Patterning mechanism of metal based hybrid EUV resists

EUV lithography is nowadays considered as one of the most feasible choices for high volume manufacturing. In this work, we wish to report a series of studies aiming at shedding more light on the development mechanism of metal based EUV hybrid photoresists. We have studied zirconium (Zr) and hafnium (Hf) based hybrid resists which have shown high sensitivity, they suffer though from scumming issues. On the other hand, our clusters based on zinc (Zn) which absorbs strongly in EUV seem to be free of scumming but still Zr and Hf outperform in terms of sensitivity. In an effort to understand better what controls sensitivity and scumming phenomena we have employed a combination of analytical techniques (Electrospray ionization mass spectrometry ESI-MS, X-ray photoelectron spectroscopy XPS, and Fouriertransform infrared spectroscopy FT-IR) to study the patterning mechanism in detail, in order to be able to optimize the development process and develop systems with optimal features.