Optimizing lithographic imaging: the interplay of optical aberrations and image performance metrics

Designing and building an illumination or projection system for lithography requires translating lithographic performance measures into optical aberrations. This study focuses on the intensity distribution above and within the resist (aerial image) and demonstrates that the relationship between wavefront errors, expressed in Zernike coefficients, and contrast is complex. As error budgets become smaller, more detailed analysis is required. To address these challenges, we employ an automated method that integrates lens design with the calculation of image performance metrics, considering the field of view to achieve a balanced design without incurring unnecessary expenses or compromising performance. The goal of this work is to show that the relationship is indeed complex and that a systematic (automated) analysis is necessary to extract system design decisions.