Electronic transport characterization of B+ ion-implanted silicon wafers with nonlinear photocarrier radiometry

Abstract

A nonlinear photocarrier radiometry (PCR) based quantitative defect characterization method is applied to determine the electronic transport parameters of the implantation layer of B+ ion-implanted silicon wafers with different implantation doses. A rigorous two-layer nonlinear PCR model is employed to fit the experimental modulation frequency dependences of PCR amplitude and phase to determine the transport parameters, that is, the carrier lifetime, carrier diffusion coefficient, and front surface recombination velocity of the implantation layer via multiparameter fitting. In the multiparameter fitting, the effects of the implantation layer thickness determination on the extraction of the electronic transport properties of the implantation layer are discussed via setting the thickness as a free parameter in the multiparameter fitting and fixed parameters determined by Monte Carlo based TRIM calculation. The fitted implantation layer thicknesses are in good agreement with that determined via TRIM calculation with a modified electronic damage threshold. Monotonic dependences of the transport properties of the implantation layers on the implantation dose are observed, and the effects of impurity density on the transport properties of the implantation layers are discussed. Good agreements between the experimental implantation dose dependence of the nonlinearity coefficient and corresponding theoretical calculations with the determined transport parameters are obtained. These results show that the two-layer nonlinear PCR model is accurate for quantitatively characterizing the transport properties and thickness of the ion-implantation layers of silicon wafers, and the nonlinear PCR technique is appropriate for precise defect characterization in the semiconductor manufacturing processes.