A COMPARATIVE-STUDY OF HEAVILY IRRADIATED SILICON AND NON IRRADIATED SI LEC GAAS DETECTORS

Silicon p(+)n junctions irradiated with neutron and proton fluences in the range 5x10(11)-4x10(15) cm(-2) and non-irradiated SI LEC GaAs Sch ottky barriers have been analyzed. In silicon the concentration N-t, o f the main radiation-induced deep traps (Et approximate to 0.44 - 0.54 eV) is found to increase as N-t alpha f achieving values up to 5x10(1 5) cm(-3) and a mobility saturation at 100cm(2)/Vs has been observed a t the highest fluences. A quantitative comparison between heavily irra diated silicon and non-irradiated GaAs evidenced similar charge collec tion efficiencies, a quasi-intrinsic bulk and similar concentrations o f deep defects. On this basis, a unique model, correlating the lattice disorder and the detector performance, is suggested.