DEFECTS IN LOW-TEMPERATURE ELECTRON-IRRADIATED P-TYPE SILICON

Defects in monocrystalline silicon have been studied in the past, in particular, defects induced by room-temperature electron and proton irradiations on both n- and p-type materials, and most of the corresponding defects have been tentatively identified. However, there are still several questions which remain to be answered such as the nature and behavior of the defects introduced in the range 4-300 K. In this work Czochralski-grown p-type material has been irradiated at three different temperatures (90, 200, and 300 K) and characterized by deep-level transient spectroscopy (DLTS) and lifetime measurements. The data show that the defects created after irradiations at 90 and 200 K are different from those reported in the literature for irradiations at 4, 77, and 300 K, showing that three annealing steps exist between 4 and 300 K. These defects are characterized and a tentative identification of them is made. Finally, an attempt to detect the defects responsible for the lifetime, i.e., the recombination centers, not observed by DLTS, using spin-dependent recombination is described.