Accuracy of photocarrier radiometric measurement of electronic transport properties of ion-implanted silicon wafers

The determination of the electronic transport properties of ion-implanted silicon wafers with the photocarrier radiometry (PCR) technique by fitting frequency scan data to a single layer model via a multiparameter fitting procedure is presented. A three-layer model is used to simulate the inhomogeneous structure of the ion-implanted wafers. The effects of the structural, electronic, and optical properties of the implanted layer, which are affected significantly by ion implantation, on the frequency behavior of the PCR signal of implanted wafers are discussed. Data simulated with the three-layer model are fitted to a single-layer model to extract the electronic transport properties of implanted wafers. The fitted carrier lifetime and diffusion coefficient are found to be close to that of the substrate layer which is assumed to remain intact after the ion implantation process. When self-normalized relative amplitude is used in the multiparameter fitting, the fitted surface recombination velocity is determined primarily by the level of electronic damage and is approximately independent of the level of optical damage. Experiments with boron implanted wafers were performed and the experimental results were in agreement with the simulations. These results show that the PCR technique is capable of measuring the bulk transport properties of ion-implanted silicon wafers. (C) 2004 American Institute of Physics.