摘要 |
Concave portions are formed, in a matrix fashion, in a substrate formed of metal or semiconductor. An electron emission layer made of material having small work function such as a diamond thin film is formed on the bottom portion of the concave portion. A protruding portion of the substrate serves as a beam formation electrode. Divergence of electrons can be suppressed with the beam formation electrode. A gate electrode for drawing out the electrons is formed above the beam formation electrode.
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