Abstract:
A method for preparing an iridium tip with atomic sharpness. The method includes tapering an iridium wire to a needle shape and heating the iridium needle in an oxygen atmosphere. Also disclosed is an iridium needle having a pyramidal structure which terminates with a small number of atoms prepared by the methods.
Abstract:
An electron source is formed on a silicon substrate having opposing first and second surfaces. At least one field emitter is prepared on the second surface of the silicon substrate to enhance the emission of electrons. To prevent oxidation of the silicon, a thin, contiguous boron layer is disposed directly on the output surface of the field emitter using a process that minimizes oxidation and defects. The field emitter can take various shapes such as pyramids and rounded whiskers. One or several optional gate layers may be placed at or slightly lower than the height of the field emitter tip in order to achieve fast and accurate control of the emission current and high emission currents. The field emitter can be p-type doped and configured to operate in a reverse bias mode or the field emitter can be n-type doped.
Abstract:
An ion source for use in a particle accelerator includes at least one cathode. The at least one cathode has an array of nano-sized projections and an array of gates adjacent the array of nano-sized projections. The array of nano-sized projections and the array of gates have a first voltage difference such that an electric field in the cathode causes electrons to be emitted from the array of nano-sized projections and accelerated downstream. There is a ion source electrode downstream of the at least one cathode, and the at least one cathode and the ion source electrode have the same voltage applied such that the electrons enter the space encompassed by the ion source electrode, some of the electrons as they travel within the ion source electrode striking an ionizable gas to create ions.
Abstract:
The present invention relates to a conductive nanostructure, to a method for molding same, and to a method for manufacturing a field emitter using same. More particularly, the present invention relates to a field-emitting nanostructure comprising: a conductive substrate; a conductive nanostructure arranged on the conductive substrate; and a conductive interface compound disposed in the interface between the conductive substrate and the conductive nanostructure, as well as to a method for molding same, and to a method for manufacturing a field emitter using same.
Abstract:
A methodof manufacturing field-emitter arrays by a molding technique is described, wherein the shape of the mold holes (113) is uniformly controlled to obtain field emitter tips having diameters below 100 nm and blunted side edges. The method utilizes the repeated oxidation and etching of the mold substrate (101) consisting of single-crystal semiconductor mold wafers, where the mold holes (110) for individual emitters are fabricated by utilizing the crystal orientation dependence of the etching rate.
Abstract:
Methods for fabrication of self-aligned gated tip arrays are described. The methods are performed on a multilayer structure that includes a substrate, an intermediate layer that includes a dielectric material disposed over at least a portion of the substrate, and at least one gate electrode layer disposed over at least a portion of the intermediate layer. The method includes forming a via through at least a portion of the at least one gate electrode layer. The via through the at least one gate electrode layer defines a gate aperture. The method also includes etching at least a portion of the intermediate layer proximate to the gate aperture such that an emitter structure at least partially surrounded by a trench is formed in the multilayer structure.
Abstract:
A method of producing field emitters having improved brightness and durability relying on the creation of a liquid Taylor cone from electrically conductive materials having high melting points. The method calls for melting the end of a wire substrate with a focused laser beam, while imposing a high positive potential on the material. The resulting molten Taylor cone is subsequently rapidly quenched by cessation of the laser power. Rapid quenching is facilitated in large part by radiative cooling, resulting in structures having characteristics closely matching that of the original liquid Taylor cone. Frozen Taylor cones thus obtained yield desirable tip end forms for field emission sources in electron beam applications. Regeneration of the frozen Taylor cones in-situ is readily accomplished by repeating the initial formation procedures. The high temperature liquid Taylor cones can also be employed as bright ion sources with chemical elements previously considered impractical to implement.