Electrical Characterization of 1 keV He-, Ne-, and Ar-Ion Bombarded n-Si Using Deep Level Transient Spectroscopy

We report on the electrical properties of defects introduced in epitaxially grown n-Si by 1 keV He-, Ne-, and Ar-ion bombardment. Epitaxial layers with different O contents were used in this study. We demonstrate using deep level transient spectroscopy that the low energy ions introduced a family of similarly structured defects (DI) with electronic levels at ∼0.20 eV below the conduction band. The introduction of this set of identical defects was not influenced by the presence of O. Ion bombardment of O-rich Si introduced another family of prominent traps (D2) with levels close to the middle of the band gap. Both sets of defects were thermally stable up to ∼400 °C, and their annealing was accompanied by the introduction of a family of secondary defects (D3). The “D3” defects had levels at ∼0.21 eV below the conduction band and were thermally stable at 650 °C. We have proposed that the “DI”, “D2”, and “D3” defects are higherorder vacancy clusters (larger than the divacancy) or complexes thereof.