ABSTRACT
Thin film transistors (TFTs) made from amorphous or organic semiconductors are commonly used in the control circuits of large-area display electronics such as flat-panel TV screens. Thin films of spontaneously ordered and closely packed nanocolumns of zinc oxide (ZnO) were used to fabricate high-speed and transparent TFTs. Ordered nanocrystalline (nc)-ZnO thin films composed of closely packed nanocolumns offer a unique solution to improving TFT performance to levels comparable to single crystal semiconductors while maintaining their thin film properties. TFTs are mostly used in circuits that do not require high-speed operation because of electron mobility limitations. However, with the demonstrated high electron mobility and the anticipated high electron velocity, ZnO-based TFTs have a greater potential for high-speed circuit applications than amorphous TFTs. The high-speed potential of nc-ZnO TFTs was examined in a series of designs fabricated on high-resistivity silicon substrates. Pulsed laser deposition-grown ZnO thin films were used to fabricate high-speed and transparent thin film transistors.
