Back to results
US 5,627,427 AGranted
Silicon tip field emission cathodes
AssigneeCornell Research Foundation, Inc.
InventorsJohn H. Das, Noel C. MacDonald, James W. Mayer, James P. Spallas
Life of this patent
Estimating the term…
Abstract
A micrometer scale emitter tip or array is disclosed having precisely located tips and surrounding gates. A silicide on the tips reduces tip work function.
Claims23
A densely packed micro-cathode field emitter array for producing high current density emissions at low voltage, comprising:
- a silicon substrate;
- a plurality of upwardly and inwardly tapered, generally conical silicon emitter tips arranged in a predetermined array and having bases integral with said substrate, said upwardly extending tips having terminal diameters of less than 20 nm, the height of each said tip being between about 500 nm and 900 nm with adjacent tips having a spacing of between about 1.0 and 10.0 micrometers;
- a generally planar, horizontal gate electrode metal layer supported on and spaced from said substrate and including an upwardly extending, inwardly tapering dimple portion spaced closely to and coaxial with each of said tips, each dimple portion being formed from said metal layer and having an upper end forming an aperture surrounding a corresponding emitter tip, each said aperture being self-aligned with its corresponding tip and being closely spaced thereto to form a gap of uniform width between each tip and its corresponding dimple, with the tip extending upwardly through its corresponding aperture by a predeterminable distance;
- and
- means dividing said gate electrode to electrically separate selected emitter tips within said array from other emitter tips within said array.
2 more elements
A silicon tip field emission micro-cathode, comprising:
- a silicon substrate having a top surface;
- a silicon emitter tip integral with said silicon substrate and extending upwardly from the top surface thereof, said tip having a base portion at said substrate and tapering inwardly and upwardly from said base portion to a terminal tip end;
- an electrically insulating layer on said substrate top surface and covering at least the base portion of said tip, said insulating layer having a predetermined thickness on said base portion;
- a metal gate electrode layer on said insulating layer and surrounding said base portion, said metal gate electrode layer including an upwardly extending, inwardly tapering dimple portion spaced from and surrounding said tip below said terminal end thereof, said dimple portion having an open upper end forming an aperture surrounding and self-aligned with said tip and spaced therefrom by a gap determined by the thickness of said insulating layer on said tip base portion, the diameter of said aperture being determined by the height of said open upper end of said dimple portion with respect to the terminal end of said tip.
1 more element
Dependencies are inferred from the claim text.