Fabrication and properties of Al2O3/Cu/InSnO3 multilayer cathode electrodes in carbon nanotube field emission display

Multilayer cathode electrodes consisting of Al2O3 bufferlayer, Cu conductive layer and InSnO3 current limiting layer, used in carbon nanotube (CNT) field emission display, were prepared by direct current magnetron sputtering and wet etching. Compared with conventional monolayer cathode electrodes, the multilayer electrodes possess higher current limiting resistance with lower inherent resistance variation. Profilometer measurement indicates the etched edges of the multilayer electrodes were abrupt and regular. Nano Indenter experiment shows that the multilayer electrodes remained intact after annealing treatment and were resistance to scratch damage at loads up to 12.6 mN. X-ray diffraction analysis reveals that no oxidized copper was formed during the annealing treatment. Atomic force microscope images show that the surface of the multilayer electrodes became smoother after plasma bombardment, and the maximum protrusion height decreased from 48.6 nm to 15.4 nm. With the multilayer cathode electrodes, the field emission properties of CNT film cathodes, such as uniformity, lifetime and stability are improved.