Mechanism of atomic layer deposition of Al2O3 on carbene-derived small molecule inhibitors

Area-selective atomic layer deposition (AS-ALD) is a self-aligned thin-film deposition technique that has a potential to address several challenges associated with semiconductor chip miniaturization and energy efficiency in semiconductor manufacturing. A key component of AS-ALD is the deposition growth resist that inhibits ALD. Small molecule inhibitors (SMIs) are a novel class of ALD resists that can potentially achieve higher spatial resolution and better compatibility with a wider variety of substrates and ALD chemistries than traditional polymer and self-assembled monolayers (SAMs) resists. In this study, we introduce a novel carbene-derived SMI and investigate its performance and the growth mechanism of Al₂O₃ ALD on silicon surfaces modified with this resist. Our results show that the selectivity of Al₂O₃ growth can be tailored via simple surface reactions of the reactive SMI. The developed monolayers show comparable inhibition efficiency to a standard H-terminated silicon surface and other common types of inhibitors but offer enhanced stability under ambient conditions. Furthermore, we demonstrate that the mechanism of Al₂O₃ film growth on the SMI differs from that conventional SAMs-based resists reported in literature. These findings provide insights into the design and further development of advanced SMI in AS-ALD applications.