Photobase generator and photo decomposable quencher for high-resolution photoresist applications

As the critical pitch continues to shrink for advanced technology nodes and the EUV tool is not yet mature, the demand for ArF high-contrast resist becomes stronger than ever. In this paper, we discuss the impact of photosensitive quenchers to lithographic performance. Two types of photosensitive quencher, photo-base generator (PBG) and photo decomposable quencher (PDQ), are studied for its ability to extend the life of immersion ArF lithography. With conventional photoresists using normal non-photosensitive quenchers, the aerial image was substantially linearly transferred to the acid image of the photoresist stimulated by photo acid generator (PAG). The new PBG or PDQ serves as one additional photosensitive component. Such photosensitive quencher changes its base level after exposure. Thus, it modifies the aerial image for better imaging performance. We will present and discuss the imaging results from various formulations of photosensitive quencher and variation in its concentration. The defect performance of these new approaches will also be characterized.