Structural, optical, and electrical properties of Cu-doped ZrO₂ films prepared by magnetron co-sputtering

Copper (Cu)-doped ZrO₂ (CZO) films with different Cu content (0 at.%~8.07 at.%) are successfully deposited on Si (100) substrates by direct current (DC) and radio frequency (RF) magnetron co-sputtering. The influences of Cu content on structural, morphological, optical and electrical properties of CZO films are discussed in detail. The CZO films exhibit ZrO₂ monocline (111) preferred orientation, which indicates that Cu atoms are doped in ZrO₂ host lattice. The crystallite size estimated form x-ray diffraction (XRD) increases by Cu doping, which accords with the result observed from the scanning electron microscope (SEM). The electrical resistivity decreases from 2.63 Ω.cm to 1.48 Ω·cm with Cu doping content increasing, which indicates that the conductivity of CZO film is improved. However, the visible light transmittances decrease slightly by Cu doping and the optical band gap values decrease from 4.64 eV to 4.48 eV for CZO films.