The Influence of Mandrel Materials in Self-Aligned Multiple Patterning Process

Due to limitations in lithography resources, the application of immersion lithography in advanced nodes has reached a bottleneck. The Self-Aligned Double Patterning (SADP) and Self-Aligned Quadruple Patterning (SAQP) processes within Double Patterning Technology (DPT) not only ensure precise overlay accuracy but also effectively reduce pitch, making them essential in the production of high-end process chips. However, different devices have varying material requirements and technical standards for SADP or SAQP. Thus, the impact of the SADP film layer structure design—particularly material selection—on the final process outcomes has received increasing attention. This paper compares the effects of poly and carbon mandrels on SADP pattern transfer, focusing on mandrel material formation, key step profiles, and line roughness. It also discusses how process optimization and material selection can further enhance SADP performance.