Enhance Electrical Performance and Stability of InSnMgO Thin-Film Transistors by Optimizing Carrier Concentration via Mg Doping

In this work, a low-temperature co-sputtering method was employed to fabricate high-performance amorphous InSnMgO (ITMO) thin film transistors (TFTs) with ultrathin channels. The effects of different Mg content on the electrical properties and bias stability of ITMO TFTs were studied by various characterization methods. As a result, when the sputtering power of MgO was set to 80 W, the field effect mobility (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu _{\text {FE}}$ </tex-math></inline-formula>) reached 52.5 cm2/V<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\cdot $ </tex-math></inline-formula>s, the low threshold voltage (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {th}}$ </tex-math></inline-formula>) of −0.28 V, and the subthreshold swing (SS) was as low as 0.239 V/decade. The super performance of the device is attributed to the reduction of oxygen vacancy concentration and the optimization of carrier concentration in the channel due to the doping of Mg. This study confirms the potential application of ITMO TFTs in the field of transparent flexible electronic devices and is expected to become a promising material for the next generation of high-resolution, low-power flat panel displays.