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

Abstract

"Copper oxide atomic layer deposition on thermally pretreated multi-walled carbon nanotubes for interconnect applications", Microelectron. Eng. 107, 223-228 (2013 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 Cu x O from the liquid Cu(I) β-diketonate precursor [( n Bu 3 P) 2 Cu(acac)] and wet oxygen at 135°C. This paper focuses on different thermal in-situ pre-treatments of the CNTs with O 2 , H 2 O and wet O 2 at temperatures up to 300°C prior to the ALD process. Analyses by transmission electron microscopy show that in most cases the Cu x O 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 O 2 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. Abstract:Carbon nanotubes (CNTs) are a highly promising material for future interconnects due to the remarkable properties they combine such as high thermal conductivity [1,2], ballistic transport over distances in the µm-range [3,4] and the ability to carry high current densities with low electro migration [5]. To make CNT-based interconnects competitive to the currently used copper technology, several challenges have to be overcome, such as formation of low-resistivity contacts, aligned growth both for vertical and horizontal interconnects with high density [6].

A Survey of Carbon Nanotube Interconnects for Energy Efficient Integrated Circuits

“…6). The integration of aligned CNT-Cu composite materials in interconnect structures is now actively studied [88][89][90][91][92] and can lead to significant performance gain and reliability enhancement of integrated circuits.…”

N-Type Coating of Single-Walled Carbon Nanotubes by Polydopamine-Mediated Nickel Metallization

“…To fulfil the first two requirements, highly oxidative, toxic, and, in general, environmentally harmful chemicals [23][24][25] or expensive, energy-consuming processes have been widely applied [23][24][25], and result in chemical modifications of the surface to improve the wetting of the CNTs and, therefore, the compatibility with the partner material(s) of the composite. A further disadvantage of chemical surface functionalization is the difficult control of the balance between functionalization and the damage degree of CNTs.…”

“…Different metallization methods [1,23,24,41,42] such as powder metallurgy techniques, electroless plating, electroplating, physical and chemical vapour deposition, flame-, arc-, and supersonic spraying, make a colourful bouquet for different metals or applications [5]. The most well-known method is autocatalytic electroless plating.…”