Zernike polynomial-based pupil wavefront optimization technology for extreme ultraviolet lithography

The NA 0.33 EUV lithography tool is applied at 3nm logic node where the aberrations and 3D mask effects are difficult to eliminate. It limits resolution further reduced. In this paper, a Zernike polynomial-based pupil wavefront optimization (ZBPWO) technology for NA0.33 EUV is proposed. An active wavefront is applied to the imaging model which consist of 64 Zernike polynomials using an inverse optimization algorithm. The optimal pupil wavefront can improve image quality effectively. Simulation results show that the ZBPWO method reduce the pattern error about 50%. It demonstrate the impact of aberrations and 3D mask effects are controlled very well.