Barrier metal layer for a carbon nanotube flat panel display

Abstract

An electron-emitting device, for example as used in a field emissive display device, includes a barrier layer between an emitter electrode structure and a catalyst layer, upon which microstructures of carbon nanotubes are formed. The barrier layer may act as an anti diffusion layer between the catalyst layer and, for example, a resistive layer of the emitter electrode structure. In this way, the catalyst layer may be prevented from diffusing into the resistive layer during the growing of the carbon nanotubes or other electron-emissive elements. The barrier layer may also enhance the adhesion characteristics of the catalyst layer to improve the uniformity of growth of the electron-emissive elements with the catalyst layer.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation-in-part of U.S. application Ser. No. 10 / 226,405, filed Aug. 22, 2002, which is incorporated by reference in its entirety.BACKGROUND [0002] 1. Field of the Invention [0003] The present invention relates to electron-emitting devices, such as those for use in field emissive display devices, and in particular to forming electron-emitting devices using a barrier material. [0004] 2. Background of the Invention [0005] A Cathode Ray Tube (CRT) display generally provides the best brightness, highest contrast, best color quality and largest viewing angle of prior art computer displays. CRT displays typically use a layer of phosphor, which is deposited on a thin glass faceplate. These CRTs generate a picture by using one to three electron beams, which generate high-energy electrons that are scanned across the phosphor in a raster pattern. [0006] The phosphor converts the electron energy into visible light so as t...

AI Technical Summary

Benefits of technology

[0022] To avoid the deficiencies in existing devices, an electron-emitting device includes a barrier layer between an emitter electrode structure and a catalyst layer, upon which microstructures of carbon nanotubes are formed. The barrier layer thus acts as an anti diffusion layer between the catalyst layer and the emitter electrode structure. Specifically, for example, the barrier layer may be disposed between the catalyst layer and a resistive layer of the emitter electrode structure. In this way, the catalyst layer may be prevented from diffusing into the resistive layer before the growing of the carbon nanotubes or other electron-emissive elements. The barrier layer may also enhance the adhesion characteristics of the catalyst layer to improve the uniformity of growth of the electron-emissive elements with the catalyst layer.

[0029] In some embodiments for making the electron-emitting device, a method for making the device may eliminate the need for an extra masking step to provide an initial patterning to the catalyst layer. In such embodiments, the desired pattern can be provided in the barrier layer without increasing the number of masking steps.

Problems solved by technology

However, prior art CRT displays are large and bulky due to the large vacuum envelopes that enclose the cathode and extend from the cathode to the faceplate of the display.

This size limits the number of tips per pixel possible for high-resolution displays, where large numbers (400-1000 emitters per pixel) are desirable for uniform emission to provide adequate gray levels, and to reduce the current density per tip for stability and long lifetimes. Maintaining two-dimensional registry of the periodic tip arrays over large areas, such as large TV-sized screens, can also be a problem for gated field emission constructions by conventional means, resulting in poor yields and high costs.

Weakening the adhesion capabilities of the catalyst layer makes it difficult to grow the emitter elements 140 and results in a costly fabrication process.

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