Origin of stress in radio frequency magnetron sputtered zinc oxide thin films

Journal Article · Tue Mar 15 00:00:00 EDT 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3552928· OSTI ID:21538183

Menon, Rashmi; Gupta, Vinay; Sreenivas, K ^[1]; Tan, H H; Jagadish, C ^[2]

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1. Electronic Material and Devices Laboratory, Department of Physics and Astrophysics, University of Delhi, Delhi 11007 (India)
2. Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia)

Highly c-axis oriented ZnO thin films have been deposited on silicon substrates by planar rf magnetron sputtering under varying pressure (10-50 mTorr) and oxygen percentage (50-100%) in the reactive gas (Ar + O{sub 2}) mixture. The as-grown films were found to be stressed over a wide range from -1 x 10{sup 11} to -2 x 10{sup 8} dyne/cm{sup 2} that in turn depends strongly on the processing conditions, and the film becomes stress free at a unique combination of sputtering pressure and reactive gas composition. Raman spectroscopy and photoluminescence (PL) analyses identified the origin of stress as lattice distortion due to defects introduced in the ZnO thin film. FTIR study reveals that Zn-O bond becomes stronger with the increase in oxygen fraction in the reactive gas mixture. The lattice distortion or stress depends on the type of defects introduced during deposition. PL spectra show the formation of a shoulder in band emission with an increase in the processing pressure and are related to the presence of stress. The ratio of band emission to defect emission decreases with the increase in oxygen percentage from 50 to 100%. The studies show a correlation of stress with the structural, vibrational, and photoluminescence properties of the ZnO thin film. The systematic study of the stress will help in the fabrication of efficient devices based on ZnO film.

• OSTI ID: 21538183
• Journal Information: Journal of Applied Physics, Vol. 109, Issue 6; Other Information: DOI: 10.1063/1.3552928; (c) 2011 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION SPECTRA
CORRELATIONS
CRYSTAL DEFECTS
DEPOSITION
FOURIER TRANSFORM SPECTROMETERS
INFRARED SPECTRA
MAGNETRONS
PHOTOLUMINESCENCE
PRESSURE DEPENDENCE
RADIOWAVE RADIATION
RAMAN SPECTRA
RAMAN SPECTROSCOPY
SEMICONDUCTOR MATERIALS
SILICON
STRESSES
SUBSTRATES
SYNTHESIS
THIN FILMS
ZINC OXIDES
CHALCOGENIDES
CRYSTAL STRUCTURE
ELECTROMAGNETIC RADIATION
ELECTRON TUBES
ELECTRONIC EQUIPMENT
ELEMENTS
EMISSION
EQUIPMENT
FILMS
LASER SPECTROSCOPY
LUMINESCENCE
MATERIALS
MEASURING INSTRUMENTS
MICROWAVE EQUIPMENT
MICROWAVE TUBES
OXIDES
OXYGEN COMPOUNDS
PHOTON EMISSION
RADIATIONS
SEMIMETALS
SPECTRA
SPECTROMETERS
SPECTROSCOPY
ZINC COMPOUNDS