Next generation nanopatterning using small molecule inhibitors for area-selective atomic layer deposition

Area-selective atomic layer deposition (ALD) is an approach to self-aligned, bottom-up nanofabrication with the potential to overcome many of the challenges facing the semiconductor industry around continued device downscaling. Currently, the most common method for achieving area-selective ALD uses self-assembled monolayers (SAMs) as a means of surface deactivation. Alternative routes are also being pursued that may better meet the demands of high-volume device manufacturing and overcome some disadvantages of the SAM method. One promising alternative is the use of small molecule inhibitors (SMIs). This Perspective provides an overview of the current developments in the use of SMIs for selective deposition by describing systems from the literature and providing insight into SMI selection. Although little is yet known about the mechanistic behavior of SMIs, this Perspective aims to lay the framework for both a better understanding of their inhibitive performance and strategies to innovate their design. It establishes two key interfaces—between the ALD precursor and the inhibitor, and between the inhibitor and the substrate—and discusses the role of each in selective deposition. Building upon the established understanding of SAMs together with current knowledge of SMIs, this Perspective aims to define guiding principles and key considerations for improving SMI design.