| AVS 60th International Symposium and Exhibition | |
| Thin Film | Wednesday Sessions |
| Session TF+AS+BI+EM+SE+SS-WeA |
| Session: | Applications of Self-Assembled Monolayers and Nano-Structured Assemblies |
| Presenter: | P. Campbell, University of Texas at Dallas |
| Authors: | P. Campbell, University of Texas at Dallas L. Caillard, University of Pierre and Marie Curie, France O. Pluchery, University of Pierre and Marie Curie, France Y.J. Chabal, University of Texas at Dallas |
| Correspondent: | Click to Email |
As the minimum feature size in CMOS technology continues to decrease, quantum effects begin to dominate the operation of the transistors. In order to compensate for these effects, we require a new transistor design that operates based on the quantum effects present at the nanoscale. Single-electron transistors present a viable option to create smaller, more efficient transistors but a high-yield process has not yet been developed for their manufacturing.
In addition to the increasing effect of quantum mechanics, current lithographic methods face challenges in scaling below the 10 - 20 nm scale. Several proposed lithographic methods, such as direct write methods, can provide high resolution lithography, enabling the creation of transistors in the sub-10 nm region. However, direct write methods require extensive development of multi-tip approaches to achieve throughput comparable to optical lithography.
A chemical method to fabricate devices can create high performance transistors with a high throughput. The first step of this process is the deposition of a monolayer of organic molecules on a hydrogen-passivated silicon surface. Second, mono-dispersed gold nanoparticles are deposited on the surface to form a tunnel junction. The electrical properties of the sample are determined by probing the surface with scanning tunneling microscopy (STM). This results in a double-tunnel junction. By properly tailoring the nanoparticle size, organic molecule size, and STM tip-sample distance, a Coulomb staircase can be observed in the I-V curve of the junction [1].
Using a 1.7 nm thick organic molecule, evidence consistent with a Coulomb staircase is observable on a small number of spectroscopy curves. However, the electronic response of each nanoparticle is not consistent. This suggests that thermal and electronic noise play a significant role in the measurement and behavior of double-tunnel junctions. As well, the properties of the junction are influenced greatly by the quality of the interface between the substrate and organic layer and the organic layer itself. By exploring the chemistry of varying length molecules on the surface and characterizing the quality of attachment and durability of the organic layer, optimization of the samples is possible to create more reliable double tunnel junctions.
References:
[1] K. Mullen, E. Enjacob, R.C. Jaklevic, Z Schuss. I-V Characteristics of Coupled Ultrasmall-Capacitance Normal Tunnel-Junctions. Phys. Rev. B 37 (1988) 98-105.