| 摘要 |
A method for the determination of parameters of interests of a semiconductor sample is provided. For example, the thickness of an epitaxial or implanted layer, the thickness of a transition layer, and the concentration of free carriers in a substrate layer may be determined without having to destroy th e semiconductor sample in the process. In an embodiment, a method starts by measuring an experimental reflectance spectrum of the semiconductor (202). A n analytical model of the semiconductor having a film layer, a transition laye r and a substrate layer is then constructed (208). Next, optical constants n a nd k for the film layer, transition layer, and substrate layer are expressed as a function of doping level (210). A profile of the transition layer is determined (211), and if an abrupt profile exists, the transition layer is further modeled as having a plurality of sections, wherein each of the sections is assigned an s-polarization matrix and a p-polarization matrix. A n overall modeled reflectance spectrum is then calculated (212) and the parameters therein are varied to achieve a best fit relationship with the experimental reflectance spectrum (214). Thus, the parameter of interest can be determined (216).
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