The interface study of photoresist/underlayer using hybrid x-ray reflectivity and x-ray standing wave approach

We have studied the gradient of photoacid generator (PAG) concentration across the photoresist (PR) layer. The pristine and after exposure to Extreme ultraviolet (EUV) PR layers were characterized. The model resist employed in this study was a chemically amplified resist (CAR) containing sulfur (S) as part of the PAG. The geometrical information about PR layers and element profiles was obtained by applying a hybrid x-ray reflectivity (XRR) and X-ray standing wave (XSW) data analysis using x-ray using a laboratory Cu Kα1 source. The information about S-profile was retrieved from the combined analysis of angular-dependent XRF measurements of S (the XSW data) and XRR data. We have shown that the XSW technique may efficiently be used for analyses of the geometrical parameters of PR layers and underlayers and for retrieving profiles of S concentration.