Patent ID: 6051917
Filing Date: 2000-04-18
Classification: H01J

Abstract:
An electron gun for reducing projection-microlithography system, the electron gun comprising on an optical axis:(a) a cathode comprising a planar or spherically concave electron-emission surface, the cathode being cylindrical relative to the optical axis;(b) an anode spaced from said cathode along the optical axis;(c) a Wehnelt electrode having a proximal portion proximal to the cathode and disposed around the cathode and having a distal portion between cathode and the anode and;(d) a control electrode situated between the cathode and the anode, the anode being structured and arranged so as to be electrically grounded during operation of the electron gun, the Wehnelt electrode being structured and arranged so as to have an electric potential, during operation of the electron gun, which potential tends to push electrons, in an electron beam emitted from the cathode, toward the optical axis.