US Patent 7239074 - Carbon nanotube field emitters formed in recess

http://www.freepatentsonline.com/7239074.html

Various constructions have been proposed and implemented by companies such as Nanoproprietary, Samsung, and others for forming large arrays of carbon nanotube electron emitters to enable applications in flat panel displays. Usually the fabrication of these emitter arrays requires several steps of depositing and patterning insulating films formed on a conductive or semiconductive substrate and subsequently etching the insulating film to prepare barriers and wells in which the emitters can be formed. This patent from Hon Hai Precision of Taiwan teaches a simplified fabrication process which avoids several deposition and etching steps by using an insulating substrate with a recess formed therein as a starting material. Claim 1 reads:

1. A field emission device comprising: an insulative substrate, the substrate defining a recess therein; and a cathode with a plurality of electron emitters formed thereon, the cathode being positioned in the recess.