Fabrication of Si field emitters with a focus electrode

Abstract

To realize an ultra-fine display for nanovision science, we have studied functional emitters which are capable of stabilizing the emission current or focusing the electron beam. We have developed a field emitter with a vertical type junction field effect transistor (JFET), in which the stability of the emission current is significantly improved, when the JFET is operated as a constant current source. We also developed both field emitters with an in-plain focus electrode and a vertical focus electrode. When the focus electrode is operated, beam spot size is drastically reduced for both the emitters. However, the spot image is distorted for the emitter with an in-plain focus electrode. On the other hand, almost symmetric image is obtained for the emitter with a vertical focus electrode, but the emission current is drastically reduced due to the influence of the low potential of the focus electrode. The use of a thick gate electrode of about 1 μm is effective for preventing the decrease of the emission current.