A Full-Swing a-IGZO TFT-Based Inverter With a Top-Gate-Bias-Induced Depletion Load

A high-performance inverter implemented with single-gated driving and dual-gated load amorphous-indium–gallium–zinc–oxide thin-film transistors (TFTs) is demonstrated. The threshold voltage of the load TFT shifts to the negative gate voltage direction when a constant positive bias is applied on the top gate while sweeping the bottom gate. Using a positive top gate bias, the load TFT can be operated in the depletion mode to realize inverters with excellent switching characteristics, such as a wider swing range and a higher noise margin.