Study of the Formation of Radiation Defects in Irradiated Silicon Samples, Doped with Chromium Atoms
Abstract
This work presents an investigation of radiation-induced defect formation in single-crystal n-type silicon doped with chromium (n-Si<Cr>) using positron annihilation spectroscopy. The initial silicon samples, phosphorus-doped during crystal growth, were subsequently modified by chromium diffusion and then irradiated with 2 MeV protons at a beam current of 0.5 μA using the EG-5 accelerator facility. The measurements revealed the formation of characteristic radiation-induced vacancy-type defects, including A-centers, E-centers, divacancies, and their stable complexes. A comparative analysis of chromium-doped and undoped samples demonstrated a pronounced difference in the accumulation rate of these defects. It was established that the presence of chromium atoms in the bulk of n-type silicon significantly suppresses radiation defect formation: the concentration of vacancy-related defects in n-Si<Cr> was found to be approximately 1.5–2 times lower than in the reference n-Si samples irradiated under identical conditions. These results confirm that chromium doping enhances the radiation resistance of silicon and can be considered an effective approach for modifying semiconductor materials intended for operation in environments with high radiation exposure.
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