Spindt Field Emitter Arrays

Abstract

FIGURE 4.1. The Spindt microfabricated field emitter array. A BRIEF HISTORY OF THE SPINDT CATHODE 107program to develop microfabricated vacuum integrated circuits [3]. As a part of these activities he proposed a thin display tube based on matrix-addressed arrays of microfabricated field emitters -the field emission display, now commonly known as an FED [4]. This was the genesis of the VME technology that is presently being researched in essentially every industrial country in the world. As a part of Shoulder's program, Capp Spindt developed a process for microfabricating arrays of miniature metal field emitter cones in micron-size cavities with an integrated extraction electrode (gate). These structures were shown to produce detectable electron emission to an external anode with 20 V applied between the gate and the cones, and several microamperes of emission with 100 V applied between the cones and the gate. These results were first reported at the 1966 IEEE Conference on Tube Techniques [5], and in the open literature in 1968 [6]. Shoulders left SRI in 1968 to pursue other interests, and the emitter array development work continued at a low level, with internal funding by SRI until 1973. In 1973, support for development of a cold cathode for microwave tubes based on this microfabricated FEA technology was received from the NASA Lewis Research Center under the direction of Dr. Ralph Forman. At the same time Ivor Brodie, a well-known vacuum-tube expert, joined SRI as Director of the Applied Physics Laboratory, where the work was being done. One of Brodie's first acts was to initiate publication of the significant advances that had been made in the technology up to that time [7]. These two events, along with the concurrent development of large-area silicon emitter arrays at Westinghouse by Thomas and coworkers [8], were critical in taking the technology to the point that others began to take notice. In particular Richard Greene and Henry Gray at the Naval Research Laboratory (NRL), where thermionic vacuum integrated circuits developed at SRI by Geppert [9] were being evaluated, became interested in the technology and actively promoted it within the government as well as initiating NRL in-house work. In 1985 the French group at LETI, led by Robert Meyer, announced preliminary results with their efforts to produce a flat panel, field emission display (FED) based on the Spindt cathode [10]. The enormous commercial potential for such a product was immediately recognized by many throughout the world, and activity in the field (which by now was known as Vacuum Microelectronics) accelerated virtually overnight. SRI had also been working on a FED panel, and in 1987 Chris Holland, who was leading the panel fabrication effort at SRI, reported the first three-color FED panel [11]. At this time it became clear that many teams throughout the world were independently researching VME technology, but most were working in isolation and even innocent ignorance of others that were active in the field. Recognizing this, Richard Green...

Exact analysis of surface field reduction due to field-emitted vacuum space charge, in parallel-plane geometry, using simple dimensionless equations

“…Contexts where improved FEVSC theory may be useful include the liquid metal ion source ͑LMIS͒ 36,41 ͑used in focused ion beam machines 42 and the field emission electric propulsion of spacecraft 43 ͒, Spindt arrays, 27,28,44 and the proposed use of carbon nanotubes as bright field electron sources ͑e.g., Ref. 45͒.…”

Field desorption ion source development for neutron generators

“…those that had undergone no post fabrication treatment except hydrogen firing and storage in vacuum until use [9], typically showed a wide variety of surface adsorbates. …”

“…To confirm the deuterium peak was due to desorption and not gas phase field ionization of deuterium, the gas was evacuated to 10 9 Torr and additional spectra accumulated, as shown in Figure 6. Here there is only an initial slight decrease in the height of the atomic deuterium peak, consistent with desorption of deuterium from the tip surfaces.…”

Growth of ZrC thin films by aerosol-assisted MOCVD

“…A number of materials have reported low values of work function, including selected carbides, borides, nitrides, and carbonbased thin films. By integrating these materials into a high brightness electron source, it may be possible to increase the emission current by a factor of 100 or more as compared to a device fabricated from silicon or molybdenum [9][10][11][12][13][14].…”