Built in ion pump for field emission display

A field emission display having an ion pump, said display having a baseplate and an opposing face plate, comprising:

• a substrate acting as a base for said baseplate;
• parallel, spaced conductors acting as cathode electrodes, over said substrate;
• a first insulating layer over said cathode electrodes and said substrate;
• parallel, spaced conductors acting as gate electrodes, over said first insulating layer;
• a second insulating layer over said gate electrodes;
• parallel, spaced conductors acting as focusing electrodes, over said second insulating layer;
• a plurality of openings extending through said first and second insulating layers and said gate and focusing electrodes;
• at each of said openings is a field emission microtip connected to and extending up from one of said cathode electrodes;
• said faceplate having a glass base, mounted opposite and parallel to said baseplate;
• a pattern of phosphorescent material over said glass base;
• a conducting anode electrode over said phosphorescent material, whereby when electrons which are emitted from said field emission microtips strike said pattern of phosphorescent material, light is emitted, as well as outgassed material;
• and
• ion pump cathode electrodes formed of a gettering material, over said focusing electrodes, whereby during display operation said outgassed material is collected at said ion pump cathode electrodes.

A method of manufacturing a field emission display having an ion pump, comprising the steps of:

• providing a substrate having a first conducting layer thereon, a first insulating layer over said first conducting layer, and a second conducting layer over said first insulating layer;
• patterning said second conducting layer to form parallel, spaced conductors having first openings, to act as gate electrodes for said display;
• forming second openings in said first insulating layer, under said first openings;
• forming a sacrificial layer over said second conducting layer;
• forming field emission microtips in said second openings, whereby a closure layer is formed over said second conducting layer;
• removing said sacrificial layer and said closure layer;
• forming a third conducting layer over said second conducting layer and over said field emission microtips, wherein said third conducting layer is formed of a gettering material;
• forming a photoresist layer over that portion of said third conducting layer that is formed over said second conducting layer;
• removing said third conducting layer from the surface of said field emission microtips;
• and
• removing said photoresist layer.

A method of manufacturing a field emission display having an ion pump, comprising the steps of:

• providing a substrate having a first conducting layer thereon, a first insulating layer over said first conducting layer, a second conducting layer over said first insulating layer, and a second insulating layer over said second conducting layer, and a third conducting layer over said second insulating layer;
• patterning said third conducting layer to form parallel, spaced conductors having first openings, to act as a focusing electrode for said display;
• forming second openings in said second insulating layer, said second conductive layer and said first insulating layer, under said first openings;
• forming a sacrificial layer over said third conducting layer;
• forming field emission microtips in said second openings, whereby a closure layer is formed over said third conducting layer;
• removing said sacrificial layer and said closure layer;
• forming a fourth conducting layer over said third conducting layer and over said field emission microtips, wherein said fourth conducting layer is formed of a gettering material;
• forming a photoresist layer over that portion of said fourth conducting layer that is formed over said third conducting layer;
• removing said fourth conducting layer from the surface of said field emission microtips;
• and
• removing said photoresist layer.