Search

Extreme ultraviolet (EUV) lithography faces major challenges for smaller nodes due to the impact of stochastic and processing failures.1 One of the main challenges for pitch shrink at these nodes is the optimization of the trade-off between break type defects versus bridge type defects as the process window between these defect modes gets smaller.2 In this paper, we examine EUV defect reduction techniques for Chemically Amplified Resist (CAR) and Metal Oxide Resist (MOR) via coater/developer process development combined with optimized etching processes.

Although being progressively introduced to mass production, extreme ultraviolet (EUV) lithography still faces major challenges for 5nm and smaller nodes due to the impact of stochastic and processing failures, resulting in very narrow defect process windows. 1 These failures are strongly linked to critical dimension (CD) variations.2 Therefore, careful control of CD is now directly linked to defect reduction in addition to more conventional in-film particles/developer residues reduction. Photoresist profiles are also believed to be one possible limiting factor and improvements via collapse control or increased resist mask thickness for etch transfer need to be considered. In this paper, most recent understandings regarding defect process window limitations and optimization of processes to further enable narrow pitch EUV lithography will be presented.