Uniform emitter array for display devices, etch mask for the same, and methods for making the same

Abstract

The present invention includes a method for making an emitter for a display device, an emitter array produced by such method, an etch mask used during such method, and a method for making such an etch mask. The method for making the emitter is practiced by providing a substrate, forming a conducting layer on the substrate, forming an emitting layer on the conducting layer, forming an etch mask having a controlled distribution of a plurality of mask sizes over the emitting layer, and forming at least one emitter by removing portions of the emitting layer using the etch mask. The method for making the etch mask is practiced by forming an etch mask layer over an emitting layer, forming a patterning layer having a controlled distribution of mask sizes over the etch mask layer, and forming the etch mask by removing portions of the etch mask layer using the controlled distribution of mask sizes in the patterning layer. In both methods, the controlled distribution of mask sizes preferably contains one mask size which is a median mask size with an equal number of larger and smaller mask sizes, where every larger mask size has a corresponding smaller mask size, the average of the smaller and larger mask sizes being the median mask size. The larger mask sizes are located in the periphery of the etch mask, the smaller mask sizes are located in the interior, and the median mask size is located throughout the etch mask. The emitter array comprises a plurality of pixels with each pixel having at least one emitter with a substantially similar height. The present invention provides more uniform emitter tips in a display device, leading to better emission properties for the emitter tips and a brighter image produced.