@article{gougousi_terry_parsons_2006, title={Charge generation during oxidation of thin Hf metal films on silicon}, volume={513}, ISSN={["0040-6090"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000238963600033&KeyUID=WOS:000238963600033}, DOI={10.1016/j.tsf.2006.02.004}, abstractNote={Oxidation of Hf metal films on Si appears to follow different charge generation rules than the traditional oxidation of Si described in detail by Deal et al. [B.E. Deal, M. Sklar, A.S. Grove, E.H. Snow, J. Electrochem. Soc. 114 (1967) 226]. Oxidation of thin Hf metal films on silicon in oxygen rich environments to form Hf-silicate results in rapid growth of silicon oxide interfacial layers and generation of significant charge concentration in the films. Oxidation of Hf in oxygen-deficient environment leads to improved control of the interface with much thinner interfacial layers and substantial reduction in the charge present in the films. Results from capacitance vs. voltage and X-ray photoelectron spectroscopy measurements are compared to correlate charge with chemical structure evolution during oxidation and dielectric layer formation. It is demonstrated that processing conditions may influence the quality of the Hf dielectric film significantly by generating positive charge that is not intrinsic to the material.}, number={1-2}, journal={THIN SOLID FILMS}, author={Gougousi, Theodosia and Terry, David B. and Parsons, Gregory N.}, year={2006}, month={Aug}, pages={201–205} }
 @article{barua_gougousi_young_parsons_2006, title={Supercritical-carbon dioxide-assisted cyclic deposition of metal oxide and metal thin films}, volume={88}, ISSN={["1077-3118"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000235736300065&KeyUID=WOS:000235736300065}, DOI={10.1063/1.2181651}, abstractNote={Thin films of aluminum oxide and palladium were deposited on silicon at low temperatures (70–120°C) by a cyclic adsorption/reaction processes using supercritical CO2 solvent. Precursors included Al(hfac)3, Al(acac)3, and Pd(hfac)2, and aqueous H2O2, tert-butyl peracetate, and H2 were used as the oxidants or reductants. For the precursors studied, growth proceeds through a multilayer precursor adsorption in each deposition cycle, and film thickness increased linearly with the number of growth cycles.}, number={9}, journal={APPLIED PHYSICS LETTERS}, author={Barua, D and Gougousi, T and Young, ED and Parsons, GN}, year={2006}, month={Feb} }
 @article{park_doub_gougousi_parsons_2005, title={Microcontact patterning of ruthenium gate electrodes by selective area atomic layer deposition}, volume={86}, ISSN={["0003-6951"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000227144700016&KeyUID=WOS:000227144700016}, DOI={10.1063/1.1852079}, abstractNote={Patterned octadecyltrichlorosilane monolayers are used to inhibit film nucleation, enabling selective area atomic layer deposition (ALD) of ruthenium on SiO2 and HfO2 surfaces using bis-(cyclopentadienyl)ruthenium and oxygen. X-ray photoelectron spectroscopy indicated that OTS could deactivate film growth on thermal silicon oxide and hafnium oxide surfaces. The growth rate of ALD Ru is similar on various starting surfaces, but the growth initiation differed substantially. Metal-oxide-semiconductor capacitors were fabricated directly using the selective-area process. Capacitance measurements indicate the effective work function of ALD Ru is 4.84±0.1eV on SiO2, and the effective work function is reduced on HfO2∕SiO2 layers.}, number={5}, journal={APPLIED PHYSICS LETTERS}, author={Park, KJ and Doub, JM and Gougousi, T and Parsons, GN}, year={2005}, month={Jan} }
 @article{gougousi_parsons_2004, title={Postdeposition reactivity of sputter-deposited high-dielectric-constant films with ambient H2O and carbon-containing species}, volume={95}, ISSN={["1089-7550"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000188281800087&KeyUID=WOS:000188281800087}, DOI={10.1063/1.1636513}, abstractNote={The room temperature reactivity of group III and IV based high-dielectric-constant films during long-term (>1 year) exposure to ambient atmosphere (H2O- and C-containing species such as CO2) has been studied in order to assess the stability of the materials. We prepare the films by physical vapor deposition of metal on Si (100) surfaces which is followed by oxidation in N2O (1 atm), and monitor the formation of carbonate/alkoxylate and hydroxide species using Fourier transform infrared spectroscopy. For La-based films we find that the oxidation temperature has a strong effect on the reactivity with the ambient. For Hf- and Zr-based films, formation of various carbonate or alkoxylate species is confirmed within minutes of exposure, while substantial reaction with H2O is not detected. Hf-based films, in general exhibit superior stability upon long-term exposure.}, number={3}, journal={JOURNAL OF APPLIED PHYSICS}, author={Gougousi, T and Parsons, GN}, year={2004}, month={Feb}, pages={1391–1396} }
