ISSN:
1573-2746
Keywords:
grain boundaries
;
silicides
;
DLTS
;
EBIC
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Abstract Deep-level transient spectroscopy and electron-beam-induced current measurements have been performed on Σ=25, Σ=13 and Σ=9 silicon bicrystals contaminated with Cu, Ni or Fe. Among the studied grain boundaries, only the heat-treated Σ=25 showed a barrier effect which seems to originate, for the uncontaminated samples, from the structural defects induced by the rapid disorder with temperature. An extrinsic origin would start to prevail, however, upon formation of impurity precipitates in the contaminated specimens. The evolution of the barrier height (BH) and the electronic interface states with the annealing temperature, T a, allowed one to infer that the rectifying behavior of the buried silicides could be compared to that of the same silicide layer grown on a silicon surface. This was strongly suggested by the systematic lowering of the BH with T a which is consistent with the increasingly greater contribution of type-A NiSi2 silicides with their low BH. The opposite behavior of the Cu and Fe cases appeared due to the tendency towards the pinning of the Fermi level near the mid-gap. For EBIC, the different aspects of the contrast were assigned to the various microstructures of the interfaces. Finally, the formation of impurity particles were found to involve a net degradation of the minority-carrier diffusion length, in addition to a concomitant and consistent increase of both recombination velocity and density of interface states.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00240249
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