Area-Selective Deposition: Fundamentals, Applications, and Future Outlook

This review provides an overview of area-selective thin film deposition (ASD) with a primary focus on vapor-phase thin film formation via chemical vapor deposition (CVD) and atomic layer deposition (ALD). Area-selective deposition has been successfully implemented in microelectronic processes, but most approaches to date rely on high-temperature reactions to achieve the desired substrate sensitivity. Continued size and performance scaling of microelectronics, as well as new materials, patterning methods, and device fabrication schemes are seeking solutions for new low-temperature (<400 °C) ASD methods for dielectrics, metals, and organic thin films. To provide an overview of the ASD field, this article critically reviews key challenges that must be overcome for ASD to be successful in microelectronics and other fields, including descriptions of current process application needs. We provide an overview of basic mechanisms in film nucleation during CVD and ALD and summarize current known ASD approaches for semiconductors, metals, dielectrics, and organic materials. For a few key materials, selectivity is quantitatively compared for different reaction precursors, giving important insight into needs for favorable reactant and reaction design. We summarize current limitations of ASD and future opportunities that could be achieved using advanced bottom-up atomic scale processes.