Copper gettering at half the projected ion range induced by low-energy channeling He implantation into silicon

Abstract

He + ions were implanted at 40 keV into Si 〈100〉 channel direction at room temperature (RT) and at 350 °C. The Si samples were subsequently doped with Cu in order to study the gettering of Cu atoms at the defective layer. A subsequent annealing at 800 °C was performed in order to anneal the implantation damage and redistribute the Cu into the wafer. The samples were analyzed by Rutherford backscattering channeling and transmission electron microscopy techniques. The Cu distribution was measured by secondary ion mass spectrometry (SIMS). The SIMS experiments show that, while the 350 °C implant induces gettering at the He projected range (Rp) region, the same implant performed at RT has given as a result, gettering at both the Rp and Rp/2 depths. Hence, this work demonstrates that the Rp/2 effect can be induced by a light ion implanted at low energy into channeling direction.