Interferometric lithography of sub-micrometer sparse hole arrays for field-emission display applications

Abstract

Interferometric lithography, the use of interactions between coherent laser beams to define sub- wavelength patterns, is well adapted to the periodic nature of field-emitter structures. Techniques to fabricate sparse (hole diameter to pitch ratio of 1:3 or larger) emitter arrays to improve reliability and lifetime are presented. These include: multiple exposures at two different pitches; integration of interferometric and optical imaging lithography; and various multiple beam techniques that both provide a sparse array and result in a two dimensional pattern in a single exposure. Moiré alignment techniques are demonstrated to provide a simple process for aligning multiple levels. Manufacturing related issues such as process latitude and photoresist profiles and their suitability for subsequent processing are also discussed. Exposure-dose process control using latent image monitoring is demonstrated.