Carbon Nanotube Based Interconnect Material for Electronic Applications
Carbon nanotubes (CNTs) are considered as a candidate material for future electronic
interconnect applications. This thesis summarizes the research work on the
fabrication and characterization of CNT-based interconnect systems, and explores
the possibilities of integrating CNTs into various electronic interconnect scenarios.
CNT material properties and fabrication methods are introduced as well as its potential
for solving the future interconnect challenges. The technology development
works are presented in detail in four categories: synthesis, densification, coating
The principles of the chemical vapor deposition (CVD) method for producing the
CNTs are described and discussed. Densification methods are developed in order
to increase the volume density of the pristine porous CVD-grown CNTs. Two techniques,
vapor-based densification and paper-mediated wet densification, have been
proposed and characterized. CNT transfer techniques are developed in order to
decouple the harsh CVD growth environment from the target application devices.
Two kinds of transfer medium materials, indium and polymer, have been proposed
and optimized. To improve the electrical performance of the pristine CNTs, metallic
coating techniques for both vertically aligned and randomly dispersed CNTs
are developed and characterized.
Finally, three different CNT-based interconnect scenarios: bumps, through silicon
vias, and flexible conductors, are demonstrated and characterized, using the
as-developed processes. The integration technologies developed in this thesis not
only improve the CNT process compatibility with the conventional electronics
manufacture flows, but also offers state-of-the-art electrical and mechanical performance
for the non-conventional flexible and stretchable interconnect applications.
three dimensional integration
through silicon via