Growing additional TiO2 thin films on TiO2 substrates in ultrahigh vacuum (UHV)-compatible chambers have many applications for sample preparation, such as smoothing surface morphologies, templating, and covering impurities. However, there has been little study into how to control the morphology of TiO2 films deposited onto TiO2 substrates, especially using atomic layer deposition (ALD) precursors. Here, the authors show the growth of a TiO2 film on a rutile TiO2(110) surface using titanium tetraisopropoxide (TTIP) and water as the precursors at pressures well below those used in common ALD reactors. X-ray absorption spectroscopy suggests that the relatively low sample temperature (175 °C) results in an anatase film despite the rutile template of the substrate. Using ambient pressure x-ray photoelectron spectroscopy, the adsorption of TTIP was found to be self-limiting, even at room temperature. No molecular water was found to adsorb on the surface. The deposited thickness suggests that an alternate chemical vapor deposition growth mechanism may be dominating the growth process. This study highlights the possibility that metal oxide film deposition from molecular precursors is an option for sample preparations in common UHV-compatible chambers.
Head, Ashley R., et al. "<i>In situ</i> characterization of the deposition of anatase TiO2 on rutile TiO2(110)." Journal of Vacuum Science and Technology A, vol. 36, no. 2, Feb. 2018. https://doi.org/10.1116/1.5005533
Head, Ashley R., Johansson, Niclas, Niu, Yuran, et al., "<i>In situ</i> characterization of the deposition of anatase TiO2 on rutile TiO2(110)," Journal of Vacuum Science and Technology A 36, no. 2 (2018), https://doi.org/10.1116/1.5005533
@article{osti_2561443,
author = {Head, Ashley R. and Johansson, Niclas and Niu, Yuran and Snezhkova, Olesia and Chaudhary, Shilpi and Schnadt, Joachim and Bluhm, Hendrik and Chen, Chaoyu and Avila, José and Asensio, Maria-Carmen},
title = {<i>In situ</i> characterization of the deposition of anatase TiO2 on rutile TiO2(110)},
annote = {Growing additional TiO2 thin films on TiO2 substrates in ultrahigh vacuum (UHV)-compatible chambers have many applications for sample preparation, such as smoothing surface morphologies, templating, and covering impurities. However, there has been little study into how to control the morphology of TiO2 films deposited onto TiO2 substrates, especially using atomic layer deposition (ALD) precursors. Here, the authors show the growth of a TiO2 film on a rutile TiO2(110) surface using titanium tetraisopropoxide (TTIP) and water as the precursors at pressures well below those used in common ALD reactors. X-ray absorption spectroscopy suggests that the relatively low sample temperature (175 °C) results in an anatase film despite the rutile template of the substrate. Using ambient pressure x-ray photoelectron spectroscopy, the adsorption of TTIP was found to be self-limiting, even at room temperature. No molecular water was found to adsorb on the surface. The deposited thickness suggests that an alternate chemical vapor deposition growth mechanism may be dominating the growth process. This study highlights the possibility that metal oxide film deposition from molecular precursors is an option for sample preparations in common UHV-compatible chambers.},
doi = {10.1116/1.5005533},
url = {https://www.osti.gov/biblio/2561443},
journal = {Journal of Vacuum Science and Technology A},
issn = {ISSN 0734-2101},
number = {2},
volume = {36},
place = {United States},
publisher = {American Vacuum Society},
year = {2018},
month = {02}}
Frank Ogletree, D.; Bluhm, Hendrik; Hebenstreit, Eleonore D.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 601, Issue 1-2https://doi.org/10.1016/j.nima.2008.12.155