US Patent 7220159 - E-beam convergence in nanotube field emitter

http://www.freepatentsonline.com/7220159.html

An early commercialization area for carbon nanotubes is field emission displays. Substantial patenting has already been done by Samsung, Canon, Nanoproprietary and other companies in this area and continued efforts look toward further applications of nanotube field emission for microwave electronics and massively parallel e-beam lithography. This patent focuses on a manufacturing method used to form an integrated converging mechanism for nanotube generated focused electron beams. Claim 1 reads:

1. A manufacturing method for a converging-type cathode of a field-emission display, comprising the following steps in the order named: a) providing a substrate of the cathode; b) forming a first electrode layer on the substrate; c) forming a second electrode layer composed of a plurality of electron emission sources on the first electrode layer; d) forming a third electrode layer directly on the first electrode layer, the third electrode encircling each electron emission source of the second electrode layer and having a height higher than that of the second electrode layer; e) sintering the first, second and third electrode layers on the substrate.