Patent ID: 6329745
Filing Date: 2001-12-11
Classification: H01J

Abstract:
An electron gun, comprising:a carbon-based body having two layers, the first layer having a thickness greater than about 0.5 micrometers and the second layer having a thickness greater than the thickness of the first layer, the layers being formed by placing a substrate in a reactor at a selected pressure and bringing the substrate to a selected range of temperature and supplying a mixture of gases comprising hydrogen and a carbon-containing gas at a first concentration to the reactor while supplying energy to the mixture of gases near the substrate for a time sufficient to grow the first layer and then reducing the concentration of the carbon-containing gas to a second lower concentration and growing the second layer and subsequently removing the substrate from the first layer;a dielectric layer on the carbon body, the dielectric layer having openings therein;an electrode on the dielectric layer having openings therein continuous with the openings in the dielectric layer;a plurality of electron optic lenses positioned above the electrode; andelectrical contacts to the carbon-based body, the electrode and the lenses.