Formation of iron or chromium doped epitaxial sapphire thin films on sapphire substrates
- Division of Materials Science and Technology, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
- Materials Department, University of California, Santa Barbara, California 93106-5050 (United States)
- Department of Physics, University of Western Ontario, London, Ontario N6A 3K7 (Canada)
- Chemical Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
This work summarizes results of a simple procedure to incorporate dopants into the near surface region of single-crystal sapphire. We demonstrate the formation of iron-doped and chromium-doped sapphire thin films by solid-phase epitaxial growth. Amorphous alumina films of about 200--350 nm thickness were deposited onto single-crystal sapphire substrates. Fe or Cr ions were introduced into the films during deposition. A post-deposition thermal process was performed in oxidizing ambients at 800--1400 {degree}C to induce epitaxial growth and to incorporate dopants. The epitaxial relationship of the grown film with the substrate was confirmed by both ion channeling and cross-sectional transmission electron microscopy. The growth kinetics were determined by time-resolved reflectivity measurements for different dopant concentrations. Ion channeling angular scans revealed that the Fe or Cr ions are incorporated onto octahedral sites (Al{sup 3+} sites) in the corundum structure as expected in equilibrium. External optical transmittance measurements exhibited absorption in the near ultraviolet range associated with the Fe{sup 3+} state. The substitution of Cr for Al{sup 3+} was also confirmed by the observation of {ital R}1 and {ital R}2 luminescence lines characteristic of ruby. The doping procedure has potential applications in the fabrication of thin film planar optical waveguides and thin film stress sensors. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.
- OSTI ID:
- 118396
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 9 Vol. 78; ISSN JAPIAU; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
Similar Records
Incorporation of iron cations into epitaxial sapphire thin films by co-evaporation and subsequent thermal annealing
Doping effects on the kinetics of solid-phase epitaxial growth of amorphous alumina thin films on sapphire