Analysis of interface layer characteristics

• Main Authors: Opsal, Jon, Leng, Jingmin
• Format: Patent
• Language: English
• Published: 15.10.2002

The subject invention relates to measurements of thin films on semiconductor wafers. More particularly, the invention relates to a new approach for analyzing and characterizing the interface layer between the thin film and the substrate in order to more accurately determine the characteristics of the sample. A method is described for analyzing and characterizing parameters of a semiconductor wafer. In particular, an approach is described for characterizing the interface layer between a thin oxide film and a silicon substrate in order to more accurately determine the characteristics of the sample. The wafer is inspected and a set of measured data is created. This measured data is compared with theoretical data generated based on a theoretical set of parameters as applied to a model representing the physical structure of the semiconductor. The model includes an interface layer, between the film layer and the silicon substrate, which includes a representation of the electronic structure of the underlying substrate. In the preferred embodiment, the representation is a five peak, critical point model influenced by the electronic transitions of the underlying silicon substrate. An error minimization algorithm, such as a least squares fitting routine, is used to modify the theoretical parameters until the differences between the measured data and the theoretically derived data is minimized.