Patent ID: 6939728

Claim:
A method of fabricating a high emission electron emitter that includes an electron injection layer with a layer of silicon material thereon, the layer of silicon material including an active layer of high porosity porous silicon material, and a contact layer of low porosity porous silicon material, comprising: doping an interface surface of the layer of silicon material with a dopant to form an n-type heavily doped region that extends inward of the interface surface and extends only partially into the layer of silicon material; anodizing the interface surface in a hydrofluoric acid solution in a preselected optical ambient at a first anodization current density to form the contact layer of low porosity porous silicon material therein; maintaining the first anodization current density for a first period of time until the contact layer of low porosity porous silicon material has a first thickness; switching the first anodization current density to a second anodization current density to form the active layer of high porosity porous silicon material; and maintaining the second anodization current density for a second period of time until the active layer of high porosity porous silicon material has a second thickness.