High Performance Ultrathin SnO₂ Thin-Film Transistors by Sol-Gel Method

Sol-gel processed ultrathin nanostructured SnO₂ thin-film transistors were successfully fabricated on a SiO₂/Si substrate without using a self-aligned monolayer or high-k insulator, which may be unsuitable techniques for the commercial fabrication of complementary metal-oxide-semiconductors. The highest extracted field mobility was approximately 100 cm²/V·s. In addition, by controlling the SnO₂ film thickness, we successfully increased the on/off current ratio to 10⁷. The electrical performance of the proposed transistors is sufficient for high-resolution liquid crystal or organic light-emitting diode displays, which require a high field-effect mobility (>10 cm²/V·s) and high on/off current ratio (>10⁶). Ultrathin SnO₂ is also a promising rare-metal-free starting matrix for ternary and quaternary alloys, showing promising electric properties.