A Novel IGZO-TFT Device With High Dielectric Constant Sandwich Structure Gate Dielectric Layer

Thin film transistors (TFTs), as an important component of flat panel display technology, will also become the top priority at this stage. The emergence of amorphous indium gallium zinc oxide thin-film transistors (IGZO-TFTs) quickly became the new favorite of the display technology market. This article mainly reports the sandwich structure of high dielectric constant (High-K) materials wrapped by low dielectric constant (Low-K) materials according to the combination of High-K materials and SiO 2 . Low-K materials are used to reduce interlayer capacitance, thereby reducing RC signal delay and increasing device operating frequency. High-K is used to increase the thickness of the gate layer and suppress tunneling leakage current, and this sandwich structure can better balance TFT performance.The SILVACO simulation software was used to simulate the structure and device output characteristics and transfer characteristics, and the IGZO thin-film transistors at this stage were improved by combining the relevant process flow of IGZO, and the photoelectric characteristics of IGZO thin-film transistors based on SiO 2 /hfO 2 /SiO 2 gate layer were understood. In order to ensure that the interlayer capacitance of the gate dielectric layer is stable and unchanged, but also to ensure sufficient physical thickness, the selection of a gate dielectric material with a High-K can effectively suppress the device tunneling effect caused by too small a physical thickness.hfO 2 has good thermal stability on Si substrate, high dielectric constant, large band gap, and large band compensation with Si. The technical introduction of High-K materials is mainly aimed at solving the technical problem of greatly reducing the efficiency of electronic dielectric migration caused by the thinning of SiO 2 thin film dielectric gate layer materials. The High-k medium can also be reduced to the threshold voltage of the devices. Based on SiO 2 /hfO 2 /SiO 2 gate dielectric layer, IGZO-TFT is expected to improve device stability while improving device performance.