First study of a flat vacuum image sensor with a field-emitter array

Abstract

To develop a high-definition image sensor having ultra-high sensitivity far superior to CCDs. A new compact image sensor consisting of a matrix field emitter array (FEA) and a high- gain avalanche rushing amorphous photoconductor (HARP) target is studied. Most research on devices with FEAs has so far focused on flat displays and high-frequency devices. Although the concept of a flat image sensor with FEAs has been proposed before, image sensors with FEAs have yet to be fabricated. In this paper, the fundamental driving characteristics of a new flat image sensor comprised of an X-Y matrix FEA set face to face with a HARP target have been investigated in a vacuum chamber for the first time. Experiments confirmed that the device successfully picks up images. High-sensitivity is achieved with the HARP target, and the temporal fluctuation and spatial variation of the emission currents obtained from the FEA have almost no effect on the signal output currents. Furthermore, the resolution characteristics are affected by the mesh voltage and by divergence of the emission from the field emitter tips.