Transparent conducting Nb-doped anatase TiO2 (TNO) thin films sputtered from various oxide targets

Transparent conducting Nb-doped anatase TiO 2 (TNO) epitaxial films were sputtered from TiO 2 -, Ti 2 O 3 -, and Ti-based targets at various oxygen partial pressures (Po 2 ). Using the TiO 2 - and Ti 2 O 3 -based targets, highly conductive films showing a resistivity (p) of ~3 x 10 -4 Ω cm could be formed without postdeposition treatment In the case of the TNO films formed from the Ti-based target, reductive annealing had to be carried out at a temperature of 600 °C to achieve similar resistivity values. Thus, the use of oxide targets is preferable to obtain as-grown transparent conducting TNO films. In particular, the Ti 2 O 3 -based target is practically advantageous, because it offers a wide range of optimal Po 2 values at which p values of the order of 10 -4 Ω cm are achievable.