Field emission type electron source

Abstract

In a field emission-type electron source ( ), lower electrodes ( ) made of an electroconductive layer, a strong field drift layer ( ) including drift portions ( ) made of an oxidized or nitrided porous semiconductor, and surface electrodes ( ) made of a metal layer are provided on an upper side of a dielectric substrate ( ) made of glass. When voltage is applied to cause the surface electrodes ( ) to be anodic with respect to the lower electrodes ( ), electrons injected from the lower electrodes ( ) to the strong field drift layer ( ) are led to drift through the strong field drift layer ( ) and are emitted outside through the surface electrodes ( ). A pn-junction semiconductor layer composed of an n-layer ( ) and a p-layer ( ) is provided between the lower electrode ( ) and the strong field drift layer ( ) to prevent a leakage current from flowing to the surface electrode ( ) from the lower electrode ( ), thereby reducing amount of power consumption.