 @article{gougousi_niu_ashcraft_parsons_2003, title={Carbonate formation during post-deposition ambient exposure of high-k dielectrics}, volume={83}, ISSN={["0003-6951"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000186068400033&KeyUID=WOS:000186068400033}, DOI={10.1063/1.1623316}, abstractNote={When thick films of group-III (La, Y)- and group-IV (Hf, Zr)-based high-k dielectrics are exposed to ambient for several months, Fourier transform infrared spectroscopy shows formation of carbonate species in the film bulk, likely due to reaction with atmospheric CO2. Group-III-based films show signs of carbonate feature growth within 10 min of air exposure, especially in films processed at relatively low temperatures (<600 °C). Carbonate formation is verified also for group-IV-based films, but at a significantly reduced concentration. Post-exposure annealing can reduce the carbonate observed in the IR spectra. However, post-exposure annealing likely does not remove carbon contamination, and it results in interface silicon oxide growth. The observed reactions of high-k films with the ambient may impose significant constraints on the post-deposition handling of high-k films.}, number={17}, journal={APPLIED PHYSICS LETTERS}, author={Gougousi, T and Niu, D and Ashcraft, RW and Parsons, GN}, year={2003}, month={Oct}, pages={3543–3545} }
 @article{gougousi_kelly_terry_parsons_2003, title={Properties of La-silicate high-K dielectric films formed by oxidation of La on silicon}, volume={93}, ISSN={["1089-7550"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000180630200056&KeyUID=WOS:000180630200056}, DOI={10.1063/1.1531818}, abstractNote={In this article, we present data on the properties of La-based high-k dielectric films prepared by oxidation of La deposited by physical vapor deposition on silicon. Films are characterized by x-ray photoelectron spectroscopy, infrared absorption, and capacitance versus voltage analysis. We find that when we oxidize La metal sputter deposited on Si substrates, it reacts with the silicon substrate to form La silicate. La films as thick as 300 Å will react completely with Si under moderate oxidation conditions (900 °C for 10 min) suggesting a very rapid silicidation reaction between La and Si. Under some processing conditions the as-deposited films contain a small La2O3 component that reduces to La silicate upon anneal at high temperatures. La-silicate films do not phase separate into La2O3 and SiO2 upon annealing at 1050 °C, and their resistance to H2O incorporation depends critically on the oxidation temperature. Electrical measurements show a high concentration of positive fixed charge.}, number={3}, journal={JOURNAL OF APPLIED PHYSICS}, author={Gougousi, T and Kelly, MJ and Terry, DB and Parsons, GN}, year={2003}, month={Feb}, pages={1691–1696} }
 @article{gougousi_kelly_parsons_2002, title={The role of the OH species in high-k/polycrystalline silicon gate electrode interface reactions}, volume={80}, ISSN={["1077-3118"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000175904600044&KeyUID=WOS:000175904600044}, DOI={10.1063/1.1485122}, abstractNote={In this letter, reactions occurring at the interface between polycrystalline silicon (poly-Si) and LaSiOx high-dielectric-constant (high-k) insulating layers are characterized using x-ray photoelectron spectroscopy. Dielectrics were formed by sputter deposition of metal on silicon, followed by oxidation at 900 °C. Amorphous silicon was deposited on top by plasma-enhanced chemical vapor deposition from silane, followed by anneal at 650–1050 °C. We show that if the dielectric layer is exposed to sufficient water vapor before polysilicon deposition, annealing at 1050 °C for 10 s is sufficient to completely oxidize ∼25 Å of deposited silicon. Minimal reaction is observed without deliberate water exposure. This demonstrates the importance of the dielectric surface condition in determining reactivity of high-k/polysilicon interfaces.}, number={23}, journal={APPLIED PHYSICS LETTERS}, author={Gougousi, T and Kelly, MJ and Parsons, GN}, year={2002}, month={Jun}, pages={4419–4421} }