CORRELATION ENTRE LES DISLOCATIONS, LES CONCENTRATIONS EN CARBONE ET LES LONGUEURS DE DIFFUSION DANS DU SILICIUM POLYCRISTALLIN C.G.E
Résumé
The polysilicon studied contains many cristallographic defects (grains boundaries, dislocations...) which degrade the electronic properties. As these defects are randomly distributed, the study of their detrimental effects needs the investigation of a large quantity of mesa diode N+P presenting approximately the same total length of grains boundaries Lj in order to obtain the influence of the dislocations. The dislocations densities Ndis were evaluated by counting etch pits revealed by chemical etching. The evolution of Ndis were confirmed by X topography. The photocurrents Icc of the diodes and the diffusion length Ln decreased when Ndis increased. Icc and Ln decreased also markedly when the carbon concentration (determined by I.R. analysis) in the silicon varied from 3.1017 to 2.1018 cm-3. These results suggested that dislocations and excess carbon are correlated.
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Articles anciens
Origine : Accord explicite pour ce dépôt
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