Electron emitters with dopant gradient

Abstract

Electron emitters and a method of fabricating emitters which have a concentration gradient of impurities, such that the highest concentration of impurities is at the apex of the emitters and decreases toward the base of the emitters. The method comprises the steps of doping, patterning, etching, and oxidizing the substrate, thereby forming the emitters having impurity gradients.

1 . A flat panel display having at least one emitter comprising: 
 a substrate formed of a substantially uniform material;    at least one tapered protuberance integrally formed from the material of the substrate, said protuberance having an apex and a base;    a first dopant dispersed through said protuberance in a dopant concentration having a gradient, said dopant concentration greater at said apex, decreasing toward said base, and zero at said base; and    a second dopant dispersed through said protuberance in a dopant concentration having a gradient, said dopant concentration greater at said apex, decreasing toward said base, and zero at said base, said second dopant being different than said first dopant.    
   
   
       2 . A flat panel display having at least one pixel, comprising: 
 a single-layered substrate further comprising: 
 a generally planar surface having an upper surface comprising semiconductive material having an impurity concentration the greatest at the upper surface of the generally planar surface;  
 at least one protuberance formed from said generally planar surface; and  
 an impurity offset from said generally planar surface and within said protuberance, said impurity within said protuberance has a concentration decreasing concurrently with a distance from the upper surface of said generally planar surface.  
   
   
   
       3 . The flat panel display of  claim 2 , wherein said impurity is located within said protuberance to the exclusion of said substrate.  
   
   
       4 . A flat panel field emission display, comprising: 
 a remaining portion of a single-layered substrate, the remaining portion being an uncontaminated single-layered substrate that is at least semiconductive formed from a single-layered substrate having an upper surface, the single-layered substrate having an impurity concentration greatest at the upper surface while decreasing with a distance from the upper surface; and    a micro-cathode on said substrate formed from the portion of the single-layered substrate having an impurity concentration greatest at the upper surface thereof, further comprising: 
 a contaminated apex having an impurity concentration substantially the same as portion of the single-layered substrate at the upper surface thereof; and  
 a decreasingly contaminated body, the concentrate of the impurity decreasing from the contaminated apex.  
   
   
   
       5 . The flat panel field emission display of  claim 4 , wherein said micro-cathode is integral with said substrate.  
   
   
       6 . A flat display panel, comprising: 
 a generally uncontaminated substrate comprising semiconductive material formed from a single-layered substrate having an upper surface, the single-layered substrate having an impurity concentration greatest at the upper surface while decreasing with a distance from the upper surface; and    an emitter electrode on said substrate, further comprising an apex having an impurity concentration substantially the same as portion of the single-layered substrate at the upper surface thereof, and further having an etch-resistible quality that increases with depth from said apex.    
   
   
       7 . The flat display panel in  claim 6 , wherein said emitter electrode further comprises a base and further has an oxidizable quality that increases with elevation from said base.  
   
   
       8 . The flat display panel in  claim 7 , wherein a portion of said substrate that is under said emitter electrode has an etch-resistible quality generally similar to an etch-resistible quality of said base.  
   
   
       9 . The flat display panel in  claim 8 , wherein said portion has an oxidizable quality generally similar to an oxidizable quality of said base.  
   
   
       10 . A flat panel display having at least one emitter comprising: 
 a substrate formed of a substantially uniform material;    at least one tapered protuberance having one of a fine micro-point, edge, or blade integrally formed from the material of the substrate for the emission of electrons, said protuberance having an apex and a base;    a first dopant dispersed through said protuberance in a dopant concentration having a gradient, said dopant concentration greater at said apex, decreasing toward said base, and zero at said base; and    a second dopant dispersed through said protuberance in a dopant concentration having a gradient, said dopant concentration greater at said apex, decreasing toward said base, and zero at said base, said second dopant being different than said first dopant.    
   
   
       11 . A flat panel display having at least one pixel, comprising: 
 a single-layered substrate further comprising: 
 a generally planar surface having an upper surface comprising semiconductive material having an impurity concentration the greatest at the upper surface of the generally planar surface;  
 at least one protuberance formed from said generally planar surface, the at least one protuberance having a shape comprising one of a fine micro-point, edge, or blade for the emission of electrons; and  
 an impurity offset from said generally planar surface and within said protuberance, said impurity within said protuberance has a concentration decreasing concurrently with a distance from the upper surface of said generally planar surface.  
   
