Analysis of Haze on Polyimide Substrate by ESAC (XPS)

A haze was observed on a polyimide film produced by a electronics manufacturer. The manufacturer suspected the contaminant to be a chromium residue; more specifically, it was suspected that the chromium film was not completely etched away leaving an observable residue. Therefore, the haze was analyzed using Electron Spectroscopy for Chemical Analysis (ESCA). ESCA is an excellent technique for analyzing thin films (<100 angstroms) on insulating substrates. The ESCA survey scan of the hazed area is shown in the figures below. The survey scan shows the presence of chromium in the hazed area indicating that the chromium film was not completely removed.