In this letter, we report ultrathin-body (~15 nm) TiO2 thin film transistors (TFTs) with unprecedented electrical performance: ON-current density ( $I_{\text{on}}$ ) of 16.7 mA/mm, ON/OFF current ratio ( $I_{\text{ON}}/I_{\text{OFF}}$… Click to show full abstract
In this letter, we report ultrathin-body (~15 nm) TiO2 thin film transistors (TFTs) with unprecedented electrical performance: ON-current density ($I_{\text{on}}$ ) of 16.7 mA/mm, ON/OFF current ratio ($I_{\text{ON}}/I_{\text{OFF}}$ ) of $1.2 \times 10^{9}$ and subthreshold swing (SS) of 101 mV/dec. The TiO2 channel layer was deposited by thermal atomic layer deposition (ALD) followed by post-annealing in O2 ambient. The material characterizations indicate the formation of anatase TiO2 polycrystalline films and a lack of detectable oxygen vacancies, which could have acted as charging traps in channel and channel/dielectric interface, benefiting the $I_{\text{ON}}$ and the SS. These high-performance ultrathin-body TiO2 TFTs open a new venue in many applications such as high-resolution display and radiofrequency identification (RFID) tag, where high on currents and steep SS are required.
