Skip to Main Content
Your organization might have access to this article on the publisher's site. To check, click on this link:http://dx.doi.org/+10.1116/1.581023
Secondary ion mass spectrometry shows that when CdSe is annealed in air at 350 °C oxygen diffuses inside the grains and the diffusion is enhanced at the grain boundaries. Subsequent vacuum annealing removes oxygen from inside the grains and from the grain boundaries, but leaves a film with residual tightly bound oxygen and a reduced donor concentration. Annealing in vacuum at 390 °C results in a highly conductive layer with a positive threshold voltage drift resulting from the chemisorption of oxygen. Annealing in dry or wet air at 350 °C produces a highly resistive material with lower donor concentrations at the surface and in the bulk, and a lower concentration of acceptor traps at the grain boundaries. The effects of dry- and wet-air annealing on the threshold voltage drift for unpassivated CdSe thin film transistors exposed to ambient air have been monitored. A negative threshold voltage drift, which may be enhanced by the presence of a water-related species, was observed. © 1998 American Vacuum Society.