High Performance Ti-Doped ZnO TFTs With AZO/TZO Heterojunction S/D Contacts

In this paper, we successfully fabricated Ti-doped ZnO (TZO) thin film transistors (TFTs). Al-doped ZnO (AZO) film was adopted as source/drain (S/D) electrode, forming an AZO/TZO hetero-junction S/D contact. Meanwhile, TZO TFTs with ITO S/D electrode were also fabricated for comparison. Both AZO and ITO films were fabricated using radio frequency (RF) magnetron sputtering at room temperature (RT). Compared with ITO, device with AZO S/D electrodes exhibits higher I_on/I_off ratio of 1.9 ×10 ⁹, lower I off of 570 fA, and comparable saturation mobility (μsat) of 108.6 cm² ·V ^-1 ·S ^-1. What´s more, as channel length decreases, TFTs with AZO S/D electrodes still show good performances.