Latest developments in EUV photoresist evaluation capability at Shanghai Synchrotron Radiation Facility

Evaluating the comprehensive characteristics of extreme ultraviolet (EUV) photoresists is crucial for their application in EUV lithography, a key process in modern technology. This paper highlights the capabilities of the Shanghai Synchrotron Radiation Facility (SSRF) 08U1B beamline in advancing this field. Specifically, it demonstrates how this beamline can create fringe patterns with a 15-nm half-pitch on a resist using synchrotron-based EUV lithography. This achievement is vital for evaluating EUV photoresists at the advanced 5-nm node. We provide a detailed introduction to the methods and experimental setup used at the SSRF 08U1B beamline to assess an EUV photoresist. A significant part of this research involved the fabrication of high-resolution hydrogen silsesquioxane mask gratings. These gratings, with an aspect ratio of approximately 3, were created using electron beam lithography on an innovative mask framework. This framework was crucial in eliminating the impact of zeroth-order light on interference patterns. The proposed framework propose offers a new approach to mask fabrication, particularly beneficial for achromatic Talbot lithography and multicoherent-beam interference applications.