Advancing Ultra-Thin Molecular Layer Deposition Resists for Hyper-NA EUV Lithography

Extreme ultraviolet (EUV) lithography has enabled the continued dimensional scaling of semiconductor devices beyond the 7 nm technology node. Looking ahead, Hyper-NA EUV lithography, with a numerical aperture of 0.75, will be essential to sustain Moore’s law and enable further device miniaturization. This transition places increasingly stringent demands on photoresist materials, including the need for ultra-thin films with exceptional control over stochastic variability, pattern fidelity, high quantum efficiency, chemical stability, and mechanical robustness.  Photoresists prepared by molecular layer deposition (MLD), offer a promising route to address these challenges through sub-nanometer thickness control, excellent uniformity, and broad compositional diversity. However, a structured pathway for integrating MLD-based photoresists into EUV lithography processes has not yet been established partly due to a lack of knowledge on the EUV exposure and process chemistry preventing mechanistic informed design of this novel material class.

In this role, you will investigate the feasibility of MLD-based resists with molecular-level control for lithographic scaling toward Hyper-NA EUV. You will generate fundamental insights into the deposition, exposure, and processing parameters and chemistry that govern stability and EUV response of these materials and use this understanding to guide their further optimization.

Your main tasks will include:

• Deposit MLD-based photoresist films using imec’s state-of-the-art deposition infrastructure
• Characterize deposited thin films using advanced metrology techniques, including water contact angle (WCA) measurements, atomic force microscopy (AFM), X-ray reflectivity (XRR), and X-ray photoelectron spectroscopy (XPS), with particular attention to film stability
• establish a relationship between deposition parameters and film uniformity, stability, and lithographic performance
• Evaluate the lithographic response of MLD-based resists under EUV exposure
• Investigate the EUV-induced chemistry in MLD-based photoresists and correlate them to solubility switching and patterning performance in High-NA EUV lithography (e.g. by EUV-induced outgassing, infrared spectroscopy, and X-ray photoelectron spectroscopy as a function of exposure dose)
• Progressively take ownership of experimental planning, data interpretation, and scientific communication
• Discuss research findings with imec material experts and external collaborators to help identify promising directions for future material development
• Disseminate results through scientific conferences, peer-reviewed publications, and internal knowledge sharing

Who you are:

• You hold (or will soon obtain) a Master’s degree in chemistry, materials science, nanoscience, or a related discipline
• You have a strong interest in understanding EUV exposure chemistry at a fundamental level
• You ideally have hands-on experience with deposition techniques, as well as spin coating and/or semiconductor processing
• Experience with advanced thin-film characterization techniques, as well as spectroscopic methods is considered an asset
• You are willing to develop competence in planning experiments independently, and are able to document results rigorously, and work safely with chemicals and sensitive equipment
• You are skilled in analyzing complex scientific data
• You are fully proficient in English, motivated to publish and present your work, and comfortable collaborating with interdisciplinary teams of experts at imec
• You are curious, precise, persistent, collaborative, and enthusiastic about complex, tool-based experimental research

Further reading:

Revealing Structure-Driven Performance of Molecular-Atomic Layer Deposited Resists for Extreme Ultraviolet Lithography through In Situ Analysis | ACS Nano | ACS Publications

Illuminating the Challenges in Extreme Ultraviolet Patterning Materials | Chemistry of Materials | ACS Publications

Ultralow line edge roughness of hybrid multilayer Extreme ultraviolet resist with vertical molecular wire structure - ScienceDirect

Effect of Networking Density on the Patterning Performance of Molecular Layer Deposited Alucone Electron Beam/EUV Resists | ACS Applied Materials & Interfaces | ACS Publications