| AVS 66th International Symposium & Exhibition | |
| Materials and Processes for Quantum Information, Computing and Science Focus Topic | Tuesday Sessions |
| Session QS+2D+EM+MN+NS-TuA |
| Session: | Materials for Quantum Sciences |
| Presenter: | Ka Ming Law, The University of Alabama |
| Authors: | K. Law, The University of Alabama S. Budhathoki, The University of Alabama S. Ranjit, The University of Alabama F. Martin, The University of Alabama A.J. Hauser, The University of Alabama |
| Correspondent: | Click to Email |
Superconducting resonators are important for application in quantum computing but require high quality factors. Much work has been done on superconducting resonators fabricated from aluminum thin films on sapphire, and superconducting Josephson tunnel junctions made from aluminum are used as the basis for quantum bit designs. In addition, epitaxial aluminum films has attracted attention in plasmonics due to their superior performance in the UV regime compared to Au and Ag, and their compatibility with current CMOS technology. Sapphire substrates are chemically stable and have low lattice mismatch with aluminum, allowing higher film quality without the need for elaborate substrate preparation and time-consuming growth procedures.
Epitaxial aluminum films were successfully grown by off-axis magnetron sputtering on c-plane sapphire. This study assessed the effects of varying both substrate preparation conditions and growth and prebake temperatures on crystallinity and smoothness. X-ray diffraction and reflectivity measurements demonstrate superior crystallinity and surface smoothness for films grown at 200℃ in15mTorr Ar. An additional substrate preparation procedure which involves 1) a modified RCA procedure and 2) prebake in oxygen environment is shown by atomic force microscopy to be highly effective in reducing void density and depth.