Extraction of emission area from Fowler–Nordheim plots

The process of deriving emission-area estimates from Fowler–Nordheim (FN) plots is investigated, using emission-area extraction functions and an iterative procedure suggested earlier [R. G. Forbes, J. Vac. Sci. Technol. B 17, 526 (1999)]. Simulated FN-plot data have been prepared using free-electron theory and three different tunneling-barrier models (elementary triangular barrier, image-rounded “Schottky–Nordheim” barrier, and a quadratically enhanced barrier). These have been analyzed using two area-extraction spreadsheets with different models (elementary triangular barrier and Schottky–Nordheim barrier) embedded in them. It is confirmed that significant errors in the area estimate may occur if the emission model used to analyze the FN-plot data does not correspond well with the model/physics responsible for generating the data. It is also concluded that parameters used in the area-extraction process should correspond to emission variables in the midrange of the FN-plot data.