Growth of Ultra Thin Films

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ABSTRACTPI: John G. Ekerdt Institution: University of Texas AustinProposal Number: 0553839Title: Growth of Ultra Thin FilmsIntellectual Merit This research program investigates the growth of ultra thin (less than 9 nm) metal films on amorphous substrates. Chemical growth methods will be studied and include chemical vapor deposition, atomic layer deposition and plasma-enhanced chemical vapor deposition. Metal films find applications in sensors, optics and microelectronics, and as the critical dimensions or size of the applications and systems decrease, the metal films thickness also must decrease to tens of atomic diameters at most and must have a specific microstructure. The research will focus on chemical and physical methods to increase the reactivity of the substrate toward the metal precursor to increase the density of clusters that grow into a continuous film. The research will also focus on the role of additives, with the potential to form thermodynamically stable compounds with the metals, to form dilute amorphous alloys that will interfere with the formation of polycrystalline films. Cobalt, nickel, ruthenium, rhenium and iridium metals will be studied along with carbon, nitrogen, silicon and phosphorus alloying additives. The research objectives are an understanding of the enabling reactions and processes that will lead to the thinnest possible continuous film, and to an ultra thin film with amorphous character. The program of work will involve film growth and characterization studies and it will involve surface studies to elucidate how the precursors interact with the substrates as the ligands and substrates are modified. The research leverages the expertise and experimental infrastructure at the University of Texas to grow and characterize films and to study surface reactions. Using the tools of surface science, the bonding and reactions at the substrate surface and at the film interface will be explored. Film composition and chemical bonding will be followed using X-ray photoelectron spectroscopy, secondary ion mass spectrometry and low energy ion scattering spectroscopy. A full complement of characterization facilities will be used to study the films, including spectral ellipsometry, atomic force microscopy, X-ray scattering spectroscopy, and high resolution electron microscopy.Broader ImpactsThis research is motivated in general by the key role thin and ultra thin metal films on amorphous substrates have in applications such as sensors and optics, as thermal barriers, and as diffusion barriers in microelectronics manufacturing, which could have a positive effect on the US economy.The research will directly support the training of two graduate students and indirectly provide opportunities for undergraduates to participate in open-ended research projects. The graduate students will develop mentoring skills through working with the undergraduate students. The PI and the graduate students will develop an exhibit that will help explain the revolutionary and current devices that motivate this research, sensors and microelectronics, and introduce these concepts to the general public and to pre-college students. They will present it and display it through a variety of University of Texas sponsored venues, such as the annual Austin Science Fun Day, UT Open House, and the Texas Memorial Museum.