Abstract:
A method for making a field emission cathode structure includes forming a ballast layer over a column metal layer, forming a dielectric layer over the ballast layer, forming a line metal layer over the dielectric layer, forming a trench in the line metal layer and the dielectric layer, the trench extending to the ballast layer, and forming a sidewall spacer and a sidewall blade adjacent a sidewall of the trench, where the sidewall spacer is between the dielectric layer and the sidewall blade, and where the conformal spacer is recessed as compared to the sidewall blade such that a gap is present between the sidewall blade and the line metal layer.
Abstract:
A Reflective Field Emission Display (FED) system using reflective field emission pixel elements is disclosed. In the FED system disclosed, each pixel elements is composed of at least one edge emitter that is operable to emit electrons and at least one reflector that is operable to first attract and then reflect the emitted electrons onto a transparent layer that is operable to attract the reflected electrons. The transparent anode layer is oppositely positioned with respect to the cathode or emitter edge. In a one aspect of the invention, a phosphor layer interposed between the transparent layer and the pixel element produces a light photon as reflected electrons are attracted to the transparent layer. In another aspect of the invention, a plurality of phosphor layers are applied to the transparent layer to produce a color display when reflected electrons are attracted to the transparent layer.
Abstract:
A Reflective Field Emission Display system, components and methods for fabricating the components is disclosed. In the FED system disclosed, a plurality of reflective edge emission pixel elements are arranged in a matrix of N rows and M columns, the pixel elements contain an edge emitter that is operable to emit electrons and a reflector that is operable to extract and laterally reflect emitted electrons. A collector layer, laterally disposed from said reflector layer is operable to attract the reflected electrons. Deposited on the collector layer is a phosphor layer that emits a photon of a known wavelength when activated by an attracted electron. A transparent layer that is oppositely positioned with respect to the pixel elements is operable to attract reflected electrons and prevent reflected electrons from striking the phosphor layer. Color displays are further contemplated by incorporating individually controlled sub-pixel elements in each of the pixel elements. The phosphor layers emit photons having wavelengths in the red, green or blue color spectrum.
Abstract:
A field emitter cell includes a thin film edge emitter normal to a gate layer. The field emitter is a multilayer structure including a low work function material sandwiched between two protective layers. The field emitter may be fabricated from a composite starting structure including a conductive substrate layer, an insulation layer, a standoff layer and a gate layer, with a perforation extending from the gate layer into the substrate layer. The emitter material is conformally deposited by chemical beam deposition along the sidewalls of the perforation. Alternatively, the starting material may be a conductive substrate having a protrusion thereon. The emitter layer, standoff layer, insulation layer, and gate layer are sequentially deposited, and the unwanted portions of each are preferentially removed to provide the desired structure.
Abstract:
A self-gettering electron field emitter has a first portion formed of a low-work-function material for emitting electrons, and it has an integral second portion that acts both as a low-resistance electrical conductor and as a gettering surface. The self-gettering emitter is formed by disposing a thin film of the low-work-function material parallel to a substrate and by disposing a thin film of the low-resistance gettering material parallel to the substrate and in contact with the thin film of the low-work-function material. The self-gettering emitter is particularly suitable for use in lateral field emission devices. The preferred emitter structure has a tapered edge, with a salient portion of the low-work-function material extending a small distance beyond an edge of the gettering and low resistance material. A fabrication process specially adapted for in situ formation of the self-gettering electron field emitters while fabricating microelectronic field emission devices is also disclosed.
Abstract:
Field emitter structures are described for use in arrays forming field emission displays. The field emitter structures may be either single or perferably double-gate structures. To enhance the field emission current density the emitters are formed so as to be elongate so as to form a race-track shape. The emitter layer may also be provided with sharply defined edges in order to improve electron emission.
Abstract:
A low turn-on voltage volcano-shaped field emitter, a method of fabrication, and integration into an addressable array suitable for applications in field emitter displays and other electron generating applications are disclosed. In one embodiment, the device is fabricated using a stepped insulator in which the distance between the gate and the emitter near the emission surface is significantly reduced with respect to the thickness of the insulator and separates the gate from the emitter. By keeping the large gate-to-emitter distance, the device capacitance is reduced and fabrication yield is increased, since pinholes in the insulator are significantly reduced. In another embodiment of the present invention, the integration of the device into an addressable array suitable for electron emission is described. The array incorporates a network of resistors which assures uniform emission.
Abstract:
A method for fabricating an array (300) of edge electron emitters (530) includes the steps of: forming first and second grooves (310, 320) in first and second opposing planar surfaces (101, 102), respectively, of a supporting substrate (110) to form an array of openings (330) therethrough; forming a dielectric layer (122) on the first planar surface (101) and an emission structure (120) on the dielectric layer (122); forming a plurality of cathodes (132) on the emission structure (120); forming gates (515) on a portion of the surfaces defining the first grooves (310); forming a masking film (710) on the cathodes (132)/emission structure (120); removing an outer, radial portion (726) of the masking film (710); etching the emission structure (120), the retracted masking film (710) forming a mask, thereby providing a predetermined configuration of the edge electron emitters (530) with respect to the gates (515) and cathodes (132).
Abstract:
A lateral-emitter electron field-emission display device structure incorporates a thin-film emitter having an emitting edge and extending into in direct contact with a non-conducting or very high resistivity phosphor, thereby eliminating the gap between the emitter and the phosphor. Such a gap has been a part of all field-emission display devices in the prior art. The ultra-thin-film lateral emitter of the new structure is deposited in a plane parallel to the device's substrate and has an inherently small radius of curvature at its emitting edge. A fabrication process specially adapted to make the new structure includes a directional trench etch, which both defines the emitting edge and provides an opening to receive a non-conducting phosphor. This phosphor covers an anode and is automatically aligned in contact with the emitter edge. When an electrical bias voltage is applied between the emitter and anode, electrons are injected directly into the phosphor material from the emitter edge, exciting cathodoluminescence in the phosphor to emit light which is visible in a wide range of viewing angles. With minor variations in the fabrication process, a lateral-emitter electron field emission display device may be made with an extremely small emitter-phosphor gap, having a width less than 100 times the thickness of the ultra-thin emitter. Embodiments in which the gap width is zero are characterized as edge-contact light-emitting diodes (or triodes or tetrodes if they include control electrodes).