Carbon nanotubes interconnects
The unique high current carrying capability of 109A/cm2, high aspect ratio, high thermal conductivity, high tensile strength of carbon nanotubes (CNTs) make them promising candidates to replace copper as interconnects for various applications.
Electrical interconnects are inherent part of any electronic system. Ever growing demand of faster, smaller and more efficient electronic devices forces interconnects to perform on a wide range of substrates under different environmental conditions and withstand stresses induced from electrical, mechanical and thermal factors.
Currently vertically-aligned CNTs (VACNTs) grown with conventional chemical vapour deposition (CVD) methods at low temperatures (below 600 oC), result in highly defective, low density VACNTs with low growth rates, which is unsuitable for both industrial feasibility and interconnect applications.
Here at the ATI ground-breaking work has led to the development of a system allowing for the growth of VACNTs on substrates maintained at temperatures compatible with complementary metal-oxide semiconductor (CMOS) technology. We utilise a novel photo-thermal chemical vapour deposition (PTCVD) system for the growth of high quality, high density CNTs at low temperatures (below 415 oC), on predefined surfaces. This works paves the way to industrially viable advanced interconnects as a direct replacement for copper.
The ATI has shown that incorporation of carbon nanotubes into the traditional organic solar cell structures in the form of triple junctions allows for more charges to be extracted from the cell. The main obstacle for this approach has been the deleterious effects associated with incorporating the nanotubes.
ATI has adopted a method to alter the outer tube of the multi-wall nanotube so that they can be mixed well in organic materials with suitable solvents. The technique developed by Nismy and co-workers demonstrate a unique method of overcoming the very low charge mobility in traditional organic materials, and shows how a very small modification to the charge transport system on the nanoscale can give rise to significant cost advantages when the triple junction carbon nanotube system is adopted to organic photovoltaic devices.