11:15 AM - 11:30 AM
▼ [16a-502-9] Electrical properties Improvement of Top Gate a-IGZO Thin-Film Transistor using Solution Gate Insulator by Ultraviolet-Ozone and Thermal Treatment
Keywords:solution gate insulator, ultra violet-ozone treatment, thin-film transistor
Electronic devices using a-InGaZnO thin-film transistors (TFTs) have been emerging in next generation displays. To reduce the production cost, some layers of the TFT structure have been replaced by solution processed materials such as channel layer, gate insulator (GI), or electrode [1]. However, it is difficult to control the chemical uniformity or defects of solution processed materials which cause low yield and low performance. To solve this problem, applying ultraviolet-ozone (UV/O3) treatment with appropriate temperature is an option.
We fabricated top gate TFT using siloxane hybrid polymers as a GI. UV/O3 treatment after TFT fabrication is able to enhance the electrical characteristics of the film.
In this research, we compare a UV/O3 treatment (λ = 254 nm) combined with a thermal treatment with other conditions such as without UV/O3 at room temperature (RT), UV/O3 at RT, UV with 300°C, and without UV/O3 at 300°C in improving the performance of a-InGaZnO TFTs with siloxane GI.
We demonstrate the comparison of TFT characteristics between 2 conditions; TFTs treated by thermal treatment at 300°C and TFTs treated by UV/O3 treatment with a temperature at 300°C. Unoptimized TFTs subjected to only thermal treatment show poor characteristics – with no switching behavior and high off-current. Meanwhile, TFTs treated by UV/O3 at 300°C show effective switching behavior. The TFT characteristics with UV/O3 at 300°C was measured and the resulting TFT was excellent; the mobility was 12 cm2·V-1·s-1, sub-threshold swing (SS) was 215 mV/decade, and the on-off current ratio (Ion/Ioff) was 105.
We suggest that the UV/O3 treatment with a temperature at 300°C decreases the amount of carbon residues and defect sites related to oxygen vacancies and increased metal oxide bonds between the siloxane GI and a-InGaZnO which effectively improved the TFT’s electrical characteristics. For a deeper understanding of the detailed mechanism, chemical bonding and composition changes will be examined through X-ray Photoelectron Spectroscopy and Secondary Ion Mass Spectrometry analysis.
We fabricated top gate TFT using siloxane hybrid polymers as a GI. UV/O3 treatment after TFT fabrication is able to enhance the electrical characteristics of the film.
In this research, we compare a UV/O3 treatment (λ = 254 nm) combined with a thermal treatment with other conditions such as without UV/O3 at room temperature (RT), UV/O3 at RT, UV with 300°C, and without UV/O3 at 300°C in improving the performance of a-InGaZnO TFTs with siloxane GI.
We demonstrate the comparison of TFT characteristics between 2 conditions; TFTs treated by thermal treatment at 300°C and TFTs treated by UV/O3 treatment with a temperature at 300°C. Unoptimized TFTs subjected to only thermal treatment show poor characteristics – with no switching behavior and high off-current. Meanwhile, TFTs treated by UV/O3 at 300°C show effective switching behavior. The TFT characteristics with UV/O3 at 300°C was measured and the resulting TFT was excellent; the mobility was 12 cm2·V-1·s-1, sub-threshold swing (SS) was 215 mV/decade, and the on-off current ratio (Ion/Ioff) was 105.
We suggest that the UV/O3 treatment with a temperature at 300°C decreases the amount of carbon residues and defect sites related to oxygen vacancies and increased metal oxide bonds between the siloxane GI and a-InGaZnO which effectively improved the TFT’s electrical characteristics. For a deeper understanding of the detailed mechanism, chemical bonding and composition changes will be examined through X-ray Photoelectron Spectroscopy and Secondary Ion Mass Spectrometry analysis.