Influence of annealing temperature on ZnO thin films grown by dual ion beam sputtering

• Published in: Bulletin of materials science Vol. 37; no. 5; pp. 983 - 989
• Main Authors: Pandey, Sushil Kumar, Pandey, Saurabh Kumar, Awasthi, Vishnu, Kumar, Ashish, Deshpande, Uday P., Gupta, Mukul, Mukherjee, Shaibal
• Format: Journal Article
• Language: English
• Published: India Springer India 01.08.2014; Springer Nature B.V
• Subjects: Annealing; Chemistry and Materials Science; Crystal defects; Defect annealing; Electrical properties; Electron mobility; Engineering; Interstitials; Ion beam sputtering; Ion beams; Materials Science; Optical properties; Optoelectronic devices; Photoelectrons; Photoluminescence; Point defects; Preferred orientation; Room temperature; Silicon substrates; Thin films; X ray photoelectron spectroscopy; X-ray diffraction; X-rays; Zinc oxide; XPS; ZnO; XRD; annealing; PL; DIBSD
• ISSN: 0250-4707; 0973-7669
• DOI: 10.1007/s12034-014-0035-0

We have investigated the influence of in situ annealing on the optical, electrical, structural and morphological properties of ZnO thin films prepared on p -type Si(100) substrates by dual ion beam sputtering deposition (DIBSD) system. X-ray diffraction (XRD) measurements showed that all ZnO films have (002) preferred orientation. Full-width at half-maximum (FWHM) of XRD from the (002) crystal plane was observed to reach to a minimum value of 0.139° from ZnO film, annealed at 600 °C. Photoluminescence (PL) measurements demonstrated sharp near-band-edge emission (NBE) at ~ 380 nm along with broad deep level emissions (DLEs) at room temperature. Moreover, when the annealing temperature was increased from 400 to 600 °C, the ratio of NBE peak intensity to DLE peak intensity initially increased, however, it reduced at further increase in annealing temperature. In electrical characterization as well, when annealing temperature was increased from 400 to 600 °C, room temperature electron mobility enhanced from 6.534 to 13.326 cm 2 /V s, and then reduced with subsequent increase in temperature. Therefore, 600 °C annealing temperature produced good-quality ZnO film, suitable for optoelectronic devices fabrication. X-ray photoelectron spectroscopy (XPS) study revealed the presence of oxygen interstitials and vacancies point defects in ZnO film annealed at 400 °C.