Fabrication process for electron field-emission display

Abstract

An electron field-emission display comprises one or more display cell structures, each having a field-emission cathode and an anode comprising at least one of several cathodoluminescent phosphors disclosed which are stimulable by electrons of very low energy. The display cell structures may also have gate elements for controlling electron current flowing from cathode to anode when suitable electrical bias voltages are applied. A preferred fabrication process integrates an etch stop with an in situ phosphor formation process. The etch stop precisely defines the depth of an opening in the display cell structure. Metal oxides or mixed-metal oxides of zinc, copper, tin, or indium are heated in the presence of a refractory metal such as titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, or combinations thereof to make phosphors of various chromaticities, which may also include dopants, such as a lanthanide rare earth element, manganese, chromium, or stoichiometrically excess zinc, copper, tin, or indium. A blue-light-emitting phosphor embodiment is based on ZnO treated with refractory metals, e.g. Ta, to prepare cathodoluminescent phosphor compositions, e.g. Ta.sub.2 Zn.sub.3 O.sub.8. Selective arrangement of various color phosphors may be made by selective deposition of suitable dopants. The selective deposition may be done, e.g. by chemical vapor deposition with appropriate masking, or by selective ion implantation.