MODIFICATION OF AMORPHOUS AND MICROCRYSTALLINE SILICON FILM PROPERTIESAFTER IRRADIATION WITH MEV AND GEV PROTONS

摘要

Intrinsic and differently doped amorphous and microcrystalline silicon thin films have been exposed toproton beams at two different energies in the lower MeV and in the GeV range. In order to check for the relationbetween the radiation hardness and film crystallinity, the films have been characterized before irradiation by Ramanmeasurements and the influence of the irradiation on the temperature dependence of the dark conductivity has beeninvestigated.We found even at an extremely high proton beam energy of 24GeV a degradation of all thin siliconfilms. The degradation is more pronounced for microcrystalline films than for amorphous films. For dopedmicrocrystalline films we observe for 24 GeV, 5 .1013 p/cm2 as well as for 1.7 MeV, 5.1012 p/cm2 proton irradiationroughly a doubling of the dark conductivity activation energy and a decrease of the dark conductivity. For intrinsicamorphous films, proton irradiation at both energies results in a decrease of the activation energy and an increase ofthe dark conductivity.