Carbon nanotube thin film transistors fabricated by an etching based manufacturing compatible process

Carbon nanotube thin film transistors (CNT-TFTs) have been regarded as strong competitors to currently commercialized TFT technologies. Though much progress has been achieved recently, CNT-TFT research is still in the stage of laboratory research. One critical challenge for commercializing CNT-TFT technology is that the commonly used device fabrication method is a lift-off based process, which is not suitable for mass production. In this paper, we report an etching based fabrication process for CNT-TFTs, which is fully manufacturing compatible. In our process, the CNT thin film channel was patterned by dry etching, while wet etching was used for patterning the layers of metal and insulator. The CNT-TFTs were successfully fabricated on a 4 inch wafer in both top-gate and buried-gate geometries with low Schottky barrier contact and pretty uniform performance. High output current (>1.2 μA μm^-1), high on/off current ratio (>10⁵) and high mobility (>30 cm² V^-1 s^-1) were obtained. Though the fabrication process still needs to be optimized, we believe our research on the etching fabrication process pushes CNT-TFT technology a step forward towards real applications in the near future.