Recherches sur les etats superficiels des jonctions pn de silicium a barriere de surface destinees a la spectrometrie des rayons x

Abstract The use of impedance bridges enables one to obtain the capacitance of the silicium-oxide layer, as well as the density of the superficial charges. One deduces the relationship which links the applied voltage to the space charge reduced potential. The measurement of the diodes response, when made to undergo train impulses, enables one to obtain their relaxation time, whose variations with temperature and inverse polarization voltage one can study. From this, one can deduce the density and the location of the superficial centers in relation to the conduction band. The average capacitance associated with the relaxation time has a value close to that obtained using the impedance bridge. Finally, we have determined the resistance of the ohmic contact which is involved in the pulse rise time. This information system enables one to produce more stable detectors and in particular, to produce junctions working on a preavalanche regime.