IRRADIATION EFFECTS IN SEMICONDUCTOR

Samples of crystalline silicon, porous silicon, gallium arsenide and s ilicon diodes were exposed to 50-80 MeV silicon and oxygen ions in the fluence range of the order of 10(13) to 10(14) ions/cm(2). The irradi ated samples were characterized to obtain information on the relative concentration and depth distribution of the induced defects. For compa rison a few silicon diodes and crystalline silicon samples were also e xposed to 6 MeV electrons. The main techniques used for the analysis o f silicon samples were low angle X-ray diffraction, photoluminescence spectroscopy and lifetime of minority carriers, whereas diodes were ch aracterized on the basis of switching parameters. It is observed that a large number of defects are produced in the surface region of each o f the irradiated semiconductor sample though the energy deposited in t he surface region through electronic loss is three orders of magnitude greater than that of nuclear collisions.