| 摘要 |
<p>PURPOSE:To easily attain stable electron emission characteristics by providing one or a plurality of P<+> regions and a ring-like N<+> region formed to surround the P<+> regions under a Schottky barrier electrode in a P-type semiconductor layer. CONSTITUTION:One or a plurality of P<+> regions 5 and a ring-like N<+> region 3 formed to surround the P<+> regions are provided under a Schottky barrier electrode 6 in a P-type semiconductor layer 4. Since the N<+> region 3 is provided in the vicinity of an interface with a low work function material in the P-type semiconductor base 1, a depletion layer 2 is generated at a PN<+> interface. Therefore a transfer path of electrons injected from the P<+> layer to the P layer is limited by the depletion layer 2 generated at the PN<+> interface so that they are concentrated on the P<+> layer provided at an electron emitting part resulting in easy increase of current density.</p> |
