Analysis of sub-1 keV implants in silicon using SIMS, SRP, MEISS and DLTS: the xRLEAP low energy, high current implanter evaluated

Ultra shallow junctions can be formed, amongst other techniques, by very low energy ion implantation. The Implant Division of Applied Materials have recently developed a low energy, high current ion implanter, the xRLEAP (xR family, Low Energy Advance Process). This implanter is capable of delivering product worthy beam currents, in the milli-ampere regime down to energies of few hundred electron volts. A series of B and BF₂ implants were carried out onto non-amorphised, 200 mm Si wafers using beam energies in the range 0.2 keV<E<1 keV. As-implanted and annealed samples were profiled using Secondary Ion Mass Spectrometry (SIMS). Surface damage due to implantation was evaluated using Medium Energy Ion Scattering Spectroscopy (MEISS). The carrier concentration profiles and junction depths of the annealed samples were investigated using Spreading Resistance Probe (SRP). Samples with ultra shallow junctions, <0.07 μm, were examined using Deep Level Transient Spectroscopy (DLTS) for the first time