The Influence of Temperature and Electron Irradiation on the Surface Morphology and Structural State of Oxygen-Containing Silicon

It was found that in the initial n-type monocrystalline silicon, the average surface roughness height (RZ) was 2330 nm, and the arithmetic mean deviation of the profile was 245.12 nm. After irradiation with a fluence of 2 × 1017 electrons/cm2, these parameters decreased to 1870 and 202.26 nm, respectively. After annealing the sample at 500°C for 1 h, the surface roughness height reaches 2840 nm, and the arithmetic mean deviation drops to 32.28 nm. Following irradiation, these values further decrease to 880 and 11.56 nm, respectively. It is shown that during post-crystallization cooling of silicon, oxygen precipitate nuclei form, including a hexagonal phase (sp.gr. P3221) of silicon dioxide. Irradiation with a fluence of 2 × 1017 electrons/cm2 preserves a diffuse halo at small scattering angles, and causes changes in the lattice parameters of the cubic silicon phase (sp.gr. $$Fd\bar {3}m$$ ) and the hexagonal silicon dioxide phase. After annealing at 500°C for 1 h, the phase composition remains unchanged; however, the unit cell parameters and the atomic coordinates of oxygen in the hexagonal phase (sp.gr. P3221) are modified. Irradiation of both the initial and annealed (500°C, 1 h) samples leads to changes in the size of nanocrystallites while preserving the phase composition. The hexagonal phase represents an oxygen-containing nanostructure, with a nanocrystallite size of 47.9 nm in the initial sample. Annealing and subsequent irradiation with a fluence of 2 × 1017 electrons/cm2 reduce this size to 41.3 nm.