H+ ion-implantation energy dependence of electronic transport properties in the MeV range in n-type silicon wafers using frequency-domain photocarrier radiometry.

Industrial n-type Si wafers (resistivity of 5–10 Ω cm) were H⁺ ion implanted with energies between 0.75 and 2.00 MeV, and the electronic transport properties of the implanted layer (recombination lifetime, carrier diffusion coefficient, and front-surface and implanted-interface recombination velocities s₁ and s₂) were studied using photocarrier radiometry (PCR). A quantitative fitting procedure to the diffusing photoexcited free-carrier density wave was introduced using a relatively simple two-layer PCR model in lieu of the more realistic but substantially more complicated three-layer model. The experimental trends in the transport properties of H⁺-implanted Si layers extracted from the PCR amplitude and phase data as functions of implantation energy corroborate a physical model of the implanted layer in which (a) overlayer damage due to the light H⁺ ions decreases with increased depth of implantation at higher energies, (b) the implanted region damage close to the interface is largely decoupled from the overlayer crystallinity, and (c) the concentration of implanted H⁺ ions decreases at higher implantation energies at the interface, thus decreasing the degree of implantation damage at the interface proper. [ABSTRACT FROM AUTHOR]