Nano-rheology printing of sub-0.2 μm channel length oxide thin-film transistors

Abstract

Down-scaling of the channel length of a fully solution-processed oxide thin-film transistor (TFT) to the nanometer-scale is the key to accessing next-generation devices for Internet-of-Things technology. In this work, we report on the fabrication of an oxide TFT with a channel length of 160 nm, which is far less than those obtained by the current direct-printing techniques, by a newly developed nano-rheology printing (nRP) method. The device had an on/off current ratio, subthreshold voltage, hysteresis, and field-effect mobility of approximately 107, 1.7 V, 0 V, and 0.16 cm2 Vs−1, respectively. The key to achieving the sub-micron channel printed TFT is the introduction of a new amorphous La–Ru–O material, which exhibits relatively good conductivity and excellent nRP properties at the nanoscale, for source/drain electrode patterns. Such a short-channel TFT would never be achieved with conventional printing methods, and hence, this approach is highly important for accessing next-generation low-cost, large-area and environmentally friendly printed electronics.