Study on Novel Field Emission Materials and Devices for Field Emission Display
|關鍵字:||場發射顯示器;場發射元件;奈米碳管;Field emission display;Field emission device;Carbon nanotube|
Novel field emission materials and devices are synthesized and fabricated in this thesis. For conventional metal field emission materials, chimney shape field emission array was proposed. Metal emitters with high aspect ratio can be obtained by controlling the thickness of the sputtering deposited metal film on the Si neck as the field emitter, the emission area was increased effectively to produce more emitter redundancy. The fabrication process was also simplified because no oxidation sharpening or high vacuum oblique physical vapor deposition was required to produce sharp features. The experimental results suggested that excellent field emission properties can be achieved from chimney shape field emission arrays as compared to cone shape field emission arrays. Modified chimney shape field emission arrays were also proposed to modify the physical construction of the chimney shape emitters, and the modified chimney shape triodes were fabricated to exhibit excellent triode properties. For the synthesis of novel field emission materials, carbon nanotubes (CNTs) with various morphologies have been synthesized using microwave plasma-enhanced chemical vapor deposition (MPCVD) by controlling the thickness of the catalyst film. The growth behaviors of CNTs with different catalysts (e.g. Fe, Co, Ni) were also discussed. The fabricated CNTs emission arrays showed excellent field emission properties, however, the field emission properties of the high density CNTs degraded for the screening effect of the electric field. To improve the field emission properties of the CNTs, a novel post treatment process via excimer laser was proposed. The results depicted the field emission properties can be upgraded with proper excimer laser treatment conditions. Additionally, a novel process was proposed to synthesize the CNTs with controlled density to exhibit excellent field emission properties. By applying an inactive layer on the catalyst layer during CNTs growth, the density of nanotubes can be controlled by varying the inactive layer thickness The CNTs triode structures with an extraction gate were proposed to achieve the low voltage modulation. CNTs triodes with reduced gate diameter were fabricated by the semiconductor fabrication process and the selective growth of CNTs with controlled length. The turn-on gate voltage was reduced to 30 V. To further reduce the gate voltage, an offset-gate CNTs triode structure was also proposed to reduce the distance between gate and the CNTs to enhance the controllability of the gate and the low turn-on gate voltage as low as 13 V was successfully achieved.