Exploratory Synthesis and Reactivity of Transition Metal Complexes as Chemical Vapor Deposition Precursors

The Chemical Synthesis Program of the Chemistry Division of NSF supports the project by Professor Gregory S. Girolami of the University of Illinois at Urbana-Champaign to develop new and better molecular precursors for the chemical vapor deposition (CVD) of thin films. The development of new and better molecular precursors for the CVD of thin films is a important need of the microelectronics industry.

The current work will develop new classes of transition metal compounds that can be used in the CVD of metals and metal oxides. The research will lead to deeper understandings of the chemistry of volatile transition metal compounds and lead to better ways to deposit the wires and insulators that are key components of modern-day computer chips. The work will enhance already existing interactions between Professor Girolami’s group and leading companies in microelectronics development.

This project will contribute directly to the education and training of B.S. and Ph.D. students, and the results will be disseminated by presentations at international conferences, and by publication in scientific journals. This award will contribute to the education of a diverse group of undergraduate and graduate students and enable Professor Girolami to write short radio spots highlighting recent scientific advances of interest to the public.

The project focuses on developing new volatile precursors for the CVD of thin films of electronic materials, investigations of their chemical reactivities, and studies of their volatilities and utilities as thin film precursors. A major thrust will address the synthesis and chemistry of metal CVD precursors containing new chelating borohydride ligands.

The guiding hypothesize is that such complexes should have reduced London forces owing to the presence of the BH3 group, but that the substituent group can be chosen to tune the ligand’s steric and electronic properties. Initial targets include metal complexes of the boranatodimethylaminomethyl group. The hypothesis is that these will form volatile complexes of easily reducible metals due to the donor ability of the alkyl or amido group at one end of the chelate.

The behavior of these complexes will be investigated by solution mechanistic studies and theoretical investigations in collaboration with Prof. Kostantinos Vogiatzis at the University of Tennessee – Knoxville. The CVD depositions of the compounds will be studied with collaborator Prof.

John Abelson at the University of Illinois. These studies are aimed at elucidating the chemical steps by which CVD precursors transform into the finished films on the growth surface. The development of these new molecules will lead to better performing materials and new fabrication methods that will enable the continued miniaturization of integrated circuits.

The project lies at the interface of inorganic and materials chemistry and is well suited for the education of scientists at all levels. Professor Girolami’s group is also well positioned to provide the highest level of education and training for students underrepresented in science. Outreach activities involving the production and broadcast of TinyTech radio spots will also be part of the funded project.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.