Integrated field emission array for ion desorption
An integrated field emission array for ion desorption includes an electrically conductive substrate; a dielectric layer lying over the electrically conductive substrate comprising a plurality of laterally separated cavities extending through the dielectric layer; a like plurality of conically-shaped emitter tips on posts, each emitter tip/post disposed concentrically within a laterally separated cavity and electrically contacting the substrate; and a gate electrode structure lying over the dielectric layer, including a like plurality of circular gate apertures, each gate aperture disposed concentrically above an emitter tip/post to provide a like plurality of annular gate electrodes and wherein the lower edge of each annular gate electrode proximate the like emitter tip/post is rounded. Also disclosed herein are methods for fabricating an integrated field emission array.
1. An integrated field emission array for ion desorption, comprising:
an electrically conductive substrate;
a dielectric layer lying over the electrically conductive substrate comprising a plurality of laterally separated cavities extending through the dielectric layer;
a plurality of conically-shaped emitter tips, each emitter tip disposed concentrically within a laterally separated cavity and electrically contacting the substrate; and
a gate electrode structure so conformed as to define a plurality of annular gate electrodes, each said annular gate electrode disposed concentrically above an emitter tip to provide a plurality of respective gate apertures, and
wherein each said annular gate electrode comprises a ring of rounded or ovular cross section suspended from an inner face of a concentric support member so as to overhang a respective one of the laterally separated cavities.
2. The integrated field emission array of claim 1 , wherein the electrically conductive substrate comprises degenerately doped silicon.
3. The integrated field emission array of claim 2 , wherein the plurality of emitter tips comprise degenerately doped silicon.
4. The integrated field emission array of claim 2 , wherein the plurality of emitter tips comprise tungsten.
5. The integrated field emission array of claim 1 , wherein the each said annular gate electrode comprises tungsten.
6. The integrated field emission array of claim 1 , wherein a radius of the rounded lower edge of each said annular gate electrode is at least ten times greater than a radius of the emitter tip.
7. The integrated field emission array of claim 1 , wherein the dielectric layer comprises trenches etched in the substrate and filled with a dielectric material laterally separating the cavities.
8. The integrated field emission array of claim 7 , wherein the dielectric material comprises silicon nitride.
9. The integrated field emission array of claim 1 , wherein the dielectric layer comprises silicon oxide.