Transparent conducting thin films by co‐sputtering of ZnO‐ITO targets

Abstract

Transparent and conductive Zn‐In‐Sn‐O (ZITO) amorphous thin films have been deposited at room temperature by the rf magnetron co‐sputtering of ITO and ZnO targets. Co‐sputtering gives the possibility to deposit multicomponent oxide thin films with different compositions by varying the power to one of the targets. In order to make ZITO films with different Zn content, a constant rf power of 50 W was used for the ITO target, where as the rf power to ZnO target was varied from 25 W to 150 W. The as deposited films showed an increase in Zn content ratio from 17 to 67% as the power to ZnO target was increased from 25 to 150 W. The structural, electrical and optical properties of the as deposited films are reported. The films showed an average transmittance over 80% in the visible wavelength range. The electrical resistivity and optical band gap of the ZITO films were found to depend on the Zn content in the film. The ZITO films deposited at room temperature with lower Zn content ratios showed better optical transmission and electrical properties compared to ITO film. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

The electronic structure of co-sputtered zinc indium tin oxide thin films

“…1 yielded the work function and the VBM energy for each of the investigated films. In addition, using the recently published band gap energies for each of the investigated ZITO compositions, 10 the respective conduction bands minima (CBM) can also be estimated for each of the films. The results of this evaluation are shown in Fig.…”

“…More detail about the sample preparation process can be found in Ref. 10. After deposition, the sample conductivity was measured by four-point probe to ensure identical conductivity to the samples investigated in Ref.…”

“…After deposition, the sample conductivity was measured by four-point probe to ensure identical conductivity to the samples investigated in Ref. 10.…”

Compositional influence on the electrical performance of zinc indium tin oxide transparent thin-film transistors

“…In fact, threshold voltage starts from negative values for low Zn concentration, meaning that these films present a high carrier concentration [12] as appointed also by resistivity measurements.…”

“…All the TFTs with ZITO active channel studied herein have been fabricated using a bottom gate-top contact structure as depicted in figure 1 Increasing the Zn content increases the O vacancy density at the film surface, as it has been reported by Carreras et al [5,12], thus resulting in a highly conductive surface layer [13]. To reduce this effect, one sample of each kind was annealed in air atmosphere.…”