Deep-level defects in high-dose proton implanted and high-temperature annealed silicon

We review the principal mechanisms of deep-level defect formation after proton irradiation and subsequent annealing of float zone grown crystalline silicon. Various reaction paths commonly related to vacancy-complexes, interstitial oxygen and hydrogen are discussed. In the experimental part DLTS results of proton irradiated pn-diode structures are presented. It appears that some detected defects show a thermal stability differing from that reported in literature. Furthermore the metastability of two defects at 300 meV and 418 meV below the conduction band is examined. This behavior commonly designated to a negative-U defect is for the first time reported in a sample annealed at 350° C.