Radiation Induced Defects in Semiconductors

Abstract

Radiation-induced defects in semiconductors is an important field of research. The study of radiation effects on the deep levels in semiconductors is very interesting both from the point of view of electronic device performance as well as fundamental physics of defects in semiconductors. Degradation of semiconductor devices due to radiation damage is a major problem in their use in radiation-rich environment because of the fact that fast particle bombardment introduces lattice defects into crystalline solids. In semiconductors, radiation studies assume paramount importance in view of the extreme sensitivity of their electronic characteristics to the defects produced by interaction with radiation. Therefore, characterization of radiation induced deep levels in semiconductors as an important subject in the development of semiconductor technology. In this project we have carried out experiments using the deep level transient spectroscopy (DLTS). This technique (DLTS) has been used to measure various parameters characterizing a deep level defect. These include thermal emission rates, activation energies, carrier capture cross-sections and the temperature dependence of the capture cross-sections. The samples used in our measurements were prepared from prefabricated n pp junctions. These samples were irradiated using 5.48 MeV alpha particles from an Am source. The study of radiation-induced deep levels was carried out using different semiconductor materials such as Si, GaP and InP.