Journal of the Korean Physical Society

pISSN 0374-4884 eISSN 1976-8524


J. Korean Phy. Soc. 2007; 51(4): 1378-1382

Published online October 15, 2007

Copyright © The Korean Physical Society.

Annealing Effect on the Electrical and the Optical Characteristics of Undoped ZnO Thin Films Grown on Si Substrates by RF Magnetron Sputtering

Do Kyu Lee, Sung Kim, Min Choul Kim, Sung Hwan Eom, Hyoung Taek Oh and Suk-Ho Choi


Undoped ZnO films have been grown on Si wafers by RF-magnetron sputtering and have been characterized as a function of annealing temperature (T$_a$) by employing X-ray diffraction, photoluminescence (PL), and Hall effect measurements. The samples were annealed from 500 to 1000 $^circ$C for 3 min under an oxygen ambient in a rapid thermal annealing apparatus. The ZnO films consisted of (100) and (002) polycrystals, and their relative portion changed with varying T$_a$. After annealing at T$_a$ $sim$ 800 $^circ$C, the (100) polycrystals dominantly existed, and the near-band-edge PL peak was most intense, whilst the n-type character was most weakened. We propose that native structural defects play a key role in enhancing the n-type character of ZnO films, judging from the close correlation between the relative intensity of the bound-exciton-related PL lines and the Hall parameters as a function of T$_a$.

Keywords: ZnO films, Photoluminescence, Sputtering, Annealing, Hall effect, X-ray diffraction