Field emission-type electron source and manufacturing method thereof

Abstract

A field emission-type electron source ( ) is provided with a conductive substrate ( ), a semiconductor layer formed on a surface of the conductive substrate ( ), at least a part of the semiconductor layer being made porous, and a conductive thin film ( ) formed on the semiconductor layer. Electrons injected into the conductive substrate ( ) are emitted from the conductive thin film ( ) through the semiconductor layer by applying a voltage between the conductive thin film ( ) and the conductive substrate ( ) in such a manner that the conductive thin film ( ) acts as a positive electrode against the conductive substrate ( ). The semiconductor layer includes a porous semiconductor layer ( ) in which columnar structures ( ) and porous structures ( ) composed of fine semiconductor crystals of nanometer scale coexist, a surface of each of the structures being covered with an insulating film ( ). Further, an average dimension of each of the porous structures ( ) in a thickness direction of the semiconductor layer is smaller than or equal to 2 &mgr;m.