Field emission arrays by silicon micromachining

Abstract

A new method for the fabrication of field emission arrays based on bulk/surface silicon micromachining and diamond-like carbon coating was developed. A matrix of self-aligned electron field emitters is formed in silicon wafers. Anisotropic etching in alkali solution of the front silicon film through micropatterned holes opened in a hard masking trilayer results in microtip pixels. The field emission of the emitter tips is enhanced by a diamond-like-carbon (DLC) film formed by chemical vapor deposition on the microtips. The DLC coating allows a field-emission current of about 80 μA per tip at 300 V and a distance of 60 μm. High accuracy of patterning combined with batch processing enables cost effective production of dense arrays. Flat panel displays, electrostatic scrubbers and other applications requiring efficient electron emission are among the possible applications of the proposed technology.