Nanocrystalline diamond lateral vacuum microtriode

Abstract

A vacuum field emission microtriode in lateral configuration utilizing nanocrystalline diamond is presented. The nanodiamond lateral triode is a completely integrated device comprising a fingerlike emitter geometry with an ∼15nm tip radius of curvature, built-in gate, and anode with gate-cathode spacing of 3μm and anode-cathode spacing of 12μm. Triode characteristics, demonstrating gate-controlled emission current modulation with an anode current of 4μA and high transconductance of 0.3μS from a single emitter-finger at low device voltages (Vg<40V and Va∼65V), are obtained. The anode-induced electron emission conforms to Fowler–Nordheim tunneling. These observations from the first diamond lateral vacuum microtriode demonstrate a robust device for integrated circuit-compatible, temperature-, and radiation-insensitive vacuum micro-nanoelectronics.

On the role of graphite in ultrananocrystalline diamond films used for electron field emitter applications

“…In addition to the versatility in microstructural control, the NCD (UNCD as well) films show other fascinating characteristics of ultra‐small smooth surface and extremely small grains. These materials can be coated on ultra‐sharp tips (and arrays) conformally for fabricating electron field emitters . Not long after the report on the marvelous EFE properties of UNCD films in the year 1998 , Corrigan et al reported low turn‐on voltage (∼150 V) with extremely high emission current (60∼100 µA/tip) for conformal coating of UNCD on Si‐microtip emitters, the very first conformally coated UNCD/Si emitters (unfortunately, the E 0 value is not available as the cathode to anode distance is not reported).…”

“…Madaleno et al also showed that conformal UNCD coated silica‐rod templates, of submicron size, possess extremely good EFE behavior, that is, E 0 = 5.5 V/µm with 10.0 mA/cm 2 EFE capacity at an applied field of 11 V/µm. On the other hand, Subramanian et al illustrated another marvelous feature of UNCD films. They fabricated the first all diamond vacuum field emission lateral micro‐triode.…”

Nanodiamond lateral field emission vacuum logic OR gate

“…Also, the turn-on field and maximum current capability are limited by the properties of the material used and the processes employed to fabricate the devices. With suitable nanocrystalline diamond possessing field enhancement factors and low work function with nitrogen incorporation [8], efficient and reliable batch-fabricated lateral diodes have been achieved with lowest reported turn-on, and this virtually eliminates the other sources of forward voltage drop. Thus, a structure limited forward voltage drop leads to the mismatch in the input output logic highs.…”

“…Device fabrication: The single-mask fabrication process began with the deposition of nanodiamond film on SOI wafer using microwave-plasmaenhanced CVD (MPECVD) [8]. Then, a thin aluminium (Al) layer was deposited by e-beam evaporation followed by patterning using conventional photolithography.…”

Faceted magnetron concept using field emission cathodes

“…Here, the emitter arrays are placed on either side of a slit but back from the exit opening of the slit to prevent back bombardment. The emitters are lateral devices 7 which emit along the surface of the substrate. The device configuration shows lateral tips with symmetric gates.…”