GAN-SRAF: Sub-Resolution Assist Feature Generation Using Conditional Generative Adversarial Networks

As the integrated circuits (IC) technology continues to scale, resolution enhancement techniques (RETs) are mandatory to obtain high manufacturing quality and yield. Among various RETs, sub-resolution assist feature (SRAF) generation is a key technique to improve the target pattern quality and lithographic process window. While model-based SRAF insertion techniques have demonstrated high accuracy, they usually suffer from high computational cost. Therefore, more efficient techniques that can achieve high accuracy while reducing runtime are in strong demand. In this work, we leverage the recent advancement in machine learning for image generation to tackle the SRAF insertion problem. In particular, we propose a new SRAF insertion framework, GAN-SRAF, which uses conditional generative adversarial networks (CGANs) to generate SRAFs directly for any given layout. Our proposed approach incorporates a novel layout to image encoding using multi-channel heatmaps to preserve the layout information and facilitate layout reconstruction. Our experimental results demonstrate $\sim 14. 6 \times $ reduction in runtime when compared to the previous best machine learning approach for SRAF generation, and $\sim 144 \times $ reduction compared to model-based approach, while achieving comparable quality of results.