Hydrogen-rich, low dielectric constant gate insulator for field emission device

Abstract

An emitter structure 12 for use in a field emission display device comprises a ballast layer 17 overlying ah electrically conductive coating 16 (cathode electrode), which is itself formed on an electrically insulating substrate 18. A gate electrode comprises a coating of an electrically conductive material 22 which is deposited on an insulating layer 20. Cone-shaped microtips 14 formed within apertures 34 through conductive layer 22 and insulating layer 20. In the present invention, insulating layer 20 comprises a dielectric material capable of desorbing at least ten atomic percent hydrogen, which may illustratively comprise hydrogen silsesquioxane (HSQ). HSQ is an abundant source of hydrogen which keeps deleterious oxides from forming on microtip emitters 14. HSQ also reduces the capacitance formed by cathode electrode 16 and gate electrode 22, since its relative dielectric constant is less than 3.5. In alternative embodiments, the gate insulation layer 20 additionally includes one or more sublayers of a more dense insulating material 20b and 20c, typically a plasma deposited silicon dioxide.

Dependencies are inferred from the claim text.