Structural and optical properties of ZnO fabricated by reactive e‐beam and rf magnetron sputtering techniques

Abstract

Zinc oxide thin films have been grown on (100)-oriented silicon substrate by reactive e-beam evaporation and rf magnetron sputtering techniques and a comparative study is discussed in this paper. Structural, electrical and optical characteristics have been studied before and after annealing in air by measurements of X-ray diffraction, real parts of the dielectric coefficient, and electrical resistivity. X-ray diffraction measurements have shown that ZnO films are highly c-axis-oriented with a full width at half maximum (FWMH) lower than 0.5°. The electrical resistivity is about 1011 Ω.cm for magnetron sputtered films and it increases from 10–2Ω.cm to about 109Ω.cm after annealing at 750 °C for electron beam evaporated films. Ellipsometry measurements have shown some improvement of the real dielectric coefficient after annealing treatment at 750 °C of the ZnO evaporated by electron beam. The AFM images show that the surfaces of the e-beam evaporated ZnO and of the sputtered ZnO are relatively smooth. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)