   
   
       12 . The flat panel display of  claim 11 , wherein said impurity is located within said protuberance to the exclusion of said substrate.  
   
   
       13 . A flat panel field emission display, comprising: 
 a remaining portion of a single-layered substrate, the remaining portion being an uncontaminated single-layered substrate that is at least semiconductive formed from a single-layered substrate having an upper surface, the single-layered substrate having an impurity concentration greatest at the upper surface while decreasing with a distance from the upper surface; and    a micro-cathode on said substrate formed from the portion of the single-layered substrate having an impurity concentration greatest at the upper surface thereof, the micro-cathode having a shape of one of a fine micro-point, edge, or blade for the emission of electrons further comprising: 
 a contaminated apex having an impurity concentration substantially the same as portion of the single-layered substrate at the upper surface thereof; and  
 a decreasingly contaminated body, the concentrate of the impurity decreasing from the contaminated apex.  
   
   
   
       14 . The flat panel field emission display of  claim 13 , wherein said micro-cathode is integral with said substrate.  
   
   
       15 . A flat display panel, comprising: 
 a generally uncontaminated substrate comprising semiconductive material formed from a single-layered substrate having an upper surface, the single-layered substrate having an impurity concentration greatest at the upper surface while decreasing with a distance from the upper surface; and    an emitter electrode on said substrate having a shape of one of a fine micro-point, edge, or blade for the emission of electrons, further comprising an apex having an impurity concentration substantially the same as portion of the single-layered substrate at the upper surface thereof, and further having an etch-resistible quality that increases with depth from said apex.    
   
   
       16 . The flat display panel in  claim 15 , wherein said emitter electrode further comprises a base and further has an oxidizable quality that increases with elevation from said base.  
   
   
       17 . The flat display panel in  claim 15 , wherein a portion of said substrate that is under said emitter electrode has an etch-resistible quality generally similar to an etch-resistible quality of said base.  
   
   
       18 . The flat display panel in  claim 17 , wherein said portion has an oxidizable quality generally similar to an oxidizable quality of said base.  
   
   
       19 . A flat panel display having at least one emitter comprising: 
 a substrate formed of a substantially uniform material;    at least one tapered protuberance having one of a fine micro-point, edge, or blade integrally formed from the material of the substrate for the emission of electrons, said protuberance having an apex and a base, said protuberance having an aspect ratio of greater than 1:1;    a first dopant dispersed through said protuberance in a dopant concentration having a gradient, said dopant concentration greater at said apex, decreasing toward said base, and zero at said base; and    a second dopant dispersed through said protuberance in a dopant concentration having a gradient, said dopant concentration greater at said apex, decreasing toward said base, and zero at said base, said second dopant being different than said first dopant.    
   
   
       20 . A flat panel display having at least one pixel, comprising: 
 a single-layered substrate further comprising: 
 a generally planar surface having an upper surface comprising semiconductive material having an impurity concentration the greatest at the upper surface of the generally planar surface;  
 at least one protuberance formed from said generally planar surface, the at least one protuberance having a shape comprising one of a fine micro-point, edge, or blade for the emission of electrons, said at least one protuberance having an aspect ratio of greater than 1:1; and  
 an impurity offset from said generally planar surface and within said protuberance, said impurity within said protuberance has a concentration decreasing concurrently with a distance from the upper surface of said generally planar surface.  
   
   
   
       21 . The flat panel display of  claim 20 , wherein said impurity is located within said protuberance to the exclusion of said substrate.  
   
   
       22 . A flat panel field emission display, comprising: 
 a remaining portion of a single-layered substrate, the remaining portion being an uncontaminated single-layered substrate that is at least semiconductive formed from a single-layered substrate having an upper surface, the single-layered substrate having an impurity concentration greatest at the upper surface while decreasing with a distance from the upper surface; and    a micro-cathode on said substrate formed from the portion of the single-layered substrate having an impurity concentration greatest at the upper surface thereof, the micro-cathode having a shape of one of a fine micro-point, edge, or blade for the emission of electrons,, said micro-cathode having an aspect ratio of greater than 1:1, said micro-cathode further comprising: 
 a contaminated apex having an impurity concentration substantially the same as portion of the single-layered substrate at the upper surface thereof; and  
 a decreasingly contaminated body, the concentrate of the impurity decreasing from the contaminated apex.  
   
   
   
       23 . The flat panel field emission display of  claim 22 , wherein said micro-cathode is integral with said substrate.  
   
