Continued device scaling demands improvements in lithographic resolution, which have historically been achieved by reducing wavelength and increasing numerical aperture (NA). With 0.33 NA EUV lithography now in production, current efforts are directed toward high-NA (0.55) EUV systems, aiming to extend resolution capabilities even further for future nodes. As the next logical step beyond 0.55 NA EUV, either reducing the wavelength ( 0.55) presents a pathway toward further scaling. This paper discusses the opportunities and technical challenges of these approaches, evaluating their feasibility and potential impact on imaging performances.
Lee et al. (Sun,) studied this question.