Al-doped ZnO (AZO) thin films have been prepared on the c-Si oriented direction of (100) and glass substrates, by radio frequency magnetron sputtering from ZnO-2 wt.% Al2O3 ceramic targets. The effects of the working pressure on the optical and electrical properties of the films have been studied. The optical properties, measured by the ultraviolet-visible system, show that the transmittance and optical bandgap energy are influenced by the working pressure. The Hall resistivity, mobility, and carrier concentration were obtained by a Hall measurement system and these parameters were also influenced by the working pressure. The AZO thin-film transistors (TFTs) were fabricated on highly doped c-Si substrates. The TFT structures were made up AZO as the active layer and SiOxNy/SiNx/SiOx as the gate layer with 20 nm and 35 nm thickness, respectively. The ultra-thin TFTs had an on/off current ratio of 104 and a field-effect mobility of 0.17 cm2/V·s. These results show that it is possible to fabricate an AZO TFT that can be operated with an ultra-thin gate dielectric.
Bibliographical noteFunding Information:
This research was supported by a grant ( F0004062-2009-32 ) from Information Display R&D Center , one of the Knowledge Economy Frontier R&D Program funded by the Ministry of Knowledge Economy of Korean government.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry