Microstructural and conductivity comparison of Ag films grown on amorphous TiO2 and polycrystalline ZnO [electronic resource].
- Published:
- Washington, D.C. : United States. Dept. of Energy. Office of Basic Energy Sciences, 2001.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy. - Physical Description:
- 42 pages : digital, PDF file
- Additional Creators:
- Lawrence Berkeley National Laboratory
United States. Department of Energy. Office of Basic Energy Sciences
United States. Department of Energy. Office of Scientific and Technical Information - Access Online:
- www.osti.gov
- Summary:
- 8 nm thick Ag films were sputter deposited onto amorphous TiO₂ underlayers 25 nm thick, and also amorphous TiO₂ (25 nm)/ZnO (5 nm) multiunderlayers. The substrates were back-etched Si with a 50 nm thick LPCVD Si₃N₄ electron transparent membrane. The ZnO, sputtered onto amorphous TiO₂, formed a continuous layer with a grain size of 5 nm in diameter, on the order of the film thickness. There are several microstructural differences in the Ag dependent on the underlayers, revealed by TEM. First a strong {l_brace}0001{r_brace} ZnO to {l_brace}111{r_brace} Ag fibre-texture relationship exists. On TiO₂ the Ag microstructure shows many abnormal grains whose average diameter is about 60-80 nm, whereas the films on ZnO show few abnormal grains. The background matrix of normal grains on the TiO₂ is roughly 15 nm, while the normal grain size on the ZnO is about 25 nm. Electron diffraction patterns show that the film on ZnO has a strong {l_brace}111{r_brace} orientation, and dark field images with this diffraction condition have a grain size of about 30 nm. In a region near the center of the TEM grid where there is the greatest local heating during deposition, Ag films grown on amorphous TiO₂ are discontinuous, whereas on ZnO, the film is continuous. When films 8 nm films are grown on solid glass substrates, those with ZnO underlayers have sheet resistances of 5.68 Ω/, whereas those on TiO₂ are 7.56 Ω/, and when 16 nm thick, the corresponding sheet resistances are 2.7 Ω/ and 3.3 Ω/. The conductivity difference is very repeatable. The improved conductivity is thought to be a combined effect of reduced grain boundary area per unit volume, the predominance of low grain boundary resistivity Coincidence Site Lattice boundaries from the Ag {l_brace}111{r_brace} orientation, and Ag planarization on ZnO resulting in less groove formation on deposition, concluded from atomic force microscopy.
- Subject(s):
- Note:
- Published through SciTech Connect.
03/26/2001.
"lbnl--47666"
Sieck, Peter; Stach, Eric; Dannenberg, Rand; Glenn, Darin; Hukari, Kyle. - Type of Report and Period Covered Note:
- Topical;
- Funding Information:
- AC03-76SF00098
503601
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