger than 10 MV/cm, the observable anode material effect disappears. Our results show that the anode hole generation is the dominant mechanism on both the thin and thick oxide layers for oxide electric fields smaller than 10 MV/cm. For oxide electric fields larger than 10 MV/cm, further analysis is needed to identify the dominant mechanism of high-field-induced oxide hole currents