S. Belkouch et al., EFFECTS OF INITIAL ANNEALING TREATMENTS ON THE ELECTRICAL CHARACTERISTICS AND STABILITY OF UNPASSIVATED CDSE THIN-FILM TRANSISTORS, Journal of vacuum science & technology. A. Vacuum, surfaces, and films, 16(2), 1998, pp. 860-863
Citations number
14
Categorie Soggetti
Physics, Applied","Materials Science, Coatings & Films
Secondary ion mass spectrometry shows that when CdSe is annealed in ai
r at 350 degrees C oxygen diffuses inside the grains and the diffusion
is enhanced at the grain boundaries, Subsequent vacuum annealing remo
ves oxygen from inside the grains and from the grain boundaries, but l
eaves a film with residual tightly bound oxygen and a reduced donor co
ncentration. Annealing in vacuum at 390 degrees C results in a highly
conductive layer with a positive threshold voltage drift resulting fro
m the chemisorption of oxygen. Annealing in dry or wet air at 350 degr
ees C produces a highly resistive material with lower donor concentrat
ions at the surface and in the bulk, and a lower concentration of acce
ptor traps at the grain boundaries. The effects of dry-and wet-air ann
ealing on the threshold voltage drift for unpassivated CdSe thin film
transistors exposed to ambient air have been monitored, A negative thr
eshold voltage drift, which may be enhanced by the presence of a water
-related species, was observed. (C) 1998 American Vacuum Society. [S07
33-2101(98)04402-9].