Abstract:
An electron emitter plate (110) for an FED image display has an extraction (gate) electrode (122) spaced by an insulating layer (25) from a cathode electrode including a conductive mesh (118). Circular arrays (112) of microtips (14) are located concentrically within circular mesh spacings (116) on a resistive layer (15), within apertures (26) formed in extraction electrode (122). Microtips (14) are laterally spaced from mesh structure (118) by substantially identical paths of a ballast-providing resistive layer (15), placing all microtips (14) at generally the same potential.
Abstract:
A field emission device has a rear substrate (11), a titanium or aluminum adhesive layer (12) and disposed on the substrate (11), a tungsten cathode (13) disposed on the adhesive layer (12), a micro-tip (13') protruding from the cathode (13), a titanium or aluminum mask layer (14) disposed on the cathode (13), and a metal pattern (15) formed on the mask layer (14) for supporting the cathode (13). The micro-tip (13') is formed by the simultaneous etching of the tungsten cathode (13), the adhesive layer (12), and the mask layer (14') resulting in a large internal stress in the micro-tip (13'). The residual internal stress in the micro-tip (13') results in the micro-tip (13') curving away from the substrate (11) which, consequently, facilitates electron emission.
Abstract:
Lateral field emission devices ("FEDs") for display elements and methods of fabrication are set forth. The FED includes a thin-film emitter oriented parallel to, and disposed above, a substrate. The FED further includes a columnar shaped anode having a first lateral surface. A phosphor layer is disposed adjacent to the first lateral surface. Specifically, the anode is oriented such that the lateral surface and adjacent phosphor layer are perpendicular to the substrate. The emitter has a tip which is spaced less than the mean free distance of an electron in air from the phosphor layer. Operationally, when a voltage potential is applied between said anode and said emitter, electrons are emitted from the tip of the emitter into the phosphor layer causing the phosphor layer to emit electromagnetic energy. Further specific details of the field emission device, fabrication method, method of operation, and associated display are set forth.
Abstract:
An improved high-frequency field-emission microelectronic device (10) has a substrate (20) and an ultra-thin emitter electrode (30) extending parallel to the substrate and having an electron-emitting lateral edge (110) facing an anode (40) across an emitter-to-anode gap (120). A control electrode (70), having a lateral dimension only a minor fraction of the emitter-to-anode gap width, is disposed parallel to the emitter and spaced apart from the emitter by an insulator (60) of predetermined thickness. A vertical dimension of the control electrode is only a minor fraction of the height of the anode. The control electrode may substantially surround a portion of the anode, spaced from the anode in concentric relationship. Inter-electrode capacitance between the emitter and the control electrode has only an extremely small value, consisting of only a very small area term and a very small fringing-field term, thus allowing operation of the microelectronic device at higher frequencies or switching speeds than heretofore. Inter-electrode capacitance between the control electrode and the anode also has only an extremely small value, thus improving higher frequency performance further. Devices having a plurality of control electrodes may also be made with improved inter-electrode capacitance. In order to consistently realize improved performance, a fabrication process (S1-S18) is specially adapted for manufacturing the device with small and precise dimensions and suitably precise alignment. The specially adapted process uses two sacrificial materials (150 and 160), one of which forms a temporary mandrel, and uses a conformal conductive layer to form each control electrode while automatically achieving the required alignment precision.
Abstract:
A vertical field emitter structure and field emission device such as a flat panel display utilizing such structure. Self-aligned gate and emitter fabrication is described, together with virtual column field emitter structures, comprising an emitter or gated emitter with conductive columns connecting the emitter to an underlying resistor or conductor structure formed by chemical or other modification of portions of an underlying layer. The display of the invention utilizes field emission structures with low turn-voltages and high accelerating voltages, thereby permitting high brightness, small pixel size, low manufacturing costs, uniform brightness, and high energy efficiency to be achieved.
Abstract:
An electron emitter plate (110) for an FED image display has an extraction (gate) electrode (22) spaced by a dielectric insulating spacer (125) from a cathode electrode including a conductive mesh (18). Arrays (12) of microtips (14) are located in mesh spacings (16), within apertures (26) formed in clusters (23) in extraction electrode (22). Microtips (14) are deposited through the apertures (26). Apertures (26) are arranged in regular, periodic arrays (23, 23', 123, 123') defining lattices having occupied apertured positions and internal unapertured vacancy positions (150, 150'). The insulating spacer (125) is etched to undercut electrode (22) to connect apertured lattice positions, forming a common cavity (141) for microtips (14) within each mesh spacing (16), and leaving central posts (143) at the unapertured vacancies (150, 150'). The etch-out reduces the dielectric constant factor of gate-to-cathode capacitance in the finished structure. Placing posts at vacancy positions enables gate support over the cavity without sacrificing high microtip density.
Abstract:
A field emission device including a substrate, an emitter layer, a spacer layer and a gate layer. In one preferred embodiment, the emitter layer is made of a resistive material, and has a side end that has an edge. The spacer layer is on and over only a portion of the emitter layer to expose the edge. The gate layer, on the spacer layer, also has a side end that is tapered to form a wedge with an edge. In one application, the device is used in a flat panel display, with a screen. The screen is at a selected positive voltage and is positioned above the gate layer. When a selected potential difference is applied between the emitter layer and the gate layer, an electron-extraction field is established between the edge of the gate layer and the edge of the emitter layer to extract electrons from the edge of the emitter layer. Then, the electrons are attracted to the screen. The wedge reduces the amount of electrons collected at the gate and increases the efficiency of the device. The resistive nature of the emitter layer enhances the uniformity of the electrons emitted along the edge of the emitter layer.
Abstract:
A vertical field emitter structure and field emission device such as a flat panel display utilizing such structure. Self-aligned gate and emitter fabrication is described, together with virtual column field emitter structures, comprising an emitter or gated emitter with conductive columns connecting the emitter to an underlying resistor or conductor structure formed by chemical or other modification of portions of an underlying layer. The display of the invention utilizes field emission structures with low turn-voltages and high accelerating voltages, thereby permitting high brightness, small pixel size, low manufacturing costs, uniform brightness, and high energy efficiency to be achieved.
Abstract:
A field emission electron emitter comprising an electrode formed of at least one diamond, diamond-like carbon or glassy carbon composite fiber, said composite fiber having a non-diamond core and a diamond, diamond-like carbon or glassy carbon coating on said non-diamond core, and electronic devices employing such a field emission electron emitter.
Abstract:
A field emission display that may be viewed through the back plate, thus providing increased luminous efficiency, and methods for making such a display, are described. A glass substrate is provided as a base for the display faceplate. There is a reflective, conductive layer over the glass substrate. A phosphor layer is formed over the reflective, conductive layer. A second glass substrate acts as a transparent base for the display baseplate, which is mounted opposite and parallel to the faceplate. A first transparent insulating layer is formed over the second glass substrate. There are parallel, transparent cathode electrodes with auxiliary metal electrodes, over the first insulating layer. Parallel, transparent gate electrodes are formed over, separate from, and orthogonally to the parallel, transparent cathode electrodes, and also have auxiliary metal electrodes. A second transparent insulating layer is between the gate electrodes and the cathode electrodes. A plurality of openings extend through the second insulating layer and the gate electrodes. At each opening is a field emission microtip connected to and extending up from a cathode electrode, whereby electrons may be selectively emitted from each microtip to form a display image on the faceplate phosphor layer, which is viewable through the baseplate.