PSCAR is a modified CAR which contains a photosensitizer precursor (PP) in addition to other standard CAR components such as a protected polymer, a photo acid generator (PAG) and a quencher. In the PSCAR process, an improved chemical gradient can be realized by dual acid quenching steps with the help of increased quencher concentration. The addition of the PP, as well as other material optimization, offers more degrees of freedom for getting high sensitivity and low LER, but also makes the system more complicated. Thus coupling simulation and experimentation is the most rational approach to optimizing the overall process and for understanding complicated 2-D structures.
In this paper, we will provide additional background into the simulation of PSCAR chemistry, explore the effects of PSCAR chemistry on chemical contrast of complex structures (e.g. T structures, slot contacts, I/D bias for L/S), and explore the sensitivity enhancement levels capable while improving or maintaining lithographic performance. Finally, we will explore modifications of PSCAR chemistry on performance.