1
|
Thakur N, Vockenhuber M, Ekinci Y, Watts B, Giglia A, Mahne N, Nannarone S, Castellanos S, Brouwer AM. Fluorine-Rich Zinc Oxoclusters as Extreme Ultraviolet Photoresists: Chemical Reactions and Lithography Performance. ACS Mater Au 2022; 2:343-355. [PMID: 36855383 PMCID: PMC9888611 DOI: 10.1021/acsmaterialsau.1c00059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The absorption of extreme ultraviolet (EUV) radiation by a photoresist strongly depends on its atomic composition. Consequently, elements with a high EUV absorption cross section can assist in meeting the demand for higher photon absorbance by the photoresist to improve the sensitivity and reduce the photon shot noise induced roughness. In this work, we enhanced the EUV absorption of the methacrylic acid ligands of Zn oxoclusters by introducing fluorine atoms. We evaluated the lithography performance of this fluorine-rich material as a negative tone EUV photoresist along with extensive spectroscopic and microscopic studies, providing deep insights into the underlying mechanism. UV-vis spectroscopy studies demonstrate that the presence of fluorine in the oxocluster enhances its stability in the thin films to the ambient atmosphere. However, the EUV photoresist sensitivity (D 50) of the fluorine-rich oxocluster is decreased compared to its previously studied methacrylic acid analogue. Scanning transmission X-ray microscopy and in situ X-ray photoelectron spectroscopy in combination with FTIR and UV-vis spectroscopy were used to gain insights into the chemical changes in the material responsible for the solubility switch. The results support decarboxylation of the ligands and subsequent radical-induced polymerization reactions in the thin film upon EUV irradiation. The rupture of carbon-fluorine bonds via dissociative electron attachment offers a parallel way of generating radicals. The mechanistic insights obtained here will be applicable to other hybrid materials and potentially pave the way for the development of EUV materials with better performance.
Collapse
Affiliation(s)
- Neha Thakur
- Advanced
Research Center for Nanolithography, Science Park 106, Amsterdam 1098 XG, The Netherlands,
| | | | - Yasin Ekinci
- Paul
Scherrer Institute, Forschungstrasse 111, Villigen 5232, Switzerland
| | - Benjamin Watts
- Paul
Scherrer Institute, Forschungstrasse 111, Villigen 5232, Switzerland
| | | | | | | | - Sonia Castellanos
- Advanced
Research Center for Nanolithography, Science Park 106, Amsterdam 1098 XG, The Netherlands,
| | - Albert M. Brouwer
- Advanced
Research Center for Nanolithography, Science Park 106, Amsterdam 1098 XG, The Netherlands,van
‘t Hoff Institute for Molecular Sciences, University of Amsterdam, P.O. Box 94157, 1090 GD Amsterdam, The Netherlands,
| |
Collapse
|