Abstract
We have prepared thin films of c-axis oriented YBa 2 Cu 3 O x (YBCO) with a very smooth surface and roughness of less than a monomolecular layer of YBCO by atomic layer-by-layer metalorganic chemical vapor deposition on SrTiO 3 (100) and NdGaO 3 (110) substrates. A YBCO film with a large terrace width of 660 nm has been obtained on a NdGaO 3 (110) substrate. We have clarified the correlation between boulder formation and dislocations in the substrates by atomic force microscope observation. We have attempted to avoid producing boulder nuclei on dislocations exposed on the substrate surface by changing the usual sequence of source supply, Ba/Cu/Ba/Cu/Y/Cu, for 1 cycle into a new sequence, Ba/Ba/Y/Cu/Cu/Cu, and have successfully prevented the boulders. We also discuss issues of third generation precursors which are used in the liquid phase. We have also investigated hetero epitaxy of Sm 2 O 3 ultrathin insulating films on YBCO thin films.
Original language | English |
---|---|
Pages (from-to) | 30-37 |
Number of pages | 8 |
Journal | Applied Surface Science |
Volume | 112 |
DOIs | |
Publication status | Published - 1997 Mar |
Externally published | Yes |
Keywords
- Atomic force microscope (AFM)
- Liquid precursor
- Metalorganic chemical vapor deposition (MOCVD)
- Preferential growth
- Surface migration
- YBa Cu O
ASJC Scopus subject areas
- Chemistry(all)
- Condensed Matter Physics
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Surfaces, Coatings and Films