Residual defects in Si produced by recoil implantation of oxygen

Abstract

The defect structures remaining in Si wafers after implantation of O⁺ and As⁺ ions together with subsequent annealing treatment have been studied using the transmission electron microscope. For implantation of 10¹⁶ 150‐keV As⁺/cm² through 430 Å of SiO₂ and subsequent annealing at 1000 °C in dry N₂, the resulting defect structures show many similarities to those obtained following a 1–2×10¹⁶ 10‐keV O⁺/cm² implantation and annealing sequence. However, if 150‐keV As⁺ ions are implanted into bare Si, the general lattice disorder remaining after annealing is much smaller and the residual defects are much more widely spaced. The differences between the residual defects produced by the different As⁺ implantations are interpreted with the proposal that the recoil of oxygen from SiO₂ is an important by‐product of implantations through SiO₂ layers.