Surface-initiated growth of copper using isonicotinic acid-functionalized aluminum oxide surfaces

Abstract

Isonicotinate self-assembled monolayers (SAM) were prepared on alumina surfaces (A) using isonicotinic acid (iNA). These functionalized layers (iNA-A) were used for the seeded growth of copper films (Cu-iNA-A) by hydrazine hydrate-initiated electroless deposition. The films were characterized by scanning electron microscopy (SEM), electron-dispersive X-ray spectroscopy, atomic force microscopy, Xray photoelectron spectroscopy, X-ray diffraction, and advancing contact angle measurements. The films are Cu 0 but with surface oxidation, and show a faceted morphology, which is more textured (R q = 460 ± 90 nm) compared to the SAM (R q = 2.8 ± 0.5 nm). In contrast, growth of copper films by SnCl 2 /PdCl 2 catalyzed electroless deposition, using formaldehyde (CH 2 O) as the reducing agent, shows a nodular morphology on top of a relatively smooth surface. No copper films are observed in the absence of the isonicotinate SAM. The binding of Cu 2+ to the iNA is proposed to facilitate reduction to Cu 0 and create the seed for subsequent growth. The films show good adhesion to the functionalized surface.

Understanding the Effect of Functional Groups on the Seeded Growth of Copper on Carbon Nanotubes for Optimizing Electrical Transmission

“…[20][21][22] We have also shown that functionalization with pyridine, phosphines, and thiols of CNTs can be achieved in a number of ways and this allows for coordination of metal ions, compounds or 4 nanoparticles. [23][24][25][26][27] Of these substituents, pyridine functionality not only acts as an efficient ligand, 24,28,29 but also facilitates a decrease in the copper reduction potential, resulting in the preferential reduction of the surface bound Cu(II) to Cu(I). [29][30][31][32][33][34][35] This coordinated Cu can then act as a catalyst for the deposition of further Cu(II) ions from solution, allowing controlled seeded growth by electroless deposition.…”

“…[29][30][31][32][33][34][35] This coordinated Cu can then act as a catalyst for the deposition of further Cu(II) ions from solution, allowing controlled seeded growth by electroless deposition. 28,29,36 In the case of CNTs, we have reported that pyridine (py) functionalization may be achieved through 1,3-dicyclohexylcarbodiimide (DCC) coupling of isonicotinic acid (with CNT-OH groups) or 4-hydroxypyridine (with CNT-CO 2 H groups). 24 Based upon the forgoing, we proposed a study to understand and control the seeded growth of Cu on functionalized CNTs in order to synthesize templates for subsequent Cu growth.…”

“…[37][38][39] In the study we contrast the difference between Cu seeded on pyridine functionalized and carboxylic acid functionalized CNTs; to our knowledge there is no prior study of pyridine functionality in the Cu seeding of CNTs, although we have reported pyridine versus hydroxyls activation on alumina surfaces. 28 The comparison between py-functionalized SWNTs (py-SWNTs) and py-functionalized US-SWNTs (py-US-SWNTs) allows for the effects of the concentration of the functional groups (i.e., py:C ratio) to be studied.…”

Understanding the effect of carbon nanotube functionalization on copper electrodeposition

“…Arai et al prepared Cu-MWCNT and Cu-SWCNT composites using glyoxylic acid as a reducing agent; however, surfactants and high-energy disaggregation methods (e.g., mechanical atomization) were necessary to obtain well-dispersed CNTs in copper matrix [12][13][14]. Using a different approach, our group has successfully transferred expertise in electroless deposition of copper from alumina to CNT surfaces [15,16]. Covalent functionalization with nitrogen bearing molecules, such as isonicotinic acid and pyridine on the surface of alumina and SWCNTs, respectively, allowed an even distribution of copper particles thanks to seeding effect of nitrogen functionalities [16].…”

“…Using a different approach, our group has successfully transferred expertise in electroless deposition of copper from alumina to CNT surfaces [15,16]. Covalent functionalization with nitrogen bearing molecules, such as isonicotinic acid and pyridine on the surface of alumina and SWCNTs, respectively, allowed an even distribution of copper particles thanks to seeding effect of nitrogen functionalities [16]. On the other hand, CNT functionalization can also affect electrodeposition; for this reason, we have performed this study to closely examine the effect of CNT functionalization during electrodeposition of copper.…”