   
       24 . A flat display panel, comprising: 
 a generally uncontaminated substrate comprising semiconductive material formed from a single-layered substrate having an upper surface, the single-layered substrate having an impurity concentration greatest at the upper surface while decreasing with a distance from the upper surface; and    an emitter electrode on said substrate having a shape of one of a fine micro-point, edge, or blade for the emission of electrons, said emitter electrode having an aspect ratio of greater than 1:1, said emitter electrode further comprising an apex having an impurity concentration substantially the same as portion of the single-layered substrate at the upper surface thereof, and further having an etch-resistible quality that increases with depth from said apex.    
   
   
       25 . The flat display panel in  claim 24 , wherein said emitter electrode further comprises a base and further has an oxidizable quality that increases with elevation from said base.  
   
   
       26 . The flat display panel in  claim 24 , wherein a portion of said substrate that is under said emitter electrode has an etch-resistible quality generally similar to an etch-resistible quality of said base.  
   
   
       27 . The flat display panel in  claim 26 , wherein said portion has an oxidizable quality generally similar to an oxidizable quality of said base.  
   
   
       28 . An in-process flat panel display having at least one emitter comprising: 
 a substrate formed of a substantially uniform material;    at least one tapered protuberance having one of a fine micro-point, edge, or blade integrally formed from the material of the substrate for the emission of electrons, said protuberance having an apex and a base;    a first dopant dispersed through said protuberance in a dopant concentration having a gradient, said dopant concentration greater at said apex, decreasing toward said base, and zero at said base; and    a second dopant dispersed through said protuberance in a dopant concentration having a gradient, said dopant concentration greater at said apex, decreasing toward said base, and zero at said base, said second dopant being different than said first dopant.    
   
   
       29 . An in-process flat panel display having at least one pixel, comprising: 
 a single-layered substrate further comprising: 
 a generally planar surface having an upper surface comprising semiconductive material having an impurity concentration the greatest at the upper surface of the generally planar surface;  
 at least one protuberance formed from said generally planar surface, the at least one protuberance having a shape comprising one of a fine micro-point, edge, or blade for the emission of electrons; and  
 an impurity offset from said generally planar surface and within said protuberance, said impurity within said protuberance has a concentration decreasing concurrently with a distance from the upper surface of said generally planar surface.  
   
   
   
       30 . The in-process flat panel display of  claim 29 , wherein said impurity is located within said protuberance to the exclusion of said substrate.  
   
   
       31 . An in-process flat panel field emission display, comprising: 
 a remaining portion of a single-layered substrate, the remaining portion being an uncontaminated single-layered substrate that is at least semiconductive formed from a single-layered substrate having an upper surface, the single-layered substrate having an impurity concentration greatest at the upper surface while decreasing with a distance from the upper surface; and    a micro-cathode on said substrate formed from the portion of the single-layered substrate having an impurity concentration greatest at the upper surface thereof, the micro-cathode having a shape of one of a fine micro-point, edge, or blade for the emission of electrons further comprising: 
 a contaminated apex having an impurity concentration substantially the same as portion of the single-layered substrate at the upper surface thereof, and  
 a decreasingly contaminated body, the concentrate of the impurity decreasing from the contaminated apex.  
   
   
   
       32 . The in-process flat panel field emission display of  claim 31 , wherein said micro-cathode is integral with said substrate.  
   
   
       33 . An in-process flat display panel, comprising: 
 a generally uncontaminated substrate comprising semiconductive material formed from a single-layered substrate having an upper surface, the single-layered substrate having an impurity concentration greatest at the upper surface while decreasing with a distance from the upper surface; and    an emitter electrode on said substrate having a shape of one of a fine micro-point, edge, or blade for the emission of electrons, further comprising an apex having an impurity concentration substantially the same as portion of the single-layered substrate at the upper surface thereof, and further having an etch-resistible quality that increases with depth, from said apex.    
   
   
       34 . The in-process flat display panel in  claim 33 , wherein said emitter electrode further comprises a base and further has an oxidizable quality that increases with elevation from said base.  
   
   
       35 . The in-process flat display panel in  claim 33 , wherein a portion of said substrate that is under said emitter electrode has an etch-resistible quality generally similar to an etch-resistible quality of said base.  
   
   
       36 . The in-process flat display panel in  claim 35 , wherein said portion has an oxidizable quality generally similar to an oxidizable quality of said base.