| Anodization of a heavily doped silicon wafer followed by oxidation can build a structure of an insulated layer with vertical voids on the substrate. When a positive potential is applied on the top of the insulating layer, electron field emission occurs in the voids. This field emission current is neither constrained by the external energy supply as in thermionic electron tube, nor is it constrained by the low carrier supply as in semiconductor devices. The study has led to the development of the oxidized porous silicon field emission devices. These devices are temperature independent. They operate at a voltage below 10 volts with high current density. The application of the devices are anticipated in vacuum integrated circuits, flat panel displays, and high frequency circuits. |
