Advances in area-selective atomic layer deposition: surface chemistry, challenges, and future perspectives

The relentless scaling of semiconductor devices demands advanced patterning strategies for overcoming the intrinsic limitations of conventional top-down lithography. In this context, area-selective atomic layer deposition (AS-ALD) has emerged as a promising bottom-up technique for achieving nanoscale pattern fidelity by confining the growth of thin films to predefined surfaces while suppressing nucleation on non-growth regions. Leveraging the self-limiting surface chemistry of ALD, AS-ALD provides intrinsic self-alignment, reduces edge placement errors, and minimizes multi-patterning steps, thereby offering a scalable pathway for next-generation integrated circuits. This review provides a comprehensive summary of recent advances in AS-ALD, emphasizing three main approaches: (i) inhibitor-free strategies that exploit intrinsic or activation-induced reactivity differences; (ii) inhibitor-based techniques employing self-assembled monolayers, small-molecule inhibitors, and polymeric blocking layers; and (iii) emerging superlattice AS-ALD (SAS-ALD). Unlike conventional methods driven by chemical reactivity, SAS-ALD utilizes strain-driven kinetics on lateral 2D heterostructures to achieve atomic-level selectivity, representing a distinct paradigm in area-selective growth. The fundamental mechanisms governing the selectivity are discussed, along with representative material systems, integration challenges, and recovery schemes designed for sustaining long-cycle selectivity. SAS-ALD, which affords sub-10 nm pitch scalability, is highlighted as it holds significant promise for enabling future device architectures beyond Moore's Law. Finally, the critical remaining obstacles, such as defect-induced nucleation, inhibitor durability, and integration compatibility, as well as perspectives on how AS-ALD can evolve into a key enabler of advanced semiconductor manufacturing are presented.