Design and fabrication of JFET-controlled carbon nanotube field emitter arrays

In this paper, a novel structure design, JFET-controlled carbon nanotubes (CNTs), is proposed. CNTs may very well be the closest one that can come to having "ideal" field emitters. Further, they are stable at high temperatures, can have high electrical and thermal conductivity, and they exhibit ballistic electron transport. The built-in JFET was designed by a 2-D device simulator ATLAS. It is to control the stability of the emission current of the CNTs while it is operating in saturation region. The dose and ion energy of BF₂ in the ion implantation for p₊ region were 5×10¹⁵ /cm and 200 keV, respectively. The vertical diffusion as well as the lateral diffusion of the boron ions in the high temperature process steps was taken into consideration in the simulation. Si post structure was chosen since it improves control of CNT length and allows for thick gate insulators. Our simulation results predict that the breakdown voltage of Si JFETs increases with the height of the Si post. We observe from that when V_gs is more negative, the depletion region extends in the channel and less current is flowing from the drain to source. By controlling the electron source supply to the CNTs, we can prevent disruptively excessive emission current.