Improvement in the Device Characteristics of Tin Oxide Thin-film Transistors by Adopting Ultralow-Pressure Sputtering

Here in, thin film transistors (TFTs) were fabricated with the tin oxide channel, deposited by using ultralow-pressure sputtering (ULPS), are reported. The effect of ULPS on the device performance of the tin oxide TFTs was investigated. The TFTs with tin oxide channel, deposited by conventional sputtering pressure (CSP), did not show a promising performance. However, the saturation mobility and threshold voltage of the ULPS SnOx TFTs were improved to similar to 3.9 cm(2)/Vs and similar to 0.6 V, respectively. The improved device performance of ULPS film was attributed to the decreased carrier concentration, which was originated from the formation of nano-crystalline phase and the higher film density compared to CSP film. We also compared the crystalline structure of ULPS and CSP film by using high-resolution transmission electron microscopy.