LithoDreamer: A Physics-Informed World Model for Multi-Stage Computational Lithography

As semiconductor technology nodes continue to shrink, computational lithography has become critical to yield and performance. However, real-world lithography is a continuous, multi-stage physical process driven by implicit interventions, which cannot be captured by the existing static or stage-wise models. To address these issues, we present \textbf{LithoDreamer}, the first physics-informed World Model (WM) framework for computational lithography, designed to represent the ``Layout-Mask-Resist Image-After Development Image (ADI)'' pipeline as a decision-driven multi-stage physical evolution system, enabling multi-step latent state rollouts within stages and intervention-aware decision-making across stages. First, we learn the feature variations between adjacent states in latent spaces to capture the physical dynamics of each stage. Second, the model plans continuous process interventions through physical mappings in the spaces, which in turn drive subsequent state transitions. Furthermore, we propose a contrastive variational optimization paradigm that jointly explores the evolutions of the interventions and states without discrete action supervision, enabling stable and continuous process rollouts in the WM. Extensive experiments show that LithoDreamer achieves state-of-the-art accuracy and generalization performance.