Micro-Raman Investigation of Hydrogen Localized in Cone-Shaped Defects Formed on the Silicon Wafer Surface

Abstract

The goal of this work is the micro-Raman study of molecular hydrogen localized in cone-shaped defects, which are formed on the surface of previously helium implanted and annealed Czochralski Si wafers as a result of hydrogen plasma treatment. The line at ≈ 4158 cm corresponding to molecular hydrogen is observed in the Raman spectra when the laser beam is focused both on cone-shaped defects or defect-free regions of the surface. The laser irradiation of cone-shaped defects during micro-Raman experiments leads to intensity increase of this line when the irradiation time is increasing, with subsequent appearance of lines at ≈ 3621 and ≈ 3698 cm–1 and simultaneous disappearance of 4158 cm–1 line. No such effect was observed when the laser beam was focused on defect-free regions. The experiments have shown that heat treatment of the samples studied causes the appearance in the Raman spectra of lines at ≈ 3468, ≈ 3621, and ≈ 3812 cm–1, which can be associated with molecular hydrogen.