Co-Optimization of a-InGaZnO Framework for Enhancing Thin Film Transistors Stability and Electrical Properties

The coexistence of high bias stress stability and high performance is the key problem of low-temperature application of amorphous indium gallium zinc oxide (a-IGZO) thin film transistors (TFTs). However, the main treatment strategy of regulating a-IGZO TFTs bias stress stability by specific gas is usually obtained at the expense of a certain degree of electrical performance. Here, we have innovatively designed a-IGZO framework (IGZO <tex-math notation="LaTeX">I</tex-math> /IGZO <tex-math notation="LaTeX">I</tex-math> :N/IGZO <tex-math notation="LaTeX">II</tex-math> /IGZO <tex-math notation="LaTeX">II</tex-math> :O) TFTs with simple structure and without extra processing to synergistically achieve outstanding bias stress stability and good performance. Therefore, the threshold voltage offset (4.) under negative bias stress (NBS) decreased significantly from <tex-math notation="LaTeX">$-$</tex-math> 5.08 to <tex-math notation="LaTeX">$-$</tex-math> 0.79 V. The field effect mobility (7.) has some-what optimized to 18.23 cm <tex-math notation="LaTeX">²</tex-math> /Vs. The results showed that the strategy of fabricating a-IGZO framework (IGZO <tex-math notation="LaTeX">I</tex-math> / IGZO <tex-math notation="LaTeX">I</tex-math> :N/IGZO <tex-math notation="LaTeX">II</tex-math> /IGZO <tex-math notation="LaTeX">II</tex-math> :O) TFTs may reduce the defects of bulk and the interface between the channel and the gate insulation layer, decrease the surface oxygen vacancy defect concentration, and avoid the interaction with extra oxygen or water vapor. This simple and ingenious framework provided a universality strategy for synergistically improving the bias stress stability and electrical properties of amorphous metal-oxide TFTs.