Method of Fabricating Ultra-Short-Gate-Length Thin-Film Transistors Using Optical Lithography

The speed of thin-film transistors (TFTs) relates directly to their gate length, which must be kept as short as possible to lower electron transport time between electrodes, and improve its high-frequency response characteristics. Since current density is proportional to W/L, where W is the gate width and L is the gate length, reduced gate length improves device current capability. Photolithography, which is the main technology used in defining electrode dimensions for TFTs, is limited in scope to fabrication line widths larger than 1 micrometer.