Structural and electrical damage induced by high‐energy heavy ions in SiO2/Si structures

The structural and electrical properties of SiO2/Si structures irradiated by high‐energy (≳0.5 GeV) Xe and Ni ions have been investigated. Structural analysis of the irradiated SiO2 films, performed with infrared spectroscopy, points to atomic displacements and broken and strained Si—O bonds induced by the irradiation. Using ir data, the damage cross section of the Xe and Ni ions has been deduced. The values are of about 8×10−13 and 6×10−14 cm2 for, respectively, 762 MeV Xe and 551 MeV Ni ions. Electrical measurements of irradiated SiO2/Si structures show an increase of the interface‐state density Dit and of the oxide trapped‐charge density N0t with the ion fluence. These results are compared with defects induced by heavy‐ion irradiation in bulk silica and by light particle radiation in silicon dioxide. Electrically active point defects have been detected in irradiated silicon and are associated with vacancy complexes.