This paper describes a Deep Level Transient Spectroscopy (DLTS) study of the electron traps that are created by high-energy electron or proton irradiations in n-type Czochralski silicon, doped with different Group IV elements. It is shown that while Sn is an efficient vacancy trap, leading to the formation of SnV centers, no specific Pb-related deep levels have been found in the upper half of the band gap. The dominant electron trap is the A center, while similar concentrations of SnV's are formed in Sn- and Pb+Sn-doped n-Cz material. A number of as yet unidentified deep levels has also been observed, together with some grown-in peaks, whereof some could be hydrogen-related. From a viewpoint of radiation hardening, these initial results demonstrate that Pb is little effective in suppressing the formation of radiation defects.
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