Characterisation of MeV neon damage in silicon

Ion backscattering (RBS)/channeling and transmission electron microscopy (TEM) have been combined to characterise the radiation damage produced in crystalline silicon during irradiation with 1.5 MeV Ne⁺. The resulting damage structures and distributions are found to be a sensitive function of substrate temperature. In particular, for temperatures between 20 and 300°C the disorder is found to increase gradually from the surface to a peak at the projected ion range, whereas, for temperatures greater than 300°C the disorder is observed to have a very distinctive distribution, consisting of a narrow band of extended defects at the projected ion range but with the surface region essentially defect free to depths of ~ 1.4 μm. This latter structure has been employed to obtain an accurate measure of the channeled to random stopping power ratio (0.53 ± 0.05) for 3 MeV He⁺ incident along a 〈001〉 silicon axial direction.