EXPERIMENTS OF HIGHLY EMISSIVE METAL-OXIDE-SEMICONDUCTOR ELECTRON-TUNNELING CATHODE

An effective mean-free path of hot electrons in the conduction band of SiO2 in a Si-gate metaloxide-semiconductor (MOS) electron tunneling c athode was measured and found to be about 0.7 nm. Following these obse rvations, we proposed and fabricated a depletion gate MOS electron tun neling cathode. The highest transfer ratio of 13.3% was achieved in th e cathode at the low emission current level, which was considerably hi gher than that of tunneling cathodes studied in the past. However, the ratio decreased drastically at high current due to the hole injection into the depletion region from the gate. (C) 1996 American Vacuum Soc iety.