| 摘要 |
<p>PURPOSE:To take out large probe current stably by adsorbing a metal having specific work function through nitrogen onto the surface of area where the electron is emitted from a needle cathode with the depth not exceeding that of monoatomic layer. CONSTITUTION:In a vacuum ambient where the field emission can be performed, a metal having the work function lower than that of needle cathode 1 is deposited with depth approximately same with that of monoatomic layer onto the surface of area where at least the electron is emitted from a needle cathode 1. Thereafter proper amount of nitrogen gas is provided into the vacuum ambient to adsorb the nitrogen gas with the depth approximately same with that of monomolecular layer onto the metallic monoatomic layer, then the needle cathode 1 is heated under the temperature range of 800-1,300 deg.C. Thereafter the nitrogen gas is evacuated to return to the vacuum ambient where the field emission can be performed, and the needle cathode 1 is heated for 1-10sec under the temperature range of 1,300- 1,500 deg.C.</p> |
