Improved Reflectivity Fitting using SERF (Spreadsheet Environment Reflectivity Fitting)

Abstract

Specular reflectivity is a powerful technique for determining composition depth profiles. In general, extraction of profiles from reflectivity data requires model fitting, the inverse scattering problem. Fitting software exists to calculate reflectivity from profiles, but typically the profiles used are constructed from independent layers. Profiles based on mathematical functions are often more useful, but require interdependent layers, typically not allowed, or requiring source code modification. A new reflectivity fitting package, SERF (Spreadsheet Environment Reflectivity Fitting), is demonstrated, which uses a spreadsheet as the host environment for calculation and data plotting. SERF simplifies the insertion of function-dependent profiles using interdependent layers. SERF uses additional spreadsheet features to improve reflectivity fitting, including reduced command structure via automatic recalculation and easier evaluation of fit quality via simultaneous display of graphical and numerical information. Examples of SERF and Internet download information are presented. Function-dependent profiles and reduced fitting time with SERF extends the reflectivity technique.