Additive chemistry and distributions in photoresist thin films

The lithographic performance of thin photoresist films is a function of the distribution of formulation components, such as photoacid generator (PAG) molecules, and how these components undergo chemical modification and migrate within the film during the lithography processing steps. Argon gas cluster ion beam – secondary ion mass spectrometry depth profiles were used to monitor the PAG and quencher base distributions before and after exposure and postexposure bake processing steps for different photoresist formulations. PAG and quencher base distributions were correlated to depth of focus lithographic performance results.