DEVELOPMENT OF DIAMOND MICROTIP FIELD EMITTER DEVICE

摘要

Electron field emitters with low operating electric field, high and stable emission current are the most desirable devices for a variety of potential applications in vacuum microelectronics. Diamond is an excellent material for electron field emitter and has been observed experimentally to yield high emission current at low electric field. However, reported diamond coated silicon tips, planar diamond film, and irregular ion etched conical structures, suffer a common shortcoming ― non-uniformity. These non-uniform diamond emitter structures have inconsistent emission behavior and poor stability. We have developed a consistent practical technique for fabrication of efficient diamond field emitters with well-controlled and uniform micro-emitter structures from a molding process. In addition, we have derived practical modifications involving the sp~2 content, surface treatment, and boron doping to further enhance diamond field emission. In this paper, we report recent developments of a new fabrication process for achieving ultra-sharp diamond tips with a radius of curvature less than 5 nm, which shows significant improvement in emission characteristics. We also report the development of a new technique to fabricate self-aligned gate diamond emitters, which achieve very high emission characteristics at extremely low applied voltage. Also, the latest development of micro-fabricated diamond tips with high density of uniform microtips arrays for electron field emission will be discussed. Discussion of this enhanced emission in diamond microtips will be presented in accordance with the analysis of the emission behavior.