Taehun Lee1,Jaewon Jang1
Kyungpook National University1
Taehun Lee1,Jaewon Jang1
Kyungpook National University1
We demonstrate an ultra-thin aluminum layer deposited sol-gel processed SnO<sub>2</sub> thin-film transistors (TFTs) showing high stability performance under bias stress condition. The sol-gel process, one of the printing techniques, is a useful method for depositing metal oxide materials having a high film quality and purity. The properties of deposited film can be simply controlled by adjusting the concentration or other variables of precursor. The advantages of this process allows fabricating metal-oxide layer in large-area applications. Metal Oxide TFTs have gradually alternated silicon based TFTs due to their high field effect electron mobility, simple fabrication process and transparency. Metal Oxide TFTs, Unfortunately, contain electrical instability problems because of oxygen vacancies and defects that are the origin of trap formation. To solve this problem, we deposited an ultra-thin aluminum layer on the active layer of SnO<sub>2</sub> TFTs. In this experiment, we first fabricated pure SnO<sub>2</sub> TFTs via sol-gel process. Then aluminum was thermally evaporated on the prepared device followed by an annealing process at 300°C for 20 minutes. Under the positive bias illumination stress, pure SnO<sub>2</sub> TFTs have a mobility change from 6.27 cm<sup>2</sup>/Vs to 5.91 cm<sup>2</sup>/Vs and +6.51 V threshold voltage shift. Meanwhile, SnO<sub>2</sub> TFTs with Al deposited layer show the mobility change from 6.03 cm<sup>2</sup>/Vs to 5.51 cm<sup>2</sup>/Vs and +1.47 V threshold voltage difference. The results reveal that the deposited aluminum layer clearly advanced the positive bias illumination stability. We expect that the ultra-thin aluminum layered SnO<sub>2</sub> TFTs are an excellent candidate for high stability application in transparent electronics.