@article{carroll_margavio_parsons_2024, title={"Dual-Tone" Area-Selective Deposition: Selectivity Inversion of Polymer on Patterned Si/SiO<sub>2</sub> Starting Surfaces}, volume={2}, ISSN={["1520-5002"]}, url={https://doi.org/10.1021/acs.chemmater.3c03158}, DOI={10.1021/acs.chemmater.3c03158}, abstractNote={Area-selective deposition (ASD) has recently emerged as a promising augmentation of lithographic patterning of small device features. However, current ASD processes are restricted to predefined growth and nongrowth surfaces, limiting their flexibility in industrial processing. In this work, we define the concept of “dual-tone ASD,” where a patterned surface is tuned to enable ASD on one of two adjacent surfaces while avoiding growth on the other surface. For the example case in this work, starting with ASD of the poly(3,4-ethylenedioxythipohene) (PEDOT) conjugated polymer on SiO2 vs on hydrogen-terminated silicon (Si–H), we demonstrate a method to modify a patterned Si–H/SiO2 surface to invert the selectivity, enabling PEDOT to grow selectively on the modified Si region and not on the modified SiO2. The selectivity inversion was achieved by selective modification of the substrate surface energy via treatments with dilute hydrofluoric acid (DHF), (dimethylamino)trimethylsilane (DMATMS), and water. Versatile control over selectivity configurations during ASD has implications for deposition of lateral control layers to reduce overgrowth defects, blocking layers for nonselective deposition steps, and sacrificial layers for recently reported simultaneous deposition and etching processes. Through this study, we identify generalized requirements for selectivity inversion as a patterning strategy in the ASD toolbox and show how this strategy is consistent with previous reports of ASD on metal–dielectric patterned surfaces. Extension of these surface energy treatment strategies to other materials will provide additional opportunities for selectivity inversion, leading to flexible applications of ASD in manufacturing settings.}, journal={CHEMISTRY OF MATERIALS}, author={Carroll, Nicholas M. and Margavio, Hannah R. M. and Parsons, Gregory N.}, year={2024}, month={Feb} }
 @article{nye_carroll_morgan_parsons_2024, title={Vapor-phase zeolitic imidazolate framework-8 growth on fibrous polymer substrates}, volume={42}, ISSN={["1520-8559"]}, url={https://doi.org/10.1116/6.0003183}, DOI={10.1116/6.0003183}, abstractNote={The use of metal-organic frameworks (MOFs) in practical applications is often hindered by synthesis related challenges. Conventional solution-based approaches rely on hazardous solvents and often form powders that are difficult to integrate into practical devices. On the other hand, vapor-phase approaches generally result in MOF films on silicon substrates that make it difficult to characterize the MOF surface area, which is an important quality indicator. We address these challenges by introducing a solvent-free synthesis method to form MOF–fiber composites, which can be more easily integrated into devices. Additionally, these vapor-phase-formed MOF–fiber composites are compatible with Brunauer–Emmett–Teller surface area analysis to characterize MOF quality. Atomic layer deposition is used to form a ZnO film on polypropylene, polyester, and nylon fibrous substrates, which is subsequently converted to zeolitic imidazolate framework-8 (ZIF-8) using 2-methylimidazole vapor. We describe the effects of the ZnO film thickness and MOF conversion conditions on MOF crystallinity and surface area. We report a ZIF-8 surface area of ∼1300 m2/gMOF, which is comparable to reported surface areas of ∼1250–1600 m2/gMOF from conventional synthesis techniques, demonstrating good quality of the solvent-free MOF–fiber composites. We expect these results to extend vapor-phase MOF formation to new, practical substrates for advanced sensing and catalytic applications.}, number={1}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A}, author={Nye, Rachel A. and Carroll, Nicholas M. and Morgan, Sarah E. and Parsons, Gregory N.}, year={2024}, month={Jan} }