Field-emission properties of arrays and extended areas of laser-fabricated silicon microstructures

Abstract

The current paper presents a review of the formation of spikes under pulsed laser irradiation of crystalline silicon. Large areas of spikes are fabricated, having uniform shapes and arrays of spots with a wide distribution of spike morphologies per spot. Cold electron emission studies show that, in all cases, the formation of these three-dimensional, quasiperiodical structures leads to significant emission at low applied voltages. Emission properties are improved for the spikes fabricated under the longest laser pulse, at the irradiation wavelength utilized. The observed currents are correlated to localized field enhancement originating from the geometry of the spikes. The extent to which geometry can account for the observed emission results is discussed and the plausible physical mechanisms responsible for the formation of these structures are commented on.