Seminar
Tuesday, April 16, 2019 - 12:00am
Graduate Student Kiran Khadka will present
"Synthesis, Characterization, and Reactivity of Aminosiloxane and 1, 2-Diaminosiloxane Monolayers on Silicon/Silicon Dioxide without Byproducts"
on April 16, 2019 at 4:10 pm in Neville Hall, room 3
Silicon-based interfaces are almost ubiquitously used in the electronic industry ( $1172 billion market value-2018), and 95% of known rocks and 27% of Earth’s crust contain silicon.1,2 Various silanes that form self-assembled monolayers (SAMs) with one molecular-layer thickness, and terminated with desired functional groups, have been used as coupling agents to make strong bonds between the native oxide on a silicon substrate and other materials (e.g., polyimides) to create composite structures.2,3 Failure of these engineered interfaces have a severe consequence for microelectronic devices.4 Traditionally used silane coupling agents contain hydrolyzsable groups, are adsorbed from solution, require a catalytic amount of water to increase the kinetics of their reaction, and generate by-products.3,4
We have worked with a new class of compounds, called cyclic azasilanes, which can be deposited from solution or vapor phase and create no by-products.5,6 Two of the compounds studied were N-methyl-aza-2, 2, 4-trimethylsilacyclopentane and N-(2-aminoethyl)-2, 2, 4-trimethyl-1-aza-2-silacyclopentane, whose adsorption produces amine and diamine functionality, respectively.5,6 I will present the kinetics of adsorption, as well as Brønsted basicity of the newly formed surface, using a combination of analytical techniques: contact angle titration, optical ellipsometry, and X-ray photoelectron spectroscopy.5,6 To understand the potential efficacy of the amine functionality as a coupling agent, I will also present the reaction of the newly formed surfaces with the common electrophiles, maleic and succinic anhydride. Their surface-reaction kinetics and characterization will also be presented in this talk.
1. Consumer Electronics Market by Product, Global Industry Perspective, Comprehensive Analysis and Forecast, 2017 – 2024’’ New York, NY, June 29, 2018 (GLOBE NEWSWIRE).
2. Dabrowski, J.; Müssig, H-J. Silicon Surfaces and Formation of Interfaces, 344-384, World Scientific, 2000
3. Arkles, B.; Pan, Y.; Larson, J.; Berry, H. D. Cyclic azasilanes: Volatile coupling agents for nanotechnology, in Silanes and Other Coupling Agents. K. Mittal Ed.; VSP (Brill), 2004, Vol. 3, pp 179-191.
4. Semiconductor Industry Association - International Technology Roadmap for Semiconductors (ITRS) http://www.semiconductors.org/clientuploads/directory/DocumentSIA/ITRS_2... (accessed 3/24/2016, 2016).
5. Khadka, K.; Strandwitz, N.; Ferguson, G.S. Byproduct-free route to aminosiloxane monolayers on silicon/silicon dioxide. Langmuir 2017, 33, 1639-1645.
6. Khadka, K.; Carpenter (IV), G.K.; Ferguson, G.S. Byproduct-Free Synthesis, Characterization, and Reactivity of 1, 2-Diaminosiloxane Monolayers on Silicon/Silicon Dioxide. In review