Copper oxide atomic layer deposition on thermally pretreated multi-walled carbon nanotubes for interconnect applications

• Published in: Microelectronic engineering 2013-07, Vol.107, p.223-228
• Main Authors: Melzer, Marcel, Waechtler, Thomas, Müller, Steve, Fiedler, Holger, Hermann, Sascha, Rodriguez, Raul D., Villabona, Alexander, Sendzik, Andrea, Mothes, Robert, Schulz, Stefan E., Zahn, Dietrich R.T., Hietschold, Michael, Lang, Heinrich, Gessner, Thomas
• Format: Article
• Language: English
• Subjects: APPLICATIONS; Applied sciences; Atomic layer deposition (ALD); CARBON BASE MATERIALS; Carbon nanotubes; Carbon nanotubes (CNT); CONNECTORS (ELECTRICAL); Copper; COPPER OXIDE; Copper oxides; Corrosion; Corrosion mechanisms; Cross-disciplinary physics: materials science; rheology; Damage; DEPOSITION; Design. Technologies. Operation analysis. Testing; Destruction; Electronics; Exact sciences and technology; Fractures; Integrated circuits; Interconnect; Interconnections; Liquids; Materials science; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Nanoscale materials and structures: fabrication and characterization; Nanotubes; OXIDES; Physics; PRETREATMENT; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Thermal oxidation; TUBE
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2012.10.026

Influence of thermal pre-treatments of CNTs onto a subsequent copper oxide ALD process. [Display omitted] ► Study of CuxO atomic layer deposition on thermally pretreated MWCNTs. ► Most pre-treatments resulted in the formation of CuxO particles. ► Areas with layer-like growth occurred after a pre-treatment with wet O2 at 300°C. ► This growth behavior suggests a partial destruction of the outer CNT shell. ► Damage introduced to the MWCNTs is too low to be detected by Raman spectroscopy. Carbon nanotubes (CNTs) are a highly promising material for future interconnects. It is expected that a decoration of the CNTs with Cu particles or also the filling of the interspaces between the CNTs with Cu can enhance the performance of CNT-based interconnects. The current work is therefore considered with thermal atomic layer deposition (ALD) of CuxO from the liquid Cu(I) β-diketonate precursor [(nBu3P)2Cu(acac)] and wet oxygen at 135°C. This paper focuses on different thermal in situ pre-treatments of the CNTs with O2, H2O and wet O2 at temperatures up to 300°C prior to the ALD process. Analyses by transmission electron microscopy show that in most cases the CuxO forms particles on the multi-walled CNTs (MWCNTs). This behavior can be explained by the low affinity of Cu to form carbides. Nevertheless, also the formation of areas with rather layer-like growth was observed in case of an oxidation with wet O2 at 300°C. This growth mode indicates the partial destruction of the MWCNT surface. However, the damages introduced into the MWCNTs during the pre-treatment are too low to be detected by Raman spectroscopy.