Enhanced Electron Field Emission From Oriented Aln Films

(002) and (100) oriented AlN films were deposited on silicon substrates and tungsten tips by radio frequency magnetron reactive sputtering. The electron field emission (FE) properties of (002) and (100) oriented AlN films were investigated and found to be significantly different in emission threshold and current density. The threshold electric field was only 0.14 V/mu m for (002) oriented AlN film-far lower than the threshold of 1.13 V/mu m for (100) oriented AlN film on tungsten tips. Maximum FE currents of 183 and 27 mu A were obtained for (002) and (100) oriented AlN films on tungsten tips, respectively. Comparative analysis showed that the absence of linear relation in Fowler-Nordheim plots could be attributed to the high current density integrated over the emitting areas. The excellent FE property of (002) oriented AlN film can be attributed to its vertically oriented grains and the broad distribution of defect-related subbands within its band gap as analyzed by photoluminescence spectra from (002) and (100) oriented AlN films. (C) 2006 American Institute of Physics.