Parallel Fabrication and Transport Properties of Carbon Nanotube Single Electron Transistors

Single electron transistors (SET) have attracted significant attention as a potential building block for post CMOS nanoelectronic devices. However, lack of reproducible and parallel fabrication approach and room temperature operation are the two major bottlenecks for practical realization of SET based devices. In this thesis, I demonstrate large scale single electron transistors fabrication techniques using solution processed single wall carbon nanotubes (SWNTs) and studied their electron transport properties. The approach is based on the assembly of individual SWNTs via dielectrophoresis (DEP) at the selected position of the circuit and formation of tunnel barriers on SWNT. Two different techniques: i) metal-SWNT Schottky contact, and ii) mechanical templating of SWNTs were used for tunnel barrier creation. Low temperature (4.2K) transport measurement of 100 nm long metal-SWNT Schottky contact devices show that 93% of the devices with contact resistance (RT) > 100 K? show SET behavior. Majority (90%) of the devices with 100 K? < RT < 1 M?, show periodic, well-de?ned Coulomb diamonds with a charging energy ~ 15 meV, represents single electron tunnelling through a single quantum dot (QD), defined by the top contact. For high RT (> 1M?), devices show multiple QDs behaviors, while QD was not formed for low RT ( < 100 K?) devices. From the transport study of 50 SWNT devices, a total of 38 devices show SET behavior giving an yield of 76%. I also demonstrate room temperature operating SET by using mechanical template technique. In mechanical template method individual SWNT is placed on top of a Al/Al2O3 local gate which bends the SWNT at the edge and tunnel barriers are created. SET devices fabricated with a template width of ~20 nm shows room temperature operation with a charging energy of ~150 meV. I also discussed the detailed transport spectroscopy of the devices.

Author dc:creator

• Islam, Muhammad

Contributors dc:contributor

• Khondaker, Saiful

• Carbon nanotube
• large scale assembly
• dielectrophoresis
• field effect transistor
• single electron transistor
• Physics
• Dissertations, Academic -- Sciences; Sciences -- Dissertations, Academic

Language dc:language

English

Identifier

CFE0006037

OAI identifier oai:identifier

oai:stars.library.ucf.edu:etd-2485