Products > Field Emitters > Vapor Deposited Carbides

In the 1970's, Capp Spindt of SRI in Menlo Park, California developed a deposition technique to fabricate arrays for sub-micron sized metal cones. Commonly referred to as 'Spindt arrays,' these devices can be configured as triode field emitters with the addition of an insulator layer and extractor electrode. Modern arrays can be fabricated to very high emitter densities.

The potential applications for nano-scale field emitter arrays are numerous. Over the past 15 years, several groups have pursued their implementation in flat panel displays, typically targeting each sub-pixel with a cluster of micro-tips. This architecture allows very thin (< 9mm) panels with theoretical resolution limits in the tens of microns range. Ion propulsion systems for use in satellite positioning and deep space drives require an efficient, low voltage electron source to neutralize ejected ions and prevent charge accumulation on the craft. field emitter arrays would be ideal for this, as the extraction voltages can be quite small without any energy wasted in thermal losses. These advantages permit the use of compact battery power sources. Currently, there are serious efforts to apply this technology to high-density memory devices, electron lithography, metrology, and microscopic klystron sources.

APTech's involvement with field emitter arrays began in the early 1990’s at Linfield Research Institute. Mackie and co-workers began coating the molybdenum tips of Spindt’s arrays with carbides to lower the work function and create a more robust emitting surface, capable of higher and more stable currents in poor vacuum. This progressed into the fabrication of arrays in which the tips were solid carbide. In 2000, a state-of-the-art vacuum deposition system was built at Applied Physics Technologies to further these efforts. In this new system, we can deposit or overcoat arrays at the chip or full wafer level in a highly controlled manner. APTech has co-developed a proprietary process for depositing carbide emitter tips at the apex of truncated metal cones, and have studied tips of NbC, ZrC, HfC, TiC, Pt, and Ir to date.