High-speed mechanically flexible single-crystal silicon thin-film transistors on plastic substrates

This letter describes the fabrication and properties of bendable single-crystal-silicon thin film transistors formed on plastic substrates. These devices use ultrathin single-crystal silicon ribbons for the semiconductor, with optimized device layouts and low-temperature gate dielectrics. The level of performance that can be achieved approaches that of traditional silicon transistors on rigid bulk wafers: effective mobilities>500cm²/V·s, ON/OFF ratios >10⁵, and response frequencies > 500 MHz at channel lengths of 2 μm. This type of device might provide a promising route to flexible digital circuits for classes of applications whose performance requirements cannot be satisfied with organic semiconductors, amorphous silicon, or other related approaches.