Technical: The objective of this project is to develop a better molecular-level understanding of chemical reactions associated with atomic layer deposition (ALD) of semiconductor and related materials. The project uses a surface-science approach, combining kinetic studies of deposition processes in reactors operating under realistic conditions with the use of surface-sensitive techniques such as x-ray photoemission spectroscopy (XPS), infrared spectroscopy (IR), Auger electron spectroscopy (AES), low-energy ion scattering (LEIS), and temperature programmed desorption (TPD). The initial focus will be on the study of processes for the deposition of metal nitride diffusion barriers and copper metal interconnects. Specific questions will be addressed in terms of the kinetics and mechanisms of the reactions involved as well as in connection with the composition and morphology of the resulting films. Information gained will be directed to the design of ALD processes that operate under mild conditions and deposit stoichiometric, pure films with good density, low resistance, and smooth surfaces.
Although ALD is on the Semiconductor Roadmap, the ALD field is largely empirical. There is a clear need for more basic studies of the surface chemistry of ALD. The project is interdisciplinary, providing students with training that bridges chemistry, materials science, and physics. The research results can also be of great use for educational purposes, to illustrate kinetic principles in undergraduate and graduate classes. Emphasis will be placed on encouraging student participation from underrepresented groups, and on forging international collaborations.
