| 摘要 |
<p>PURPOSE:To increase electron emission efficiency by providing a cathode electrode base formed in polygonal weight-like form on a semiconductor substrate where the one end of a second compound semiconductor layer is used as a first tip end and also providing a metal film for forming a second tip end in the first tip end part. CONSTITUTION:A first compound semiconductor layer 12 has a superlattice in which an atomic number ratio is sequentially inclined from the surface of a semiconductor substrate 1 and an etching rate is gradually reduced. Also, a second compound semiconductor layer 13 is jointed on the one surface of the layer 12 and has extremely small thickness, and a third compound semiconductor layer 14 has a superlattice in which an atomic number ratio is sequentially inclined from the other surface of the layer 13 and an etching rate is gradually increased. And the layers 12, 13, 14 are sequentially accumulated on the substrate 1, and a cathode electrode base 10 is formed in polygonal weight-like form on the substrate 1 in which the one end of the layer 13 is formed into a first tip end 11 and a metal film 20 with a low work function is so provided as to cover the base 10 and form a second tip end 21 in the tip end 11 part. Thereby, an extremely thin and sharp tip end may be formed regardless of the mechanical strength, so that electron emission efficiency may be increased.</p> |
