FIELD EMISSION TYPE ELECTRON SOURCE

摘要

PROBLEM TO BE SOLVED: To provide a field emission type electron source with small spreading of energy distribution of electrons emitted. SOLUTION: A field emission type electron source element 10a and Peltier element 30 are formed on the side of a main surface of an n-type silicon substrate 1. The electron source element 10a is structured with an n-type silicon substrate 1, a semiconductor layer 3 consisting of a polycrystalline silicon layer formed on the main surface of the n-type silicon substrate, a high-field drift layer consisting of an oxidized porous polycrystalline silicon layer formed on the semiconductor layer 3, and a surface electrode 7 formed on the high-field drift layer 6. The high-field drift layer 6 constitutes a drift part, and the n-type silicon substrate 1 and an ohmic electrode (not illustrated) on the rear surface of the n-type silicon substrate 1 constitute a lower electrode. The Peltier element 30 constitutes a cooling means for cooling the electron source element 10a.