SUBJECT: Ph.D. Proposal Presentation
BY: Songkil Kim
TIME: Friday, October 18, 2013, 1:00 p.m.
PLACE: MARC Building, 201
TITLE: Engineering of Carbon Electronic Devices Using Focused Electron Beam Induced Deposition(FEBID) of Graphitic Nanojoints
COMMITTEE: Dr. Andrei G. Fedorov, Chair (ME)
Dr. Satish Kumar (ME)
Dr. Baratunde A. Cola (ME)
Dr. Vladimir V. Tsukruk (MSE)
Dr. Seungsoon Jang (MSE)


Continuing technological advances in semiconductor industry requires further scale down in device features down to and below 20 nm. However, this presents significant challenges to lithographic patterning of very small features as well as material behavior issues due to electron scattering at surface/grain boundaries, resulting in an increased resistivity of interconnects and mechanical breakdown due to electromigration effects. Carbon nanotubes (CNTs) and graphene have been under intense exploration as alternative electronic materials, owing to their unique electronic as well as mechanical and thermal properties. While carbon-based materials show potentials as alternatives of silicon and copper, large contact resistance between CNTs/graphene and metal electrodes has been preventing application of these materials to electronic devices. In this Ph.D research, the overarching goal is to develop and characterize the fabrication protocols for reducing electrical contact resistance through chemical contacts by FEBID graphitic carbon nanostructures at the MWCNT/graphene and metal interfaces. The proposed research is divided into two interrelated themes, one is focusing on MWCNT-metal interface and another one is on FEBID of graphene devices. The preliminary work provides a comprehensive framework for development of fabrication protocols and electrical/structural characterization of FEBID graphitic carbon contacts to the open-ended MWCNTs, starting from opening and exposing the multiple conducting shells of MWCNTs, following by dielectrophoretic alignment of multiple MWCNTs between metal electrodes in an array to finally making the FEBID graphitic carbon nanostructures at the exposed ends of MWCNTs, establishing an Ohmic “end” contact to multiple conducting channels. Using these advances of FEBID technique, fabrication strategies of electrical contact between the multilayered graphene and a metal interconnect using graphitic nanojoints have been proposed and demonstrated experimentally. In the proposed work, a patterned CVD grown few layer graphene, which is promising for large area graphene device fabrication, will be contacted to metal electrodes through the FEBID graphitic ‘interlayer’. The transmission line method (TLM) test structures will be used for evaluating the contact resistance of fabricated graphene-metal interfaces and eventually developing a robust fabrication protocol of high performance graphene electronic devices with FEBID graphitic nanojoints.